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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. Ser. No. 13/582,065 filed on Aug. 31, 2012 which is the US National Stage of International Application No. PCT/EP2010/059399, filed Jul. 1, 2010 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 10155292.5 EP filed Mar. 3, 2010. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
The invention describes a method of attaching a magnet to a rotor or a stator of an electrical machine. The invention further describes a magnet mounting arrangement, a generator, and a wind turbine.
BACKGROUND OF INVENTION
An electrical machine such as a generator can have a large field (usually the rotor), to which a corresponding large number of permanent magnets or poles is attached. During manufacture, each magnet must be firmly attached to the rotor so that it cannot come loose during operation. For a rotor with a diameter in the range of 2-6 m, a magnet can typically be 1-3 cm in height and 10-20 cm wide. A permanent magnet usually comprises a number of magnet pieces, each with a weight in the region of 10-15 kg. Prior art methods of mounting magnets usually involve attaching each magnet to a steel base of the same width as the magnet, for instance using an adhesive layer, and attaching this unit to the rotor by covering it with a U-shaped steel housing and soldering each housing along its lower edges onto the rotor. The housings ensure that the magnets are protected from corrosion and from mechanical impact. However, this approach is inflexible and expensive, since it requires a steel base for each magnet, a closely-fitting housing for each magnet, and a time-consuming soldering step. Another disadvantage is the additional weight contribution on account of the steel bars.
In an alternative approach, the magnets can be attached to the rotor by gluing them into place, and then wrapping the rotor and magnet arrangement in a fibreglass bandage or envelope. While this solution is considerably more economical than the other prior art technique, it does not provide satisfactory protection against corrosion or mechanical impact.
SUMMARY OF INVENTION
It is therefore an object of the invention to provide an improved method of attaching magnets to the field of an electrical machine.
The object of the invention is achieved by the method of the claims of attaching a magnet to a rotor or a stator of an electrical machine, by the magnet mounting arrangement of the claims, by the generator of the claims, the wind turbine of the claims, and by the use of such a method according to the claims in mounting a plurality of magnets to the rotor of a generator of a wind turbine.
According to the invention, the method of attaching a magnet to a rotor or a stator of an electrical machine comprises the steps of arranging a magnet along a surface of the rotor; arranging a pair of retainers one on each side of the magnet; enclosing the rotor, magnet and retainers in a vacuum bag; and performing vacuum evacuation to consolidate the magnet to the retainers by means of an adhesive.
An obvious advantage of the invention is that, because a pair of retainers is used for the fixation of a magnet, these can be manufactured in a much more straightforward manner than the single prior art U-shaped housing, which must be shaped precisely to fit over the magnet while not leaving too much leeway. Furthermore, the retainers according to the invention need not be soldered into place. Instead, the vacuum consolidation step ensures they are effectively glued to the magnet and to the rotor/stator.
According to the invention, the magnet mounting arrangement for a rotor or a stator of an electrical machine comprises a magnet arranged along an outside surface of the rotor or stator; a pair of retainers arranged one on each side of the magnet; and an adhesive layer bonding the retainers to the magnet.
According to the invention, the generator comprises a rotor and a stator, wherein the rotor comprises such a magnet mounting arrangement.
According to the invention, the wind turbine comprises such a generator.
Particularly advantageous embodiments and features of the invention are given by the dependent claims, as revealed in the following description. Features of the different embodiments can be combined as appropriate to give further embodiments.
The field of an electrical machine can be the rotor or the stator, depending on the way in which the electric machine—for example a generator—is constructed. Usually, however, particularly in large generators, the rotor is the field and bears the magnets, while the stator is the armature and carries the coil windings. Therefore, in the following but without restricting the invention in any way, it is assumed that the electrical machine is a generator and that the magnets are mounted on the rotor, although the method according to the invention for determining a magnet arrangement would be equally applicable to a realisation in which the magnets are mounted on the stator. Here, the term ‘surface of the rotor’ is to mean the appropriate surface of the rotor to which the magnets are attached. For an electrical machine with the rotor on the outside, enclosing the stator, the magnets will generally be mounted on the interior surface of the rotor to face the stator across an air gap. For an electrical machine with the rotor on the inside and the stator on the outside, the magnets will generally be mounted on the exterior surface of the rotor to face the stator across the air gap. Magnets (or ‘poles’) are generally rectangular in shape and are attached along their length on the surface of the rotor in a direction parallel to the rotational axis of the rotor. In the following, the term ‘upper face of a magnet’ is to be understood to mean the face of the magnet opposite to the magnet face that is attached to the rotor/stator. A ‘side face’ of a magnet is to be understood to mean a face that is essentially perpendicular to the rotor/stator.
The two retainers used to hold a magnet in place may be referred to in the following as a ‘retainer arrangement’. In a particularly preferred embodiment of the invention, a retainer is made of sheet metal, whereby the retainer can be manufactured using any suitable process such as deep drawing or pressing. Preferably, the sheet metal is chosen to be easily formed and to maintain its finished shape. For example, steel would be a favourable choice of metal.
The retainers of a retainer arrangement are preferably formed to fit closely along the magnet on at least one face of the magnet. For example, one retainer could be formed by bending a strip of sheet metal lengthwise to give a 90 fold, so that the retainer, when put into place, lies along one vertical face of the magnet. The other retainer could then comprise a complementary part formed by bending a strip of sheet metal lengthwise twice to give two opposite 90 folds. This complementary retainer is preferably shaped so that a central region lies along the opposite vertical face of the magnet, and one side region lies along the upper horizontal face of the magnet so that the outer edge of this retainer meets the outer edge of the other retainer along an upper edge of the magnet. However, the cutting and bending of these two differently-shaped retainers requires some precision in order that they fit satisfactorily, since the part of the second retainer that lies on top of the magnet should, for obvious reasons, not be any larger than the upper magnet face. Therefore, in a particularly preferred embodiment of the invention, a retainer is shaped to essentially cover a side face and at least part of the upper face of the magnet.
In particularly preferred embodiment of the invention, a retaining arrangement comprises a pair of Z-profile retainers, wherein each Z-profile retainer is arranged alone one long side of the magnet. In this preferred embodiment, each retainer is formed by bending a strip of sheet metal lengthwise twice to give a Z-profile. The part of the retainer that is to lie on top of the magnet is preferably at least half the magnet width and at most as wide as the magnet, and the width of this part of the retainer can be anywhere in between these bounds.
In a further particularly preferred embodiment of the invention, therefore, the retainers of a pair are dimensioned to overlap on the upper face of the magnet. In this way, the magnet can be optimally held in place, but the retainers can be manufactured in a fairly straightforward way.
The magnets of a magnet arrangement should preferably be held in place so that they cannot be displaced laterally. Therefore, in a preferred embodiment of the invention, a retainer is shaped to partially lie on the surface of the rotor. After vacuum consolidation, this part of the retainer can be affixed by adhesive to the surface of the rotor. In this case, the part of the retainer that makes contact with the rotor surface can comprise a narrow strip of the retainer material. Alternatively, for adjacent retainers of a pair of neighbouring magnets, the retainers can be dimensioned to meet essentially halfway between the magnets. The part or strip of the retainer that lies on the surface of the rotor can be designed for economy, for example by punching out regions of this strip, or by cutting the strip in a toothed or comb-like manner. In this way, sufficient retainer surface remains to ensure a good contact with the rotor, but only a minimum amount of metal is actually used.
There are a number of ways in which to carry out the steps of arranging the magnets and performing vacuum consolidation. Initially, the retainer and magnet arrangement must be secured in some way to prevent the arrangement from slipping before the vacuum extraction step can be carried out. For example, the retainers could be screwed or bolted into place. However, this is time-consuming and cost-intensive, requiring many small parts and threaded openings. In a particularly simple approach, a magnetic attraction between the magnet and the rotor may be sufficient to hold the magnet in place until it is consolidated to the rotor. If the retainers are also magnetised, the force of magnetic attraction may be sufficient to hold them in place until after consolidation. However, this approach may be insufficient owing to the curved shaped of the rotor and the considerable weight of the magnets, particularly in the case of a large generator.
Therefore, in a preferred embodiment of the invention, the magnets and retainers can be provisionally attached to the rotor and/or to each other. Preferably, the method according to the invention comprises the step of applying an adhesive between the magnet and the retainers. For example, a pair of sheet metal Z-profile retainers can be glued onto a magnet such that the retainers overlap on the upper face of the magnet. In order to ensure that the magnet and retainer arrangement does not slide along the rotor before the curing process can be completed, the method according to the invention preferably also comprises the step of applying an adhesive between the magnet and the rotor.
The step of applying an adhesive can comprise coating the inner surfaces of the retainers sparingly or generously with adhesive, depending on the wetting qualities and the strength of the adhesive used. The lower surface of the magnet (or the corresponding surface of the rotor) can similarly be coated with a layer of adhesive. The entire rotor/magnet/retainer arrangement can then be enclosed in the vacuum bag and any air can be extracted. Atmospheric pressure then acts to press the retainers onto the magnet and to press the magnet onto the rotor, thereby causing the adhesive to spread and fill any spaces. Heat may also be applied to cure the adhesive.
In another approach, the magnets can be provisionally attached to the rotor by spot gluing, i.e. by applying only small amounts of glue to the rotor before putting the magnets in place. Similarly, the retainers can be provisionally attached to the magnet and/or the rotor by spot gluing. Again, this entire rotor/magnet/retainer arrangement can then be enclosed in the vacuum bag and any air can be extracted.
As long as the adhesive is not hardened, the magnets and/or retainers should preferably be prevented from slipping from their desired positions. Therefore, in a preferred embodiment of the method according to the invention, once the magnets and retainers are all in place and before this arrangement is enclosed in the vacuum bag, the method comprises the step of placing inserts between adjacent magnets of the arrangement prior to the vacuum evacuation step. The inserts can be made of any suitable material, for example a light solid material that can be easily cut to shape. Alternatively, the inserts can be made of a thermoplastic material that expands during the vacuum extraction step to fill the space between adjacent magnets. In this way, the inserts effectively prevent the magnets from being displaced until the adhesive has cured or hardened.
Preferably, the vacuum evacuation step comprises a vacuum-assisted resin transfer (VART) step in which an adhesive or resin such as an epoxy resin is pumped into the vacuum bag and drawn or sucked by negative pressure into any spaces between magnet and rotor or between magnet and retainer. As long as the vacuum is applied to the vacuum bag and its contents, atmospheric pressure acts to press the retainers onto the magnet and to press the magnet onto the rotor. Heat may also be applied at this stage to cure the adhesive resin. In this way, the retainers, the magnet and the rotor are consolidated by means of the adhesive during the vacuum evacuation step.
After the curing step, the vacuum bag may be removed. If inserts have been used, these may also be removed. Of course, if the inserts are firmly consolidated between the magnets, and if they do not obstruct the rotor during operation of the electrical machine, they may simply be left in place.
The performance of an electrical machine can be less than ideal, owing to deviations from the ideal in the geometry of the components, the available material, losses in the circuitry, etc. For example, a motor or generator is subject to some amount of cogging and ripple torque. Some approaches to reducing these unwanted forces involve specific arrangements of the rotor magnets. For example, the magnets can be arranged at different distances to each other (‘pole-pitching’) on the rotor, a magnet can comprise a plurality of staggered magnet elements, etc. In such an arrangement, for a rotor with a diameter in the range of 2-6 m, a magnet can comprise up to about ten magnet pieces or magnet elements, each with a weight of 10-15 kg. In a preferred embodiment of the invention, therefore, the magnet mounting arrangement comprises a number of magnet elements arranged in a staggered manner, and the retainers are dimensioned to overlap on the outer faces of each of the magnet elements of the magnet. In other words, the retainer arrangement is realised to accommodate such magnet arrangements. For example, for such a staggered magnet, the parts of the retainers that are to lie along the upper magnet surfaces are preferably wide enough so that they still overlap, even when the magnet elements are staggered on both sides.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed descriptions considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention.
FIG. 1 shows a prior art magnet mounting arrangement;
FIG. 2 illustrates steps of the inventive method of mounting a magnet to a rotor according to a first embodiment;
FIG. 3 illustrates steps of the inventive method of mounting a magnet to a rotor according to a second embodiment;
FIG. 4 illustrates a magnet mounting arrangement according to an embodiment of the invention.
In the drawings, like reference numbers refer to like objects throughout. Objects in the diagrams are not necessarily drawn to scale.
DETAILED DESCRIPTION OF INVENTION
FIG. 1 shows a prior art magnet mounting arrangement 9 for a magnet 1 and a rotor 2 . Many such magnets 1 may be attached to the rotor 2 , but only one is shown here for the sake of clarity. The magnet 1 is shown in cross-section, and it will be understood that, for a rotor 2 with a diameter in the region of 2-6 m, such a magnet 1 can typically have a cross-sectional area in the region of 10-60 cm 2 . In this prior art approach, the magnet 1 is first glued to a steel base 90 by means of an adhesive layer 91 . The combined base and magnet unit is then covered by a fitted steel housing 92 , which in turn is soldered along its outer edges to the rotor 2 .
FIG. 2 illustrates steps of the inventive method of mounting a magnet 1 to a rotor 2 . In a first stage, as shown in the top of the diagram, an adhesive layer 6 A is applied to the surface of the rotor 2 , and the magnets 1 are positioned as appropriate. Then, a pair of retainers 3 A, 3 B are put into place, one on each side of the magnet 1 , such that a first retainer 3 A lies alongside a first side face 11 of the magnet 1 , and the second retainer 3 B lies alongside the opposite side face 12 . The retainers 3 A, 3 B are dimensioned so that they overlap on the upper side face 13 of the magnet 1 .
Once all the magnets 1 have been covered by retainer pairs 3 A, 3 B, inserts 4 of thermoplastic material are placed between adjacent magnets 1 , as shown in the next stage. Then, the entire arrangement of rotor 2 , magnets 1 , retainers 3 A, 3 B and inserts 4 is enclosed in a vacuum bag 5 . During a vacuum extraction step, the adhesive 6 A can be drawn into the spaces between magnet 1 and retainer 3 A, 3 B. Additionally, an epoxy resin adhesive 6 C can be pumped into the vacuum bag by means of a suitable nozzle (not shown in the diagram) and distributed by negative pressure into any gaps and spaces between the magnets 1 , the rotor 2 and the retainers 3 A, 3 B. Heat may be applied to the entire assembly—for example infrared or UV radiation—to cure the adhesive 6 A, 6 C. Once the adhesive 6 A, 6 C has hardened, the magnets 1 , retainers 3 A, 3 B and rotor 2 are consolidated in a magnet mounting arrangement 8 , as shown in the lower part of the diagram. In this way, the magnets 1 are protected from corrosion and mechanical impact b the retainers 3 A, 3 B, while also being fixed firmly in place by the adhesive bond between retainers 3 A, 3 B and rotor 2 .
FIG. 3 illustrates the steps of an alternative method according to the invention. Here, the magnets 1 are spot-glued to the rotor 2 using small amounts of adhesive 6 B. Similarly, retainer pairs 3 A, 3 B are spot-glued to the corresponding magnet 1 and/or the rotor 2 as shown in the upper part of the diagram. In this way, the magnets 1 and retainers 3 A, 3 B are provisionally held in place. Inserts 4 of thermoplastic material can then be laid into place between adjacent magnets 1 , and the entire assembly—magnets 1 , retainers 3 A, 3 B, inserts 4 and rotor 2 —can be enclosed in a vacuum bag 5 , as shown in the next stage. Again, a vacuum extraction step is then performed, in which an adhesive resin 6 C is drawn into any spaces between magnets 1 , rotor 2 and retainers 3 A, 3 B in a VART process. After the resin 6 C has cured, the vacuum bag 5 and inserts 4 are removed to expose the consolidated magnet mounting arrangement 8 , as shown in the lower part of the diagram, in which the magnets 1 are securely fastened to the rotor 2 and protected from corrosion by the retainers 3 A, 3 B.
FIG. 4 illustrates part of a magnet mounting arrangement according to an embodiment of the invention. Here, a magnet 1 comprises several magnet elements 7 , arranged in a staggered manner on the basis of an optimisation of the performance of the electrical machine of which the magnet 1 is a part. For example, the staggered magnets 7 may serve to reduce the cogging torque of the machine. The staggered arrangement of magnet elements 7 results in a wider overall width of the magnet 1 . Therefore, retainers 3 A, 3 B are dimensioned accordingly so that they overlap to cover the upper surfaces of all the magnet elements 7 parallel to the axis of rotation of the rotor 2 , as shown in the plan view on the upper right of the diagram. The vacuum extraction step is performed in the same way as described above, with the use of inserts between the magnets 1 if required, and any spaces between the magnet elements 7 and the retainers 3 A, 3 B can be filled with epoxy 6 C during the VART process. In this way, even such a complex arrangement of magnet elements 7 can be easily and securely affixed to the rotor 2 in a particularly straightforward and economical manner.
Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.
For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. | A wind turbine is provided. The wind turbine includes a generator including a rotor and a stator and a magnet mounting arrangement. The magnet mounting arrangement includes a magnet arranged along a surface of the rotor or stator, a pair of retainers arranged one on each side of the magnet, and an adhesive bonding the pair of retainers to the magnet and the magnet to the rotor or stator. | 8 |
RELATED APPLICATIONS
This patent application is a Continuation of U.S. patent application Ser. No. 10/441,067, filed on May 20, 2003 now U.S. Pat. No. 6,892,187 entitled “Debit Purchasing of Stored Value Card For Use By And/Or Delivery To Others”, which is a continuation of U.S. patent application Ser. No. 09/102,0441, filed Jun. 22, 1998, now U.S. Pat. No. 6,615,189. The disclosures of these priority applications are hereby incorporated herein by reference in their entirety.
The present application is also related to U.S. patent application Ser. No. 10/987,086 filed concurrently herewith and entitled “Stored Value (Rebate),” U.S. patent application Ser. No. 10/987,079 filed concurrently herewith and entitled “Stored Value (Sponsor Funded),” U.S. patent application Ser. No. 10/987,085 filed concurrently herewith and entitled “Stored Value (Private Label Network),” U.S. patent application No. 10/987,104 filed concurrently herewith and entitled (Stored Value Card (Wu), and U.S. patent application Ser. No. 10/987,078 filed concurrently herewith and entitled Stored Value Card (Phelan), all claiming benefit of U.S. patent application Ser. No. 10/441,067, filed on May 20, 2003 entitled “Debit Purchasing of Stored Value Card For Use By And/Or Delivery To Others”, which is a continuation of U.S. patent application Ser. No. 09/102,044, filed Jun. 22, 1998, now U.S. Pat. No. 6,615,189, the entireties of which are incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to a system for purchasing or transferring of stored value or debit purchasing cards, which can be pre-arranged to be given as a gift to a designated recipient.
BACKGROUND OF THE INVENTION
On many occasions, consumers, other bank customers, credit card holders, and other persons find it is desirable to arrange for another person, perhaps a relative, to have access to a specified sum of money. For example, a parent might want to arrange for a child to have access to money when the child is taking a trip or going away to college. One may also find it desirable to mail a gift to another person who is geographically distant. In these and other cases, it is often undesirable to give away or send cash. If lost or stolen, cash is practically unrecoverable. Traveler's checks are also undesirable as they must be purchased at a bank and are not acceptable for many types of purchases. Gift certificates are also undesirable because they require the recipient to purchase from the merchant that issued the gift certificate. These and other drawbacks exist to the aforementioned alternatives.
SUMMARY OF THE INVENTION
An object of the invention is to overcome these and other drawbacks in existing purchase schemes.
Another object of the invention is to provide a method for issuing a purchase card comprising: presenting a purchaser with the opportunity to buy the purchase card, determining whether the purchaser has sufficient funds to pay for the purchase card, creating a purchase card account for a recipient designated by the purchaser; and issuing the purchase card.
A further object of the invention is to provide a purchase card where the recipient activates the purchase card.
A further object of the invention is to provide a purchase card where the purchase card account contains a monetary amount determined by the purchaser of the purchase card.
A further object of the invention is to provide a purchase card where money can be added to the balance of an issued purchase card account.
A further object of the invention is to provide a purchase card where the purchase card is activated when the issuer of the purchase card is notified that the recipient has received the purchase card.
A further object of the invention is to provide a purchase card where the issuer of the purchase card notifies the purchaser that the recipient has received the purchase card.
A further object of the invention is to provide a purchase card where the purchaser may designate with which merchants the purchase card may be used.
A further object of the invention is to provide a purchase card where the purchase card is activated for a predetermined period of time.
Another object is to provide a method for issuing a purchase card as a rebate award comprising: issuing a credit card to a cardholder, said credit card being associated with a sponsor. calculating a rebate amount based upon cardholder purchases made with said credit card, issuing a purchase card to a cardholder or to a recipient designated by said cardholder, said purchase card having a purchase value determined by said rebate amount.
A further object of the invention is to provide a purchase card where the recipient of the purchase card activates the card.
A further object of the invention is to provide a purchase card where the recipient activates the purchase card by notifying the issuer that the recipient has received the purchase card.
A further object of the invention is to provide a purchase card where the purchase card is activated for a predetermined period of time.
A further object of the invention is to provide a purchase card where the rebate is calculated based on all purchases made with the credit card.
A further object of the invention is to provide a purchase card where the rebate is calculated based on purchase from the sponsor made with the credit card.
A further object of the invention is to provide a purchase card where the sponsor notifies the issuer of the amount of rebate due a credit card holder, and the issuer creates a purchase card in that amount.
A further object of the invention is to provide a purchase card where the rebate is based on the monetary value of the purchases.
Another object of the present invention is to provide a method for converting a purchase card into a credit card comprising: creating a purchase card account for a recipient designated by the purchaser; issuing the purchase card; receiving a request from the recipient to convert the purchase card into a credit card; determining whether the recipient meets predetermined credit criteria to convert the purchase card into a credit card; creating a credit card account; and converting the purchase card into a credit card.
A further object of the invention is to provide a purchase card where the balance of the purchase card account is transferred to the credit card account.
A further object of the invention is to provide a purchase card where the credit cards is immediately activated upon being converted from a purchase card.
Other objects and advantages exist for the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a flow diagram for a portion of the purchase card system.
FIG. 2 shows a flow diagram for another portion of the purchase card system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the purchase card system is shown in FIG. 1 . In this embodiment the purchase card process begins with an offer to purchase a gift card at step 100 . The offer may be in any suitable form that would notify prospective purchasers 105 of the availability of the purchase card. For example, a written solicitation may be mailed or otherwise distributed to potential purchasers 105 . The offer may also be in the form of oral notification, for example, a telephone call to prospective purchasers 105 . Alternatively, the offer may be published over a computer network, for example, on an Internet Web site. Other forms of offering the sale of a purchase card are also possible. In one embodiment of the invention, offers are made to prospective purchasers who already have a financial relationship with the offeror. Other potential purchasers may also be offered the opportunity to obtain a purchase card.
The offer may be accepted by a purchaser 105 by notifying a customer service center 110 . The acceptance may be in any form acceptable to the customer service center 110 . For example, the purchaser may mail, fax, or otherwise transmit a written acceptance, telephone an acceptance, or electronically transmit, for example, via Web Site, an acceptance by computer or other suitable device. At step 120 , the customer service center 110 receives pertinent information to identify the purchaser 105 and the purchaser's desired spending limit for the purchase card. For example, the customer service center may identify the purchaser 105 by name, address, credit card account number, social security number, other unique identifiers or a combination of identifiers.
At step 130 , the customer service center 120 is checked to verify that the caller or purchaser was included in the solicitations for this program. If the caller or purchaser was not originally solicited, customer service 120 determines whether to extend an offer in step 135 .
If the caller or purchaser was solicited 130 , certain purchaser 105 information may be accessed at 140 . If, for example, the purchaser wishes to pay for the purchase card with a credit card, the purchaser's credit card account information may be accessed. For example, the purchaser's available credit limit may be accessed at 145 to verify that sufficient credit is available to cover the spending amount of the purchase card. If the available credit is insufficient, the purchaser 105 may be so informed at 150 . The purchaser 105 may be given the opportunity to modify the purchase card spending amount, at 155 , in order to ensure that the purchase amount does not exceed the available credit.
The process may terminate at 160 if, for example, the purchaser 105 does not wish to modify the purchase amount.
After it has been determined that the purchaser's available credit is sufficient, a transaction may be posted to the purchaser's credit card for the amount of the purchase at 170 . In another embodiment of the present invention, a purchaser may use a check, cash, or other financial methods to obtain a purchase card. Regardless of the purchasing method, the issuer of the purchase card must determine whether the purchaser has sufficient funds to purchase the card.
When the purchase card is paid for by credit or bank account, the purchaser's account balance is updated at 175 to reflect the purchase. The account balance information, as well as information identifying the purchaser 105 and the recipient, may be stored in a retrievable and accessible fashion. For example, the information may be stored in computer database 180 . After the purchaser 105 has paid (or authorized payment) for the purchase card, and it is posted to a credit card account, the acceptance process is complete and the acceptance process terminates at 160 .
An account for the purchase card is created at 190 . This may be performed by a third party processor that establishes and manages purchase card accounts. for example, at 200 . Creation of the purchase card account may comprise various actions, such as, recording the recipients 215 name, address and phone number, imprinting a card with an account number, a recipient name and an expiration date, encoding the card to record the purchase value stored thereon, and other actions, such as, for example, preparing account fulfillment documents (e.g. card carrier activation, etc.).
When the purchase card account is complete, the card is delivered. In one embodiment of the invention, card may be affiliated with a particular network, such a credit network, or debit network. For example, a card may be affiliated with the VISA® network. The delivery may be to the purchaser 105 or to the recipient 215 , as shown at 210 . The place of delivery may be arranged during the initial purchase of the card or other suitable time before delivery.
Information regarding an account is sent to account file 220 , where an account can be monitored. In one embodiment, account file 220 allows monitoring of the current balance of an account, any activity in the account, including debits and credits, transaction updates, and the like. Other information about an account, such as purchase dispute resolutions, the history provided by the customer, and account status, may also be monitored.
Before the purchase card can be used to make purchases, it must be activated as shown in FIG. 2 at 230 . Activation may be accomplished in any suitable manner. For example, the recipient 215 of the card may place a telephone call to an activation center 240 . Activation center 240 may act as a telemarketing vendor by verifying information about the recipient (i.e. name, address, telephone number, etc.) before the purchase card is activated. The activation center 240 may then transmit the data about the recipient to Data Service 200 to activate the purchase card for use. Activation center 240 may also modify information about a recipient, such as, for example, a change of address. Other forms of activation, such as by computer network may also be used.
During activation certain verifications may be made at 250 to ensure that the intended recipient 215 is the person attempting to activate the purchase card. These security checks 250 may entail questions about personal information (e.g., name, address, telephone number, etc.) or may utilize other well known methods of authenticating the recipient 215 . If the person attempting to activate the purchase card does not pass the security check 250 , the purchase card will be denied activation at 255 and the activation process may terminate at 260 . If the person attempting to activate the purchase card passes the security check 250 , they may be prompted at 252 for more information. The information may be used for subsequent security checks, should they be required, or to verify or complete the purchase card account information.
After activation the purchase card is ready for use. In some embodiments of the invention the activation process will end at this point. The recipient 215 may now use the purchase card to make purchases where ever, for example, VISA® cards are accepted. Each time a purchase is made using the card, the amount of the purchase will be debited from the card's available balance. The purchase card will continue to operate as long as a positive balance remains on the card. Some embodiments of the purchase card may have the capacity to have additional purchase value added to them after they have been activated.
If the recipient of a purchase card is someone other than the purchaser, the issuer of the card may notify the purchaser regarding various aspects of the card. For example, in one embodiment of the invention, the issuer could notify the purchaser that the purchase card has been received and activated by the intended recipient. An issuer may also notify a purchaser where the purchase card is being used, or what products are being purchased with the purchase card.
Some embodiments of the purchase card will include an expiration date. After the expiration date has passed the purchase card will be de-activated and cease to operate. In another embodiment of the present invention, a recipient or a purchaser of a purchase card may add to the balance of the purchase card account. This may take place in a manner substantially similar to the original purchasing of the purchase card. For example, a recipient of a purchase card may request that an amount be posted to the recipient's credit card and that the same amount then be credited to the recipient's purchase card account. Other methods of adding to the balance of a purchase card account may also be used.
Another embodiment of the invention allows the recipient 215 to convert the purchase card into a credit card. Conversion may be accomplished in the following manner. The recipient 215 calls the activation center 240 to activate the purchase card and the security check 250 may be performed in the usual manner. After passing the security check, the age of the recipient 215 is determined at 270 . If the recipient 215 is an adult (e.g., over the age of 18 ) an offer to convert the purchase card into a credit card may be extended at 271 . At step 275 the recipient 215 may decline the offer to convert, in which case the process may terminate at 280 . If the recipient 215 elects to convert the purchase card to a credit card the activation center 240 may capture additional data 285 from recipient 215 , in order to complete a credit card application. At step 290 the credit card application data is forwarded to a credit decisioning office 300 . The credit decisioning office 300 may make inquiries to a credit bureau 305 , for example, obtaining a credit report on the recipient 215 . At 310 the decision is rendered whether to approve the credit card application. If the application for a credit card is declined at 315 , the recipient 215 may be notified at 320 . Notification may be in any suitable form, for example, a letter explaining the declined application may be mailed at 320 to the recipient 215 . Other forms of notification may also be used to notify recipient 215 of the declined application.
Even though the credit card application is declined at 310 , the purchase card is activated for use. At 330 , the account settings allowing a card to be used at merchants are sent to the data service 200 and the card will be activated as a purchase card account. Information pertaining to the purchase card account is stored in a retrievable and accessible manner. For example, the purchase card account information may be stored in a computer 332 .
If the decision at 310 is to accept the application for a credit card, the recipient 215 may be notified at 340 . Again, notification may be in any suitable form, for example, a letter or other suitable notification. Regardless of the decision whether to convert the purchase card into a credit card, the purchase card is activated at the end of the activation call. If the purchase card is not already active, it may be activated at 345 . At 350 the purchase card is converted to a credit card. The credit card will function in a manner usual for such credit instruments. For example, a credit limit may be assigned, periodic account activity statements may be generated and finance charges may be applied to any outstanding balance. In one embodiment, any remaining balance from the purchase card account may be transferred and applied to the credit card account. At 355 an update is sent to a retrievable data storage system, for example, computer 360 . The update 355 sends credit card application decisions into a database.
In another embodiment of the purchase card, a financial institution (e.g., a bank) issues a credit card to a cardholder. The card may be a co-branded card issued in cooperation with a sponsor. In this embodiment, the sponsor offers a rebate to the cardholder based upon the dollar value amount of purchases made with the co-branded credit card. The rebate may apply to all purchases made or just to purchases made from the sponsor. The rebate may be calculated in a manner specified by the terms of the cardholder agreement or other disclosures to the cardholder. In one embodiment of the invention, disclosure about the rebate is provided to the cardholder in a separate form included with the cardholder agreement. For example, the sponsor may offer a flat percentage rebate for purchases made. In one embodiment of the invention, the card issuer calculates the rebate due the cardholder based on the balance paid.
In another embodiment, the sponsor notifies the financial institution of the amount of rebate to be awarded to the cardholder. The financial institution will then issue a purchase card for the amount of the rebate. The purchase card may be used for purchases in the above described manner, for example, everywhere VISA® is accepted, or the purchase card may be used for purchases solely with the sponsor or other designated entities.
Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples should be considered exemplary only. The scope of the invention is only limited by the claims appended hereto. | A method of issuing a purchase card is provided. The method includes the steps of presenting a purchaser with the opportunity to buy the purchase card, determining whether the purchaser has sufficient funds to pay for the purchase card, creating a purchase card account for a recipient designated by the purchaser, and issuing the purchase card. The purchase card may also be issued in connection with another credit card, for example as a rebate for purchases on the credit card. The purchase card may also be converted to a credit card. | 6 |
RELATED APPLICATION
This application is a continuation of application Ser. No. 11/295,917 filed on Dec. 7, 2005, which issued as U.S. Pat. No. 7,827,936 on Nov. 9, 2010 and which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
The present invention relates, in general, to a bird feeder and pertains more particularly to a bird feeder having a removable base.
BACKGROUND
The typical bird feeder available on the market has the base firmly attached to the bird seed container. This makes it difficult to clean the bottom end of the container housing.
Accordingly, it is an object of the present invention to provide a bird feeder with a removable or releasable base so as to facilitate cleaning of both the base and the lower end of the bird feeder container or housing.
Another object of the present invention is to provide a removable base for a bird feeder in which the base is held relatively firmly in place in its closed position and yet is relatively easy for the user to remove from the container housing.
Still another object of the present invention is to provide a bird feeder with a removable base in which the base can be readily removed by a user but that is not able to be removed by an animal such as a squirrel.
Another object of the present invention is to provide an improved support structure for a bird feeder.
SUMMARY OF THE INVENTION
The foregoing and other objects of the invention are achieved by providing a bird feeder that is comprised of a housing for storing bird feed therein, including one or more ports through which access is provided to the bird feed and having an open lower end and a base assembly adapted to close the open end of the housing. The base assembly has a main body portion adapted to fit within the housing at the open end of the housing so that the main body portion is rotatably fixed but removable with respect to the housing, and a manually operated latch coupled to the main body portion. The latch is supported for rotation with respect to the main body portion to releasably secure the base assembly to the housing.
In accordance with other aspects of the present invention one of the housing and the latch has a first engaging member and the other of the housing and the latch has a second engaging member adapted to releasably engage the first engaging member upon positioning the first and second engaging members adjacent one another; one or more bird feed perches extends from the housing under a port; the bird feed port may comprise an insert releasably engaged with the housing, the insert having one of the first and second engaging members; the first engaging member may comprise a projection internally of the housing and the second engaging member may comprise a slot and ridge on the latch for capturing said projection; the main body portion may have an open bottom into which the latch is disposed, the latch including stops spaced apart to engage said projection at opposite open and closed positions of said latch; and the main body portion of the base assembly may have an annular rim adapted to sealingly engage the housing at the open end of the housing.
In accordance with another embodiment of the present invention there is provided the bird feeder comprises a housing for storing bird feed therein, including at least two ports through which access is provided to the bird feed; at least two bird feed port inserts, each insert adapted to be received in a corresponding port and each having a hood portion extending into the housing; and an interconnecting member for interconnecting the hood portions of the inserts to one another with a snap fit to secure the inserts within the housing.
In accordance with still other aspects of the present invention each insert may further comprise a collar portion adapted to be positioned outside the housing and defined by an annular ridge that is urged against the housing wall about the port; each insert may further comprise a bird perch, formed on the collar portion, extending away from the housing and disposed under the port; and the interconnecting member may comprise a pair of resilient fasteners, one for each insert, each resilient fastener being adapted to be releasably secured to a receptacle formed in the hood portion of its corresponding insert.
In accordance with another embodiment of the present invention there is provided a bird feeder that includes a bird feed holder having open top and bottom ends; a plurality of feeding ports disposed in a sidewall defining the holder; a plurality of perches each associated with an inlet of an associated feeding port; a removable base for engaging with the bottom end of the holder, the removable base having a closed position for sealing the bottom end of the holder so as to retain the bird feed therein and an open position in which the base is removed from the holder to enable access to the bottom end of the holder; and a manually operated latch member supported by the base. The manually operated latch member is supported for radial engagement so as to enable releasable securing of the removable base to the holder.
In accordance with still other aspects of the present invention each feeding port may comprise a port member having the perch integrally formed therewith; the port member may further include a projection extending internally of the housing for locking engagement with said latch member; may include a plurality of port members circumferentially disposed about the holder and a like plurality of projections; the latch member may have a plurality of latch pieces, the same in number as the number of projections, and circumferentially disposed so that each latch piece is engageable with a projection; each latch piece may be depressable radially so as to disengage it from a projection; may include a stop over each projection; each projection may be an internal extension of a perch; and may include an interconnecting member comprising a pair of resilient fasteners, one for each port, each resilient fastener being adapted to be releasably secured to a receptacle formed in a hood portion of its corresponding port.
In accordance with another embodiment of the invention there is provided a support apparatus for a bird feeder that comprises a plurality of support arms; an upright member; the plurality of support arms being constructed and arranged so as to extend radially from a base of the upright member; a ground engagement element extending downwardly from the base of the upright member and for engagement into the ground for support of the upright member; and means for attaching the bird feeder to the upright member.
In accordance with still other aspects of the present invention the support arms are disposed in a symmetric pattern and are slid onto respective legs that extend radially from the base of the upright member, and the ground engagement element comprises a screw element fixed to the base of the upright member. The support apparatus may include end caps on the support arms, the upright member may be a hollow tube and the means for attaching may include a thumb screw for attaching a support pole to the bird feeder.
DESCRIPTION OF THE DRAWINGS
Numerous other objects, features and advantages of the present invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of a bird feeder in accordance with the first embodiment of the present invention;
FIG. 2 is a perspective view of the bird feeder base of FIG. 1 ;
FIG. 3 is a perspective view directed at the bottom of the base;
FIG. 4 is a plan view of the base as viewed from the bottom;
FIG. 5 is a fragmentary perspective view illustrating the bottom end of the bird seed container and the construction of one of the port members;
FIG. 6 is a perspective view of the port member of FIG. 5 ;
FIG. 7 is a cross-sectional view through the port member as taken along line 7 - 7 of FIG. 6 ;
FIG. 8 is a fragmentary perspective view of the base of the feed container illustrating one of the port members in place and furthermore illustrating the base assembly;
FIG. 9 is a perspective view illustrating the base supported within the bottom end of the bird feed container;
FIG. 10 is a cross-sectional view taken along line 10 - 10 of FIG. 9 ;
FIG. 11 is a perspective view of the interconnecting member that is used for coupling together the port members;
FIG. 12 is a plan view of the interconnecting member of FIG. 11 ;
FIG. 13 is a cross-sectional view illustrating the interconnecting member as positioned relative to the port member;
FIG. 14 is a cross-sectional view with the interconnecting member engaged with the port member;
FIG. 15 is a cross-sectional view showing the interconnecting member as coupled with three port members;
FIG. 16 is a cross-sectional view similar to that depicted in FIG. 15 and illustrating the manner in which a port member may be released at the interconnecting member;
FIG. 17 is a bottom plan view of the base assembly as engaged with the container;
FIG. 18 is a cross-sectional view similar to that depicted in the cross-sectional view of FIG. 10 but showing the manner in which the latch member is released;
FIG. 19 is a perspective view of a second embodiment of a bird feeder in accordance with the present invention;
FIG. 20 is a further embodiment of an interconnecting member;
FIG. 21 is a cross-sectional view illustrating the interconnecting member of FIG. 20 as used with a port member;
FIG. 22 is another cross-sectional view illustrating the interconnecting member of FIG. 20 as used for connecting together two oppositely disposed port members;
FIG. 23 is an exploded perspective view illustrating a further embodiment of the present invention in which the base assembly is removable by rotation;
FIG. 24 is an exploded perspective view of the base assembly;
FIG. 25 is a bottom view as observed along line 25 - 25 of FIG. 24 ;
FIG. 26 is a cross-sectional view taken along line 26 - 26 of FIG. 25 ;
FIG. 27 is a plan view as taken along line 27 - 27 of FIG. 24 ;
FIG. 28 is a cross-sectional view taken along line 28 - 28 of FIG. 27 ;
FIG. 29 is a perspective view of the base of FIG. 24 ;
FIG. 30 is a bottom view of the base of FIG. 29 as taken along line 30 - 30 of FIG. 29 ;
FIG. 31 is a cross-sectional view through the base assembly of FIG. 30 as taken along line 31 - 31 ;
FIG. 32 is a view like that illustrated in FIG. 30 with the base assembly in its lock position;
FIG. 33 is a cross-sectional view taken along line 33 - 33 of FIG. 32 ;
FIG. 34 is a perspective view of a support apparatus for a bird feeder in accordance with the present invention;
FIG. 35 is a partial perspective view illustrating the manner in which an arm of the support apparatus is engaged with the main support member;
FIG. 36 is a partially cut-away plan view of the support apparatus of FIG. 34 ;
FIG. 37 is a fragmentary cross-sectional view showing further details;
FIG. 38 is an illustration of the support apparatus of the present invention as engaged in the ground and as for supporting a bird feeder;
FIG. 39 is a cross-sectional view taken along line 39 - 39 of FIG. 38 ; and
FIG. 40 illustrates the support apparatus of the present invention as used for supporting a bird feeder from the bottom thereof.
DETAILED DESCRIPTION
A first embodiment of the present invention is illustrated in FIGS. 1-18 . In this embodiment the base is removably supported from the feed container. The base is removable by means of a set of latch fingers that are depressed in a radial direction to release the base from the bottom end of the feed container. The embodiment of FIGS. 1-18 also illustrates the construction of the interconnecting member that is used for connecting together the separate port members. The preferred embodiment of the interconnecting matter is illustrated in FIGS. 11 and 12 .
Reference is now made to FIG. 1 which is a perspective view of a bird feeder constructed in accordance with the principles of the present invention. This feeder includes a container or holder 10 that is preferably constructed of a clear plastic material. The container 10 holds the bird seed or other type of bird feed. The container 10 is open at its top and bottom. A top or cover 12 is supported over the top end of the container 10 . The top 12 may be supported on a bale wire 14 that enables the top 12 to be slid up and down the wire. The top 10 is moved upwardly for the purpose of introducing seeds into the container and is illustrated in FIG. 1 in its bottom closed position.
FIG. 1 also illustrates the base assembly 20 of the bird feeder, along with a plurality of port members 30 . In the particular embodiment illustrated in FIG. 1 , three port members are used, each extending radially in the container and symmetrically disposed. For further details of each of the port members 30 , refer to FIGS. 5-7 . Each port member is comprised of a collar 32 , a hood 34 and a perch 36 . The collar, hood and perch are preferably all integrally formed of a single piece of plastic. The hood 34 is adapted to pass through a circular aperture 11 in the side wall of the container 10 . The inner end of the hood 34 is provided with a passage 35 for receiving an interconnecting member. The collar 30 also supports the projection 37 and a stop 38 . The slits 13 and 15 in the sidewall of the container 10 are adapted to respectively receive the stop 38 and the projection 37 . FIG. 5 shows the port member 30 exploded away from the container with the hood 34 in alignment with the aperture 11 . FIG. 8 shows the port member 30 in place within the container with the stop end projection fitting within their associated slits. FIGS. 9 and 10 also show the position of the port member as engaged with the container or holder 10 .
As noted in FIGS. 7 and 10 , the projection 37 is integral with the collar 30 and essentially is an internal projection or extension of the perch 36 . As indicated in FIG. 10 , the stop 38 defines a limit for the seating of the base assembly 20 in the bottom of the container 10 . FIG. 10 illustrates the stop 38 bearing against a top wall of the base assembly. The projection 37 , as particularly illustrated in FIG. 10 , is for engagement with the base assembly. FIG. 10 illustrates the locked position of the base assembly.
Reference is now made to FIGS. 2-4 for further details of the base assembly 20 . The base assembly 20 is basically comprised of two components including the main base 22 illustrated in FIG. 2 and the latch member 24 illustrated in FIG. 3 . Refer also to the cross-sectional view of FIG. 10 that illustrates these components. The main base 22 includes a circumferential base rim 23 and circumferential wall 25 . The top of the base 22 is formed by three tapered walls 26 each of which is in alignment with a port member and each of which has formed therein a slot 27 . The projection 37 on the port member is adapted to slidably engage in the slot 27 . The surfaces 26 are tapered so as to direct feed toward the port member.
The latch member 24 , such as illustrated in FIGS. 3 , 4 and 10 is comprised of a series of support legs 42 that are used for supporting the latch member from the base 22 . For this purpose there are provided a series of screws or bolts 44 and support posts 46 . The latch member 24 also includes three latch fingers 48 , each of which is adapted to engage with one of the projections 37 . In this regard, refer to FIG. 10 which illustrates the end lip 49 of the finger 48 engaged with the projection 37 . FIG. 10 shows the locked position of the base relative to the container 10 .
The base is released from the container by means of depressing each of the three latch fingers 48 . One of the latch fingers 48 is illustrated in FIG. 18 having been depressed in the direction of the arrow 51 . This disengages the end lip 49 away from the slot 27 allowing the base to be slid downwardly in the direction of arrow 52 in FIG. 18 . The lip 49 is thus disengaged from the projection 37 . In FIG. 18 the lip 49 is shown extending in the slot 27 . In an alternate embodiment the lip 49 may extend through a top slot above the wall 26 .
Reference is now made to the interconnecting member 50 shown in further detail in FIGS. 11 and 12 . The member 50 is used to interconnect the three port members 30 . As such, the interconnecting member 50 has three sets of legs identified as a leg set 52 A, 52 B and 52 C. The interconnecting member 50 may constructed of a lightweight plastic material or a lightweight spring steel material and each of the separate legs is able to be partially deflected so as to engage with the hood portion 34 of the port member. More particularly and as illustrated in FIG. 13 , the leg set 52 A is shown as movable in the direction of arrow 54 to engage with the end passage 35 in the hood 34 . The leg set 52 A engages in the passage 35 . FIG. 14 illustrates the main leg set 52 A engaged fully in the passage 35 . The pointed ends of each of the legs of the set 52 A provides a tight locked interengagement between the member 50 and the port member 30 .
Refer now to FIGS. 15 and 16 . This illustrates the manner in which the other leg sets 52 B and 52 C engage with the two other port members 30 . FIG. 15 shows all port members interlocked with the interconnecting member 50 . One of the legs 55 of each set 52 B and 52 C has an engagement lip 56 that enables the port member to interlock with the interconnecting member. At the same time, as illustrated in FIG. 16 , the leg 55 may be engaged by the user's thumb 58 to depress the leg 55 so that the port member 30 that is retained by the leg 55 can then be disengaged. FIG. 16 shows the thumb 58 engaging the leg 55 and the port member 30 being partially withdrawn.
Reference is now made to FIGS. 19-22 for an illustration of a second embodiment of the present invention. This embodiment is similar to that described in FIGS. 1-18 . However, in the embodiment of FIGS. 19-22 , only two port members 30 are employed. These port members are disposed in line with each other as illustrated in FIGS. 19 and 22 . FIG. 20 illustrates the construction of the interconnecting member 60 that is employed with this embodiment. This interconnecting member includes only two sets of legs, namely leg sets 62 A and 62 B. The leg set 62 A interlocks with the aperture 35 in the hood 34 , as illustrated in FIG. 21 . FIG. 22 illustrates the other leg set 62 B engaging with the other hood 34 . The other leg set 62 B also includes the leg 66 , similar to the leg 55 depicted in FIG. 16 . This is the leg that may be depressed by the user's thumb to release the interconnecting member, enabling the separate port members to be disengaged from the housing.
Reference is now made to a third embodiment of the present invention illustrated in FIGS. 23-33 . In this embodiment of the present invention, the base is removable with the use of a rotatable latch member associated with the base. FIG. 23 illustrates the bottom end of the feed container 70 . The top of the container may be the same as depicted previously such as in FIGS. 1 and 19 . FIG. 23 also shows the apertures 72 for receiving the port member 74 . The port member 74 is substantially the same as the port member previously described, such as illustrated in FIG. 6 . The port member 74 includes a collar 75 , a hood 76 , perch 77 , a projection 78 and stop 79 . The inside end of the hood 76 may also include a passage for receiving an interconnecting member not specifically illustrated in this embodiment.
The primary difference between the embodiment in FIG. 23-33 and the first embodiment is that there is a different removable base 80 . Refer to FIGS. 24-28 for further details of the base assembly 80 . The base assembly 80 includes a base member 82 and a latch member 90 . These two members may be intercoupled by means of a retaining ring 83 .
The base member 82 includes a circumferential ring 84 , an upstanding wall 85 and tapered top surfaces 86 . Between the circumferential upstanding wall 85 and each of the top surfaces are three slots 87 . An internally threaded post 88 (see FIG. 26 ) extends downwardly from the top surfaces of the base member. As illustrated in FIG. 25 , the post 88 also includes three longitudinally disposed ridges 89 . These ridges engage with a particular slot structure on the latch member as will be described hereinafter.
The latch member 90 has a rim 91 that extends circumferentially. The latch member 90 is somewhat cup-shaped having internal shoulders 92 that define therebetween finger grips 94 . These finger grips are used to rotate the latch member 90 between locked and released positions.
The base member 82 is meant to be engaged with the bottom of the container but is held nonrotatable. The latch member 90 , on the other hand, is adapted for limited rotation limited to the base member 82 .
In order to interlock the base assembly with the bottom of the container in the embodiment that is disclosed, the interlocking occurs between the base assembly and the projection 78 . The projection 78 may be simply an internal extension of the perch 77 . The projection 78 is meant to fit within the slot 87 and is adapted for engagement with the latch member. For this purpose, the latch member 90 is provided on its rim 91 with three slots 95 disposed circumferentially in the same manner that the slots 87 are arranged. One side of the slot 95 is defined by a stop 96 . There is also a second stop 97 that will limit the amount of rotation of the latch member 90 .
As depicted in FIG. 24 , the bottom wall 98 of the latch member 90 has a substantially circular opening 99 . A detent arrangement is provided about the opening 99 including a small channel 100 and an arcuate channel 102 . The channels 100 and 102 are meant to engage with the post 88 of the base member, particularly with the ridge 104 on the post 88 .
FIGS. 30 and 31 illustrate the latch member in its open position. In that position it is noted that the projection 78 passes through the slot 87 in the base member 82 and engages the slot 95 (see FIG. 27 ) of the latch member 90 . In that position FIG. 32 illustrates the position of the detents. The channel 100 is engaged with the ridge 104 (see FIG. 30 ) of the post of the base member 82 . In that position the entire base assembly can engage with the base of the container.
FIGS. 32 and 33 illustrate the rotation of the latch member by means of the arrows 105 . This action causes the lip of the rim 91 to capture the projection 78 . This is illustrated at 107 in FIG. 33 . The stop 97 limits the extent of rotation of the latch member 90 .
Reference is now made to FIGS. 34-40 for an illustration of a support apparatus that may be used with any of the different embodiments illustrated hereinbefore in FIGS. 1-33 . In, for example, FIG. 1 the bird feeder is provided with a hanger so that the feeder can be supported from above. In an alternate embodiment of the invention, the bird feeder may be supported from its base by means of an apparatus such as shown in FIGS. 34-40 . For that purpose the feeder is preferably provided with a receiving post at its base that is internally threaded as depicted, for example, in FIG. 10 .
Existing arrangements for supporting a bird feeder from the ground have not been effective, particularly for the placement of a bird feeder pole into the ground soil. This is particularly the case where the soil is rocky and it has thus been difficult to have an effective means for supporting a bird feeder from the ground. The present invention provides an effective way to secure a support with the ground. In this regard, in accordance with the present invention, there is provided a upright base member that is equipped with extending arms that enable easy insertion of the support into the ground, as well as providing a stable platform for the base member once fully inserted.
The support apparatus comprises a plurality of support arms 110 . Each of these support arms is of tubular metallic construction, although each of the arms could also be constructed of a rigid plastic material. The arms 110 could also be of solid construction for insertion into a leg of the main support structure. Each of the arms preferably includes an end cap 112 which may be a plastic piece fitted onto the end of each arm as illustrated, for example, in FIGS. 34 and 35 . It is preferred to use an end cap to keep water or other debris from entering the tubular arm 110 .
The other main component of the support apparatus of the present invention comprises a main upright member 115 . The member 115 may be constructed of metal or a hard plastic material and includes an upright post 118 and a plurality of legs 120 . Each of the legs 120 are relatively short in length, as depicted in FIG. 35 . Each of the legs 120 has a diameter slightly smaller than the inside diameter of an arm 110 so that the arms can be slid over the legs, such as to the position illustrated in FIG. 34 . This fit is preferably a relatively tight fit so that the arms are held in place. A ground engagement element extends downwardly from the base of the upright member 115 and is for engagement into the ground for support of the upright member. This is illustrated in the drawings by the helical screw element 125 . FIG. 38 shows the screw element 125 screwed into the ground 127 . The helical screw element 125 may be welded to the very bottom of the upright post 118 .
The upright post 118 is also hollow, such as illustrated in FIGS. 38 and 39 . This is illustrated as supporting a feeder support post 130 . The bottom end of the post 130 simply fits inside of the support post 118 . A thumb screw 132 is illustrated threaded through the post 118 for tightly securing the bird feeder support post 130 in place. The top end of the bird feeder support post 130 may be threaded, as illustrated in FIG. 38 , so as to thread with the base of the bird feeder. Alternatively, the top of the pole 130 may receive an adaptor in which case it need not be threaded. The adaptor may be of the type shown in co-pending application Ser. No. 10/832,051 which is hereby incorporated by reference in its entirety.
In FIGS. 38 and 39 there is illustrated the bird feeder 140 and its associated base 142 . The bird feeder 140 and its base 142 may be substantially the same as illustrated in earlier embodiments in FIGS. 1-33 . See, for example, FIG. 10 and the threaded member 51 . The support post 130 may be made in different lengths depending upon the distance that one wishes to support the bird feeder above the ground level.
The support apparatus illustrated in FIGS. 34-40 is constructed with three support arms. However, in other embodiments of the present invention more or less than three arms may be employed. These arms are preferably symmetrically disposed so that there is a symmetric engagement with the ground surface. Initially the arms 110 are engaged with the legs 120 , and once assembled, the device is screwed into the ground by screwing the element 125 into the ground surface. It is preferred that this be done with the arms 110 attached to the legs 120 , as this will provide additional leverage in the screwing operation. Also, once fully screwed into the ground, as seen in FIGS. 34 and 38 , the arms form a broad support structure for the upright member engaging against the ground surface and locking or bearing tightly against the ground surface.
Also, there has been depicted arrangements in which one member engages into another, such as the arms 110 engaging over the legs 120 . In an alternate embodiment, however, the arms 110 can be dimensioned smaller so as to slide inside of the legs 120 . Also, the post 130 may be dimensioned to fit over the post 118 in which case the thumb screw would be on the post 130 . Other securing means may also be provided between the posts 118 and 130 including providing engaging threaded members.
Having now described a limited number of embodiments of the present invention it should be apparent to those skilled in the art that numerous other embodiments and modifications thereof are contemplated as falling within the scope of the present invention, as defined by the appended claims. For example, in the embodiments disclosed herein, in one embodiment three port members are used, and in another embodiment two port members are used. In another embodiment of the present invention, greater than three port members may be aligned essentially in the same plane. In that instance the interconnecting member would then have four sets of legs. In the embodiment disclosed herein, it is also noted that port members are only provided at the bottom of the seed chamber. In other embodiments of the invention, the port members may be disposed, not only circumferentially as illustrated, but may also be disposed at different heights between the top and bottom of the container. In still another embodiment of the present invention, the port members may be provided only at locations above the base. For those port members disposed above the base the projection and stop are not necessary. In the case where no port member is provided at the base, instead of the port member that is illustrated, a simpler collar member may be provided without any port but including the perch and the inner extension from the perch to provide the projection for engagement with the base assembly. In still another embodiment of the present invention, all of the port members and perches may be disposed above the base, in which case there is provided only a collar member and an inwardly directed projection for engagement with the base assembly. This embodiment may also include the stop as illustrated herein. | A bird feeder that includes a bird feed holder having open top and bottom ends, a plurality of feeding ports disposed in a sidewall defining the holder, a plurality of perches each associated with an inlet of an associated feeding port and a removable base for engaging with the bottom end of the holder, the removable base having a closed position for sealing the bottom end of the holder so as to retain the bird feed therein and an open position in which the base is removed from the holder to enable access to the bottom end of the holder. One embodiment has a manually operated latch member supported by the base and supported for radial engagement so as to enable releasable securing of the removable base to the holder. In another embodiment a manually operated latch couples to a main body portion, the latch being supported for rotation with respect to the main body portion to releasably secure the base assembly to the housing. Also disclosed is a feeder support apparatus. | 0 |
PRIORITY STATEMENT
This application takes priority from U.S. Provisional Application 61/529,329 filed on Aug. 31, 2011, entitled “Full Flow Pulser for Measurement While Drilling (MWD) Device” and U.S. Nonprovisional application Ser. No. 13/336,981 filed on Dec. 23, 2011 and entitled “Controlled Pressure Pulser for Coiled Tubing Applications”, of which this application is a continuation. The entire contents of both applications are hereby incorporated by reference.
FIELD OF DISCLOSURE
The current invention includes an apparatus and a method for creating a pulse within the drilling fluid, generally known as drilling mud, that is generated by selectively initiating flow driven bidirectional pulses. Features of the device include operating a flow throttling device [FTD] that operates without a centrally located valve guide within a newly designed annular flow channel providing more open area to the flow of the drilling fluid in a measurement-while-drilling device to provide for reproducible pressure pulses that are translated into low noise signals. The pulse is then received “up hole” as a series of pressure variations that represent pressure signals which may be interpreted as inclination, azimuth, gamma ray counts per second, etc. by oilfield engineers and managers and utilized to increase yield in oilfield operations.
BACKGROUND
Current pulser technology utilizes pulsers that are sensitive to different fluid pump down hole pressures, and flow rates, and require field adjustments to pulse properly so that meaningful signals from these pulses can be received and interpreted uphole.
An important advantage of the present disclosure and the associated embodiments is that it decreases sensitivity to fluid flow rate or pressure within easily achievable limits, does not require field adjustment, and is capable of creating recognizable, repeatable, reproducible, clean [i.e. noise free] fluid pulse signals using minimum power due to a unique flow throttling device [FTD] with a pulser that requires no guide, guide pole or other guidance system to operate the main valve, thus reducing wear, clogging and capital investment of unnecessary equipment as well as increasing longevity and dependability in the down hole portion of the MWD tool. This MWD tool still utilizes battery, magneto-electric and/or turbine generated energy. The mostly unobstructed main flow in the main flow area enters into the cone without altering the main flow pattern. Without the mudscreen obstructing the main flow area there is no reduction in the differential pressure so that the original orifice opening (area and volume) and the cone geometry (area and volume) causes a restriction in flow leading to a large differential in flow rate leading to a larger associated pressure differential (as described in the Bernoulli equation). The increased flow rate and change in pressure produces a very efficient pilot valve response and associated energy pulses. Specifically, as the pilot valve closes faster (than in any known previous designs) this produces a water hammer effect much like that is heard when shutting off a water faucet extremely quickly. The faster flow and corresponding larger pressure differential also moves the pilot valve into an open and closed position more rapidly. The faster the closure, the more pronounced the water hammer effect and the larger the pulse and associated measured spike associated with the pulse. These high energy pulses are also attributed to the position and integrity of the pilot channel seals ( 240 ) which ensure rapid and complete closure while maintaining complete stoppage of flow through the channel. The controllability of the pulser is also significantly enhanced in that the shape of the pressure wave generated by the energy pulse can be more precisely predetermined. The pulse rise and fall time is sharp and swift—much more so than with conventional devices utilizing guide pole designs. These more easily controlled and better defined energy pulses are easily distinguished from the background noise associated with MWD tools. Distinguishing from the “background” noise leading to ease of decoding signals occurring on an oil or gas rig offers tremendous advantages over current tools. Being able to control and determine pulse size, location, and shape without ambiguity provides the user with reproducible, reliable data that results in reduced time on the rig for analysis and more reliable and efficient drilling. It is estimated that each work day on a rig, on average, amounts to more than 1 million US dollars, so that each hour saved has extreme value.
SUMMARY
The present disclosure involves the placement of a Measurement-While-Drilling (MWD) pulser device including a flow throttling device located within a drill collar in a wellbore incorporating drilling fluids for directional and intelligent drilling. In the design, the pilot channel location is very different than in any prior application in that the channel is now located on the outside annulus. The present invention discloses a novel device for creating pulses in drilling fluid media flowing through a drill string. Past devices, currently in use, require springs or solenoids to assist in creating pulses and are primarily located in the main drilling fluid flow channel. U.S. Pat. No. 7,180,826 and US Application Number 2007/0104030A1 to Kusko, et. al., the contents of which are completely and hereby fully incorporated by reference, disclose a fully functional pulser system that requires the use of a pulser guide pole to guide and define the movement of the main valve together with a different hydraulic channel designs than that of the present application and associated invention. The pilot flow for the present invention without the guide pole allows for more efficient repair and maintenance processes and also allows for quickly replacing the newly designed apparatus of the present disclosure on the well site as there is at least a 15-20 percent reduction in capital costs and the costs on the maintenance side are drastically reduced. In the previous designs, guide pole failures accounted for 60-70 percent of the downhole problems associated with the older versions of the MWD. With the guide pole elimination, reliability and longer term down hole usage increases substantially, providing a more robust tool and much more desirable MWD experience.
Additionally, previous devices also required onsite adjustment of the flow throttling device (FTD) pulser according to the flow volume and fluid pressure and require higher energy consumption due to resistance of the fluid flow as it flows through an opened and throttled position in the drill collar.
The elimination of the centralized guide pole and pilot channel allows in the current design larger pressure differential to be created between the pilot flow and the main flow at the main valve thus increasing the control and calibration and operation of the pulser. The ability to precisely control the pulser and thus the pressure pulse signals is directly related to cleaner, more distinguishable and more defined signals that can be easier detected and decoded up hole.
The device provided by the current invention allows for the use of a flow throttling device that moves from an initial position to an intermediate and final position in both the upward and downward direction corresponding to the direction of the fluid flow. The present invention still avoids the use of springs, the use of which are described in the following patents which are also herewith incorporated by reference as presented in U.S. Pat. Nos. 3,958,217, 4,901,290, and 5,040,155.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overview of at the full flow MWD.
FIG. 2 is a close up of the pilot flow screen assembly
FIG. 3 is a detailed cross section of the main valve actuator assembly including the seals.
FIG. 4 shows the lower portion of the pilot actuator assembly, drive shaft and motor.
DETAILED DESCRIPTION OF THE DRAWINGS
With reference now to FIG. 1 , the pulser assembly [ 400 ] device illustrated produces pressure pulses in drilling fluid main flow [ 110 ] flowing through a tubular hang-off collar [ 120 ] and includes a pilot flow upper annulus [ 160 ]. The flow cone [ 170 ] is secured to the inner diameter of the hang off collar [ 120 ]. Major assemblies of the MWD are shown as provided including aligned within the bore hole the pilot flow screen assembly [ 135 ] and main valve actuator assembly [ 229 ] and pilot actuator assembly [ 335 ].
In FIG. 1 , starting from an outside position and moving toward the center of the main valve actuator assembly [ 226 ] comprising a main valve [ 190 ], a main valve pressure chamber [ 200 ], a main valve support block [ 350 ], main valve seals [ 225 ] and flow guide seal [ 240 ]. The same figure shows the main valve feed channel [ 220 ], the pilot orifice [ 250 ], pilot valve [ 260 ], pilot flow shield [ 270 ], bellows [ 280 ] and the anti-rotation block [ 290 ], as well as a cylindrical support shoulder [ 325 ] and tool face alignment key [ 295 ] that exists below the pilot flow shield for keeping the pulser assembly centered within the bore hole. This figure also shows the passage of the main flow [ 110 ] past the pilot flow screen [ 130 ] through the main flow entrance [ 150 ], into the flow cone [ 170 ], through the main orifice [ 180 ] into and around the main valve [ 190 ], past the main valve pressure chamber [ 200 ], past the main valve seals [ 225 ] through the main valve support block [ 350 ], after which it combines with the pilot exit flow [ 320 ] to become the main exit flow [ 340 ]. The pilot flow [ 100 ] flows through the pilot flow screen [ 130 ] into the pilot flow screen chamber [ 140 ], through the pilot flow upper annulus [ 160 ], through the pilot flow lower annulus [ 210 ] and into the pilot flow inlet channel [ 230 ], where it then flows up into the main valve feed channel [ 220 ] until it reaches the main valve pressure chamber [ 200 ] where it flows back down the main valve feed channel [ 220 ], through the pilot flow exit channel [ 360 ], through the pilot orifice [ 250 ], past the pilot valve [ 260 ] where the pilot exit flow [ 320 ] flows over the pilot flow shield [ 270 ] where it combines with the main flow [ 110 ] to become the main exit flow [ 340 ] as it exits the pilot valve support block [ 330 ] and flows on either side of the rotary magnetic coupling [ 300 ], past the drive shaft and the motor [ 310 ].
The pilot actuator assembly [ 335 ] includes a magnetic pressure cup [ 370 ], and encompasses the rotary magnetic coupling [ 300 ]. The magnetic pressure cup [ 370 ] and the rotary magnetic coupling [ 300 ] may comprise several magnets, or one or more components of magnetic or ceramic material exhibiting several magnetic poles within a single component. The magnets are located and positioned in such a manner that the rotary movement or the magnetic pressure cup [ 370 ] linearly and axially moves the pilot valve [ 260 ]. The rotary magnetic coupling [ 300 ] is actuated by the adjacent drive shaft [ 305 ].
FIG. 2 provides details of the pulser assembly in the open position; the pilot flow [ 100 ] and main flow [ 110 ] both flow through the pilot flow screen assembly [ 135 ] and pilot flow screen [ 130 ] where a portion of the main flow [ 110 ] flows through the pilot flow screen [ 130 ]. The pilot flow [ 100 ] flows through the pilot flow screen chamber [ 140 ] and into the pilot flow upper annulus [ 160 ]. Pilot flow [ 100 ] and main flow [ 110 ] within the pilot flow screen assembly [ 135 ] flows through the main flow entrance [ 150 ] and through the flow cone [ 170 ] and into the main orifice [ 180 ] to allow for flow within the main valve feed channel [ 220 ].
FIG. 3 describes the main valve actuator assembly [ 229 ] and illustrates the flow of the pilot flow [ 100 ] and main flow [ 110 ] areas with the main valve [ 190 ] in open position. The main flow [ 110 ] passes through openings in the main valve support block [ 350 ] while the pilot flow [ 100 ] flows through the pilot flow lower annulus [ 210 ], into the pilot flow inlet channel [ 230 ] and into the main valve feed channel [ 220 ] which puts pressure on the main valve pressure chamber [ 200 ] when the pilot valve [ 260 ] is in closed position. The pilot flow [ 100 ] then flows out through the pilot flow exit channel [ 360 ], through the pilot orifice [ 250 ] and over the pilot valve [ 260 ]. Also shown are the seals [ 225 , 226 , 227 , 228 & 240 ] of the main valve actuator assembly.
When pilot valve [ 260 ] closes, pressure increases through the main valve feed channel [ 220 ] into the main valve pressure chamber [ 200 ]. The upper outer seal [ 227 ], upper inner seal [ 225 ], lower inner seal [ 226 ], lower outer seal [ 228 ] and flow guide seal [ 240 ] keep the pilot flow [ 100 ] pressure constrained and equal to the pressure that exists in main flow entrance [ 150 ] area.
Upper outer seal [ 227 ] and lower outer seal [ 228 ] exclude large particulates from entering into the space where the upper inner seal [ 225 ] and lower inner seal [ 226 ] reside. The upper outer seal [ 227 ] and lower outer seal [ 228 ] do not support a pressure load and allow a small amount of pilot flow [ 100 ] to bypass while excluding particulates from entering the area around the upper inner seal [ 225 ] and lower inner seal [ 226 ]. This eliminates pressure locking between the inner seals [ 225 , 226 ] and the outer seals [ 227 , 228 ]. By excluding the particulates from entering into the space where the inner seals reside [ 225 , 226 ] the seals are protected and the clearances of the inner seals [ 225 , 226 ] can be reduced to support high pressure loads. Very small particulates can bypass the outer seals [ 227 , 228 ], but the particulates must be very small in relative to the clearances of the inner seals [ 225 , 226 ] to penetrate the space between the outer seals [ 227 , 228 ] and inner seals [ 225 , 226 ].
Referring to FIG. 4 , an embodiment of the rotary magnetic coupling [ 300 ] and motor [ 310 ] is shown. The Main exit flow [ 340 ] flows parallel along each side of the rotary magnetic coupling [ 300 ] which is contained within the magnetic pressure cup [ 370 ], past the drive shaft and parallel along each side of the motor [ 310 ] down toward the cylindrical support shoulder [ 325 ] that includes a tool face alignment key [ 295 ] below the pilot flow shield [ 270 ]. The magnetic pressure cup [ 370 ] is comprised of a non-magnetic material, and is encompassed by the outer magnets [ 302 ]. The outer magnets [ 302 ] may comprise several magnets, or one or more components of magnetic or ceramic material exhibiting several magnetic poles within a single component. The outer magnets [ 302 ] are housed in an outer magnet housing [ 303 ] that is attached to the drive shaft. Within the magnetic pressure cup [ 370 ] are housed the inner magnets [ 301 ] which are permanently connected to the pilot valve [ 260 ].
The outer magnets [ 302 ] and the inner magnets [ 301 ] are placed so that the magnetic polar regions interact, attracting and repelling as the outer magnets [ 302 ] are moved about the inner magnets [ 301 ] The relational combination of magnetic poles of the moving outer magnets [ 302 ] and inner magnets [ 301 ], causes the inner magnets [ 301 ] to move the pilot valve [ 260 ] linearly and interactively without rotating. The use of outer magnets [ 302 ] and inner magnets [ 301 ] to provide movement from rotational motion to linear motion also allows the motor [ 310 ] to be located in an air atmospheric environment in lieu of a lubricating fluid environment. This also allows for a decrease in the cost of the motor [ 310 ], decreased energy consumption and subsequently decreased cost of the actual MWD device. It also alleviates the possibility of flooding the sensor area of the tool with the drilling fluid like in the use of a moving mechanical seal.
Operation—Operational Pilot Flow—All When the Pilot is in the Closed Position;
The motor [ 310 ] rotates the rotary magnetic coupling [ 300 ] which transfers the rotary motion to linear motion of the pilot valve [ 260 ] by using an anti-rotation block [ 290 ]. The mechanism of the rotary magnetic coupling [ 300 ] is immersed in oil and is protected from the drilling fluid flow by a bellows [ 280 ] and a pilot flow shield [ 270 ]. When the motor [ 310 ] moves the pilot valve [ 260 ] forward [ upward in FIG. 1 ] into the pilot orifice [ 250 ], the pilot fluid flow is blocked and backs up as the pilot fluid in the pilot flow exit channel [ 360 ], pilot flow inlet channel [ 230 ] and in the pilot flow upper annulus [ 160 ] all the way back to the pilot flow screen [ 130 ] which is located in the lower velocity flow area due to the larger flow area of the main flow [ 110 ] and pilot flow [ 100 ] where the pilot flow fluid pressure is higher than the fluid flow through the main orifice [ 180 ]. The pilot fluid flow [ 100 ] in the pilot flow exit channel [ 360 ] also backs up through the main valve feed channel [ 220 ] and into the main valve pressure chamber [ 200 ]. The fluid pressure in the main valve pressure chamber [ 200 ] is equal to the main flow [ 110 ] pressure, but this pressure is higher relative to the pressure of the main fluid flow in the main orifice [ 180 ] in front portion of the main valve [ 190 ]. This differential pressure between the pilot flow in the main valve pressure chamber ( 200 ) area and the main flow through the main orifice [ 180 ] into the main orifice ( 180 ) causes the main valve [ 190 ] to act like a piston and to move toward closure [still upward in FIG. 1 ] causing the main orifice [ 180 ] to stop the flow of the main fluid flow [ 110 ] causing the main valve [ 190 ] to stop the main fluid flow [ 110 ] through the main orifice [ 180 ].
Opening Operation
When the motor ( 310 ) moves the pilot valve [ 260 ] away [downward in FIG. 1 ] from the pilot orifice [ 250 ] allowing the fluid to exit the pilot exit flow [ 320 ] and pass from the pilot flow exit channel [ 360 ] relieving the higher pressure in the main valve pressure chamber [ 200 ] this causes the fluid pressure to be reduced and the fluid flow to escape. In this instance, the main fluid flow [ 110 ] is forced to flow through the main orifice [ 180 ] to push open [downward in FIG. 1 ] the main valve [ 190 ], thus allowing the main fluid [ 110 ] to bypass the main valve [ 190 ] and to flow unencumbered through the remainder of the tool.
Pilot Valve in the Open Position
As the main flow [ 110 ] and the pilot flow [ 100 ] enter the main flow entrance [ 150 ] and combined flow through into the flow cone area [ 170 ], by geometry [decreased cross-sectional area], the velocity of the fluid flow increases. When the fluid reaches the main orifice [ 180 ] the fluid flow velocity is increased [reducing the pressure and increasing the velocity] and the pressure of the fluid is decreased relative to the entrance flows [main area vs. the orifice area] [ 180 ]. When the pilot valve [ 260 ] is in the opened position, the main valve [ 190 ] is also in the opened position and allows the fluid to pass through the main orifice [ 180 ] and around the main valve [ 190 ], through the openings in the main valve support block [ 350 ] through the pilot valve support block [ 330 ] and subsequently into the main exit flow [ 340 ].
DETAILED DESCRIPTION
The present invention will now be described in greater detail and with reference to the accompanying drawings. With reference now to FIG. 1 , the device illustrated produces pressure pulses for pulsing of the pulser within a main valve actuator assembly of the flow throttling device (FTD) in the vertical upward and downward direction using drilling fluid that flows through a tubular rental collar and an upper annulus which houses the pilot flow. There is a flow cone secured to the inner diameter of a hang off collar with major assemblies of the MWD that include a pilot flow screen assembly, a main valve actuator assembly, and a pilot actuator assembly.
To enable the pulser to move in a pulsing upward and downward direction, the passage of the main flow of the drilling fluid flows through the pilot flow screen into the main flow entrance then into the flow cone section and through the main orifice and main valve past the main valve pressure chamber, past the seals, and finally into and through the main valve support block with the flow seal guide.
At this point, the initial drilling fluid combines with the pilot exit fluid and together results in the exit flow of the main fluid. The pilot fluid flow continues flowing through the pilot flow screen and into the pilot flow screen chamber then through the pilot flow upper annulus section, the pilot flow lower annulus section and into the pilot flow inlet channel where the fluid flows upward into the main valve feed channel until it reaches the main valve pressure chamber causing upward motion of the pulser. There, the fluid flows back down the main valve feed channel through the pilot flow exit channel and through the pilot orifice and pilot valve at which point the fluid exits the pilot area where it flows over the pilot flow shield and combines with the main flow to comprise the main exit flow as it exits the pilot valve support block and flows down both sides of the rotary magnetic coupling, outside the magnetic pressure cup and eventually past the drive shaft and the motor.
In operation to accomplish the task of providing for the pilot to attain the closed position, the motor rotates the rotary magnetic coupling transfers rotary motion to linear motion of the pilot valve by using an anti-rotation block. The mechanism of the rotary magnetic coupling is protected from the fluid flow by the use of a bellows and a pilot flow shield. When the motor moves the pilot valve forward—upward into the pilot orifice—the pilot valve blocks and backs up the pilot fluid in the pilot flow exit channel, the pilot flow inlet channel, and in the pilot flow upper annulus, such that the fluid back up and reaches all the way back to the pilot flow screen (which is located in the lower velocity flow area due to the geometry of the larger flow area of the main flow and pilot flow sections such that the pilot flow fluid pressure is higher than the fluid flow through the main orifice).
The pilot fluid flow in the pilot flow exit channel also backs up through the main valve feed channel and into the main valve pressure chamber. The fluid pressure in the main valve pressure chamber is now equal to the main flow pressure but the fluid pressure is higher relative to the pressure of the main fluid flow in the main orifice in the front portion of the main valve. The differential pressure between the pilot flow and the main flow through the main orifice causes the main valve to act like a piston and moves toward closure of the main orifice (upward direction in the Figures provided), thereby causing the main valve to provide a stoppage of the flow of the main fluid flow within the main orifice.
In another embodiment, the MWD device utilizes a turbine residing near and within the proximity of a flow diverter. The flow diverter diverts drilling mud in an annular flow channel into and away from the turbine blades such that the force of the drilling mud causes the turbine blades and turbine to rotationally spin around an induction coil. The induction coil generates electrical power for operating the motor and other instrumentation mentioned previously. The motor is connected to the pilot actuator assembly via a drive shaft. The pilot actuator assembly comprises a magnetic coupling and pilot assembly. The magnetic coupling comprises outer magnets placed in direct relation to inner magnets located within the magnetic pressure cup or magnetic coupling bulkhead. The magnetic coupling translates the rotational motion of the motor, via the outer magnets to linear motion of the inner magnets via magnetic polar interaction. The linear motion of the inner magnets moves the pilot assembly, comprising the pilot shaft, and pilot valve, linearly moving the pilot into the pilot seat. This action allows for closing the pilot seat, pressurizing the flow throttling device, closing the flow throttling device orifice, thereby generating a pressure pulse. Further rotation of the motor, drive shaft, via the magnetic coupling, moves the pilot assembly and pilot away from the pilot seat, depressurizing the flow throttling device sliding pressure chamber and opening the flow throttling device and completing the pressure pulse. Identical operation of the pilot into and out of the pilot seat orifice can also be accomplished via linear to linear and also rotation to rotation motions of the outer magnets in relation to the inner magnets such that, for example, rotating the outer magnet to rotate the inner magnet to rotate a (rotating) pilot valve causing changes in the pilot pressure, thereby pushing the FTD (flow throttling device) up or down.
Unique features of the pulser include the combination of middle and lower inner flow channels, flow throttling device, bellows, and upper and lower flow connecting channels possessing angled outlet openings that helps create signals transitioning from both the sealed [closed] and unsealed (open) positions. Additional unique features include a flow cone for transitional flow and a sliding pressure chamber designed to allow for generation of the pressure pulses. The flow throttling device slides axially on a pulser guide pole being pushed by the pressure generated in the sliding pressure chamber when the pilot is in the seated position. Additional data (and increased bit rate) is generated by allowing the fluid to quickly back flow through the unique connecting channel openings when the pilot is in the open position. Bi-directional axial movement of the poppet assembly is generated by rotating the motor causing magnets to convert the rotational motion to linear motion which opens and closes the pilot valve. The signal generated provides higher data rate in comparison with conventional pulsers because of the bi-directional pulse feature. Cleaner signals are transmitted because the pulse is developed in near-laminar flow within the uniquely designed flow channels and a water hammer effect due to the small amount of time required to close the flow throttling device.
The method for generating pressure pulses in a drilling fluid flowing downward within a drill string includes starting at an initial first position wherein a pilot (that can seat within a pilot seat which resides at the bottom of the middle inner flow channel) within a lower inner flow channel is not initially engaged with the pilot seat. The pilot is held in this position with the magnetic coupling. The next step involves rotating the motor causing the magnetic fields of the outer and inner magnets to move the pilot actuator assembly thereby moving the pilot into an engaged position with the pilot seat. This motion seals a lower inner flow channel from the middle inner flow channel and forces the inner fluid into a pair of upper connecting flow channels, expanding the sliding pressure chamber, causing a flow throttling device to move up toward a middle annular flow channel and stopping before the orifice seat, thereby causing a flow restriction. The flow restriction causes a pressure pulse or pressure increase transmitted uphole. At the same time, fluid remains in the exterior of the lower connecting flow channels, thus reducing the pressure drop across the, pilot seat. This allows for minimal force requirements for holding the pilot in the closed position. In the final position, the pilot moves back to the original or first position away from the pilot orifice while allowing fluid to flow through the second set of lower connecting flow channels within the lower inner flow channel. This results in evacuating the sliding pressure chamber as fluid flows out of the chamber and back down the upper flow connecting channels into the middle inner flow channel and eventually into the lower inner flow channel. As this occurs, the flow throttling device moves in a downward direction along the same direction as the flowing drilling fluid until motionless. This decreases the FTD created pressure restriction of the main drilling fluid flow past the flow throttling device orifice completing the pulse.
An alternative embodiment includes the motor connected to a drive shaft through a mechanical device such as a worm gear, barrel cam face cam or other mechanical means for converting the rotational motion of the motor into linear motion to propel the pilot actuator assembly.
Opening Operation
When the pilot valve moves away (downward in the vertical direction) into the pilot orifice allowing the fluid to flow through the pilot exit and pass from the pilot flow exit channel causing relief of the higher pressure in the main valve pressure chamber. This allows for the pressure to be reduced and the fluid to escape the chamber. The fluid is then allowed to flow into the main fluid flow and flow through the main orifice pushing open (downward) or opening the main valve, thus allowing the main fluid to by pass the main valve and to flow unencumbered through the remainder of the tool.
When the main flow and pilot flow enters the main flow entrance and flows through into the flow cone area where the velocity of the fluid flow increases such that the fluid reaches the main orifice and the fluid flow velocity is increased (reducing the pressure and increasing the velocity of the fluid). The pressure of the fluid is decreased relative to the entrance flows (main area vs. the orifice area). When the pilot valve is in the opened position, the main valve is also in the open position and allows the fluid to pass through the main orifice and around the main valve and through the openings in the main valve support block allowing for the fluid to flow through the opening of the pilot and through the pilot valve support block. Subsequently the fluid flows into the main exit flow channel.
With reference now to FIG. 1 , the device illustrated produces pressure pulses in drilling fluid flowing through a tubular drill collar and upper annular drill collar flow channel. The flow cone is secured to the inner diameter of the drill collar. The centralizer secures the lower portion of the pulse generating device and is comprised of a non-magnetic, rigid, wear resistant material with outer flow channels.
These conditions provide generation of pulses as the flow throttling device reaches both the closed and opened positions. The present invention allows for several sized FTD's to be placed in a drilling collar, thereby allowing for different flow restrictions and/or frequencies which will cause an exponential increase in the data rate that can be transmitted up hole.
Positioning of the main valve actuator assembly within the drill collar and utilizing the flow cone significantly decreases the turbulence of the fluid and provides essentially all laminar fluid flow. The linear motion of the flow throttling device axially is both up and down (along a vertical axial and radial direction without the use of a guide pole).
Conventional pulsers require adjustments to provide a consistent pulse at different pressures and flow rates. The signal provided in conventional technology is by a pulse that can be received up hole by use of a pressure transducer that is able to differentiate pressure pulses (generated downhole). These uphole pulses are then converted into useful signals providing information for the oilfield operator, such as gamma ray counts per second, azimuth, etc. Another advantage of the present invention is the ability to create a clean [essentially free of noise] pulse signal that is essentially independent of the fluid flow rate or pressure within the drill collar. The present invention thereby allows for pulses of varying amplitudes (in pressure) and frequencies to increase the bit rate.
While the present invention has been described herein with reference to a specific exemplary embodiment thereof, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings included herein are, accordingly to be regarded in an illustrative rather than in a restrictive sense. | An apparatus, method, and system described for generating pressure pulses in a drilling fluid utilizing a flow throttling device longitudinally and axially positioned within the center of a main valve actuator assembly is described. The main valve actuator assembly includes a main valve pressure chamber, a magnetic cup encompassing a rotary magnetic coupling, and a pilot actuator assembly. Passage of drilling fluid through a series of orifices, valves, shields, and screens where the fluid eventually combines with a pilot exit fluid that flows toward a main exit flow such that as the fluid becomes a pilot fluid that ultimately combines with the main flow such that the combined fluid causes one or more flow throttling devices to generate large, rapid controllable pulses that produce transmission of well developed signals easily distinguished from other noise resulting from other vibrations due to nearby equipment that is within or exterior to the borehole such that the signals also provide predetermined height, width and shape. | 4 |
BACKGROUND OF THE INVENTION
The use of 6-amino-9-substituted benzyl purines for the treatment of coccidiosis is well known. See U.S. Pat. No. 3,846,426 to Lira et al. issued Nov. 5, 1974. In particular, the compound 6-amino-9-(2-chloro-6-fluorobenzyl)purine is described which is particularly active and is currently sold under the generic name of arprinocid. In addition, certain N 6 methyl arprinocid derivatives are disclosed. See Great Britain Pat. No. 1,534,163. The instant N 6 amidino compounds are highly active anticoccidial compounds in their own right and are also intermediates in the preparation of the N 6 methyl arprinocid compound from arprinocid.
SUMMARY OF THE INVENTION
The instant disclosure is concerned with 6-amidino-9-substituted benzyl purines which compounds are active anticoccidial agents. Thus, it is an object of this invention to describe such compounds. It is a further object of the invention to describe processes for the preparation of such compounds. It is a still further object of this invention to describe compositions and methods of treatment using the compounds of this invention for the administration to poultry, in particular chickens, for the treatment of coccidiosis. Further objects of the invention will become apparent from a reading of the following description.
DESCRIPTION OF THE INVENTION
The instant invention is best described in the following structural formula: ##STR1## wherein R 1 , R 2 and R 3 are independently hydrogen and loweralkyl and R 4 and R 5 are independently halogen.
It will be appreciated by those skilled in the art that when R 2 or R 3 is hydrogen, the above 6-amidino derivatives also exist in the corresponding tautomeric form. The definition of the substituents remains the same, however, the structure may be represented as: ##STR2##
When R 2 is hydrogen the two above structures are interchangeable and in fact the compound may exist in both forms simultaneously. When R 2 is other than hydrogen, structure II can be permanently prepared and isolated using the procedure described below.
When used in the instant application, the term "loweralkyl" is intended to include those alkyl groups containing from 1 to 6 carbon atoms exemplified by methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl and the like.
The term "halogen" when employed in the instant application is intended to include the halogen atoms, fluorine, chlorine, bromine and iodine.
The preferred compounds of this invention are realized in the above-structural formula wherein R 1 is hydrogen or loweralkyl; R 2 and R 3 are loweralkyl; and R 4 and R 5 are fluorine or chlorine.
Still further preferred compounds of the instant invention are realized when R 1 is hydrogen or methyl, R 2 and R 3 are independently methyl or ethyl, R 4 is fluorine and R 5 is chlorine.
The compounds of the instant invention are prepared from a 6-amino-9-substituted benzyl purine and an acetal of an aliphatic amide as outlined in the following reaction scheme. ##STR3## wherein R 1 , R 2 , R 3 , R 4 and R 5 are as previously defined and R' is loweralkyl.
The foregoing reaction is carried out by mixing the two reactants neat or by dissolving them in a co-solvent. The reaction may be carried out equally well using either procedure, and the choice of whether to use a co-solvent or not depends more on the availability of the acetal of the aliphatic amide than upon the differences in reaction rates to be expected. If the aliphatic amide acetal is relatively expensive, the choice would be to use a co-solvent. Where a co-solvent is to be employed the preferred co-solvents are N,N-dimethylformamide, dimethylacetamide (except in those cases where acetal exchange occurs), sulfolane, methylpyrrolidone, dimethylsulfoxide, hexamethylphosphoramide and the like. The preferred solvents are N,N-dimethylformamide and dimethylsulfoxide. The reaction is preferably carried out at room temperature in order to maximize the yields and minimize the production of reaction by-products. However, if desired, the reaction may be carried out up to the boiling point of the reaction mixture. The reaction is generally complete in from 1 to 48 hours, however, most reactions are complete in about 24 hours. The desired product is isolated from the reaction mixture using techniques known to those skilled in the art.
The acetal reactant in the foregoing reaction scheme may be prepared using techniques described in the literature. References for the production of the above acetals of alipatic amides by O-alkylation of an aliphatic tertiary amide to give a carbonium ion which is neutralized with alkoxide are Meerwein et al., Ann., 641, 1, (1961) and Bredereck et al., Angew Chem, 73, 493 (1961).
The 6-amino-9-substituted benzyl purines used as starting materials are also known compounds which are described in U.S. Pat. No. 3,846,426, issued Nov. 5, 1974 to Lira et al.
Other procedures are also available for the preparation of the compounds of this invention. Another such process involves the use of Compound II or III above, in reaction with an alkyl imidate or alkyl imidate salt of the formula: ##STR4## wherein R 1 and R 3 are as previously defined and R" is loweralkyl or phenyl. The reaction is carried out in a solvent, preferably an alcohol such as methanol or ethanol, and is complete in from 1 to 48 hours. The reaction is preferably carried out at the reflux temperature of the reaction mixture however temperatures of from RT to reflux are successful.
The imidate reactants are prepared by known procedures such as the well-known Pinner Reaction from alkyl nitriles. The reactants are also prepared by the o-alkylation of primary and secondary amides using triethyloxonium fluoroborate or dialkylsulfate. See D. A. Nelson in Chemistry of Amidines and Imidates, S. Patai ed. page 385 (1975).
Another procedure for the preparation of the instant compound involves the reaction of compound III with an orthoester followed by reaction with an amine. ##STR5## wherein R 1 , R 2 , R 3 , R 4 , R 5 and R' are as previously defined. The reaction is carried out in two steps; the first being the reaction with the orthoester. This step is generally carried out neat, or optionally with an inert solvent, with an excess of the orthoester. The reaction is heated to reflux for from 1 to 24 hours. Then the reaction mixture is cooled to room temperature, the excess orthoester and solvent removed, and the amine added. The use of a solvent for this step is optional, however if a solvent is employed, dioxane, sulfolane, dimethyl sulfoxide and the like are preferred. If a solvent is used the reaction is generally slower and from 1-48 hours is generally required for the reaction. The reaction with the amine is generally carried out at room temperature for from 6 to 48 hours. In the tautomeric form of compound II, the above procedure is employed using as the starting material the compound of Formula III with R 2 substituted at the 6-position of compound III, R 2 being other than hydrogen as set forth in Formula IV. ##STR6## Compound IV can be allowed to react with an alkylimidate of the formula [R 1 -C(OR")NR 3 ] to form the compound of Formula II wherein R 2 is other than hydrogen.
Coccidiosis is a widespread poultry disease which is produced by infections of protozoa of the genus Eimeria which causes severe pathology in the intestines and ceca of poultry. Some of the most significant of these species are E. tenella, E. acervulina, E. necatrix, E. brunetti and E. maxima. This disease is generally spread by the birds picking up the infectious organism in droppings on contaminated litter or ground, or by way of food or drinking water. The disease is manifested by hemorrhage, accumulation of blood in the ceca, passage of blood in the droppings, weakness and digestive disturbances. The disease often terminates in the death of the animal, but the fowl which survive severe infections have had their market value substantially reduced as a result of the infection. Coccidiosis is, therefore, a disease of great economic importance and extensive work has been done to find new and improved methods for controlling and treating coccidial infections in poultry.
The novel compounds of this invention are orally administered to poultry for the control and prevention of coccidiosis. Any number of conventional methods are suitable for administering the coccidiostats of this invention to poultry, as for example, they may be given in the poultry feed. The actual quantity of the coccidiostats administered to the poultry in accordance with this invention will vary over a wide range and be adjusted to individual needs, depending upon species of the coccidia involved and severity of the infection. The limiting criteria are that the minimum amount is sufficient to control coccidiosis and the maximum amount is such that the coccidiostat does not result in any undesirable effects.
A feed will typically contain from about 0.0005 to about 0.05 percent, preferably from about 0.0025 to about 0.01 percent, by weight of one of the coccidiostats of this invention. The optimum levels will naturally vary with the specific compound utilized and species of Eimeria involved, and can be readily determined by one skilled in the art. Levels of 6-amino-9-(2,6-dichlorobenzyl)purine and its corresponding N 1 -oxide, which are among the most preferred coccidiostats of this invention, in poultry feed of from about 0.0035 percent to about 0.0075 percent by weight of the diet are especially useful in controlling the pathology associated with E. tenella, while the preferred concentration for similar control of intestinal-dwelling species is from about 0.0025 percent to about 0.0065 percent by weight of the diet.
Depending on the compound employed, levels of 0.001 percent to 0.0035 percent possess the novel effects of reducing the number of oocysts passed in the droppings of infected chickens and/or inhibiting the subsequent division and maturation to infectivity, scientifically designated as the process of sporulation. Thus, the combination of prevention of pathology, coupled with the inhibiting effect on the reproductive product of these organisms, the oocysts, present a unique two-fold method for the control of coccidiosis in poultry.
The quantity of concentration of a novel coccidiostat of this invention in any admixture in which it is administered to the poultry will, of course, vary in accordance with the type of admixture utilized.
Of the various methods of administering the coccidiostats of this invention to poultry, they are most conveniently administered as a component of a feed composition. The novel coccidiostats may be readily dispersed by mechanically mixing the same in finely ground form with the poultry feedstuff, or with an intermediate formulation (premix) that is subsequently blended with other components to prepare the final poultry feedstuff that is fed to the poultry. Typical components of poultry feedstuffs include molasses, fermentation residues, corn meal, ground and rolled oats, wheat shorts and middlings, alfalfa, clover and meat scraps, together with mineral supplements such as bone meal and calcium carbonate and vitamins.
The following non-limiting examples will serve to further illustrate the instant invention.
EXAMPLE 1
6-(N,N-dimethylaminomethylidineamino)-9-(2-chloro-6-fluorobenzyl)purine
A mixture of 1.00 g of 6-amino-9-(2-chloro-6-fluorobenzyl)purine in 15 ml of dimethylformamide dimethylacetal is heated at 100° C. After 10 minutes, a solution forms which shortly thereafter starts producing a crystalline precipitate. The heating is continued for 2 hours. The thickened reaction mixture is then cooled in an ice bath and filtered. The solid is washed twice with 8 ml portions of ether. The solid material is dried in vacuo to give 1.139 g of 6-(N,N-dimethylaminomethylidineamino)-9-(2-chloro-6-fluorobenzyl)purine, melting point 172°-173° C.
EXAMPLE 2
6-Aminoethylidenimino-9-(2,6-dichlorobenzyl)purine hydrochloride
A mixture of 9-(2,6-dichlorobenzyl)adenine (1.0 g), ethyl acetimidate hydrochloride (0.5 g), and absolute ethanol (200 ml) is heated at reflux under nitrogen for 18 hours. The product crystallizes during the course of the reaction. The reaction mixture is cooled, filtered and the product washed with a small amount of water and then with ether. Recrystallization from aqueous isopropanol affords homogenous 6-Aminoethylidenimino-9-(2,6-dichlorobenzyl)purine hydrochloride, mp. 198° C.
EXAMPLE 3
6-Ethylaminomethylidenimino-9-(2-chloro-6-fluorobenzyl)purine
One gram of 9-(2-chloro-6-fluorobenzyl) adenine is covered with 25 ml of triethyl orthoformate and heated at reflux for 12 hours. The solution is cooled and evaporated in vacuo to an amorphous solid. This ethoxymethylidene derivative was used without further purification in the next step. Aqueous ethylamine (20 ml of 40%) is added and the mixture allowed to stand at room temperature for 18 hours. The solid which deposited is filtered, dried in vacuo and recrystallized from isopropanol affording 6-Ethylaminomethylidenimino-9-(2-chloro-6-fluorobenzyl)purine, mp. 147°-8° C. | This invention is concerned with 6-(substituted amidino-9-substituted benzyl purine derivatives and in particular 6-(aminomethylideneamino)-9-substituted benzyl purines. The compounds are active anticoccidial agents and suitable compositions and methods are described for the administration of such compounds to poultry for the prevention and treatment of coccidiosis. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of continuation-in-part application Ser. No. 09/206,777, filed Dec. 7, 1998 now U.S. Pat. No. 6,221,268, which is a divisional of prior application Ser. No. 08/632,254, filed Apr. 15, 1996 now U.S. Pat. No. 5,928,527.
TECHNICAL FIELD
This invention relates to a method used for the production of atmospheric pressure plasmas of various gaseous mixtures and their usage for the surface modification of materials.
BACKGROUND OF THE INVENTION
Atmospheric pressure plasmas have been known since the dawn of man. A classic example is lightning. These atmospheric plasmas (DC-type) occur when a high potential causes the dielectric breakdown of air (>8 KV/cm in air). This type of plasma is used for producing various types of ceramic coatings in an apparatus known in the industry as a “plasma gun”. Most other plasma producing devices do so in a vacuum system. Such vacuum-based systems are widely used in the microelectronics industry both for the deposition of thin films and for various etching and surface modification applications. Most of these vacuum-based plasma generating systems use RF or microwave energy excitation to sustain a stable plasma environment. Whereas a stable plasma is relatively easy to generate and maintain at low pressures it is much harder to do so at ambient pressures, due to the very short mean free paths and large recombination rate of the plasma radicals. Discussions of vacuum-type plasmas are given in “Handbook of plasma processing technology”, edited by S. Rossnagel, J. Cuomo, and W. Westwood.
Whereas the capabilities of vacuum-type plasmas are limited by the size of the vacuum chamber and the associated pumping system, an atmospheric pressure plasma system can be configured with very little limitation on the size and shape of the objects treated. It can be made compact and portable as described in our co-pending U.S. application Ser. No. 08/572,390 filed Dec. 14, 1995, details of which are incorporated herein by reference. This system can also be scaled up with very little additional cost either through a large parallel plate configuration or through an array of small orifices, it can be installed in a variety of environments without any facilitation needs and its operating costs and maintenance requirements are minimal.
PRIOR ART PUBLICATIONS
H. Koinuma et al, “Development and Application of a Microbeam Plasma Generator” Appl. Phys. Lett. vol. 60, p. 816-817, (1992) K. Inomata, “Open Air Deposition of SiO 2 Film From a Cold Plasma Torch of Tetramethoxysilane-H 2 -Ar System” Appl. Phys. Lett., vol. 64, p. 46-48 (1994)
SUMMARY OF THE INVENTION
The present invention relates to a device and a method for producing stable atmospheric pressure glow discharge plasmas using low power RE excitation applied through a tuner to a resonant LC circuit, said resonant circuit having as one of its components a discharge chamber capacitor through which a mixture of gases is passed. In addition, the discharge chamber can be configured so that a magnetic field is provided along the direction of the flowing gases such that it provides a force on the charged species in the plasma region thus increasing the ionization ratio. The magnetic field can be provided either through a set of permanent magnets or a coil attached on the external surface of the discharge chamber. These atmospheric pressure plasmas can be generated in various gases flowing through the discharge chamber, the typical case being a combination of a noble gas such as Helium or Argon and a reactive gas such as Oxygen or Nitrogen. The specific gases used and their respective percentages depend on type of surface modification processing sought such as etching of organic materials, surface modification of composites and polymers, and chemical interactions with surface layers of materials.
It is an object of this invention to provide a source for generating atmospheric pressure glow discharge plasmas which is simple and relatively inexpensive to construct.
Another object of this invention is to provide an atmospheric pressure glow discharge plasma source utilizing a resonant circuit and RF excitation to ionize the gas molecules without the need of a vacuum chamber or pumping systems.
Yet another object of this invention is to enhance the ionization rate of the molecules using a magnetic field extended parallel to the gas flow.
It is also an object of this invention that the ionized gases generated in the discharge chamber be used as a source of reactants for etching organic materials and in general modifying the surface characteristics of material.
These and other objects of the invention will be apparent from the following detailed description of preferred embodiment when read in connection with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a block diagram of an atmospheric glow discharge system utilized in surface modification in accordance with the invention;
FIG. 1B is a cross sectional view of the gas chamber and nozzle of the atmospheric glow discharge plasma source used in the system of FIG. 1A to effect surface modification in accordance with the invention;
FIG. 2A is a graph illustrative of etch rate vs. power for various gas flows achieved in accordance with the method according to the invention;
FIG. 2B is a graph illustrative of etch rate vs. power for polyimide and polylene;
FIG. 3A is a graph illustrative of etch rate vs. spacing distance form tip of the RF electrode shown in FIG. 1B;
FIG. 3B is a graph illustrative of etch rate vs. percentage of oxygen in the feed gas;
FIG. 4 is a schematic representation of a series of atmospheric pressure glow discharge sources distributed along and concentrically disposed about the center conductor of a coaxial cable;
FIG. 5 is a schematic representation of an atmospheric pressure parallel plate RF glow discharge plasma source nozzle; and,
FIG. 6 is a diagram showing flame length vs. flowrate.
DETAILED DESCRIPTION OF THE INVENTION
There are a number of distinct advantages in the use of the hereinafter described atmospheric pressure plasma as opposed to one in a vacuum chamber. Its compact packaging makes it portable and easily reconfigurable, it eliminates the need for high priced vacuum chambers and pumping systems, it can be scaled up with very little additional cost, it can be installed in a variety of environments without any facilitization needs and its operating costs and maintenance requirements are minimal.
A schematic representation of the present atmospheric pressure glow discharge plasma source utilized in accordance with the hereinafter described method of the present invention is shown in FIG. 1 A. FIG. 1B shows the gas chamber and nozzle portion of the system of FIG. 1 A and is described in more detail in hereinbefore referenced copending application Ser. No. 08/572,390 U.S. Pat. No. 5,977,715. The system is comprised of three elements: The RF power supply, the tuning network, and the gas chamber/nozzle. The RF power supply is presently an ordinary power supply used for vacuum, thin film sputtering applications. The RF frequency used is 13.56 MHz, which is the frequency allowed by the F.C.C. (Federal Communications Commission) for industrial applications. The tuning network is necessary to be able to maintain a stable RF plasma at atmospheric pressure. The nozzle configuration is comprised of an inner electrode where the RF power is introduced, a gap where the discharge occurs, a ceramic spacer and the grounded gas chamber as shown in FIG. 1 B.
The feed gases are introduced to the annular region where the plasma is generated through the ground shield chamber. Different configurations of the center electrode, the ceramic spacer and the gap will result in different flow patterns. These flow patterns can be tailored to a specific application.
One configuration uses a 1 mm wide annular region as the plasma generation region. This plasma extends to a distance of roughly 3-10 mm in length from the tip of the inner electrode. The typical power used for the plasma is 2-60 Watts. The gas flow can be varied using a gas manifold fitted with mass flow controllers. Even though the gas flow can be varied over a wide range of values the typical flow used is 1000 sccm.
The ability to generate a stable plasma using a variety of gas compositions. Some examples are: Helium, Helium+Oxygen, Argon, Argon+Oxygen, Helium+Nitrogen, and Helium+CF 4 has been demonstrated.
COLD ATMOSPHERIC PRESSURE PLASMA APPARATUS AND METHOD OF OPERATION
One major feature of the present atmospheric pressure plasma systems is that the plasma generated is a “cold” one, i.e., less than 100 C as measured by a thermocouple, and similar to those generated ordinarily in vacuum chambers. The exact temperature of the plasma is a function of several parameters such as power, gas flow, electrode geometry, and distance from the tip of the RF electrode. When the discharge feed gas is an inert gas (He, Ar) the plasma generates a short-lived source of ions of this particular gas which can bombard a surface of interest and change its surface electronic states, by creating broken bonds or altering the surface bonding configurations. A small admixture of a reactive gas in this plasma such as oxygen creates a localized source of atomic oxygen, oxygen radicals, and ozone around the plasma region. The parameters that influence these processes are: RF power, gas flow, electrode geometry, and gas composition.
According to the present method of surface modification a variety of materials have been exposed to the atomic oxygen plasma source under various plasma parameters. When an organic material is exposed to this process, it reacts with these strong oxidizers and is essentially “etched away”. Two representative materials include polyimide, and parylene. Other materials examined include photoresist, grease, machine oil, epoxy, soldering flux, and paints. The size of the glow discharge depends on the power, the gas flow rate, the gas composition, and the geometry. This is shown in FIGS. 2A and 2B.
The etch rate also depends on the distance from the plasma glow and the relative percentage of Oxygen in the gas. These are shown in FIGS. 3A and 3B. The distance is measured from the tip of the RF electrode.
APPLICATIONS OF THE COLD ATMOSPHERIC PRESSURE PLASMA APPARATUS
Method of Surface Cleaning Organic Contaminants
As hereinbefore mentioned, the present cold atmospheric pressure plasma surface treatment process etches all types of organic compounds, including hydrocarbons. It does not require the use of a vacuum and it can operate over a wide range of parameters which can be optimized for the specific application. Its by-products are gaseous and are most likely oxides of the respective elements the organic material is made of, typically CO 2 and water. It can operate in a room environment with a relatively low gas flow. For safety purposes, it may be desirable to operate such a device under a hood or with the attachment of small, localized vacuum pump, if needed. This device will not harm an underlying metallic surface, nor will it etch any oxides such as ceramic materials or glasses. It can be fitted with a fiber optic end-point detector so that no unnecessary processing takes place. Finally, a modified version of the apparatus can be incorporated at a section of an RF cable which will allow for it to be inserted in long, bent tubes or other tight spots for hydrocarbon or other organic contaminant removal by the use of atomic oxygen without the use of vacuum. Such an embodiment is shown in FIG. 4. A schematic representation of a set of these plasma devices fitted in the middle of an RF cable is shown. Parallel tubes bring the reactive gases to the plasma region and are fitted with end-point detectors (fiber). In this embodiment the plasma region would have to be moved slowly through the tube while monitoring the CO 2 emissions from the plasma region. The end-point detector is very useful in this embodiment because different regions of the tube may have different degrees of contamination.
An important use of the present cold atmospheric pressure plasma apparatus is in the etching of materials. These include organic coatings or contaminates. A feed gas mixture that contains oxygen will result in the generation of atomic oxygen in the plasma. This atomic oxygen is responsible for the etching. Because of the importance of plasma cleaning, most of the experimentation has involved the removal of organic materials (parylene and polyimide).
Two (2) different feed gas mixtures have been investigated. Argon/Oxygen and Helium/Oxygen. Both of these mixtures result in the generation of atomic oxygen. Helium/Oxygen mixtures that contain less than 3% oxygen are unstable. Argon/Oxygen plasmas exhibit a strong relationship between flame length and the amount of oxygen in the feed gas.
In order to etch a material, the sample needs to be placed close to the discharge. If the sample is placed inside the discharge itself, the etching will occur very rapidly. (See FIG. 3 A). However, if the sample is placed inside the discharge electrical arcing from the electrode tip to the sample may occur. This is unacceptable, because arcing can easily damage a sample.
As the power to the plasma is increased, the etch rate increases. This is shown in FIG. 2 B. Increasing the power increases both the length of the discharge and the generation of reactive species within the plasma.
Another way to change the size of the discharge is to change the gas flow rate through the nozzle. (See FIG. 2 A). Any plasma species that are generated in the glow discharge are consumed through recombination. A higher gas flow rate will ‘push’ the species out faster, before they have had a chance to recombine. FIG. 6 shows and optimal flow rate at 1000 sccm for the nozzle shown in FIG. 1 B.
Stripping of Paint
Most of the parameter studies were carried out using parylene and polyimide as the organic material. Epoxy and urethane based paints have also been etched from composite and aluminum substrates. The present system is capable of etching the organic binder in the paint formulation, but the inorganic components remain on the surface. They accumulate as a fine powder that appears to be bound electrostatically to the surface of the sample. This powder can easily be wiped off the part using a dry rag. The best way to strip paint with the present system is to etch the part for a period of time (about 5-10 minutes), wipe the residue off with a rag, and then etch the paint some more. (Using this technique, paint can be stripped at a rate of 2000 Angstroms per minute.)
Surface Modification of Composites and Other Organics Prior to Bonding
Exposure to plasmas, especially for insulating materials creates modifications in the surface states present, typically making them more active chemically by the creation of surface charges, broken bonds etc. It is believed that surface treatment with a noble gas plasma or a combination of gases may enhance the bonding of various composites and organic binders, thereby helping to eliminate various toxic chemicals used in such operations.
Electronic Manufacturing
Removal of parylene which is used as an overcoat for the protection of electronic parts in circuit boards has been accomplished. This is necessary if one needs to do any rework/replacement of parts. At present the removal of parylene is extremely difficult and requires some very strong chemicals which attack not only the parylene layer but also the circuit board itself.
A second application involves flux removal from electronic or opto-electronic parts. The etching of various types of flux in localized areas has been demonstrated.
Medical Applications
An oxygen plasma can be used as a means of sterilization of medical/surgical parts without any use of chemicals. This can be done in a localized fashion and without the need of autoclaves or other expensive non-portable equipment.
Other Applications Utilizing the Present Method
Fiber Optic Cables:
Fiber optic cables are often coated with a polyimide layer. This layer must be removed for installation of the cable into connector terminals. This can be accomplished through the use of concentrated acids or it can be done using the present apparatus and method. The present system will quickly and safely remove the coating without the generation of any hazardous wastes or the potential of employee exposure to corrosive solutions.
Thick Film Resistors:
Manufacturers of printed circuit boards use a screen printed resistor material to fashion resistor on the boards. This material consists of a polymer matrix with graphite particles embedded in it. Conventional trimming techniques do not work for these resistors. Resistors have been trimmed utilizing the present apparatus and method. By slowly removing the material from the device, the value of the resistor can be raised in a controlled fashion.
Comparison With Other Approaches
The present cold atmospheric pressure plasma system and method has a distinct advantage over competing methods such as laser etching because of its very low cost and its ability to be scaled up without any loss in throughput. For example, laser etching can increase the size of the area to be etched by defocusing the beam but this reduces the incident power density per unit area. Whereas in contrast the present system can be scaled up using a large array of such devices which can cover a large processing area in accordance with the present method for surface modification without a significant cost penalty. Another advantage of the method utilizing the present exemplary apparatus is its portability which allows for field operations. A further advantage of this approach is its capability of having an optic fiber in the nozzle region to monitor the CO 2 emissions from the plasma region so as to be able to do end-point detection. Finally, the fact that the present system does not require a vacuum system makes it highly useful in many remote operations. | A method for producing stable atmospheric pressure glow discharge plasmas using RF excitation and the use of said plasmas for modifying the surface layer of materials. The plasma generated by this process and its surface modification capability depend on the type of gases used and their chemical reactivity. These plasmas can be used for a variety of applications, including etching of organic material from the surface layer of inorganic substrates, as an environmentally benign alternative to industrial cleaning operations which currently employ solvents and degreasers, as a method of stripping paint from surfaces, for the surface modification of composites prior to adhesive bonding operations, for use as a localized etcher of electronic boards and assemblies and in microelectronic fabrication, and for the sterilization of tools used in medical applications. | 2 |
TECHNICAL FIELD
The present invention relates generally to hydraulic transmissions, and more particularly to an improved hydrostatic differential transmission with an input shaft carrying a housing which provides power through a set of pinion gears on a differential to the output housing carried on the output shaft.
BACKGROUND OF THE INVENTION
Hydraulic transmissions are used in a wide variety of vehicles and other equipment to change the ratio of input shaft speed relative to output shaft speed. Conventionally, a high hydraulic pump unit and cooperating swash plate on the input side of the transmission interact to displace hydraulic fluid to an outside pump which in turn interacts with an output side swash plate in a manner to rotate the output shaft. The transmission ratio essentially depends on the fluid displacement ratio of the two pumps.
In standard hydrostatic pumps, a greater flow of hydraulic fluid creates a faster output transmission shaft rotation. Thus, as the ratio of input shaft speed approaches one to one with output shaft speed, the oil flow is greatest. However, this condition also results in many moving parts resulting in wear of the various components during the highest output of the drive.
SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to provide an improved hydrostatic differential transmission in which the transmission ratio is infinitely variable between a neutral condition and a direct drive condition.
Another object of the present invention is to provide a hydrostatic transmission with a differential unit that controls the ratio of the power transmitted.
A further object is to provide a hydrostatic transmission wherein the rotation of pinion gears on a differential unit is controlled by a pair of swash plate pumps.
Yet another object of the present invention is to provide a hydrostatic transmission in which the greatest power output occurs when no oil is being pumped, and no parts are moving.
These and other objects will be apparent to those skilled in the art.
The hydrostatic differential transmission of the present invention includes a pair of hydraulic pumps rotatably mounted for free rotation on coaxial input and output shafts respectively. A pivotable swash plate is mounted to the input shaft adjacent the first pump and presents a surface interacting with pistons slidably mounted in bores in the first pump to effect reciprocating movement of the pistons when the swash plate is oriented at an angle away from perpendicular from the axis of the input shaft. The swash plate is pivotable between a direct-drive position perpendicular to the axis of the input shaft, preventing reciprocation of the pistons, and a neutral position disposed at an angle from perpendicular to the input shaft axis which is the same as the angle of a second swash plate adjacent the second pump. An adjustable control selectively pivots the swash plate to control the ratio of the rotational speeds of the input and output shafts. The second swash plate is mounted on the output shaft adjacent the second pump, to effect reciprocating movement of pistons within bores in the second pump. A differential is rotatably mounted for free rotation between the pumps, and connected to the pumps to rotate therewith. A pair of valve plates are disposed between the differential and each pump, and are freely rotatable mounted on the respective input and output shafts. The valve plates control fluid flow from the pumps through the differential, all of which forms a substantially closed hydraulic circuit. Pinion gears are rotatably mounted around the circumference of the differential, and freely rotate about axes extending radially from the differential. A forward ring gear is located in engagement with a forward tangential side of the pinion gears, and is mounted on an input housing which is directly connected to the input shaft for rotation therewith. A second ring gear is located for operable engagement with the pinion gears diametric to the first ring gear, and is mounted on an output housing which is directly mounted to the output shaft for rotation therewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view taken centrally through a hydrostatic differential transmission according to a preferred embodiment of the invention, with the transmission in a neutral setting;
FIG. 2 is a sectional view similar to FIG. 1, but showing the variable swash plate rotated to a position wherein the transmission is in a direct drive setting;
FIG. 3 is an elevational view of one face of a valve plate of the transmission;
FIG. 4 is a sectional view taken at lines 4--4 in FIG. 3;
FIG. 5 is an elevational view of one face of the differential housing; and
FIG. 6 is an enlarged portion of FIG. 1 showing the differential housing, two valve plates and the rearward pump of the transmission.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, in which similar or corresponding parts are identified with the same reference numeral, and more particularly to FIG. 1, the hydrostatic differential transmission of the present invention is designated generally at 10 which is constructed according to a preferred embodiment of the invention. Transmission 10 transfers power in a variable ratio from an input shaft 12 to an output shaft 14 which is axially aligned therewith. In a normal application, input shaft 12 is rotated by a drive motor, engine, or other power source (not shown).
Input shaft 12 extends through a central opening formed in one end 16a of a generally cylindrical transmission housing 16. Input shaft 12 is connected by splines 18 to housing 16, such that housing 16 rotates with the rotation of shaft 12. Output shaft 14 is mounted for rotational movement within a carrier bearing 20 mounted within an aperture located centrally in second end 16b of housing 16. An oil seal 22 contains oil inside transmission housing 16.
For ease of description, end 16a of housing 16 will be considered the forward end, and end 16b will be considered the rearward end relative to the longitudinal axes of input and output shafts 12 and 14. A fixed swash plate 24 is mounted to the base 26a of a cup-shaped output shaft housing 26, mounted to output shaft 14 with splines 28. Output shaft 14 is mounted through a central aperture through swash plate 24 and outer shaft housing 26, for rotation with output shaft housing 26. Output shaft housing 26 includes a cylindrical side wall 26b projecting forwardly from the perimeter of base 26a within transmission housing 16. A ring gear 30 is formed on the forward end of side wall 26b. A forward ring gear 32 is affixed to the interior surface of housing 16, spaced forwardly from ring gear 30, and coaxial therewith.
The differential housing 34 is a generally disk-shaped member with an annular flange 36 projecting forwardly and rearwardly from the circumference thereof, said differential housing mounted for rotational movement coaxial with input and output shafts 12 and 14. A pair of pinion gears 38 and 40 are rotatably mounted on diametric sides of differential housing 34 on a pair of coaxial shafts 42 and 44 respectively. Shafts 42 and 44 extend along a line forming a diameter through differential housing 34, such that pinion gears 38 and 40 rotate in parallel planes parallel to the axes of input and output shafts 12 and. 14. As shown in FIG. 1, pinion gears 38 and 40 engage ring gears 30 and 32, and are located therebetween on diametric sides of differential housing 34. Pinion gears 38 and 40 are interconnected with the rotor unit 46 of a charge pump (gerotor) along the periphery of shafts 38a and 40a, concentric with rotational shafts 42 and 44. Rotor units 46 of the charge pump provide makeup oil to the supply side of the pump through a passageway 48 extending radially inwardly from rotor unit 46 through differential housing 34.
A pair of disk-shaped forward and rearward valve plates 50 and 52 (see also FIG. 6) are affixed to the inwardly projecting ends of input and output shafts 12 and 14 respectively, by splines 54 and 56 respectively, for rotation with input and output shafts 12 and 14 respectively. Forward valve plate 50 has a diameter less than the interior diameter of the forwardly projecting lip 36a of flange 36, to fit snugly therein in flush contact with the forward circular face 34a of differential housing 34. Similarly, rearward valve plate 52 has a diameter to fit within the diameter of rearwardly projecting lip 36b of flange 36 in contact with the rearward face 34b of differential housing 34. A cylindrical-shaped forward pump 58 is rotatably mounted on input shaft 12 with a collar bearing 60, and having a diameter equal to that of forward valve plate 50, such that the rearward circular face 58b fits within the diameter of forward lip 36a of flange 36 in contact with the forward face 50a of valve plate 50. Similarly, a rearward pump 62 is rotatably mounted on output shaft 14 with a collar bearing 64 and fits within the diameter of rearwardly projecting lip 36b of flange 36 in contact with the rearward face 52b of rearward valve plate 52. A spring and keeper assembly 66 mounted on input shaft 12 applies a rearwardly directed biasing force on an inwardly and radially directed shoulder 68 of forward pump 58 to keep forward pump 58 in contact with forward valve plate 50 and thereby maintain the contact of forward valve plate 50 with differential housing 34. A similar spring and keeper assembly 70 mounted on output shaft 14 provides a biasing force against a shoulder 72 on rearward pump 62 (as shown in FIG. 6) to provide pressure to keep rearward pump 62 in contact with rearward valve plate 52 and thereby maintain the contact of rearward valve plate 52 with the rearward face of differential housing 34.
The speed of rotation of pinion gears 38 and 40 is determined by the transfer of power from forward ring gear 32 (interconnected to input shaft 12) to rearward ring gear 30 (interconnected to output shaft 14). The rotation of pinion gears 38 and 40 controlls the rotation of differential housing 34 on its rotational axis. When the transmission is in a neutral condition, as shown in FIG. 1, the input shaft will be rotating, while the output shaft will not rotate. In this condition, the differential housing 34 will rotate at a rate one-half of the rotational rate of input shaft 12 by virtue of pinion gears 38 and 40. Thus, if input shaft 12 is rotating at 100 rpm, differential housing 34 will be rotating at 50 rpm, and output shaft will be rotating at 0 rpm.
Fixed swash plate 24 has a forward face including a flat annular face 24a, oriented perpendicularly to the longitudinal axis of output shaft 14, and a ring-shaped swash face 24b radially inwardly of annular face 24a which lies within a plane oriented at a predetermined angle between 0° and 45° relative to a plane perpendicular to the output shaft 14. Preferably, the plane of swash face 24b is oriented at an angle of approximately 15° from a plane perpendicular to the longitudinal axis of output shaft 14.
A friction pad 74 is mounted to the ends of each piston 78', 80', 82' and 84' of rearward pump 62 for contact with swash plate faces 24a and 24b, as described in more detail below.
Rearward pump 62 includes eighteen piston chambers arranged along two concentric rings forming inner and outer rings of pistons. The sectional view of FIG. 1 shows two pistons 80' and 82' from the inner ring and two pistons 78' and 84' from the outer ring.
FIGS. 1 and 6 show four cylindrical piston chambers 78, 80, 82 and 84, extending forwardly from the rearwardly face 62b of pump housing 62 not entirely through the thickness of the pump housing. Cylindrical pistons 78', 80', 82' and 84' are slidably mounted for reciprocation within their associated chambers 78-84 respectively. As shown in FIG. 1, outermost pistons 78' and 84' are located at a radius matching the radius of annular swash face 24a, while inner pistons 80' and 82' are each located at a radius to contact ring-shaped swash face 24b. Rearward pump housing 62 is engaged with rearwardly projecting lip 36b of flange 36 on differential housing 34 by splines 86 for rotation with differential housing 34.
Forward pump 58 is identical to rearward pump 62, but reversed such that pistons 88', 90', 92' and 94° are slidably mounted for reciprocation within piston chambers 88, 90, 92 and 94 formed in the forward face 58a of forward pump housing 58. Forward pump housing 58 engages the forwardly projecting lip 36a of flange 36 via splines 96 for rotation with differential housing 34. The rearward pump housing 62 is similarly connected for rotation with the differential housing 34.
An annular wall 98 projects rearwardly from the interior surface of the forward end 16a of housing 16, and has an annular surface on which the friction pads 100 mounted on outer piston heads 88'a and 94'a is in continuous contact. An adjustable swash plate 101 is pivotally connected to annular wall 98 by a pivot pin 104 extending perpendicularly to the longitudinal axis of input shaft 12 for pivotal movement of the plane of swash plate 101 from a 0° angle perpendicular to the longitudinal axis of input shaft 12, and an angle of 15° relative to a plane perpendicular to the longitudinal axis of input shaft 12 (and parallel to the angle of fixed swash plate swash face 24b). Adjustable swash plate 101 is pivoted on pin 104 by a link 106 connecting one edge of swash plate 101 to a threaded adjustment nut 108 on the end of a threaded shaft 110. Rotation of the head 110a of threaded shaft 110 will cause adjustment nut 108 to move along shaft 110, thereby pivoting swash plate 101 on pivot pin 104, to increase or decrease the angle of tilt.
Referring now to FIGS. 5 and 6, differential housing 34 has a rearward face 34b identical to the forward face 34a. Four annular concentric grooves 112, 114, 116 and 118 are formed in the forward and rearward faces 34a and 34b of differential housing 34, the grooves being separated by annular ridges, and decreasing in diameter from an outer groove 112 to a small diameter inner groove 118. A plurality of passageways are formed through the thickness of differential housing 34, for the passage of hydraulic oil. As shown in FIG. 5, a plurality of passageways 120 formed through a thickness of housing 34 are aligned along the groove 114 to pass between groove 114 of face 34b and groove 114 on face 34a. A second set of passageways 122 are located along groove 112, a third set of passageways 124 are formed along groove 116, and a fourth set of passageways 126 are located in groove 118.
Referring now to FIGS. 3 and 4, only one valve plate 52 is shown in face and sectional view, since valve plate 50 is identical thereto but reversed when placed within transmission 10. Valve plate 52 includes an upper half and lower half, if a center line is drawn through the rotational axis thereof. Valve plate 52 includes a differential-abutting face 52a, and a pump-abutting face 52b. As shown in FIG. 4, four ports, 128, 130, 132 and 134 are formed through the thickness of valve plate 52 to permit the passage of hydraulic fluid therethrough.
The correspondence of the ports of the valve plates with the differential housing passageways and piston chambers is best described by referring to FIG. 1. Rearward valve plate 52 rotates with swash plate 24 and directs the flow of hydraulic oil from piston chamber 80 (in rearward pump housing 62) through the passageways in differential housing 34 to a forward valve plate 50. It can be seen that the rotation of differential housing 34 will cause forward and rearward pump housings 58 and 62 to rotate therewith. When adjustable swash plate 101 is located in the neutral position, shown in FIG. 1, output shaft 14 will not rotate, thereby holding swash plate 24 still relative to rotating rearward pump housing 62. Thus, the rotation of differential unit 34 will cause pistons 80' and 82' to move in and out of rearward pump housing 62 as the pistons with friction pads 74 slide along on swash plate 24 (which is oriented at a 15° angle).
As piston 80' is moved to the position shown in FIG. 1, it will displace hydraulic oil in piston chamber 80 through rearward valve plate port 130 (see FIG. 6), thence through differential passageway 124 to forward valve plate port 130', and into forward pump housing piston chamber 90, thereby forcing piston 90' against adjustable swash plate 100. Thus, this would be the high pressure side of forward and rearward pumps 58 and 62. Simultaneously, piston 92' will be forcing hydraulic oil from piston chamber 92 through forward valve plate port 132' (see FIG. 6), differential housing passageway 122, rearward valve plate port 132 and into rearward piston chamber 82 to force piston 82' outwardly to the end of the piston stroke against fixed swash plate 24.
Oil pressure from the high pressure side of the pump is transferred from passageway 124 through radial passage 136 to passageway 120. Oil in passage 120 is directed along annular grooves 114 (see FIG. 6) to ports 134 and 134' in valve plates 52 and 50 and into piston chambers 84 and 94. Thus, the high pressure oil exerts pressure on pistons 94' and 84', respectively and against swash plates 98 and 24a. This pressure maintains the seals between pump housings 58 and 62, valve plates 50 and 52 and differential housing 34.
As discussed above, passageway 48 supplies oil from the charge pump rotor unit 46 to passageways 126 and 122 to grooves 112 and 118. This oil is thereby supplied through ports 128 and 128' to piston chambers 78 and 88, and through ports 132 and 132' to piston chambers 82 and 92, so as to maintain pistons 78' and 88' in contact with surface 98 and swash plate 24a.
When adjustable swash plate 101 is in the "neutral" position shown in FIG. 1, differential housing 34 will be rotating at a velocity one-half of the rotational speed of input shaft 12 and transmission housing 16, while output shaft 14 and swash plate 24 will not be rotating. In this position, oil will be directed to forward pump housing 58. As shown in FIG. 1, swash plate 101 is tilted at the same angle as swash plate surface 24b, when in the "neutral" position, such that piston chamber 90 will accept oil pumped from piston chamber 80. Referring to FIG. 2, adjustable swash plate 24 is oriented at a 0° angle such that piston chamber 90 will not accept any oil pumped from piston chamber 80. This results in a direct drive connection between input and output shafts 12 and 14, wherein transmission housing 16 rotates along with output housing 26, and wherein pumps 58 and 62, differential 34 and valve plates 50 and 52 all rotate at the same speed. Because all of these components are rotating at the same speed, pinion gears 38 and 40 will not be rotating, and no components within transmission housing 16 will be moving.
As adjustable swash plate 101 is moved between the direct drive position of FIG. 2 and the neutral position of FIG. 1, the speed of rotation of the differential unit 34 will vary, thereby changing the ratio of rotation of input shaft 12 with respect to output shaft 14. This adjustment of adjustable swash plate 101 occurs by rotation of shaft head 110a of threaded shaft 110 by an external electric motor (not shown).
Whereas the invention has been shown and ,described in connection with the preferred embodiment thereof, many modifications, substitutions and additions may be made which are within the intended broad scope of the appended claims. | A hydrostatic differential transmission includes a pair of cylinder housings (58, 62) rotatably mounted for free rotation on coaxial input and output shafts, respectively, with a first pivotable swash plate (101) and second fixed swash plate (24b) fixed to the input and output shafts, respectively and a differential. An adjustable control selectively pivots the first swash plate between a neutral position, where the swash plate is at an angle to the input shaft equal to the angle of the second swash plate to the output shaft, and a direct drive position, where the swash plate is perpendicular to the input shaft. The differential includes a forward ring gear (32) fixed to the input shaft, a rearward ring gear (30) fixed to the output shaft and pinion gears (38, 40) between the forward and rearward ring gears. The pair of cylinder housings rotate together (via 36, 96) and have the pinion gears rotatably mounted thereto, for driving an auxiliary pump (48). | 5 |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates generally to the field of manual tools for snow removal and in particular to a new and useful snow shovel having an articulating shovel blade mounted to a carriage.
Snow shovels having a blade and an elongated handle are generally well known in the art of snow removal tools. Some snow shovels have sharply curved blades, while others are flattened, and still others have side panels.
Two types of shovel are particularly common, regardless of the specific blade or handle. One type is used to lift snow and throw it, while the other type of shovel is used primarily to push snow in front of it like a plow.
It is also generally well known that some types of snow can be particularly heavy, such as wet, slushy snow or icy snow. Attempting to shovel a walkway or driveway covered with wet snow can be difficult for many people because of the weight.
Many different solutions have been provided for making shoveling easier. Some of the solutions include adding a handle to a conventional single handle shovel, such as disclosed by U.S. Pat. No. 6,343,822. U.S. Pat. No. 6,343,822 teaches a shovel with a second, adjustable handle which can be moved from side to side around the main handle shaft to provide leverage for lifting snow or other material with the shovel.
Other patents disclose handles and blades which pivot relative to each other. U.S. Pat. No. 6,290,273, for example, describes a shovel with a blade that pivots to a greater or lesser angle between the blade surface and the handle. That is, the shovel blade pivots up and down about a horizontal axis.
U.S. Pat. No. 5,984,393 teaches a shovel having a fixed second handle near the shovel blade, and a mechanism for allowing the shovel blade to pivot about the main handle. The shovel blade is locked from pivoting until a load of snow has been lifted and is ready to be dumped. Then, a trigger is used to allow the blade to pivot to one side or the other so that the snow is dumped without having to twist the shovel handles.
U.S. Pat. No. 813,983 discloses a shovel with the shovel blade pivotally attached to the handle so that the blade can tilt to the left or right. The blade is connected to the handle by two bolts or screws arranged vertically aligned. The upper bolt is mounted through an arcuate slot in the shovel blade, while the lower bolt is the pivot point. Thus, the edges of the blade can be tilted off horizontal, theoretically to cause snow to move to one side when the shovel is used as a plow. However, it appears that if the bottom edge is not flat, some snow would remain behind when using the shovel in this manner.
A scoop shovel having the scoop blade horizontally pivotable about a vertical shaft axis is taught by U.S. Pat. No. 2,221,219. The scoop is moved by a ratchet and pawl mechanism connected to a remote lever at the end of the handle shaft. The scoop is pivotable for use scooping out ashes from a furnace having a small door, whereby the shovel can be inserted through the furnace door, pivoted, ashes scooped up and the scoop pivoted back for removal from the furnace.
A snow plow type shovel having an expandable pushing blade is disclosed by U.S. Pat. No. 6,269,558. The blade has two adjustable wings connected to form a “V” with a flat bottom where the handle is attached. The wings can be pivoted to form a greater or smaller acute angle relative to the handle.
U.S. Pat. No. 6,334,640 discloses a snow shovel having a rotating handle and a single wheel. The handle and wheel are connected to the center of the rear of the shovel blade, so that the shovel is symmetrical about a horizontal axis through the center. The handle can be rotated around the wheel so that the shovel can be flipped over to permit the other edge of the shovel blade to contact the ground. The blade does not pivot horizontally relative to the wheel or handle.
Each of the shovels having a pivoting blade still has the easiest direction of travel with the shovel being perpendicular to the surface of the shovel blade. Alternatively, these shovels result in the handle being positioned at an odd angle when the shovel blade is placed square on the ground, so that it will be difficult to move the shovel. That is, none of the prior shovels provides a means for angling the blade relative to the direction of movement of the shovel blade, so that it can truly act as a plow.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a shovel having a pivoting blade for moving snow from a sidewalk or driveway.
It is a further object of the invention to provide a shovel with an adjustably pivoted blade.
Yet another object of the invention is to provide a wheeled shovel for more easily pushing snow off a driveway or sidewalk.
Accordingly, a shovel is provided having an articulated shovel blade pivotally attached to a wheeled carriage. The shovel blade can be locked into three or more positions at different angles relative to a support bar of the carriage. The shovel blade is pivotally mounted to the support bar with a bracket so that the blade is spaced from the support bar and wheels of the carriage. A locking pin passing through the bracket and support bar is used to hold the bracket in position relative to the support bar. A handle extends upwardly from the support bar so that a person using the shovel can push it easily in a direction perpendicular to the support bar, even while the shovel blade is angled relative to the support bar.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a top, rear perspective view of a snow shovel according to the invention;
FIG. 2 is a magnified view of the joint between the bracket and support of the snow shovel of FIG. 1;
FIG. 3 is a side elevation view of the shovel of FIG. 1 with the wheels and handle removed;
FIG. 4 is a top plan view of an alternative support for the snow shovel of FIG. 1;
FIG. 5 is a top plan view of a second embodiment of a snow shovel according to the invention; and
FIG. 6 is a bottom plan view of a third embodiment of a snow shovel of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows an articulated shovel 10 of the invention with the handle 50 shown having a truncated length. The articulated shovel 10 has a pivotable shovel blade 20 connected to a support bar 35 of a carriage 30 . A bracket 25 pivotally secures the shovel blade 20 to the support bar 35 . The bracket 25 is joined to the support bar at pivot joint 36 . The other ends of the bracket 25 are riveted, welded or fastened with threaded fasteners to the shovel blade 20 .
The carriage 30 includes support bar 35 extending between a pair of wheels 33 attached to the support bar 35 by axles 32 . A handle 50 extends upwardly and to the rear from either side of the support bar 35 in an inverted “U” for pushing the carriage 30 and shovel blade 20 .
FIG. 2 illustrates the pivot joint 36 connection between the bracket 25 and support bar 35 in greater detail. As shown, the pivot joint 36 can be formed by a threaded bolt fastened through the support bar 35 and bracket 36 so as to permit rotational movement between them. When the pivot joint 36 can be non-destructively disassembled, storage of the shovel 10 is made easier, as the blade 20 can be removed to occupy less space.
Alternatively, the pivot joint 36 may be formed by a permanent connector which is arranged to permit relative movement, such as a rivet loosely joining bracket 25 and support bar 35 , a bolt and locking cotter pin or a similar shaft and locking fastener combination.
The pivot joint 36 is held in a pre-determined fixed position by a locking pin 38 . As best seen in FIGS. 2 and 3, a locking pin 38 is provided extending through one of the bracket holes 37 in the bracket 25 and a corresponding carriage hole in the support bar 35 . The locking pin 38 has a larger head than the diameter of the bracket holes 37 so that the upper end will not pass through the bracket hole 37 it is inserted into.
A number of carriage holes through the support bar 35 are positioned to align with one or more of the bracket holes 37 when the bracket 25 and shovel blade 20 are pivoted to a particular position. The locking pin 38 is then dropped into place through an aligned pair of the bracket holes 37 and carriage holes. The locking pin 38 can be threaded at one end for fastening more securely through the aligned holes, or it may simply have a length sufficient to prevent it from rising out of the aligned holes during use. For example, an unthreaded locking pin 38 used with the shovel 10 may extend about ½ inch past the lower surface of the support bar 35 .
The locking pin 38 prevents relative movement of the shovel blade 20 and carriage 30 during use. The shovel blade 20 is preferably positionable in at least three positions—left, right and center. The left and right positions orient the shovel blade 20 to push snow off to the side of the direction of travel of the carriage 30 , while the center position will push snow straight ahead in advance of the shovel 10 . By locking the shovel blade 20 position relative to the carriage 30 , the carriage 30 can be pushed straight forward while the shovel blade remains in a fixed orientation that can be oblique to the direction of travel.
Referring again to FIG. 3, a side panel 35 a of support bar 35 is shown having openings 34 , 52 for receiving axles 32 and attaching the handle 50 , respectively. The axle opening 34 is preferably slotted so that the axle 32 may be fixed at different heights to permit adjustment of the shovel 10 for differences in the blade 20 size. Alternatively, the axle opening 34 can be a simple circular opening for receiving the axle 32 and affixing the wheel 33 thereto.
The axles 32 are preferably shafts having a threaded end or hole at the end for passing through axle openings 34 and receiving a fastener such as a nut or cotter pin. The shafts permit free rotational movement of the wheels 33 in either direction, while holding them securely to the carriage 30 . Washers and other elements common to such connections may be used to improve the attachment of the wheels 33 to the carriage 30 .
The handle attachment openings 52 are arranged so that ends of the handle 50 can be affixed using threaded connectors. Two openings 52 are provided to lend additional strength and rigidity to the connection, while orienting the handle 50 upwardly and to the rear.
As seen in FIGS. 1 and 3, the bracket 25 can be either a single, unitary piece or two separate pieces joined together. Preferably, the bracket 25 is a single piece bent to form a generally “V”-shaped support with the free end of each arm secured to shovel blade 20 . The bracket 25 preferably lends support to the shovel blade 20 as well as holding it in place and preventing tilting of the blade forward and backward. While a single arm bracket 25 could be used, it is not preferred, so as to avoid undesirable movement of the shovel blade 20 relative to the carriage 30 .
The arms of bracket 25 are made sufficiently long so that the shovel blade 20 does not impinge upon the wheels 33 when the blade is pivoted to the extreme left or right lockable position. The lengths of the bracket 25 and support bar 35 , width of the shovel blade 20 , and the diameter of the wheels 33 will all affect the length of the bracket 25 required to use the shovel blade 20 at a particular angle relative to the direction of travel of the carriage 30 . In a preferred embodiment, the wheels 33 have a diameter of about 4 inches, the support bar 35 is about 24 inches long, the shovel blade is about 30 inches wide and the support bracket 25 arms extend about 8 inches forward. The shovel blade 20 is preferably longer than the total length of the support bar 35 with the wheels 33 , so that snow directly ahead of the wheels 33 is removed to avoid leaving packed snow from the wheel tracks.
The dimensions are preferably set to permit positioning the shovel blade 20 at left and right maximum angles of between 5-45°, and more preferably maximum angles between 15-35°. While the support bar 35 may have several carriage openings 39 for aligning with corresponding bracket openings 37 , preferably at least three carriage openings 39 are provided for holding the bracket 25 and shovel blade 20 at three different angles relative to the support bar 35 . The three angles are preferably one position being with the shovel blade 20 parallel to the support bar 35 and carriage 30 (centered), one position angled to the left at between 5-45°, and the third position angled to the right at between 5-45°. The carriage hole 39 positions to each side of center may be arranged symmetric or asymmetric, but symmetry is preferred so that the shovel is equally useful for either side.
FIG. 4 illustrates an embodiment of the support bar 35 having five different carriage holes 39 for aligning with the bracket holes 37 to position the shovel blade 20 . The bracket 25 may include five bracket holes 37 (such shown in FIG. 5 ), each one aligning with a different one of the carriage holes 39 . Alternatively, the carriage holes 39 may all be positioned so as to align with a single bracket hole 37 for locking with a locking pin 38 .
FIG. 5 shows an alternate embodiment of the shovel 10 in which handle 50 is connected extending from the top of support bar 35 . The handle 50 has an “I” or “T” shape, with a pair of handle grips 55 extending horizontally at the far end of handle shaft 57 . The bottom end of the handle 50 can be secured using wings 59 to attach to the support bar 35 . In a further alternative, the handle 50 does not include the horizontal handle grips, and instead has only handle shaft 57 extending upwardly to the rear of the shovel blade 20 , similar to a conventional shovel.
A motorized version of the snow shovel 10 is illustrated in FIG. 6 . The support bar 35 is shown looking at the bottom, where a motor 90 and battery 92 are mounted. A pair of wheels 33 are connected to the motor 90 by axles 80 for directly driving the wheels. The motor 90 is preferably an electric motor, but a gas powered motor may be used instead, and battery 92 can be replaced by a gas tank. The motor 90 is preferably activated by a switch 98 either mounted on the top surface of support bar 35 (not shown) or connected by a wire 95 and secured at the upper end of handle 50 for easier activation.
The self-propelled snow shovel 10 shown in FIG. 6 is easily operated by persons of any strength with minimal effort. And, unlike a snow blower, the shovel 10 does not have any whirling blades which can present a significant hazard if not used properly.
As seen in FIG. 6, wheels 33 are mounted inside the side panels 35 a of the support bar 35 . The side panels 35 a do not need to be present when the wheels are mounted to the motor 90 , but can be provided to shield the wheels 33 .
As will be appreciated from the foregoing, both the manual and self-propelled versions of the shovel 10 are easily used to push snow from a driveway or walkway to the side of the area being cleared. The shovel blade 20 is oriented to one side or the other in a preferred mode of use, so as to direct snow to the so-angled side as the carriage 30 is moved straight forward. The shovel 10 permits the shovel blade 20 to be angled relative to the direction of movement without requiring a user to perform awkward movements. Similarly, a user need not strain to maintain the angled direction of the shovel blade 20 relative to the direction of travel.
The shovel 10 is easily adjusted to change the angle of the blade 20 relative to the direction of travel as well. In the preferred embodiment, the locking pin 38 is removed, the blade 20 repositioned and the pin 38 reinserted in a different pair of aligned bracket and carriage holes 37 , 39 .
As can be understood from the foregoing, the shovel 10 is very easily dismantled and stored or parts are easily removed and replaced. The ease of replacement for each of the parts makes the shovel 10 economical, and, by replacing parts which wear more quickly, such as the blade 20 , the shovel 10 can have a long useful life. Further, the storage space occupied by the shovel 10 when it is taken apart is significantly less than when it is assembled ready for use.
It should be noted as well that while the wheels 33 are shown at the outside ends of the support bar 35 in FIGS. 1-5, they can also be mounted on axles 32 to the inside of side panels 35 a . The side panels 35 a or similar depending support should be made sufficiently long to accommodate the wheel diameter selected for free rotation and avoiding contact with the support bar 35 .
The carriage 30 may have more than two wheels 33 as well. For example, a rectangular frame including the support bar 35 may be used to mount three or four wheels to add stability to the shovel 10 .
And, although the carriage 30 is shown as being manually motivated or having its own motor 90 , it is envisioned that the snow shovel blade 20 and bracket 25 can be mounted to the front of a self-propelled lawn mower. The bracket can be mounted using a support bar 35 and side panels 35 a to position the shovel blade in a similar manner as with the wheeled carriage 30 . For example, the side panels 35 a could attach to the self-propelled lawn mower at the front wheels.
A different-tool head could be substituted for the shovel blade 20 if desired, for use in other applications. For example, a rake head, a grader or a furrowing tool could be mounted to carriage 30 instead.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A shovel has an articulated shovel blade for pivoting movement relative to a wheeled carriage on which the blade is mounted. The shovel blade is adjustably locked in position at different angles relative to the direction of travel of the carriage, for pushing snow or other material to the side of the shovel as it travels across the ground. The carriage is pushed forward using a handle or a motor is provided for self-propelling the carriage. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an article and a method provide improved chassis components in a motor vehicle, and in particular, a high fiber loaded composite component to be used in transverse springs for chassis components.
[0003] 2. Description of the Prior Art
[0004] Transversely extended leaf springs are a common component in vehicles today as part of the suspension system. These springs provide vehicle height and attitude adjustment during road condition changes to maintain a suitable ride and level attitude during movement of the vehicle. Leaf springs are generally of a steel or other alloy composition and are a heavy component in the vehicle. It is an object of engineers throughout the world to reduce vehicle weight, wherever possible, to improve gas mileage. One such possibility is to replace metal components with lighter plastics and composites.
[0005] Composite components have been gaining acceptance in the aerospace, military and automotive fields because of their high strength to weight ratio. The light weight is a desirable aspect, but mechanical strength has been a major issue. With composites, the mechanical performance of the composite components is directly related to the amount of reinforcement (fiber loading) provided in the composite component.
[0006] Composite components are generally manufactured using resin transfer molding (“RTM”). RTM is a common processes that was originally introduced in the 1940s. In this process, a two-part, matched mold (or tool) is made, a preform or reinforcement is placed into the mold, and the mold is closed. A resin is then pumped at low pressure through injection ports into the mold and the resin follows a predesigned path through the preform. Both the resin and mold are generally preheated to decrease the viscosity of the resin as needed for the application.
[0007] Many patents have been issued addressing methods to produce stronger composite components. Two important factors that affect the mechanical strength of a composite component are the percentage of fibers and the number and size of voids (or air pockets) in the finished composite component.
[0008] U.S. Pat. No. 5,686,038 issued to Christensen uses porous tool and articulating inserts in the mold. The porous inserts can absorb some of the air as the articulating inserts compress the part. While functional, this make for expensive and inflexible tool design.
[0009] In U.S. Pat. No. 5,449,285 issued to Choiniere, lances are forced into the mold cavity by linear actuators to pierce the component and allow gas to escape from the component. This is also a mechanical complication to the tool.
[0010] U.S. Pat. No. 5,443,778 issued to Schlingman uses a vent design with a flow regulator so the excess resin may not escape into the vent well. This design relies on the pressure from the injection flow to push the air pockets out of the molded part. However, because of the low viscosity of composite resins, many air pockets will still be left in the component.
[0011] The above-mentioned drawbacks of U.S. Pat. No. 5,449,285 are improved in U.S. Pat. No. 5,322,109 issued to Cornie. Cornie utilizes a pressure through the vent tube. However, two separate chambers (one for vacuum and a second for pressure) are required. The mold must be transferred in the middle of the process between the chambers. This is exceptionally onerous.
[0012] U.S. Pat. No. 5,023,041 issued to Jones uses an improved process over the previous mentioned. This invention, however, does not have a vacuum inlet. Additionally, the excess resin will flow through valves that will need to be replaced after each part is formed. This is impractical for mass production applications such as automotive components.
[0013] The use of a composite components for a leaf spring has been investigated in previous patents. In U.S. Pat. No. 4,659,071, issued to Woltron, the use of a composite structure for a plastic leaf spring is described. In this patent, a continuous web of reinforcing layers is used. The fibers are impregnated with a hard plastic and the web is wound in a continuous roll and placed in the mold. While potentially functional, this is a highly complicated and expensive method.
[0014] Another method for manufacturing a plastic leaf spring is shown in U.S. Pat. No. 4,747,898, also issued to Woltron. This method uses previously cured plastic strips reinforced with high strength fibers aligned in the direction of the spring. This is also a difficult and expensive method of manufacture for a plastic leaf spring.
[0015] From the above it is seen that there remains a need for a method of manufacturing a composite structural component with further enhanced strength, reduced weight and decreased cost.
SUMMARY OF THE INVENTION
[0016] In accordance with the present invention, a method is provided for manufacturing composite structures with sufficient strength to be used in a vehicle as a structural chassis component.
[0017] Resin molding is generally a slow process due because the chemical reaction of the reactive fluid injected into the tool must be tailored such that the onset of gelatin occurs after the preform or reinforcement, which may be a fiber mat, is saturated with the resin. The flow rate of the resin through the reinforcement is a function of the resin's viscosity, the reinforcement's permeability and the driving pressure. To aid in resin flow, the mold is generally preheated. With regard to driving pressure, there is an upper limit to this pressure in order to avoid displacement of the reinforcement as caused by the flow of the resin (commonly referred to as “fiber wash”). Increased fiber loading, the parameter that is maximized for enhancing strength of the structural composite, has an exponentially decreasing effect on permeability of the reinforcement.
[0018] To decrease air pockets or voids in the final part, and therefore increase its strength, a good seal must be formed between the mold halves. This seal also allows a vacuum to be drawn within the mold cavity, prior to injection of the resin, aiding in cycle time and assisting in decreasing void production. After the injection process is complete and while the resin is still in a liquid state, the vacuum can draw air into the mold and potentially into the composite part, increasing the size of any existing voids and decreasing the mechanical strength of the finished component.
[0019] The present invention uses positive pressure on the resin while the resin is still in the liquid state after the mold cavity is filled. The purpose of this step is to remove pressure gradient in the mold cavity and collapse any voids. The mold material and inserts accordingly must be of sufficient stiffness to withstand this positive pressure.
[0020] During mold filling, the mold is vented in a manner to direct resin flow to a vent well located either in the highest point in the mold cavity or above the mold cavity. Some resin during the fill process will partially fill the vent well. When the positive pressure is applied, this resin from the vent well will be forced back into the mold cavity collapsing any voids. The flow rate will be quite low at this point, resulting in the added benefit of improved microscale wet out and the ability to achieve higher fiber loadings.
[0021] Using this technique will permit higher fiber loadings for random reinforcements. It is anticipated that fiber loading of greater than 50% by volume can readily be achieved It is generally accepted that with current liquid molding, the maximum fiber loading by volume is 30-35% by volume for random reinforcements. The benefit of increasing the fiber content in a composite component is improved mechanical properties, such as the modulus and strength, which enable lighter weight structural components to exhibit strengths approaching that of metals. This will further allow a lower cost (where fiber costs are lower than resin costs) and lower weight part to be used for structural components, particularly traverse springs for automotive applications.
[0022] While the discussion has been directed towards RTM, practitioners skilled in the art will find equal applicability of the present invention to other liquid molding processes, such as structural reaction injection molding (SRIM) and injection compression molding (ICM).
[0023] Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a perspective view of an embodiment of the present invention;
[0025] [0025]FIG. 2 is a flow chart illustrating the preferred steps in carrying out the method of the present invention; and
[0026] [0026]FIG. 3 is a front view of the vent well of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring now to the drawings, as seen in FIG. 1, a mold 2 is shown for forming a composite part, namely a square plaque 4 . In this case, uncured resin 50 (shown in FIG. 3) is introduced to a mold cavity, where a preform or reinforcement 3 , shown as a mesh grid, has been located. The resin 50 enters through resin inlet 6 and travels to the mold 2 , via an inlet runner 10 and an edge gate 8 , both of which extend the width of the mold 2 . On a side of the mold 2 , generally opposite the resin inlet 6 , is a vent well 12 . Vented uncured resin 50 is collected in vent well 12 , which is located at the top of a vented shear edge 9 and above cavity for forming the square plaque 4 itself. Both vacuum and post injection pressure are applied at a port 52 , as shown in FIG. 3, communicating with the vent well 12 .
[0028] Referring now to FIG. 1 and FIG. 2, according to the method of the present invention, the first general step, designated as block 20 , is to load a preform 3 into the mold 2 . The manner of this loading is well within the skill of the ordinary practitioner and need not be described in detail herein. Next, in block 22 , the press is closed and a vacuum is drawn through vent well 12 . With the vacuum drawn, uncured resin 50 is injected through resin inlet 6 at block 24 . The uncured resin 50 flows through the inlet 6 , through gate runner 10 and through edge gate 8 , into the mold cavity and about the preform 3 . Excess uncured resin 50 travels up through the vented shear edge 9 and pools in the vent well 12 . After the mold 2 is filled, the vacuum is ceased through the vent well 12 and positive pressure is applied through the vent well 12 . This is shown at block 26 . It is during this step that the positive pressure is used to collapse voids in the component being molded. In resin cure step of block 28 , the uncured resin 50 is allowed to cure with pressure still being applied. Once cured, the press is opened and the completed part, square plaque 4 , is removed at block 30 . The process is now complete.
[0029] Referring now to FIG. 3, the vent well 12 is shown in isolated detail. As a vacuum source 46 draws the vacuum (the step of block 22 ) on the sealed mold 2 by pulling air in vacuum direction 48 through port 52 , the uncured resin 50 enters vent well 12 through a vent inlet 40 . The vent inlet 40 may be a vented shear edge 9 as mentioned above. When the mold 2 is filled with uncured resin 50 to the desired volume, the vacuum source 46 is turned off and a positive pressure source 42 is turned on. Gas pressure from the positive pressure source 42 is applied in pressure direction 44 and through port 52 , forcing the uncured resin 50 out of the vent well 12 and back through the vent inlet 40 and into the mold cavity. Any voids in the resin of the uncured component, collapsed due to the applied back pressure, the returning uncured resin and the inability of resin 50 within the mold cavity to exit through the seals of the mold 2 or the gate runner 10 . This pressure, from the pressure source 42 is maintained until the resin 50 is cured. Once cured, the pressure source 42 is turned off, the mold is opened and the structural composite is removed.
[0030] While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims. | A method and apparatus for molding structural composite materials. The method applies positive pressure on a mold vent after filling the mold with resin to reduce the size of the voids by collapsing the voids. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a computer processor, and is more particularly concerned with a coordinate rotation digital computer processor CORDIC processor, for vector rotations for solving problems of real-time processing, constructed with a carry-save architecture.
2. Description of the Prior Art
A CORDIC processor is known from the publication of Helmut Halm, et al entitled "CORDIC-Prozessoren fuer die digitale Signalverarbeitung", published in the periodical "me", Vol. 3, No. 1, 1989, pp. 22-27.
The pipeline principle and hard-wired shift operations are thereby set forth as possibilities for increasing the data rate.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a CORDIC processor that is constructed of simple elementary cells, can be easily modified in view of accuracy and word width and mainly represents a good compromise between low chip surface and high data rate.
The above object is achieved, according to the present invention, by the provision of a CORDIC processor for vector rotations constructed in accordance with a carry-save architecture for solving problems of real-time processing, in which the processor comprises
(a) a vector path and an angle path whereby the vector path is composed of a plurality of series-connected vector iteration stages and the angle path is composed of a plurality of series-connected angle iteration stages;
(b) a plurality of devices for mutual decoupling of the vector iteration stages and a plurality of devices for mutual decoupling of the angle iteration stages in order to enable a processing according to a conveyor belt principle known as pipelining;
(c) a plurality of vector iteration stages and a plurality of angle iteration stages that contain addition/subtraction circuits, wherein, within a clock interval, only incomplete addition/subtraction operations occur and intermediate results at the end of the clock interval in the form of a carry word and of a sum word (carry-save number) are available on separate lines for carry and sum bits at the output of each vector and angle iteration stage, these words being available for further processing;
(d) the plurality of vector iteration stages and the plurality of angle iteration stages comprising structure for realizing shift operations (multiplication with powers of 2) that allow a shift of carry and sum bits;
(e) the plurality of angle iteration stages having sign detectors that employ the carry and sum bits for sign detection;
(f) a multiplier that is connected to the output lines for the carry and sum words of a last vector iteration stage of the series for multiplying both the carry word and the sum word of each vector component by a correction factor; and
(g) an adder that is connected to the output lines for the carry and sum words of a multiplier circuit that adds up the carry and sum words of both vector components to form components of a result vector.
The advantage which may be obtained in practicing the present invention is, in particular, that a significantly-improved relationship of data rate to chip surface requirement occurs in the CORDIC processor constructed in accordance with the present invention in comparison to known CORDIC processors, this resulting from the carry-save architecture, and that the data rate is independent of the overall word width.
According to a feature of the invention, the CORDIC processor set forth above is particularly characterized in that each angle iteration stage is composed of a plurality of identical angle path base cells; the sign detectors are connected parallel to angle path base cells; the input lines for angle bits of the angle path base cells are connected to lines for the non-inverted and inverted sign output signals of the respectively immediately-preceding angle iteration stage, such that this corresponds to a product formation of the sign output signal of the immediately-preceding angle iteration stage and the binary representation of a respective given, scaled negative angle step, whereby bits not modifiable by the product formation are occupied with fixed logical values; and the structures for realizing a shift operation required for scaling the carry and sum words at the output of an angle iteration stage are comprised such that the output lines for the carry-save bits of an angle path base cell are respectively connected to the outputs of the next more-significant angle path base cell of an immediately-following angle iteration stage.
According to another feature of the invention, the processor is characterized in that angle path base cells of an angle iteration stage each contain a respective full adder; that a register, respectively, for carry bit and sum bit and clock by clock signals follows the full adder for mutual decoupling of the vector iteration stages. The inputs of the angle path base cell correspond to the inputs of the full adder, whereby one input of the full adder is connected to the input line for an angle bit and two other inputs of the full adder are connected to the output lines for the carry and sum bits of the immediately-preceding angle path base cell insofar as the preceding angle path base cell exists, and are respectively connected with logical "0" in case a preceding angle path base cell does not exist. The output line for the carry bit comes from the next less-significant base cell and is only looped through the angle path base cell. The output bit line for the sum bit is connected to the output of the first register that, in turn, has its input side connected to the sum output of the full adder; and the output line for the carry bit is connected to the output of the second register for the forwarding of the next more-significant angle path base cell, the input side of the second register, in turn, being connected to the carry output of the full adder.
According to another feature of the invention, the processor is particularly characterized in that each vector iteration stage is composed of a plurality of identical vector path base cells. One vector path base cell has its input side connected to the output lines for carry and sum bits of the immediately-preceding vector path base cell insofar as the immediately-preceding angle path base cell exists and, otherwise, either the input lines for the carry bits or the input lines for the sum bits at the input side of the vector path base cell are connected to the processor input lines for inputting a starting vector. The structure for realizing a shift operation in a vector iteration stage is structured such that a respective angle path base cell has its input side connected to the output lines for carry and sum bits of an i-times more-significant, immediate-preceding vector path base cell and when such a vector path base cell does not exist, has its input side connected to the most-significant, immediately-preceding vector path base cell.
According to another feature of the invention, in the processor, a vector path base cell is composed of two multiplexers, of four full adders and of a decoupling device for decoupling the vector iteration stages, the decoupling device being in the form of ten transmission gates. An input line for the sum bit of a first vector component is connected to a first input of a first full adder and an input line for the sum bit of a second vector component is connected to a first input of a second full adder. An input line for the carry bit of a first vector component is connected to a first input of a third full adder via a first transmission gate clocked by a first clock signal and an input line for the carry bit of a second vector component is connected to a first input of a fourth full adder via a fourth transmission gate that is likewise clocked by the first clock signal. An input line for the i-fold more-significant carry bit of the second vector component is connected via the first multiplexer to a second input of the first full adder, the i-fold more-significant sum bit of the second vector component is likewise connected via the first multiplexer to the third input of the first full adder, the i-fold more-significant carry bit of the first vector component is connected via the second multiplexer to a second input of the second full adder and the i-fold more-significant sum bit of the first vector component is connected to the third input of the second full adder, likewise via the second multiplexer, whereby the multiplexers invert or do not invert the carry and sum bits dependent on the sign signals of the immediately-preceding vector iteration stage. The sum output of the first full adder is connected via the second transmission gate to a second input of the third full adder and the sum output of the second full adder is connected via a fifth transmission gate to a second input of the fourth full adder, whereby both of the second and fifth transmission gates are clocked by the first clock signal. An output line for a first-stage carrier bit of a vector component is connected via a third transmission gate to the carry output of the first full adder and an output line for a first-stage carry bit of the second vector component is connected via a sixth transmission gate to the carry output of the second full adder, whereby both of the third and sixth transmission gates are clocked by the first clock signal. An input line for a first-stage carry bit of a vector component from the next less-significant vector path base cell is connected to a third input of the third full adder and an input line for a first-stage carry bit of a vector component for the next less-significant vector path base cell is connected to the third input of the third full adder and an input line for a first-stage carrier bit from the second vector component of the next less-significant vector base path cell is connected to the third input of the fourth full adder. The input lines for the second-stage carry bits of the vector components from the next less-significant vector path base cell are looped through onto the output lines for the immediate-following vector iteration stage of the vector path base cell. The sum output of the third full adder is connected via a seventh transmission gate to the output line for the sum bit of a first component of the immediately-following iteration stage and the sum output of the fourth full adder is connected via a ninth transmission gate to the output line for the sum bit of the second component of the immediately-following vector iteration stage, whereby the seventh and ninth transmission gates are clocked by a second clock signal. An output line for a second-stage carry bit of a first vector component is connected via an eighth transmission gate to the carry output of a third full adder and an output line for a second-stage carry bit of the second vector component is connected via a tenth transmission gate and to the carry output of the first full adder, whereby the eighth and tenth transmission gates are clocked by the second clock signal.
According to another feature of the invention, the processor is particularly characterized in that at least one vector path iteration stage is redundantly arranged, for example, in order with a given accuracy of the final result vector to allow greater ambiguity regions in the sign detection in the individual angle iteration stages and in order to simultaneously enable an identical correction factor for all combinations of processor input signals.
According to another feature of the invention, the processor is particularly characterized in that the number of redundantly-arranged vector and angle iteration stages is of such a magnitude that, at most, the foremost-significant carry and sum bits and a sign output signal of the respective immediately-preceding angle iteration stage are required for sign detection in order to enable an optimized sign detector which is identical for all angle iteration stages and which is more simply constructed than a combination of full adders.
According to another feature of the invention, the processor as featured above, is particularly characterized in that an identical, optimized sign detector for all angle iteration stages forms a sign output signal from the foremost-significant carry and sum bits of an immediately-preceding angle iteration stage and from the non-inverted sign output signal of an immediately-preceding angle iteration stage in that the sign output signal of the immediately-preceding angle iteration stage is connected to one of two inputs of an equivalence element and the output of the equivalence element is connected to one of two inputs of a first EXOR (EXCLUSIVE-OR) gate; the most significant carry and sum bits are operated with a second EXOR gate and the output of the second EXOR gate is connected to the second of the two inputs of the equivalence elements; the second most-significant carry and sum bits are operated with a NOR gate, whereby the output of the NOR gate is connected to one of the two OR inputs of a first OR-NAND gate and these carry and sum bits are likewise operated with a first NAND gate. The output of the first NAND gate is connected to one of the two inputs of a second NAND gate and the output of the second NAND gate is connected to a direct NAND input of the first OR-NAND gate. The respective third most-significant carry and sum bits are operated with the input OR gate of a second OR-NAND gate, whereby the output of the second OR-NAND gate is connected to one of the two OR inputs of a third OR-NAND gate and the third most-significant carry and sum bits are operated by a third NAND gate. The output of the third NAND gate is connected to the respective direct NAND input of the second and third OR-NAND gates. The fourth most-significant carry and sum bits are operated with a fourth NAND gate, the output of the fourth NAND gate being connected to the second OR input of the third OR-NAND gate, and the output of the third OR-NAND gate being connected to the respective second OR input of the first OR-NAND gate and to the second input of the second NAND gate. The output of the first OR-NAND gate is connected to the second input of the first EXOR gate and the output of the first EXOR gate supplies the sign output signal of the optimized sign detector.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention, its organization, construction and operation will be best understood from the following detailed description, taken in conjunction with the accompanying drawings, on which:
FIG. 1 is a schematic illustration of the structure for a CORDIC algorithm for vector rotations;
FIG. 2 is a schematic representation of the ambiguity region in the sign estimation of carry-save numbers;
FIG. 3 is a block diagram directed to an exemplary embodiment of a CORDIC processor for vector rotations constructed in accordance with the present invention and comprising a vector path and an angle path;
FIG. 4 is a schematic representation of an excerpted portion of the angle path of a CORDIC processor constructed in accordance with the present invention and showing angle path base cells and detectors;
FIG. 5 is a schematic representation of an excerpted view of the vector path of FIG. 3 of the CORDIC processor constructed in accordance with the present invention showing vector path base cells;
FIG. 6 is a schematic representation of an angle path base cell which may be employed in practicing the present invention;
FIG. 7 is a schematic illustration of a vector path base cell which may be employed in practicing the present invention; and
FIG. 8 is a schematic logic circuit diagram of an optimized sign detector which may be employed in practicing the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to illustrate the operation of the CORDIC processor of the present invention in greater detail, the CORDIC algorithm and special characteristics in view of the sign estimating of carry-save numbers shall be briefly set forth below.
The idea of the CORDIC algorithm is to execute the rotation of a vector P o (X o , Y o ) by the angle Z o , not in one step, but to approach the rotational angle on the basis of a sum of permanently-prescribed sub-angles alpha i . With a definition of the sub-angles alpha i as
alpha=atan (2.sup.-i),
the trigonometric operations needed given vector rotations are replaced by shift operations that are easy to realize (right shift of binary number by i places corresponds to the factor 2 -i ).
When, by continued addition or subtraction of the sub-angles alpha i via N stages, the output Z n is iterated towards zero, then the coordinates of the vector P o rotated by Z o (rotate mode) are obtained for P n ' (X n ', Y n ').
When the aforementioned values are introduced into the general equations for a two-dimensional vector rotation, then the following equations are obtained:
X.sub.N '=X.sub.o * cos (Z.sub.o)-Y.sub.o * sin (Z.sub.o)
Y.sub.N '=X.sub.o * cos (Z.sub.o)+X.sub.o * sin (Z.sub.o)
The iteration equations for this can be written as:
X.sub.i+1 =X.sub.i -Y.sub.i * sign (Z.sub.1)*2.sup.-i
Y.sub.i+1 =Y.sub.i +X.sub.i * sign (Z.sub.i)*2.sup.-i
Z.sub.i+1 +Z.sub.i -sign (Z.sub.i)*W.sub.i
where W i =atan (2 -i ).
Whereby,
X.sub.N '=X.sub.N *K
Y.sub.N '+Y.sub.N *K
hold true for the outputs X n ' and Y n ', where ##EQU1##
FIG. 1 illustrates the principle of the CORDIC algorithm for vector rotations. The rotation of a vector is therefore realized by a plurality of identical stages that are composed only of adder/subtractor circuits, devices for realizing shift operations and a sign detection of Z i (sign (Z i )). The iteration stage i=0 has inputs for the coordinates X o and Y o of a vector to be rotated, for the rotational angle Z o and for a 0 th angle step W o =atan (1/2), whereby the sign signal (sign Z o ) formed from the rotation angle Z o allows the adder/subtractor circuits (identified by circles) to unambiguously become adders or subtractors. With adders and subtractors, a coupling of the vector coordinates X o , Y o is achieved and a residual angle iterated to zero is formed from the rotational angle Z o and from the 0 th angular step. This is likewise true of the further stages i=1 to i=n, whereby, indicated by oblique strokes, an i-fold shift occurs and the angular steps become smaller. The vector coordinates X n and Y n , in addition to a residual angle Z n , are available at the output of the stage i=n.
In a carry-save architecture, the intermediate result of an addition of two's compliment numbers is represented by a sum word and by a carry word, whereby a final result arises only by the addition of the sum word and the carry word. As a result of the redundant number representation, the sign of this number cannot be unambiguously determined. The sign of a result in carry-save representation can therefore only be estimated in that a defined plurality of leading significance r are considered. FIG. 2 illustrates the ambiguity region U arising in the sign estimation, showing this ambiguity in a diagram that illustrates the sign (sign result) of the result dependent on the result value RESULT on the word width m and on the number of most significant bits r. It becomes clear from FIG. 2 that the arising ambiguity region U in the sign estimation becomes all the smaller the more leading significance are utilized for the sign decision. In order to preserve the advantage of a high data rate for the carry-save architecture independent of the overall word width, the number of significance to be considered, however, should be kept as low as possible.
FIG. 3 is a block diagram directed to an exemplary embodiment of a CORDIC processor constructed in accordance with the present invention for vector rotations. This processor is composed of a vector path VP, an angle path WP, a multiplication circuit MULK, an adder circuit VMA (vector merging adder) and a clock generator CG. The input quantities of the angle path are the components X o , Y o of the start vector and the input quantity of the angle path WP is the rotational angle Z o . The vector path VP is composed of angle iteration stages IXY 0 . . . IXY 11b; the same holds true of the angle path WP that is of the angle iteration stages IZ 0 . . . IZ 11b, whereby each of the angle iteration stages supplies sign signals sign (Z i '), sign (Z i ') to the appertaining iteration stage IXY. In the exemplary embodiment shown in FIG. 3, all odd-numbered iteration stages are redundantly present and are referenced with "a" and "b" for further distinction. The output lines for carry and sum words of the two rotated vector components X N , Y N of the last vector iteration stage IXY 11b are connected to the multiplier MULK and the output lines thereof for the carry and sum words XC N ', SX N ', YC N ', YS N ' of the multiplied vector are, in turn, connected to the adder circuit VMA, whereby the adder circuit VMA supplies the final result vector X N ', Y N ' at its outputs. In addition, FIG. 3 illustrates a clock generator CG that generates four clock signals CK 4 from a single clock signal CK.
In order to satisfy an accuracy requirement of g=10 -3 , an input word width of, respectively, eleven bits must be provided for the components X o , Y o of the start vector. Given a rotational angle Z o between +pi/2 and -pi/2 and an accuracy requirement of g=10 -3 , two additional bits for places preceding the decimal point are required, so that the input word width of the rotational angle amounts to 13 bits. An internal word width of 17 bits results from the 11 bits of the input word width, one bit for the extreme case that both vector components are added, one bit for a magnification factor 1/K that results on the basis of the iteration and four bits in order to avoid rounding errors. Due to the right shifts needed in each stage, lower significance are shifted out of the presentable numerical range. So that the accuracy requirement is met at the outputs X N ' and Y N ' despite to these rounding errors across all stages, the internal word width must be additionally increased by four places following the decimal point. Following the adder VMA, the output word width for X N ' and Y N ' given the aforementioned accuracy requirement, can be respectively reduced to a minimum of 11+1 bits for adding up the vector components, which is equal to 12 bits.
The amount of the residual angle Z i becomes small from iteration stage-to-iteration stage, so that the word width in the angle path can be reduced by one bit after each stage. In order to fully exploit the existing word width in order to achieve the given accuracy and so that sign detectors DET need not be arranged shifted, a scaling of Z i with 2 i occurs. Applied to the equations set forth above,
Z.sub.i+1 '=2*(Z.sub.i '+W.sub.i ')
where W i '=-sign (Z i ')*2 i * atan (2 -i )
results when the amount of the current residual angle Z i ' at the output of the angle iteration stage IZi lies in the ambiguity region U of the sign decision, then a decision "zero" would have to be introduced in addition to the sign decisions "positive" and "negative", so that the values X i and Y i are not changed. The value of Z i ' in this iteration stage is multiplied by 2 in accordance with the scaling, so that the amount of the residual angle again becomes so large in the next stage (or in one of the next stages) that a reliable decision "positive" or "negative" is possible. Decision errors concerning the sign of Z i ' due to the ambiguity region U would therefore be impossible.
The iteration stages not implemented given a "zero decision" would then, however, also have to be taken into consideration in the calculation of correction factor K. Instead of a simple multiplication of the outputs X N and Y N by the constant correction factor K, an extremely involved multiplier logic would therefore have to be introduced. In order to obtain a correction factor K that is constant for all rotational angles Z o , the "zero decision" can be replaced by a doubling of all iteration stages.
When, due to the ambiguity region U, an incorrect decision concerning the sign is made in an angle iteration stage, for example the stage IZ 1a, then the amount of the residual angle is enlarged instead of being reduced. In the following, double-up angle iteration stage, for example IZ 1b, a reliable sign decision is then guaranteed, so that the preceding iteration step is, in turn, canceled. The result across two stages then corresponds to the result of one stage having a "zero decision", with a difference that all stages are always executed and the factor K therefore remains constant for arbitrary input angles Z o . This solution, however, leads to a considerable added expense for hardware due to the redundant design of each iteration stage. The proposals that have been presented proceed from the opinion that errors in the sign recognition should not be made in any stage in order to guarantee the convergency of the CORDIC algorithm. The convergency condition, however, can be more generally formulated as: in case of an incorrect sign decision in the angle iteration stage IZ i, all further angle iteration stages IZ i+1 through IZ n must satisfy the elimination of the error and keep the output Z N within the framework of a given accuracy g.
This formulation leads to a fixed relationship between the number of stages to be doubled (factor p j ) and the number of leading significances r that must be taken into consideration for the sign decision of each stage. ##EQU2## where p j =1 for a regular iteration stage and p j =2 for a redundant iteration stage.
When, for example, the residual angle should remain below 10 -3 after N=11 stages, then at least nine leading signifcances must be utilized for sign estimating without redundant stages. When each stage is doubled up (p j =2), only two bits now have to be taken into consideration. When, by contrast, only all odd-numbered stages are doubled (p j =1 when j is an even number and p j =2 when j is an odd number), then four bits are adequate. This consideration leads to a compromise in the architecture between the obtainable data rate (r as small as possible) and the necessary chip surface (stage i as small as possible). When the convergency is guaranteed, then the plurality of iteration steps defines the obtainable accuracy at the outputs X n ' and Y n '. With the following inequality, the minimum number of iteration cycles N can be calculated for a given accuracy.
N≧-1d(tan (acos (1-(1/2*g).sup.2))
Given the desired accuracy of g=10 -3 , r=4 leading significances result for the sign estimating in the exemplary embodiment illustrated in FIG. 3 and a number of N=11 angle iteration stages that are required results given doubling of all odd-numbered iteration stages.
The multiplier circuit MULK can be realized on a hard-wired basis since the multiplication always occurs with a constant correction factor. Due to the redundant stages, a modified correction factor K' results. ##EQU3##
Given the selected configuration, a value of K'=0.5387 decimally and K'=0.1000101000-1 in the CSD code results. The representation in K' in the CSD code enables the realization of the multiplication with only three shift/addition operations corresponding to the significances differing from zero. The adder circuit VMA is executed either as a carry-look ahead adder (CLA) or as a carry-ripple adder (CRA), whereby the carry-look ahead adder CLA has the advantage of a higher processing speed and the carry-ripple adder CRA can be more easily modified in terms of word width. The CORDIC processor realized in 1.5 μm CMOS technology can be operated with clock frequencies up to, typically, 60 MHz.
FIG. 4 illustrates an excerpted view of an angle path of the structure of FIG. 3 composed of angle path base cells BCZ and detectors DET, shown in the region of the doubled first angle iteration stages IZ 1a and IZ 1b as well as of the following, regular angled iteration stage IZ 2. At the angle iteration stage IZ 1a, an input word Z 1b ' that is likewise composed of carry and sum words is formed in the cells BCZ 1a, 0, . . . BCZ 1a, 12 according to the CORDIC calculating rule, being formed therein from the input words Z 1 a' composed of carry and sum words and the angle step W 1 a that is either inverted or noninverted by the sign signals sign (Z 1 a'), sign (Z 1 a'). Parallel thereto, sign signals sign (Z 1 b'), sign (Z 1 b') for the following angle iteration stage IZ 1b are formed from the four most-significant bits in a detector DET 1a. The angle iteration stages IZ 1a and IZ 1b are identical. Due to the connection to the next iteration stage, a left shift by one bit occurs at the output of the redundant stages, for example, IZ 1b, as well as at the regular stage, this corresponding to a scaling with the factor 2.
The wiring of the base cells results from the evaluation of the following equation.
W.sub.i '=-2.sup.i * atan (2.sup.-i)* sign (Z.sub.i ')
The following values result therefrom for the iteration stages:
______________________________________W.sub.0 ' = 11.00110111000 * sign (Z.sub.0 ')W.sub.1 ' = 11.00010010101 * sign (Z.sub.1 ')W.sub.2 ' = 11.00000101001 * sign (Z.sub.2 ')W.sub.3 ' = 11.00000001011 * sign (Z.sub.3 ')W.sub.4 ' = 11.00000000011 * sign (Z.sub.4 ')W.sub.5 ' = 11.00000000001 * sign (Z.sub.5 ')W.sub.6 ' - W.sub.1 ' = 11.00000000000 * sign (Z.sub.1 ')______________________________________
When sign (Zi') is negative, all bits of the zero-one sequence of the expression -2 i * atan (2 -i ) must be inverted and one is added at the place of the lsbs. A fixed zero occupation (GND) of the lsbs W o .o ', a respective fixed one occupation (VDD) of the isbs W 1 .0 ' . . . W 5 .0 ' thereby result and only the msb is respectively dependent on the sign signal sign (Z i ') given W 6 '-W 11 '. In the case of regular stages and in the case of doubled stages, the Z inputs of the least significant angle path base cells BCZ i ,0 are connected to the output of the immediately-preceding angle path base cells.
FIG. 5 illustrates an excerpted view of the vector path of FIG. 3 in accordance with the invention comprising vector base cells BCXY i ,k in the region of the regular vector iteration stage IXY 2, of the basic stage IXY 3a and of the redundant stage IXY 3b pertaining to the basic stage IXY 3a. The inputs XY 2 ,0 . . . XY 2 ,16 and the outputs XY 4 ,0 . . . XY 4 ,16 are formed of the lines for the carry and sum bits of the vector components X, Y. A respective vector path base cell (BCXY i, k) has its input side connected to the output lines for carry and sum bits (XC i , k, YC i , k, XS i , k, YS i , k) of the immediately-preceding vector path base cell (BCXY i-1, k), insofar as the immediately-preceding vector path base cell exists and, otherwise, either the input lines for carry bits or the input lines for sum bits at the input side given the vector path base cells (BCXY, 0, k) are connected to the processor input lines for inputting a starting vector (X o , Y o ).
In a vector iteration stage, the structure for realizing a shift operation comprises a respective vector path base cell BCXY i , k with its input side connected to the output lines for the carry and sum bits XC i ,k+1, YC i ,k+i, XS i , k+i, YS i , k+i of an ifold more-significant, immediately-preceding vector path base cell (BXY i-1 , k+i) and, when this vector path base cell does not exist, has its input side connected to the most-significant, immediately-preceding vector path base cell BXY i-1 ,116 (msb). In accordance with the equations set forth above, the input word X i must be added to or subtracted from the input word Y i shifted left i times in each vector iteration stage and vice-versa. In order to minimize the wiring expense for the shift operations between two stages, both data paths for X and Y are bit-by-bit interlaced with one another.
FIG. 6 illustrates an angle path base cell BCZ of the present invention. The inputs of the angle path base cell correspond to the inputs of the full adder VA, whereby the one input of the full adder VA is connected to the input lines for an angle bit W i ,k and two other inputs of the full adder VA are connected to the output lines for the carry and sum bits ZC i , k, ZS i , k of the immediately-preceding angle path base cell BCZ i-1 , k insofar as this preceding angle path base cell exists. When such a preceding angle path base cell does not exist, then the inputs of the full adder VA are respectively occupied with a logical "zero" (GND). For mutual decoupling of the vector iteration stages, C 2 MOS registers R1 and R2 are provided, these being clocked by the clock signals CKM and CKS. The clock generator CG mentioned in connection with FIG. 3 generates output signals CK 4, whereby these correspond to the clock signals CKM and CKS and to the clock signals respectively inverted relative thereto. The chronologically-offset clock signals CKM and CKS allow a data transfer according to the master-slave principle.
The output line for the carry bit ZC i+1 ,k comes from the next less-significant base cell BCZ i, k-1 and is only looped through the angle path base cell. The output bit line for the sum bit ZS i+1 , k is connected to the output of the first register R1 that, in turn, has its input side connected to the sum output of the full adder VA. The output line for the carry bit ZC i+1 , k+1 is connected to the output of the second register R2 for forwarding to the next most-significant angle path base cell BCZ i, k1, this second register R2 having its input side, in turn, connected to the carry output of the full adder VA.
FIG. 7 illustrates a vector path base cell of the present invention that is composed of two multiplexers MUX 1 and MUX 2, four full adders VA1 . . . VA4 and 10 transmission gates 1-10 for decoupling the vector iteration stages. An input line for the sum bit SX i , k of a first vector component X is connected to a first input of the first full adder VA1, and an input line for the sum bit YS i , k of a second vector component Y is connected to a first input of the second full adder VA2. An input line of the carry bit XC i , k of the first vector component X is connected to a first input of the third full adder VA3 via the first transmission gate 1 clocked by a first clock signal CKM, and an input line for the carry bit YC i , k of the second vector component Y is connected to a first input of the fourth full adder VA4 via the fourth transmission gate 4 that is likewise clocked by the first clock signal CKM. An input line for the i-times more-significant carry bit YC i , k+i of the second vector component Y of the second vector component Y is connected via the first multiplexer MUX1 to a second input of the first full adder VA1, and the i-times more significant sum bit YS i , k+i of the second vector component Y is connected to the third input of the first full adder VA1, likewise via the first multiplexer MUX1. The i-times more-significant carry bit XC i , k+1 of the first vector component X is connected via the second multiplexer MUX2 to a second input of the second full adder VA2 and the i-times more-significant sum bit XS i , k+i of the first vector component is likewise connected to the third input of the second full adder VA2, likewise via the second multiplexer MUX2. The multiplexers MUX1 and MUX2 connect through the carry and sum bits of the immediately-preceding vector iteration stage to the full adder VA1 or, respectively, VA2 either inverter or noninverted dependent on the sign signals sign (Z i '), sign (Z i '). The sum output of the first full adder VA1 is connected via the second transmission gate 2 to a second input of the third full adder VA3 and the sum input of the second full adder VA2 is connected via the fifth transmission gate 5 to a second input of the fourth full adder VA4, whereby both transmission gates 2 and 5 are clocked by the first clock signal CKM. An output line for a first-stage carry bit XCI i+1 , k+1 of a first vector component is connected via the third transmission gate 3 to the carry output of the first full adder VA1, and an output line for a first-stage carry bit YCI i+1 , k+1 of the second vector component is connected via the sixth transmission gate 6 to the carry output of the second full adder VA2, whereby both transmission gates are clocked by the first clock signal CKM. An input line for a first-stage carry bit XCI i+1 , k of a first of the first vector component X from the next less-significant vector path base cell BCXY i, k-1 is connected to the third input of the third full adder VA3, and an input line for a first-stage carry bit YCI i+1 , k from the second vector component Y of the next less-significant vector path base cell BCXY i, k-1 is connected to the third input of the fourth full adder VA4. The input lines for second-stage carry bits XC i+1 , k, YC i+1 , k of the vector component X and Y from the next less-significant vector path base cell BCXY i, k-1 are looped through onto the output lines for the immediate-following vector interaction stage of the vector path base cell VCXY i, k. The sum output of the third full adder VA3 is connected via the seventh transmission gate 7 to the output line for the sum bit XS i+1 , k of a first component of the immediately-following interaction stage, and the sum output of the fourth fill adder VA4 is connected via the ninth transmission gate 9 to the output line YS i+1 , k for the sum bit of the second component of the immediately-following vector iteration stage, whereby the transmission gates 7 and 9 are clocked by the second clock signal CKS. An output line for a second-stage carry bit XC i+1 , k+1 of a first vector component is connected via the eighth transmission gate 8 to the carry output of the third full adder VA3, and an output line for a second-stage carry bit YC i+1 , k+1 of the second vector component is connected via the tenth transmission gate 10 to the carry output of the fourth full adder VA4, whereby the transmission gates 8 and 10 are clocked by the second clock signal CKS.
A simple realization of the logic for sign estimating is comprised in a carry ripple adder (CRA) for the four highest significances of Z i ' whose sign is interpreted as the sign of the corresponding carry-save number. Since the four most-significant bits of the scaled angle steps W 0 ' . . . W 11 ', as set forth initially, all begin with the most-significant bits, 11,00, the four-bit ripple adder can be simplified to the optimized detector DET opt illustrated in FIG. 8. The sign estimating therefore occurs parallel to the addition of Z i ' and W i ' in order to therefore shorten the running time of the stage. As a result of the optimized sign detector DET opt , a sign output signal (Z i+1 ') is formed from the foremost significant carry and sum bits ZC i , 9, ZS i , 9 ' . . . ZC i , 12 ', ZS i , 12 ' of an immediately-preceding angle interaction stage IZ i-1 and of the non-inverted sign output signal sign (Z i ') of an immediately-preceding angle iteration stage IZ i-1. The sign output signal sign (Z i ') of the immediately-preceding angle iteration state is connected to one of the two inputs of an equivalence gate EQ and the output of the equivalence gate EQ is, in turn, connected to one of the two inputs of a first EXCLUSIVE-OR (EXOR) gate EX1. The most-significant carry and sum bots ZC i , 12, ZS i , 12 are operated with a second EXOR gate circuit EX2 and the output of the EXOR gate EX2 is connected to the second of the two inputs of the equivalence gate EQ. The second most-significance carry and sum bits ZC i , 11 ', ZS i , 11 ' are operated with a NOR gate, whereby the output of the NOR gate is connected to one of two OR inputs of a first OR-NAND gate ONA1, and these carry and sum bits are likewise operated with a first NAND gate NA1, whereby the output of the first NAND gate NA1 is connected to one of the two inputs of a second NAND gate NA2, and the output of the second NAND gate NA2 is connected to a direct NAND input of the first OR-NAND gate ONA1. The respective third most significant carry and sum bits ZC i , 10 ', ZS i , 10 ' are operated with the input OR gate of a second OR-NAND gate ONA2, whereby the output of the second OR-NAND gate ONA2 is connected to one of two OR inputs of a third OR-NAND gate ONA3. The third most-significant carry and sum bits are likewise operated by a third NAND gate NA3, whereby the output of the third NAND gate NA3 is connected to the direct NAND input of the second and third OR-NAND gate ONA2, ONA3. The fourth most-significant carry and sum bits ZC i , 9 ', ZS i , 9 ' are operated with a fourth NAND gate NA4. The output of the fourth NAND gate NA4 is connected to the OR input of the third OR-NAND gate ONA3, and the output of the third OR-NAND gate ONA3 is connected to the second OR input of the first OR-NAND gate ONA1 and to the second input of the second NAND GATE NA2. The output of the first OR-NAND gate ONA1 is connected to the second input of the first EXOR gate EX1, and the output of the first EXOR gate EX1 supplies the sign output signal SIGN (Z i+1 ') of the optimized sign detector DET opt .
There is also the possibility of realizing the CORDIC algorithm for other modi (multiplication, division, square root or hyperbolic functions) in carry-save architecture. A universal CORDIC processor, controlled via all parameters, would therefore have to be operated in all modi, whereby Y or Z must be optionally iterated to zero. Farther-reaching convergency considerations have shown that a combination of the different modi in a processor with carry-save architecture is basically realizable.
Although we have described out invention by reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. We therefore intend to include within the patent warranted hereon all such changes and modifications as may reasonably and properly be included within the scope of our contribution to the art. | A CORDIC processor is provided in carry-save architecture in connection with intense pipelining for vector rotations, particularly given problems in real-time processing. The processor comprises a plurality of vector iteration stages and a plurality of angle iteration stages that are partially redundantly present in order to guarantee a convergency of the CORDIC algorithm despite an ambiguity region in the sign detection of carry-save numbers and in order to simplify other circuit components, for example a multiplier. As a result of the carry-save architecture, only incomplete addition/subtraction operations are executed in the iteration stages, and intermediate results in the form of carry and save words are fed through the CORDIC processor on separate line paths until they are added in an adder at the processor output to form the final result vector. The invention is advantageous in the low chip surface requirement that results from a high regularity of the overall structure and from simply-constructed base cells of the vector and angle iteration stages and in the extremely-high processing speed that results from the combination of intense pipelining and the carry-save architecture. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a pilot control valve especially for use in mining hydraulics with a valve insert configured as a valve cartridge which can be arranged in the valve accepting boring of a valve block or similar forming a multi-way valve whose valve housing has an inlet for pressure fluid, a connecting opening for a load, an outlet opening into a return feed and an axial boring for the acceptance of a valve closing body provided with a sealing surface, which can be lifted by means of a switching device fixed to the valve housing, against the return force of a spring from a valve sealing seat arranged between the inlet opening and the connecting opening, whereby with the lifting movement of the valve closing body from the valve sealing seat an at least two part closing mechanism arranged between the connecting opening and the outlet opening is coupled for their separation.
Previously proposed pilot control valves are employed in underground mining for the switching of main control valves arranged after them with which then hydraulic working cylinders of advancing support frames or other hydraulic equipment can be actuated. Due to the high working pressure and the corrosion promoting underground atmosphere, severe requirements are placed upon valves employed underground in respect of their switching power, switching distance and construction. In mining hydraulics the switching devices in the main comprise electromagnetic actuators which are designed to be intrinsically safe and are connected to corresponding electrical circuits. Using intrinsically safe electro-magnetic switching devices, the switching power which can be applied and the switching distance which is available for actuation is limited.
A previously proposed pilot control valve is known from DE 92 11 629 U1. It has a three part valve closing body which comprises two valve closing elements with cone shaped sealing surfaces and a coupling rod, which are accepted axially parallel to each other and with cone surfaces facing each other in a housing part comprising two valve housing parts screwed together to form a cartridge in which they can move too and fro. Each housing part has a valve seat associated with one of the closing surfaces and the distance of the valve seats from each other can be adjusted by the setting of the screw connection between the valve casing parts so as to facilitate an initial and subsequent adjustment of the valve setting. So that dependent upon the valve switching setting in the this pilot control valve a fluid current can take place between the high pressure line and the load or from the load to the return, both the coupling rods and also the valve closing elements are provided on their cylindrical outer surfaces with axially running flats or grooves, which at the same time limit and determine the cross section of flow and consequently the nominal bore of the pilot control valve. The manufacturing effort for the valve sealing elements comprising the valve sealing body and the coupling rod is therefore comparatively high and the functional integrity of this pilot control valve is dependent upon the precise adjustment of the separation of the two valve sealing seats.
It is an aim of the invention to produce a pilot control valve which has short switching paths, is simply constructed and has a simply produced valve sealing body in production engineering terms.
SUMMARY OF THE INVENTION
Accordingly the present invention is directed to a pilot control valve as described in the opening paragraph of the present specification wherein a single part valve closing body has the closing surface and the moving part of the closing mechanism, whereby the moving part comprises a shaft section of the valve closing body which plunges with the lifting movement into a boring section of the axial boring, closing a radial opening. In the pilot control valve according to the invention consequently only the valve seal between the pressure line and the user is made with a completely sealing valve sealing seat and associated closing surface, the valve sealing between the load connection and the return line works in accordance with a different principle and comprises a gap sealing, which from a determined point in the switching separates the connection between the load connector and the return line and requires no adjustment. The use of two different switching and sealing principles not only makes possible the omission of adjustment or re-adjustment, but at the same time simplifies the production engineering effort for the valve closing body, since this can be manufactured from one piece without the expensive matching and coupling surfaces as in a multiple part valve closing body. Owing to the single part valve closing body made as a valve pusher, the switching path and consequently the necessary valve lift is extremely short.
In a preferred embodiment the valve closing body has a ring-shaped collar whose rear side facing the valve sealing seat forms the closing surface or the support surface for a sealing body. The ring-shaped collar is simply manufactured and makes for a further simplification of construction of the valve closing body since expensive cone shaped closing surfaces on the valve closing body can be dispensed with. The preferably flat rear side of the ring shaped collar can hereby itself form the closing surface abutting the valve sealing seat or serve as a supporting surface for a sealing body, which can possibly b e exchanged in the event of wear. In order to increase the sealing function of the closing surface and to reduce the liability to wear, the collar can be equipped with an additional seating material on its rear side. The ring shaped collar which is impacted in the closed position of the pilot control valve with the pressure from the pressure line effects an automatic closing of the pilot control valve itself when the return spring fails or the actuator of the switching device blocks the free movement of the valve closing body.
Preferably the shaft section, i.e. the moveable part of the closing mechanism, forms one end of the valve closing body and a pin section forms the other end of the valve closing body whereby the pin and the shaft sections have the same diameter and form the guide surfaces of the valve closing body in the boring sections of the axial boring. Both can be provided with a sealing ring groove for the acceptance of an O-ring or a sliding ring. The measures quoted have the advantage that the valve closing body is guided by the shaft and the pin section in the axial boring of the valve housing and owing to the mutually matched diameters a pressure equalised opening position of the valve closing body can be achieved with the collar lifted from the sealing seat.
Advantageously the valve closing body has a diameter reducing cut-out with a conical transition section to the shaft section and/or collar between the collar and the shaft section forming the moving part of the closing mechanism. In a preferred embodiment the valve sealing seat is a component an exchangeable valve sleeve which can be inserted, especially pressed, into blind boring extensions of the axial boring. By means of the exchangeable valve sleeves not only is maintenance of the pilot control valve eased but the possibility exists with an otherwise unchanged construction of pilot control valve of matching the material of the valve sealing seat and/or the geometry of the valve sealing seat to the specific application profile of the pilot control valve. Preferably the internal diameter of the valve sleeve at the valve sealing seat is essentially the same diameter as the shaft and the pin sections and forms the inner side of the valve sleeve sections of the axial boring.
The arrangement of the exchangeable valve sealing seat depends on the construction of the valve case. In a prefered embodiment the valve case comprises a single case part with a stepped blind hole extension, in which a valve sleeve is inserted the sleeve end of which inserted into the blind hole forms the valve sealing seat with its inside and has the radial opening between two boring sections at a distance from the valve sealing seat, whereby preferably the radial opening opens into a circulating groove on the inner side of the valve sleeve. In a single part valve housing, adjustment of the valve setting is not possible since the distance established between the valve sealing seat and the radial opening by the construction of the valve sleeve determines the switching path the pilot control valve. At the same time however the risk of assembly errors is reduced to a minimum since the exact setting of the switching path is established exclusively by the matching between the switching pin of the switching device, the valve sleeve encompassing the valve sealing seat and the valve closing body inserted and guided therein. The groove on the inner side of the valve sleeve can in a modification of the valve sleeve embodiment also be constructed in that the valve sleeve is made stepped on the inside and the circulating grove is formed by means of an, especially screwed in, valve sleeve insert in the steps of the valve sleeve which is made shorter than the depth of the step, so that between the end of the valve sleeve insert and the bottom of the step a groove is formed.
In an alternative embodiment the valve case can comprise a first case part and a second case part joined to it, especially screwed, which is provided with a stepped bind hole extension, in which from the separation plane between the first and second parts a valve sleeve is inserted, whose free end forms the valve sealing seat and between its other end and the stepped section of the blind hole extension, forms the radial opening by means of gap openings at the sleeve end or the extension of the length of the valve sleeve between the abutment surface of a ring shoulder of the sleeve and the base of the sleeve is shorter than the stepped blind hole extension so as to form an annular gap as the radial opening via the shorter sleeve length. With a two-part construction of the valve casing the valve adjustment has a matching chain with four contact positions, whereby as opposed to the form of construction with a single part valve part, the first separation plane forms the additional fourth contact position.
In a third alternative embodiment the valve case comprises a first, a second and a third part of the case with a first separation plane between the first and second and a second separation plane between the second and third case parts, whereby the second case part is provided with a stepped blind hole extension, into which a free sleeve end of a valve sleeve forming a valve sealing seat at its free sleeve end is inserted. In this configuration it is especially favourable if the radial opening is formed from an intermediate gap at the second separation plane. In contrast to the form of construction with a single part or two-part valve case in the three part valve case the radial opening is not a component of the valve sealing seat, but it is for instance generated as an intermediate space or annual gap by the separation plane between two parts of the case. It is further expedient in all the forms of construction to provide at least one decentral through boring for driving out the valve sleeve. It is understood that this can be closed by means of a blanking plug, a grub screw or similar.
The application possibilities and the range of use of the pilot control valve according to the invention can be further increased as opposed to the known pilot control valves if a flow resistance for the fluid is connected in series with the valve sealing seat and the closing mechanism, since then with a single form of construction of the pilot control valve its effective nominal bore can be changed. In contrast to the known pilot control valves in accordance with the invention the seating geometry of the valve sealing seat between the pressure line and the load is not carried out differently to change the nominal bore but the effective nominal bore is controlled by the selection of the flow resistance. A flow resistance can be especially simply produced using a throttle or a shutter whereby preferably a single throttle or shutter is allocated to the load connector so that this one flow resistance is effective both in the feed flow from the pressure line to the load and also in the return flow from the load into the return line. It is also possible however to arrange a separate throttle or shutter for each connection or only one or two connections are provided with a flow resistor. In the preferred embodiment the throttle or shutter is inserted at a distance from the valve closing body in a cover boring or similar in the valve case which forms the load connection. By this arrangement there results a reduction of the flow forces acting upon the valve closing body.
As the switching device preferably an electro-magnetic or piezo-electric actuator is applied as is described in DE 101 34 947, the two which express reference is made, whereby preferably the valve insert is retained in the valve accepting boring by means of the switching device. With the fastening of the switching device to the valve block the valve insert is then immediately accommodated axial and secured in the valve accepting boring. In a multipart valve case the boring sections of the axial boring forming the guide and bearing sections for the shaft and the pin sections can be provided in each outer case part with an accepting groove for a sealing ring on the case side.
BRIEF DESCRIPTION OF THE DRAWINGS
Example of pilot control valves made in accordance with the present invention will now be explained with reference to the accompanying drawings, in which;
FIG. 1 shows a cross-sectional view of a pilot control valve in accordance with a first embodiment, inserted into a valve block and held in position in the valve accepting boring by the housing of the switching device;
FIG. 2 shows a cross-sectional view of a pilot control valve in accordance with the first embodiment with a changed arrangement of seals for the valve closing body;
FIG. 3 shows a cross-sectional view of a pilot control valve in accordance with a second embodiment with a two part valve case;
FIG. 4A shows a detailed sectional view of the valve sleeve for the pilot valve shown in FIG. 3 ;
FIG. 4B shows a view of the left hand sleeve end shown in FIG. 4A ;
FIG. 5A shows a sectional view of an alternative embodiment of a valve sleeve for use with the pilot control valve made in accordance with the second embodiment;
FIG. 5B shows a view of the left hand sleeve end of the valve sleeve according to FIG. 5A ;
FIG. 6 shows a cross-sectional view of a pilot control valve according to a third embodiment with a single part valve case; and
FIG. 7 shows a cross-sectional view of an alternative embodiment for a pilot control valve with a single part valve case.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a vertical section through a valve accepting boring 1 of a valve block 2 possibly having several adjacent and superimposed valve-accepting borings. The valve accepting boring 1 is made as a blind hole into which a pilot control valve 10 made as a cartridge shaped valve insert according to a first embodiment is pushed in from the end 3 of the valve block 2 . The valve insert forming the pilot control valve 10 has a three part valve case with a first valve case part 11 , a second valve case part 12 and a third valve case part 13 which are screwed together individually at their separation planes 38 and 41 and are held together in the valve acceptance boring 1 by means of the case 4 of the switching device 5 indicated only schematically. The case end 4 ′ of the switching device 5 sits in a depression 6 on the end 3 and overlaps the cartridge of the pilot control valve 10 with a fastening flange and is screwed into the walls of the valve block 2 by means of fastening screws 7 . The switching device 5 has a switching pin 8 , which can be impacted electro magnetically or piezo electrically with a switching force F in the direction of the arrow so as to change the closing position of the pilot control valve 10 . The central axis M of the cylindrical switching pin 8 is aligned with the central axis Z of the valve insert 10 and the accepting boring 1 and the free end of the switching pin 8 presses against the end surface 15 of a valve closing body 20 comprising a single piece, which is pre-tensioned against the switching force F by means of a return spring 14 . In the embodiment according to FIG. 1 the valve closing body 20 sits in a moveable manner in an axial boring 21 , which is formed individually from a boring section 21 A, 21 B, 21 C in the case parts 11 , 12 , 13 , whereby all the boring sections 21 A, 21 B, 21 C have the same diameter D as each other. The axial guidance and bearing of the one part valve closing body 20 made as a pusher is effected by means of a shaft section 22 forming the left hand end of the valve closing body 20 with a constant diameter D and a pin section 23 forming its right hand end similarly with the diameter D, which are guided with small play in the boring section 21 A, 21 B or the axial boring 21 in the first case part 11 and the third case part 13 . The end of the switching pin 8 works on the end 15 of the shaft section 22 and on the return spring 14 presses against the end of the pin section 23 via the pressure plate 16 . Both the shaft section 22 and also the pin section 23 have a circumferential groove 24 , 25 for the acceptance of a sealing ring 26 , 27 so as to seal the centre boring section 21 C or the actual boring 21 against the outside of the valve case.
The pilot control valves shown in the FIGS. are all configured as 3/2 multi way valves and facilitate a connection or separation between the high pressure line P and the load connection A or between this and the return line T. In order to be able to perform the valve function, the first case part 11 has an inlet opening 17 , which opens into the pressure line P. The second case part 12 has a connecting opening 18 which opens into the load connection A in the valve block 2 , and an outlet opening 19 , which leads to the return T in the valve block 2 . The embodiments all show the output or rest position of the valve in which the switching pin 8 is not impacted with the force F and consequently the connection between the entry opening 17 and the connector opening 18 is separated. To achieve the fluid separation the valve closing body 20 is provided a circulating collar 28 as a single part on the pin section 23 and extending radially outwards from this, which abuts against the closing edge of a valve-sealing seat 31 . The closed position of the rear side 28 ′ of the collar 28 with the closing edge of the sealing seat 31 is provided by on the one hand the return force exerted by the return spring 14 and on the other hand by the closing pressure exerted by the pressure of the pressure fluid in the pressure line P on the ring surface 29 of the collar 28 . The shaft of the closing body 21 has a cut out 29 between the rear side 28 ′ or the collar 28 and the shaft section 22 , which for instance can result in a constant reduction of the shaft diameter to the diameter D′. The transitional section 35 to the shaft section 22 and the transitional section 36 to the collar 28 rises conically in each case. In the shown valve position of the closing body 20 the connection opening 18 is joined with the exit opening 19 via the cut out 29 and the freely cut surface of the transitional section 35 . The output opening 19 hereby does not reach up to the associated section of the axial boring 21 in the case section 12 but is open via a cross boring 37 to the separation plane 41 between the second case part 12 and the third case part 13 . Both case parts 12 , 13 are screwed together in such a manner that at the separation plane 41 a gap 39 is formed out to the height of the cross boring 37 , which in the pilot control valve 10 comprises the static part of a closing mechanism for fluid separation of the connection opening 18 from the exit opening 19 . The second moveable part of the closing mechanism comprises the shaft section 22 since its cylindrical outer side plunges into the section 21 C of the axial boring 21 when the valve closing body 20 is moved to the right, as seen in the FIG., and then seals the access to the gap 39 . The transition edge 40 between the shaft section 22 and the transition section 35 forms a sharp edged control edge for the closing mechanism, which seals the free passage between the connection opening 18 and the outward opening 19 as soon as it is at least at the same position as the end of the second case part 12 . The shaft section 22 plunging into the boring section 21 C in the case part 12 functions as a gap seal with little flow and pressure loss of fluid from the pressure line P, which can overflow due to the movement of the valve closing body 21 in the direction of the arrow F and of the collar 28 being lifted from the valve sealing seat 31 to the connecting opening A. Since both the shaft section 22 as the moveable part of the second closing mechanism and also the collar 28 as the moveable part of the first closing principle formed as a valve seat are formed as one part with the valve closing body 20 the actuating movement of both closing principles are coupled together by force.
For reasons of clarity the further description of the pilot control valve according to the first embodiment is now, continued with reference to FIG. 2 , in which similarly a pilot control valve 10 ′ with three case parts 11 , 12 , 13 is shown. The only difference between the pilot control valve 10 is FIG. 1 and the pilot control valve 10 ′ in FIG. 2 comprises the arrangement of the seals for the shaft section 22 and the shaft section 23 which in the embodiment according to FIG. 2 are each attached on the housing side. The boring section 21 A in the first case part 11 and the boring section 21 B in the third case part 13 which form the axial guide for the shaft section 22 and the pin section 23 of the valve closing body 20 , are correspondingly provided with accepting grooves 24 ′, 25 ′ into which individually a sealing ring 26 ′, 27 ′ sits. The valve-sealing seat 31 is integrated into an exchangeable valve sleeve 30 which is pressed into a blind hole 42 in the second case part 12 extending from the first separation plane 38 between the first case part 11 and the second case part 12 and sealed in place by means of a sealing ring 43 . The sealing seat 31 is here formed from the free sleeve end 33 of the valve sleeve 30 at the separation plane 38 extending into a ring shaped front space 44 of the valve. The front space 44 comprises a blind hole formed in the first case part 11 and forms the only local extension of the axial boring 21 . The entry opening 17 opens into the front space 44 , so that the through flow of fluid from the pressure line P is assured. The front space 44 also forms the free space for the movement of the collar 28 of the valve closing body 20 whereby the fluid at the collar 28 can freely flow passed the rear side 28 ′ of the collar 28 . The valve sleeve 30 is provided with a ring shoulder 32 extending out over the side walls of the blind hole 42 , which extend radially out to the position of a decentral blind boring 46 , via which the valve sleeve 30 can be driven out from the blind hole 42 when the case parts 11 , 12 and 13 are disassembled. In the assembled condition the blind boring 46 is closed by means of a blanking plug 45 or a grub screw. The geometry of the sealing seat 31 and the material of the valve sleeve 30 can be varied depending on the pressure to be switched with the pilot control valve and in the embodiments shown the valve-sealing seat 31 on the valve sleeve 30 is made in the form of a cone. When the collar is lifted from the valve sealing seat 31 the fluid flows out of the pressure line P via the entry opening 17 into the advanced area 44 , there passed the collar 28 into the annual space formed by the cut out 29 up to the transitional edge 40 to the shaft section 22 and then via the connecting opening 18 which opens into the boring section 21 C to the load A (not shown). The closing mechanism between the opening connector 18 and the exit opening 19 separate these owing to the shaft section 22 of the closing body 20 which seals the radial opening 39 .
A further special feature of the pilot control valves 10 and 10 ′ in FIGS. 1 and 2 is a throttle 47 , which is inserted or screwed in or directly set into the case 12 in a radial cover boring 18 ′ which has a larger cross section than the connecting opening 18 and forms with this the feed to the load connector A. The throttle 47 forms a stream resistance when flowed through by the fluid both from the open valve sealing seat 31 , 28 and also from the opened closing mechanism 39 , 22 . If the throttle 47 has a through flow opening which is smaller than the through flow gap on the valve sealing seat 31 , 28 or at the closing mechanism 39 , 22 , it is possible to determine the effective nominal bore of the pilot control valve 10 or 10 ′ by means of the opening cross section of the throttle 47 . By exchanging the throttle 47 for a throttle with a different cross sectional opening the effective nominal bore of the pilot control valve can consequently be varied with otherwise identical construction whereby the distance of the throttle 47 owing to the cover arrangement in the second case part 12 essentially influences the flow in the valve less than would be the case for a changing of the cross section of flow at the valve sealing seat or at the closing mechanism.
FIG. 3 shows an embodiment of a pilot control valve 110 according to a second embodiment. The same components are provided with reference numbers raised by 100 . The pilot control valve 110 has a two-part valve case with a first valve case part 111 and a second valve case part 112 . The construction of the valve closing body 120 with collar 128 , transition edge 140 and shaft section 122 is identical as in the first embodiment. Between the first case part and the second case part 112 a single plane of separation 13 B is formed, whereby the two case parts 111 , 112 are screwed together using threaded sections not shown, on the cover collar 150 of the first case part and on a pin extension 151 of the second case part 112 . A sealing of the shaft section 122 and the pin section 123 can, as in the embodiment according to FIG. 1 , be effected using sealing rings 126 , 127 which are fastened to the valve closing body 120 or by sealing rings which are set into the boring sections 121 A and 121 B in the case parts 111 , 112 . In contrast to the first embodiment in the embodiment according to FIG. 3 , both the sealing seat 131 and also the fixed part of the closing mechanism formed from the radial opening 139 are integrated into a valve sleeve 130 , which is shown in detail in FIGS. 4A and 4B , which are now referred to. The valve sealing seat 131 is formed at the free sleeve end 133 whilst the valve sleeve end 134 extending into the base of the blind hole boring 142 in the second case part 112 ( FIG. 3 ) has several radial cut outs 155 distributed around its circumference, which are interrupted by axial corner extensions 156 . With the valve closing body 120 not activated and consequently not moved as shown in FIG. 3 , fluid from the annular space 129 formed between the reduced diameter closing body shaft 120 ′ of the valve closing body 120 and the surrounding wall of the axial boring 121 can flow into the exit opening 119 to the return flow T, since the transitional edge 140 is moved towards and to the left of the radial opening 139 . The valve-sealing seat 131 is hereby closed by the collar 128 . The sealing seat of the sleeve 130 in the blind hole boring 142 is effected by means of two sealing rings 157 , 158 (FIG. 3 ), which sit in the sealing ring grooves 161 , 162 (FIG. 4 A), which are formed on either side of a connecting boring 160 to the load connection 118 . The connecting boring 160 opens into an annular groove 163 on the valve sleeve, so that the connection of the connecting boring 160 to the connecting opening 118 is assured independently of the position of the valve sleeve 130 in the blind hole boring 142 . For the exchange of the valve sleeve 130 pressing into the blind hole boring 142 a decentral blind boring 146 ( FIG. 3 ) is provided which is closed with a blanking plug 145 .
FIGS. 5A and 5B show an alternative embodiment for the valve sleeve 130 ′, which can be inserted in the second case part 112 of a two part valve case shown in FIG. 3 . The valve sleeve 130 ′ is distinguished from the valve sleeve 130 in its extended length between the abutment flange 132 ′ of the ring shoulder 132 and the sleeve base 134 ′ and/or the configuration of the sleeve base 134 ′, which here is formed as a flat surface so that over the shorter length of the valve sleeve 130 ′ relative to the extended length of the stepped blind hole boring 142 between the base of the blind hole boring 142 and the base 134 ′ of the sleeve 130 ′ an annular gap arises which is connected to the outlet opening 119 . The final edge of the valve sleeve 130 ′ on the inner circumference 121 C′ of the valve sleeve 130 ′ marks the control edge of the closing mechanism in the valve sleeve 130 ′ working together with the transitional edge 140 and the shaft section 122 of the valve closing body 120 . The partial section 121 C of the axial boring 121 is formed from the inner circumference of the valve sleeve 130 , 130 ′ by the use of the valve sleeves 130 , 130 ′ and a two-part valve case. Since the valve sleeves 130 , 130 ′ have both the sealing seat 131 and also the fixed part of the second closing mechanism, if wear occurs the sealing function of both major seals of the pilot control valve can again be established by the exchange of a component.
FIG. 6 shows an embodiment of a pilot control valve 210 with a single case part 211 forming the cartridge. Here also the valve closing body 220 has an identical construction as in the embodiments in FIGS. 1 , to 3 so that a description of the valve closing body 220 is not necessary. The valve sealing seat 231 which works together with the collar 228 on the valve closing body 220 from the end face 270 in the pre-space 244 is a component of a valve sleeve 230 which is pushed into a blind stepped boring 242 in the case part 211 , which in the assembled condition abuts the case of the switching device and extends out from the valve accepting boring. The radial opening 239 , which forms the static part of the second closing mechanism, comprises here a radial boring in the cover 280 of the valve sleeve 230 and a circulating groove 281 formed on the inner circumference 221 C of the valve sleeve 230 and aligned with the radial opening 239 . The blind hole boring 242 in the single case part 211 has correspondingly at the same height as the radial boring 239 and the circulating groove 281 a ring groove 282 , which is in connection with the exit opening 219 to the return flow T. For the flow to the user connection A the valve sleeve 230 has at the height of the connection opening 118 a radial boring 260 and a ring groove 263 . Here also as in the previous embodiments a throttle 247 can be inserted in the connecting opening 118 so as to be able to change the effective bore of the pilot control valve. The embodiment shown in FIG. 6 differs further from the previous embodiments in that the shaft section 222 is guided not in a section of the axial boring within a case part but in the boring section 221 B on the inner surface of the valve sleeve 230 . For this embodiment it therefore offers the advantages of integration of the seals 226 , 227 in the valve pusher 220 . The boring sections 221 C and 221 B end individually at the radial opening 239 or the groove 281 . Because of the single part valve case 211 assembly errors can hardly arise in the pilot control valve cartridge 210 , which is put together, from very few parts. FIG. 7 shows an alternative embodiment 210 ′ for a pilot control valve with assembled part valve case part 211 . In contrast to the embodiment in FIG. 6 , in which a circulating groove 281 on the inner circumference of the valve sleeve 230 has to be turned out, the valve sleeve 230 ′ has a stepped extension 290 in which a valve sleeve insert 291 is screwed or pressed in so as to form the circulating groove 281 ′ between the end 292 of the valve sleeve insert 291 and the base 293 , which again is connected with the outlet opening 219 and the return flow T via the radial boring 239 ′. The boring section 221 E of the axial boring 221 is here consequently formed from the inner side of the sleeve insert 291 and the shaft section 222 is guided on this boring section 221 E. The blind boring for driving out the valve insert 230 , 230 ′ is not shown.
From the foregoing description a range of modifications present themselves to a man skilled in the art, which fall within the range of protection of the attached claims. A throttle blind screwed into the connecting opening of the load connector forms the preferred embodiment for changing the effective nominal cross section of the pilot control valve according to the invention. Alternatively instead of one throttle there also can be one throttle in the inlet opening and the outlet opening or any desired combination of flow resisters can be provided. Instead of a throttle a blind or similar could be used. Further the number and the arrangement of the sealing rings between the individual components and the number of the blind borings can be varied within limits whereby such and other modifications fall in the area of the protection of the claims, insofar as with a single valve closing body, two different closing mechanisms for the multi way valve are realised. Further, the valve according to the present invention cannot only be applied as a pilot control valve but also as a main control valve for low pressures of the fluid to be controlled or switched. | The present invention relates to a pilot control valve, especially for use in mining hydraulics. The valve has a valve insert constructed as a valve cartridge, whose single or multipart valve housing has an input entry 17 for pressure fluid P, a connection opening 18 for a load connection A, an output opening 19, opening into the return flow T and an axial boring 21 to accept a valve closing body 20 provided with a closing surface, which can be lifted from a valve sealing seat 31 arranged between the entry opening 17 and the connection opening 18 by means of an electro-magnetic or piezo-electric switching device which can be fastened onto the valve housing. With the lifting movement of the valve closing body 20 from the valve sealing seat 31 is coupled an at least two part closing mechanism for their separation arranged between the connection opening 18 and the output opening 19. In accordance with the present invention a single part valve closing body 20 is provided, having the sealing surface in the form of a collar 28 and the moving part of the closing mechanism in the form of a shaft section 22, whereby the shaft section 22 enters into a boring section 21 C of the axial boring 21 during the lifting movement, closing a radial opening 39. The valve sealing seat 31 can be exchanged with a valve sleeve 130 and the nominal bore of the pilot control valve can be changed by means of a throttle 47. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a U.S. non-provisional patent application of, and claims priority under 35 U.S.C. §119(e) to, U.S. provisional patent application Ser. No. 61/609,070 filed Mar. 9, 2012, which provisional patent application is incorporated by reference herein.
COPYRIGHT STATEMENT
All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. 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 otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to slide fastener chain that includes fabric and features that allow the zipper tapes to stretch in the lateral direction. Slide fastener chain is the combination of two slide fastener tapes and fastener elements mounted thereon, and that is manufactured in bulk lengths. A slide fastener assembly, or zipper, is made by cutting a desired length of chain, mounting a slider assembly, and optionally adding top and/or bottom stops, pin boxes, etc.
There are a number of applications for slide fasteners that incorporate tapes that can stretch, such as clothing, luggage, and footwear. A conventional zipper must be very stable in the longitudinal direction (along its length) in order that the teeth of the opposing tapes properly engage, and are generally also very stable in the lateral direction (across its width). A zipper that can stretch in the lateral direction, but be stable in the longitudinal direction, is less likely to fail due to the teeth becoming disengaged when closed because the fabric tape can absorb some of the stress that would otherwise bear on the teeth. The use of such a zipper is desirable in luggage as it makes it easier to close the zipper on a fully loaded or overloaded bag. Such a zipper can also be used in applications where some amount of give is desirable even if the lateral stress is minimal, such as a dress. In one application, slide fasteners made from tapes of the present invention are used as a closure for luggage. In other applications such zippers may be use for garments such as pants or dresses. Other applications include zippers for the sides of tall form-fitting boots.
There have been many attempts at making a zipper with tapes that allow for significant lateral stretch. There have been some such zipper products that have had modest success in the marketplace, but these products have suffered from poor performance due to inadequate stretch (in proportion to the tape width), lack of rebound (the ability of the tape to quickly and repeatedly return to its non-stretched width), and lack of durability. A need exists for improvement in the field of stretchable slide fastener chain that address the shortcomings of the prior art, and from which stretchable slide fastener assemblies (zippers) may be made. This and other needs are addressed by one or more aspects of the present invention.
2. Description of Related Art
There are numerous means for making a zipper stretchable in the lateral direction by using fabric tapes that are made from stretchable weaving yarns. While such fabrics are readily available, they are not suitable for use in a zipper unless the tape is stable (non-stretchable) in the longitudinal direction (the length of the zipper from pin box to top-stop for instance). In order to weave a zipper tape, the warp weaving yarns are aligned in the longitudinal direction, and the weft weaving yarns are aligned perpendicular to the warp yarns. Since any stretch in the longitudinal direction of the zipper would allow the zipper teeth of a finished zipper assembly to become disengaged, extremely stable (no longitudinal stretch) warp weaving yarns are required. The challenge in producing a zipper tape that stretches in the direction of the weft weaving yarns is to use weaving yarns that have nominal, repeatable stretch. Excessive stretch in the lateral direction can create performance issues that interfere with the proper movement of the zipper slider and can result in dislocations between opposing fastener elements (teeth).
Stretchable tapes have been made using a variety of stretchable weft weaving yarns that include stretchable fibers such as spandex. However, tapes of the prior art that use stretchable fibers do not exhibit sufficient stretch (in terms of the ratio of the stretched width to the un-stretched width of the tape), or are not durable due to failure of the stretchable weft weaving yarns (during weaving, or during use due to physical abrasion or laundering or drying heat), or loss of stretch memory (the ability of the stretched tape to return to the original un-stretched tape width quickly and repeatedly). Therefore, it is an objective of the present invention to create a slide fastener using fabric tapes that have the desired stretch characteristics (ratio of stretched to un-stretched tape width) and acceptable durability.
The slide fastener chain and tapes of the present invention provides for a sufficient degree of stretchability and durability.
SUMMARY OF THE INVENTION
The zipper of the present invention accomplishes the above objectives as described below.
In one embodiment of the present invention, the slide fastener tapes are woven using inelastic warp weaving yarns and elastic weft weaving yarns. The inelastic warp weaving yarns are made from textured polyester yarn. The elastic weft weaving yarns are made from a stretchable fiber such as spandex, and wrapped with textured filament polyester for weavability and durability. Other factors that determine the stretch characteristics of the finished tape are the weight of the textured filament polyester, the number of strands of the core stretch fiber and the wrapping fibers, and the means of wrapping the stretch fiber with textured filament polyester. In addition, the weave pattern of the finished zipper tape further affects the stretch characteristics of the finished zipper assembly. In one embodiment of the present invention, a no point twill pattern allows for the desired degree of stretch and a smooth feel and attractive appearance. A single point or two point twill is also acceptable from an aesthetic perspective, but the transitions in the weaving patter (the twill points) result in significantly less stretch across the tape width in proportion to the un-stretched width.
BRIEF DESCRIPTION OF THE DRAWINGS
One or more preferred embodiments of the present invention now will be described in detail with reference to the accompanying drawings, wherein the same elements are referred to with the same reference numerals.
FIG. 1 is a photo showing un-stretched weft weaving yarns used in the slide fastener tape of the present invention;
FIG. 2 is a photo showing stretched weft weaving yarns used in the slide fastener tape of the present invention; and
FIG. 3 is an illustration showing the outward appearance of un-stretched slide fastener tape of the present invention.
DETAILED DESCRIPTION
As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art (an “Ordinary Artisan”) that the present invention has broad utility and application. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the present invention. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure of the present invention. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
Accordingly, while the present invention is described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present invention, and is made merely for the purposes of providing a full and enabling disclosure of the present invention. The detailed disclosure herein of one or more embodiments is not intended to, nor is to be construed to, limit the scope of patent protection afforded the present invention, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection afforded the present invention is to be defined by the appended claims rather than the description set forth herein.
Additionally, it is important to note that each term used herein refers to that which the Ordinary Artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the Ordinary Artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the Ordinary Artisan should prevail.
Regarding applicability of 35 U.S.C. §112, ¶6, no claim element is intended to be read in accordance with this statutory provision unless the explicit phrase “means for” or “step for” is actually used in such claim element, whereupon this statutory provision is intended to apply in the interpretation of such claim element.
Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. Thus, reference to “a picnic basket having an apple” describes “a picnic basket having at least one apple” as well as “a picnic basket having apples.” In contrast, reference to “a picnic basket having a single apple” describes “a picnic basket having only one apple.”
When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Thus, reference to “a picnic basket having cheese or crackers” describes “a picnic basket having cheese without crackers”, “a picnic basket having crackers without cheese”, and “a picnic basket having both cheese and crackers.” Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” Thus, reference to “a picnic basket having cheese and crackers” describes “a picnic basket having cheese, wherein the picnic basket further has crackers,” as well as describes “a picnic basket having crackers, wherein the picnic basket further has cheese.”
Referring now to the drawings, one or more preferred embodiments of the present invention are next described. The following description of one or more preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its implementations, or uses.
FIG. 1 illustrates the weft weaving yarns, in an un-stretched state, used to weave the slide fastener tape of the present invention. FIG. 2 illustrates the weft weaving yarns, in a highly stretched state, used to weave the slide fastener tape of the present invention. FIG. 3 illustrates an example of finished slide fastener tape of the present invention in an un-stretched state and further showing the finished twill pattern.
In one embodiment of the present invention, the slide fastener tapes are woven using inelastic warp weaving yarns and elastic weft weaving yarns. The inelastic warp weaving yarns are made from textured polyester yarn. The elastic weft weaving yarns are made from spandex fiber wrapped with textured filament polyester. Other factors that determine the stretch characteristics of the finished tape are the weight of the textured filament polyester, the number of strands of the cord (stretch fiber) of the weft yarns, the number of wrapping filaments, and the means of wrapping. In addition, the weave pattern further affects the stretch characteristics of the finished tape. In one embodiment of the present invention, a no point twill pattern allows for the desired degree of stretch and a smooth finished fabric feel and attractive appearance. A single point or two point twill is also acceptable, but such a twill pattern results in significantly less stretch in proportion to the un-stretched tape width.
In one embodiment of the present invention, the warp weaving yarns are dimensionally stable 2/150 polyester, and the weft weaving yarns comprises a spandex core with corespun textured filament polyester wrapped around the spandex core. It has been determined that a weft weaving yarn of 260 denier spandex with 56 picks of 70 denier textured polyester wrapper fibers with 34 filaments in the wrapper yarn (specified as 260/1/70/34) results in the desired characteristics.
In other embodiments, it is possible to create a lighter tape (which exhibits more stretch) or a heavier tape (which exhibits less stretch) by altering the denier of the core spandex. It has been determined that other embodiments of the present invention that exhibit acceptable stretch characteristics may be obtained with core spandex yarn of 100 denier to 1,040 denier. The number of filaments of wrapper yarn may also vary, with acceptable results using as few as 30 filaments and up to 48 filaments. For instance, a lighter tape may be produced using textured polyester wrapped spandex as light as 100/1/70/34, and a heavier tape may use textured polyester wrapped spandex as heavy as 1040/1/70/48.
In one embodiment of the present invention, a no point twill pattern allows for the desired degree of stretch and a smooth feel and attractive appearance. The preferred weave pattern is created by weaving the tape with a 3-5 cam pattern. For a one inch nominal finished tape width (un-stretched), a preferred pattern uses 44 ends of warp weaving yarns and a double pick filling, resulting in 56 picks per inch. A selvedge edge is incorporated into the pattern to allow for a strong sewing edge for sewing the tape to a garment. In one embodiment of the present invention, the stretch ratio of the finished tape, that is the ratio of the stretched to un-stretched tape width, is 1.48:1.
The slide fastener tape of the present invention can by dyed after weaving using conventional dyeing means that use elevated temperature and pressure. By way of example, it has been found that a dyeing temperature of 265 degrees Fahrenheit and dye vessel pressure of 55 pounds per square inch (psi) results in ideal dyeing characteristics, but a temperature range of 240-275 degrees Fahrenheit and pressure of 30-65 psi is acceptable.
In order to make slide fastener assemblies (zippers) with lateral stretch, the first step is to make slide fastener tapes that exhibit the desirable properties of the tapes of the present invention. The stretchable fabric tapes of the present invention are woven in the manner described above. While it is possible to use the stretchable fabric tapes of the present invention to make a variety of zipper types such as metal zippers (metal teeth), molded zippers (plastic teeth made from Delrin® or other materials), and coil zippers (fastener elements, or “teeth”, made from coiled polyester monofilament), it is generally recognized that coil zippers have the strongest lateral strength (that is, for any given gauge or size of zipper, coil-type teeth have the greatest resistance to the opposing teeth separating due to lateral stresses). In addition, the types of applications for which a stretchable zipper are most desired such as luggage, dresses, footwear, and dress slacks, generally use coil-type zippers due to their positive attributes related to cost, ease of dyeing, and appearance.
For a coil-type zipper, once the stretchable tapes have been woven, two stretchable tapes are fed into a coil zipper spiraling machine in parallel. Two parallel lengths of monofilament and two lengths of cord are also fed into the coil zipper spiraling machine, and one strand of monofilament is coiled around each of the cords and formed into opposing fastener elements. The two lengths of coiled monofilament are meshed together, aligned with the 2 lengths of tape, and then sewn to the tape. This results in stretchable slide fastener chain comprising the two tapes and two coils (with the opposing coils engaged). The slide fastener chain is then typically dyed as desired. To make finished zipper assemblies, the desired length of stretchable chain is cut from a bulk roll, a slider is added, and then further processed to add a pin box, top of bottom stops, and the like, resulting in stretchable zippers of the desired length. | Slide fasteners (zippers) used for certain applications function better if the zipper tape can stretch in the lateral direction. When a zipper is used to close certain articles such as luggage, boots, or certain garments, it can be difficult to easily and fully close a zipper if there is a significant lateral load pulling at the tapes perpendicular to the direction that the slider is pulled. By using a zipper that includes a zipper tape that stretches in the lateral direction, it is possible to more easily close such articles while maintaining a neat appearance of the zipper on the article. | 3 |
TECHNICAL FIELD
The present invention relates generally to the field of well completion and, more particularly to the art of sand control. Still more particularly, the present invention includes a gravel pack assembly utilizing a washpipe inside a gravel pack screen and having the gravel pack screen hydraulically released from the work string without rotation of the work string.
BACKGROUND OF THE ART
In oil and gas wells where formation sand is unconsolidated, there is migration of sand particles into the wellbore as fluid is produced. Such migration may cause production loss due to the sand bridging in the casing, the tubing or the flowbore; failure of the casing or the liners; compaction or erosion; abrasion of the downhole or the surface equipment; and handling and disposal of produced formation materials. Therefore, there is a need to prevent such sand migration by either chemical or mechanical means. One method of sand control which is used extensively is that of gravel packing. In general, gravel packing includes the installation of a screen adjacent the formation downhole followed by the packing of gravel in the perforations and around the screen to prevent the sand from migrating from the formation to the production tubing. In such an arrangement, a gravel screen assembly attached to a work string is lowered downhole through an open hole or a cased borehole and adjacent the formation to be completed. A slurry of gravel suspended in a viscous carrier fluid is pumped downhole through the work string and a cross-over assembly into the annulus. Pump pressure is applied to the slurry forcing the suspended gravel through the perforations or up against the formation sand. The gravel then accumulates in the annulus between the screen and the casing or the formation sand. The gravel forms a barrier which allows the flow of hydrocarbons therethrough but inhibits the flow of sand particles into the production tubing which would sand up the well.
There are various methods used in gravel packing operations, the most advantageous being the crossover method. The crossover method, in general, utilizes a standard gravel pack assembly including a gravel screen and a washpipe therewithin. It also utilizes a packer and a crossover assembly at the top of the gravel pack assembly. The packer is set mechanically by rotation of the work string. The packer is located above the crossover assembly and forms a lower borehole annulus adjacent the formation and an upper borehole annulus above the formation. The crossover assembly allows the slurry flowing down the flowbore of the work string above the screen assembly to cross over into the lower borehole annulus below the packer and around the gravel screen adjacent the formation. The gravel is deposited in the formation and lower borehole annulus with the fluid carrier continuing up the washpipe and flowing back through the crossover assembly to the upper annulus above the packer and up to the surface. The advantages of the crossover method are that, by pumping the slurry down the flowbore of the work string, no debris can be scoured from the casing by the slurry and deposited in the perforations to block the perforations to flow; the upper zone perforations or bond casing are subjected to less pressure; the gravel placement time and the chances of sand bridging are reduced; and the fluid and the gravel location are controlled within the work string.
Following the gravel packing operation, it is intended that the work string including a packer and a washpipe assembly be lifted to the surface leaving the gravel pack screen assembly at the bottom of the well. Therefore, a release mechanism is necessary to detach the gravel pack screen assembly from the work string. It is a principal objective that the two are separated without disturbing the completed gravel pack and that the separation does not fail because such failure will cause the destruction of the gravel pack.
Release mechanisms for releasing tools from tool strings downhole in general and, more particularly, for releasing gravel packing assemblies are well known. See for example the releasing assemblies in the gravel pack hardware manufactured by Baker Sand Control, Brown Oil Tools, Dowell and Texas Iron Works disclosed in the 1982-83 Composite Catalog of Oil Field Equipment and Services at page 991-992, 1459, 2522 and 7947 respectively. Another releasing tool used in gravel packing operations is disclosed in U.S. Pat. No. 4,175,778. Release tools for releasing tools downhole are disclosed in U.S. Pat. Nos. 2,409,811, 4,187,906, 4,190,107 and 4,289,202.
Most prior art release mechanisms of gravel packing assemblies are activated by rotating the work string. Rotation of the work string is not desirable because it is difficult to implement in slanted and crooked wells; it causes operating problems because of all the auxiliary piping extending from the surface downhole; it requires rotating equipment to rotate the packer, the crossover assembly and the washpipe assembly free from screen and hook-up nipple assembly; and it is unreliable and may not release. Release mechanisms which operate by rotation are shown in the sand control equipment on pages 991-992, 1459, 2522 and 7947 in the aforementioned Composite Catalog of Oil Field Equipment.
Prior art release tools that are not activated by rotation are disclosed in U.S. Pat. Nos. 2,409,811 and 4,175,778. The release tool disclosed in U.S. Pat. No. 2,409,811 is not specifically related to gravel packing operations, but to downhole releasing tools in general. It includes a plurality of balls partly positioned within holes in the retaining member and within apertures in the retained member, thereby locking both members together. The balls are kept in that locking position by a piston which is in intimate contact with the retaining member. If the piston is displaced, the intimate contact is eliminated and the balls move away from the apertures of the retained member whereby the connection between the two members is unlocked and the retaining member may be removed from the retained member. The piston, which has an internal passageway in series with the flowbore of the work string, is displaced by applying hydraulic pressure on it through the flowbore of the work string after the passageway is closed by a steel ball. The hydraulic pressure is not relieved by the displacement of the piston alone, but by the relative displacement of the retaining and retained members.
The tool disclosed in U.S. Pat. No. 4,175,778 is used to release gravel packing screens and discloses a plurality of blocks with chamfered surfaces partly positioned within holes in the retaining member and partly positioned within an annular groove in the hook-up nipple of the gravel packing screen thereby locking the two together. The blocks are held in that position by the interior surface of the piston which is in intimate contact with the interior of the retaining member adjacent the apertures. In order to release the hook-up nipple and the gravel packing assembly, the piston, which has an internal passageway in series with the flowbore of the tubing string, is displaced by closing the passageway with a steel ball and applying hydraulic pressure on it from the flowbore of the work string. When the piston is displaced, the blocks are no longer held in the locked position and the hook-up nipple is released. The hydraulic pressure is relieved by the displacement of the piston which exposes a relief port to the annulus.
One disadvantage of the release tools, which do not use rotation and which are disclosed in U.S. Pat. Nos. 2,409,811 and 4,175,778, is that they are not integral with the crossover assembly. This is also a disadvantage of some of the rotational releasing tools such as one of the tools shown on page 991 of the aforementioned Catalog.
Another disadvantage of the prior art, is that the release assembly cannot be activated until after the gravel packing operation is completed. Therefore, it is often necessary to repeat the time consuming and costly gravel packing operation because the release mechanism fails and such failure is not detected until the gravel packing operation has been performed. For this reason, there is a need for a release device which can release the gravel pack assembly before gravel packing commences so that any failure may be detected before valuable time and money is expended. The prior art cited above discloses release tools which release the gravel pack assembly after the operation is completed.
Some prior art release tools release the gravel pack screen together with the packer used in the operation and do not provide for the release of the gravel screen only. Therefore, an operator is often limited to using the packer for the gravel pack operation as the production packer. The Baker Sand Control, Brown Oil Tool, Dowell and Texas Iron Works Tools shown in the 1982-83 Composite Catalog of Oil Field Equipment and Services at pages 992, 1459, 2522 and 7947 are limiting in that respect.
The present invention overcomes the present deficiency of the prior art.
SUMMARY OF THE INVENTION
The method and apparatus of the present invention includes a gravel pack assembly which is suspended from a work string extending from the surface to a payzone located downhole. The gravel pack assembly is suspended approximately one and a half feet above the bottom of the borehole. The gravel pack assembly includes a packer assembly, a retrievable circulating hydraulic release assembly, and a gravel screen assembly. The packer assembly includes a packer for sealing engagement with the casing and an inner mandrel disposed within the packer. The mandrel forms a annular flow passageway with the packer to provide fluid communication between the upper casing annulus and the retrievable circulating hydraulic release assembly connected thereunder.
The retrievable circulation hydraulic release assembly includes a cylindrical body with a stinger extending downwardly from its lower end, and a release piston reciprocably disposed within the body. The piston blocks fluid flow through the flow bore of the body. Slurry ports are provided through the side wall of the body above the piston to provide fluid communication between the upper flow bore of the body and the lower borehole casing annulus below the packer. Vertical veins, not in communication with the slurry ports, provide fluid communication around the piston whereby fluid may flow from the mandrel flow passageway to the flowbore of the stinger below the piston.
The gravel screen assembly includes a nipple supporting a gravel screen, a tell-tale screen disposed between two o-ring subs, and a bull plug. The nipple telescopingly receives the polished stinger of the release assembly and is connected thereto by detent balls projecting through apertures in the stinger and into engagement with an annular groove in the nipple. The detent balls are biased into the annular groove by the piston.
The release piston is held by shear screws in the engaged position. The lower end of the stinger forms a washpipe which sealingly engages the o-ring subs on the lower end of the gravel screen to prevent fluid communication between the flowbore of the washpipe and the exterior of the screen.
To disconnect the gravel screen assembly from the release assembly, a sphere is pumped down the work string and seated onto the upper end of the piston so as to close the slurry ports through the body of the release assembly. By pressuring down the work string, the shear screw holding the piston in place is sheared permitting the piston to move downwardly thereby releasing the detent balls into an annular relief recess in the piston. In the disengaged position, the slurry ports are again open to provide fluid communication between the flowbore of the work string and the lower borehole casing annulus. Further, the washpipe is open to fluid flow from the exterior of the screen as the screen drops down after disengagement. The gravel screen assembly is now disconnected from the release assembly for the gravel pack operation and drops to the bottom of the hole. The stinger remains sealingly enjoined with the hook-up nipple of the gravel screen assembly.
The gravel pack operation is then performed by pumping a slurry of gravel and carrier fluid down the work string flowbore, through the slurry ports, and into the lower borehole casing annulus. Gravel is then forced into the perforations and into the lower borehole filling the lower borehole annulus. The carrier fluid is returned to the surface through the screen, washpipe, vertical veins and upper borehole casing annulus. When the gravel packing operation is completed, the packer is released followed by reverse circulation to remove excess gravel. The packer assembly and release assembly with washpipe are then raised and removed from the well, leaving the gravel screen assembly downhole.
These and various other objects and advantages of the present invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.
The above objects are attained in accordance with the present invention by the provision of a method of gravel packing a well and for use with apparatus fabricated in a manner substantially as described in the above abstract and summary.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of the preferred embodiments of the apparatus and method of the present invention, reference will now be made to the accompanying drawings wherein:
FIGS. 1A and 1B are a cross-sectional elevation view of the gravel pack assembly of the present invention disposed in a cased borehole adjacent the formation to be completed;
FIGS. 2A and 2B are an enlarged cross-sectional view of the release assembly of the gravel pack apparatus shown in FIGS. 1A and 1B;
FIG. 3 is a cross-sectional view taken along the plane shown by line 3--3 in FIG. 2A; and
FIGS. 4A and 4B are a cross-sectional view of the gravel pack assembly and the release assembly of FIGS. 1A and 1B after the gravel screen assembly is released.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIGS. 1A and 1B showing a typical application of the present invention, there is illustrated a cased borehole 10 having a casing 12 extending through an unconsolidated formation or payzone 14 prior to the gravel packing operation. Casing 12 is cemented into borehole 10 as shown at 16. Casing 12, cement 16 and payzone 14 have been perforated as at 18 to provide flow communication between the flowbore of casing 12 and payzone 14 for the flow of hydrocarbons from payzone 14 to the production tubing (not shown) when production commences.
In accordance with the procedure of the present invention, a gravel pack assembly 20 is lowered into the cased borehole 10 on a work string 28 until assembly 20 is a predetermined distance, such as approximately one to one and a half feet, above the preferred location of assembly 20 with respect to the perforated payzone 14 for the gravel pack operation. Although gravel pack assembly 20 is shown in FIG. 1 approximately one and a half feet above the cement bottom 27 of cased borehole 10, a bridge plug (not shown) may be used as borehole bottom 27 for properly locating and operating gravel pack assembly 20.
Gravel pack assembly 20 includes a packer assembly 22, a retrievable circulating hydraulic release assembly 24 and a gravel screen assembly 26.
The packer assembly 22 is connected to the work string 28 which extends to the surface (not shown) and includes an upper ported sub 42, an upper joint 39, a packer liner mandrel 38, a packer 32, and a lower pup joint 30. Packer 32 may be a retrievable packer, such as an R-type retrievable casing packer, well known in the art, and no further description of its assembly or operation will be provided. Packer 32 is provided for sealing engagement with casing 12 to form an upper casing annulus 34 and a lower casing annulus 36, best shown in FIG. 4A. The pack-off or packer elements of packer 32 is disposed around packer liner mandrel 38 and between joint 39, at the upper end of mandrel 38, and lower pup joint 30. Mandrel 38 extends downwardly through pup joint 30 and is received by release assembly 24 as hereinafter described.
An annular fluid passageway 40 is formed between packer liner mandrel 38 and packer 32 and extends from the interior of pup joint 30 to radial ports 44 in ported sub 42 thereby providing fluid communication between upper casing annulus 34 and the lower end of pup joint 30. Fluid passageway 40 and ports 44 permit a fluid bypass around packer 32 in its actuated position shown in FIG. 4A whereby fluid flow can be provided between the surface, via upper casing annulus 34, and retrievable circulating hydraulic release assembly 22 and gravel screen assembly 26 disposed below packer 32.
Referring now to FIGS. 1A, 1B, 2A, and 2B showing retrievable circulating hydraulic release assembly 24, assembly 24 includes an upper connecting sub 46, an intermediate crossover sub 48, a lower sub 50, a polished stinger 52 and an inner release piston 54.
Upper connecting sub 46 includes a cylindrical body having a cylindrical bore 64 therethrough and a threaded box 56 mating with the threaded pin end 57 of pup joint 30 shown in FIG. 1A. Bore 64 of sub 46 receives the lower end portion 41 of packer liner mandrel 38 with O-ring seals 74 disposed in annular grooves 78 for sealing engagement with mandrel end portion 41. A threaded box 58 is provided on the lower end of sub 46 for threadingly receiving the matingly threaded pin end 68 of crossover sub 48.
Crossover sub 48 also has a cylindrical body with pin end 68 at its upper end and a threaded pin end 66 at its lower end. The body of sub 48 includes a common bore 86 of the same diameter as bore 64 of connecting sub 46. An enlarged diameter portion of sub 48, adjacent lower pin end 66, forms a lower annular chamber 96.
A plurality of coaxial fluid veins 82 extend vertically through the walls of connecting sub 46 and crossover sub 48. Inner and outer seals 60, 62 are provided at the connection of subs 46, 48 to seal the flow path of veins 82 therethrough. Alignment of fluid veins 82 at the connection of subs 46, 48 is provided by a shoulder to shoulder connection with O-ring sealing backups. The upper ends of veins 82 communicate with an upper annular chamber 84 in connecting sub 46 which extends radially from the upper ends of veins 82 to the interior of connecting sub 46. Packer liner mandrel 38 extends beyond annular chamber 84 in sub 46, with seals 74 disposed below chamber 84, to provide fluid communication between chamber 84 and fluid passageway 40. Thus veins 82 are in fluid communication with the surface. The lower ends of veins 82 communicate with lower annular chamber 96 in crossover sub 48.
Referring now to FIGS. 2A and 3, crossover sub 48 further includes one or more slurry ports 90 providing fluid communication between bore 86 and lower casing annulus 36. Slurry ports 90 are not in fluid communication with veins 82 since ports 90 are not in the same plane as shown in FIG. 3.
Referring again to FIGS. 2A and 2B, lower sub 50 includes a cylindrical body having an upper threaded box 92 receiving and threadingly engaging the lower pin 66 of crossover sub 48. An O-ring seal 88 is disposed in an annular groove in box 92 for sealing the connection between subs 48 and 50. Box 92 forms an upwardly facing shoulder 94 forming one side of annular chamber 96. Sub 50 has a bore 98 with a diameter common to that of bores 64, 86 of subs 46, 48 respectively.
A lower threaded box end 80 is provided for connection with polished stinger 52. Lower sub 50 also includes a radial bore 100 extending through the wall thereof for housing a shear screw 102 for positioning piston 54 as hereinafter described.
Polished stinger 52 disposed on the lower end of sub 50 includes a cylindrical element having a bore 104 with a diameter equal to the diameter of bores 64, 86, 98. The upper exterior end of stinger 52 is threaded at 106 for threaded engagement with the lower box end 80 of sub 50. The upper end of stinger 52 abuts a lower shoulder formed by box end 80 of sub 50. The cylindrical element of stinger 52 includes a reduced diameter portion 112 above its lower end to form an upwardly facing conical portion or valve seat 108 adapted to receive and seal with a ball valve 110. The lower end of stinger 52 extends downwardly into and is telescopically received by gravel screen assembly 26. Stinger 52 also includes a plurality of apertures 114 extending through the wall of stinger 52 for receiving detent balls 116, and an inwardly projecting annular shoulder 118. The purpose of detent balls 116 and shoulder 118 will be hereinafter described.
Internal release piston 54 has an outer cylindrical surface 120 for the sliding reception of piston 54 within crossover sub 48, lower sub 50 and stinger 52. Piston 54 is held in position by shear screw 102 mounted in lower sub 50 and projecting into a blind bore 122 in the outer surface 120 of piston 54. A cavity 124 is provided in the upper end of piston 54 forming an upwardly facing conical actuator seat 126 for receiving an actuator sphere 128. A plurality of spring fingers 130 project upwardly from piston 54 and have radially directed flanges 132 for providing a latching engagement with a fishing tool (not shown).
Slurry ports 134 are provided in the upper end of piston 54 which extend from cavity 124 to the outer surface 120. In the engaged position shown in FIGS. 1A, 1B, 2A and 2B with shear screw 102 in place, slurry ports 134 of piston 54 are in alignment with slurry ports 90 of crossover sub 48.
Piston 54 includes a solid rod-like upper body portion or plug 140 disposed below cavity 124 and a lower cylindrical body portion 142 forming a downwardly extending blind bore 136 with a downwardly facing bottom end 138. The upper body portion or plug 140 of piston 54 blocks and prevents fluid flow through bore 86 of crossover sub 48. Circulation ports 144 are provided through the cylindrical walls of lower body portion 142 near bore bottom 138 for providing fluid communication between blind bore 136 of piston 54 and annular chamber 96 of crossover sub 48. Thus, upper body portion 140 directs flow down the flowbore 146 of mandrel 38 and bore 64 of connecting sub 46 through slurry ports 134 and 90 into lower borehole annulus 36 and directs flow up the gravel pack assembly 26 and bore 136 of piston 54 through circulation ports 144 and up veins 82 to the surface via upper casing annulus 34. Upper O-ring seals 148, 150 are disposed in the periphery of lower cylindrical body portion 142 for sealingly engaging lower sub 50, O-ring seal 148 becoming sealingly engaged in the non-engaged position of piston 54. Lower O-ring seals 152 are provided in the periphery adjacent the lower end of cylindrical body portion 152 for sealing engagement with stinger 52.
A snap ring 156 is provided in an annular groove 158 located below slurry ports 134 in the external periphery of piston 54 for engagement with the downwardly facing annular shoulder 140 on crossover sub 48, forming the upper side of lower chamber 96, when piston 54 is in the lower non-engaged position hereinafter described in further detail.
That portion of the lower cylinder body portion 142 of piston 54 received within stinger 52 includes an annular relief recess 160 which is disposed above apertures 114 and detent balls 116 in the engaged position of piston 54, and an annular notch 162 disposed below apertures 114 for housing detent balls 116 during the assembly of release assembly 24. That portion of body portion 142 between notch 162 and recess 160 provides a biasing means for biasing detent balls 116 in the attached position, hereinafter described, for connecting release assembly 24 to gravel screen assembly 26.
When the retrievable release assembly 24 is lowered into the well for gravel packing, piston 54 is intimately disposed within bores 86, 98, and 104 formed by crossover sub 48, lower sub 50 and polished stinger 52, respectively, in the unreleased or engaged position as shown in FIGS. 1A, 1B, 2A and 2B. It is retained there by shear screw 102 which is disposed in radially aligned bores 100 and 122. In that position, slurry ports 134 are aligned with slurry ports 90; circulating ports 144 are aligned with annular chamber 96; and annular relief recess 160 and annular notch 162 are respectively above and below apertures 114 whereby detent balls 116 are maintained in a position extending beyond outer surface 164 of polished stinger 52 and into groove 194 of hook-up nipple 170. Also, in the unreleased or engaged piston position, the outer cylindrical surface of plug 140 is in intimate contact with bore 86 of crossover sub 48 whereby snap rings 156 are retained within grooves 158. O-ring seal 150 provides a sealing engagement between piston 54 and lower sub 50 thereby preventing the leak of any fluids from annular chamber 96 through apertures 114. Also O-ring seals 152 provide a sealing engagement between piston 54 and stinger 52 preventing leaks from bore 112 through apertures 114.
As shown in FIG. 1B, hook-up nipple 170 and blank pipe 172 have centralizers 190, 192, respectively, mounted thereon to centrally locate the gravel screen assembly 26 within lower casing annulus 36 to facilitate the gravel pack operation. Further, it can be seen that nipple 170 telescopingly receives a substantial portion of stinger 52 and is mounted thereon by detent balls 116 radially projecting through apertures 114 and into an annular groove 194 in the inner periphery of hook-up nipple 170.
Upper and lower O-ring subs 176, 180 include O-rings 196, 198, respectively, for sealingly engaging the outer surface of polished end of washpipe 186. With subs 176 and 180 being disposed above and below tell-tale screen 178, fluid flow through screen 178 is effectively blocked.
Referring still to FIG. 1B, the gravel screen assembly 26 includes a hook-up nipple 170, a blank pipe 172, one or more main screens 174, an upper O-ring sub 176, a tell-tale screen 178, a lower O-ring sub 180, an extension sub 182, and a bull plug 184. Washpipe 186 extends through the bore 188 formed by nipple 170, pipe 172, screen 174, sub 176, screen 178, sub 180, and extension sub 182. Washpipe 186 is connected to the lower end of stinger 52 or is integral therewith and extends downwardly into extension sub 182. Tell-tale screen 178, as is well known in the art, permit the flow therethrough of the carrier fluid for the gravel slurry and main screen 174 permits the flow of production fluids from the formation 14 after gravel packing.
In operation, the gravel pack assembly 20 is lowered into the well on work string 28 until bull plug 184 tags bottom 27 set at a predetermined depth. After tagging bottom 27, the gravel pack assembly 20 is raised so that bull plug 184 is approximately one to one and a half feet above bottom 27 as shown in FIGS. 1A and 1B. Fluid is then pumped from the surface down the flowbore of work string 28 and flowbore 146 of packer liner mandrel 38. The fluid continues to flow through bore 64 of connecting sub 46 and through slurry ports 134, 90 and into the lower borehole annulus. The immediately preceding flow path may be called the "downward flow path." The circulating fluid then returns up upper casing annulus 34 to the surface to remove any debris present in its path. The packer 32 has not yet been set.
Referring now to FIGS. 4A and 4B, following circulation for the removal of debris, packer 32 is set to sealingly engage casing 12 and form upper and lower annulus 34, 36. Packer 32 is then tested by pressuring fluid down upper casing annulus 34 with ball valve 110 closed. If packer 32 is not set properly for sealing engagement with casing 12, fluid will flow around packer 32 into lower casing annulus 36. The leaking fluid will return to the surface via slurry ports 90, 134, shown in FIG. 2A, and up the flowbores of mandrel 38 and work string 28, signaling to the operator that packer 32 has failed. If no leak is detected within the flowbore of work string 28, the implication is that packer 32 has set properly and the remaining steps of the operation are carried out.
In testing packer 32, ball valve 110 is closed and prevents fluid flow into that portion of the flowbore of washpipe 186 located below valve 110. This is accomplished automatically in testing packer 32 because, as pressure is applied down upper casing annulus 34, the fluid pressure is displaced down flow passageway 40, veins 82, and into that portion of flowbore 112 above sphere 110 to hold sphere 110 in sealing relationship with valve seat 108. This arrangement allows the operator to retest the packer in any stage of the gravel packing operation i.e. whether tell-tale screen 178 is open or not.
Following packer testing, a pressure squeeze acidizing operation may be performed. Acid stimulation may provide dramatic improvement in the production of payzone 14. Therefore, in many instances it is desirable to inject acid in the perforations and the permeability system of the formation. This is done by pressuring acid downhole into the formation. In the instant case, acid is pumped down the downward flow path and into lower casing annulus 36 adjacent payzone 14. Because the return path to the surface through upper casing annulus 34 is closed by packer 32 and washpipe 186, the acid penetrates the formation to a great extent and removes debris and any other inhibitors thereby enhancing the production from payzone 14. Following the acid squeeze, the remaining fluid is pumped out of the system and the well is ready for gravel packing. It is desired that the acidizing operation be carried out with washpipe 186 blocking tell-tale screen 178 and therefore, before releasing gravel screen assembly 20 so that casing 12 in upper annulus 34 is not exposed to the high pressure present in the acid squeeze operation.
In the present invention, main screen 174 and its accessories, including hook-up nipple 170, blank pipe 172, tell-tale screen 178, subs 176, 180, 182 and bull plug 184, are released from the release assembly 24 before the gravel packing operation is commenced. In other release tools the screen is released after the gravel packing operation is completed. This often presents a significant problem because release mechanisms fail for numerous reasons, thereby forcing the operator to raise the gravel pack screen and destroy the completed gravel pack. With the present invention, the operator is assured, before the time consuming and costly gravel packing operation is commenced, that the release mechanism has not failed and that he will not have to repeat the operation.
The retrievable circulating hydraulic release assembly 24 is activated by dropping or pumping a steel ball 128 down the flowbore of work string 28 to land on ball seat 126. The flowbore of work string 28 is then filled with liquids and additional pump pressure is applied from the surface to actuate piston 54. Steel ball 128 and ball seat 126 are intimately engaged and prevent the flow of fluids out of the flowbore of work string 28 via slurry ports 134, 90. Therefore, fluid pressure may be applied to internal release piston 54. When the pressure exceeds a predetermined amount, shear screw 102 shears and piston 54 is displaced downwardly until it engages shoulder 118. As piston 54 moves downwardly, annular relief recess 160 becomes adjacent to and aligned with apertures 114 and the intimate biasing contact between piston 54 and detent balls 116 disposed in apertures 114, is terminated. Detent balls 116 are biased inwardly by the weight of the gravel pack assembly 26, and balls 116 move into annular relief recess 160, thereby releasing hook-up nipple 170 and permitting the gravel screen assembly 26 to slide downwardly until bull plug 184 hits bottom 27. As gravel screen assembly 26 moved downwardly, washpipe 186 remained stationary whereby seal 198 of lower O-ring sub 180 sealingly disengaged washpipe 186 to open tell-tale screen 178 to fluid flow.
FIGS. 4A and 4B show the environment of the present invention and retrievable circulating hydraulic release assembly 24, after release assembly 24 has been activated and has released gravel screen assembly 26. The downward displacement of piston 54 to shoulder 118, shown in FIG. 2A, has caused, as previously explained, annular relief recess 160 to move adjacent apertures 114, detent balls 116 to be displaced towards relief recess 160 and hook-up nipple 170 and its attachments to slide downwards and hit bottom 27 through bull plug 184. In this position, hook-up nipple 170 has moved below apertures 114. However, it is still in a sealing engagement with polished stinger 52 via rolling seals 148 because stinger 52 has sufficient length, i.e. over one to one and half feet, projecting into hook-up nipple 170 to maintain the sealing engagement with sealing means 148. Then the upper portion of piston 54, including ball seat 126, and steel ball 128 seated thereon, have moved below slurry ports 134, 90 whereby fluid communication is again established between the flowbore of work string 28 and lower casing annulus 36. Also, even though it is in a lower position, circulating port 144 remains adjacent and in fluid communication with annular chamber 96. Because seal 150 has been displaced to a lower location, it no longer provides sealing between piston 54 and that portion of bore 98 which is above bore 112. Sealing for these two surfaces is now provided by seal 148. In the unreleased position, seal 148 was adjacent annular chamber 96 and therefore, it was not in a sealing engagement with any surface. Furthermore, in the released position, annular grooves 158 have moved adjacent annular chamber 96 causing snap rings 156 to engage shoulder 140 thereby preventing a premature upward displacement of piston 54.
Following the release of gravel screen assembly 26, the gravel packing operation commences. Referring again to FIGS. 4A and 4B, carrier fluid containing gravel is pumped down the downward flow path. The fluid with the suspended solids enters the flowbore of work string 28 and flows to lower casing annulus 36 and through slurry ports 134, 90, shown in FIG. 2A, and down lower casing annulus 36 where the gravel is forced into perforations 18 and begins to accumulate starting from the bottom and progressing towards the top. The solid free carrier fluid continues its flow through tell-tale screen 178, washpipe 186, valve 108, bore 112, circulating ports 144, annular chamber 96, veins 82, chamber 84, flow passageway 40, port 44 and up through upper casing annulus 34 to the surface. This flow path may be called the "upward flow path." Once the gravel level is above tell-tale screen 178, a gravel pressure squeeze operation may be performed to force the gravel into perforation 18 and to increase the packing density. If the pressure resistance by the gravel accumulated around tell-tale screen 178 is not adequate for the pressure squeeze operation, the return of the carrier fluid to the surface through upper casing annulus 34 may be closed by closing the rams in the blow out preventer at the surface, whereby the pressure resistance is increased. When the gravel level in lower casing annulus 36 reaches a certain point above screen 174, the slurry circulation is discontinued. Packer 32 is then unset followed by reverse circulation of fluid down upper casing annulus 34, lower casing annulus 36, slurry ports 134, 90 and up the flowbore of work string 28 to remove excess gravel. Following reverse circulation, the gravel packing operation is completed and the gravel pack assembly including work string 28, packer assembly 22 and retrievable circulating hydraulic release assembly 24 with the attached valve seat 108, sphere 110 and washpipe 186 is raised and removed from the well. Screen 174 and its attachments hook-up nipple 170, blank pipe 172, subs 176, 180, 182, tell-tale screen 178 and bull plug 184 remain downhole with the packed gravel. The well may then be completed and production may be commenced immediately.
Another embodiment of the present invention is identical to the embodiment described above except in that it does not include an O-ring 198, an O-ring sub 180 and a portion of washpipe 186 blocking tell-tale screen 178 before gravel pack assembly 20 is released. In this embodiment gravel screen assembly 20 may be released either before or after the gravel packing operation and it is not necessary that gravel screen assembly 20 be raised after bull plug 184 tags bottom 27 at the commencement of the operation. In general, because washpipe 186 does not block tell-tale screen 178, this embodiment may not be used when acidizing operation is required. However, if casing 12 in upper annulus 34 is relatively new and can withstand high pressure, acidizing may be performed with this embodiment by closing the rams in the blow out preventer at the surface to provide the required pressure resistance for the acidizing operation.
While preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit of the invention. | A well apparatus connected to a pipe string extending down into a cased borehole for treating a formation comprising a packer assembly for sealing with the casing assembly and an integral crossover/release assembly attached to the packer assembly for supporting and releasing a gravel screen assembly before or after treating the formation without rotating the pipe string. The crossover/release assembly includes crossover ports providing a downward flow path for the treating fluid, annular veins providing an upward flow path for the returns, and a reciprocating piston reciprocating upon effecting hydraulic pressure on the piston for releasing the gravel screen assembly. | 4 |
FIELD OF THE INVENTION
The invention relates to a thermally insulated building brick, which brick comprises a structural body with at least one cavity and a thermally insulating filling arranged in the cavity, and further the invention relates to a method for providing a thermally insulated building brick.
BACKGROUND OF THE INVENTION
Although new building materials and building methods have been introduced in the past decades, traditional building bricks are still used and valued. A disadvantage of ordinary building bricks is however that the insulating value is mediocre, which with increasing cost of energy and focus on environment is a major disadvantage. Different attempts have been made to improve the insulation value of building bricks.
At present there are several types of insulated building bricks available on the market. One of these bricks is the Unipor Coriso, which is a brick filled with mineral granulate, and an example of a mineral wool filled brick is known under the trade name MZ8 from Mein Ziegelhaus. Other examples include bricks with a filling of perlite (e.g. Poroton-T8/-T9 from Wienerberger).
Patent literature does also include different concepts for insulated building bricks. One example can be found in GB Patent No. 461,314, which relates to a brick filled with an insulating filling, such as glass wool. This is a traditional building brick filled with traditional insulation materials at the time of filing of this patent more than 80 years ago, and this brick does not meet the demands for modern building bricks in terms of insulation properties and is not suited for mass production.
A more modern example is the building brick according to EP 1 752 593 A2. This building brick has a substantially cubic body comprising a plurality of cavities divided by walls and filled with insulating filling. This prior art building brick does provide state of the art insulation properties, but cannot meet future demands on insulation properties, and further is not perfectly suited for mass production.
DE 20 2007 013 074 U1 discloses vacuum insulation panels having very high insulation value. The vacuum insulation panel comprises a micro-porous core material e.g. a silica-aerogel, possibly with reinforcing fibres, such as inorganic fibres e.g. mineral wool fibres. The core material is arranged in a wrapping, evacuated and provided with an air-tight metal casing, such as an aluminium foil. It is mentioned, but not otherwise supported that the panels can be mounted in cavities of a hollow brick. The resulting brick has a high insulation value, but it is, however, an expensive solution and not suited for mass production. Further the vacuum insulation panel is fragile and subject to damage during mounting in the relatively narrow cavities of a hollow brick. The wrapping and film could for example easily be scratched, whereby the vacuum would be lost and the insulation properties reduced. Such likely damages to the insulation panel will destroy or reduce the insulation properties of the brick. Conventionally such vacuum insulation panels are filled with aerogel for the aerogel to function as an air-absorbent, which will, however, reduce the insulation value of the panel over time.
SUMMARY OF THE INVENTION
An object of the invention is hence to provide an alternative insulated building brick which allows for mass production.
This object is achieved with a thermally insulated building brick according to the introduction, wherein the insulating filling comprises an insulating material arranged in a leading-in sheath. The leading-in sheath will enable easy fitting of the insulating filling in the cavity without damaging the insulating material, thereby facilitating mass production. The insulating filling is adapted to have a first size during installation in the insulated building brick and a second size after installation in the insulated building brick, said sizes being substantially stable and the first size being smaller than the second size.
Normally, the leading-in sheath will be a sheath which mechanically restricts at least one dimension of the insulating filling to allow it to fit into the cavity of the brick. In particular, the restriction on the at least one dimension may be capable of being removed to allow the insulating filling to exert pressure on the inner surface of the cavity of the brick.
The insulating material could be any suitable material having high thermal insulation properties as will be considered by the skilled person. According to an embodiment the insulating material comprises at least one silica-based thermal insulator selected from the group consisting of aerogel, fumed silica and precipitated silica, which are all known to have very good insulation properties. Aerogels are known to have extraordinary insulating properties, but at a high cost. Fumed silica and precipitated silica have lower insulating properties (approximately 22-23 mW/m*K), but at a lower price.
In the present context aerogel should be understood as any of the dried gel products, commonly known as aerogels, xerogels and cryogels. These products are known to have excellent insulating properties, owing to their very high surface areas, high porosity and relatively large pore volume. They are manufactured by gelling a flowable sol-gel solution and then removing the liquid from the gel in a manner that does not destroy the pores of the gel.
Depending on the drying conditions, aerogels, xerogels or cryogels can be made. Where the wet gel is dried at above the critical point of the liquid, there is no capillary pressure and therefore relatively little shrinkage as the liquid is removed. The product of such a process is very highly porous and is known as an aerogel. On the other hand, if the gel is dried by evaporation under subcritical conditions, the resulting product is a xerogel composite. Although shrinkage is unhindered in the production of a xerogel, the material usually retains a very high porosity and a large surface area in combination with a very small pore size.
When the gel is dried in a freeze-drying process, a cryogel is obtained. These conventional aerogel, xerogel and cryogel products, although good insulators, are fragile, susceptible to cracking and require a long processing time.
The term aerogel should also be interpreted as aerogel, xerogel or cryogel products, which additionally comprise a matrix of fibres, the matrix serving to reinforce the material, thereby providing high-strength products. These materials are known as aerogel, xerogel and cryogel matrix composites and are commonly produced in the form of mats, which are typically manufactured by impregnating the reinforcing fibres with a flowable sol-gel solution, gelling and then removing the liquid from the gel in a manner that does not destroy the pores of the gel. Supercritical drying, subcritical drying and freeze-drying result respectively in aerogel, xerogel and cryogel matrix composites.
Aerogels may have a thermal conductivity (λ-value) of e.g. 9-22 mW/m·K, whereas mineral wool may have a thermal conductivity (λ D -value; based on measurements in accordance with European Standard EN 12667 at a reference mean temperature of 10° C.) of e.g. 30-40 mW/m-K, so with addition of aerogels to bricks it is possible to achieve better insulation properties of the building bricks. For comparison perlite will have a thermal conductivity (λ-value) of 45-60 mW/m·K.
The insulating material could be substantially incompressible and the leading-in sheath could be any kind of wrapping of the insulating filling in part or in total to facilitate introduction into the cavities of the brick. According to an embodiment, however, the insulating material is compressible and the leading-in sheath is a substantially gas impermeable film arranged as an enclosure around the insulating material. By compressible should be understood that the insulating material can be compressed by at least 5%, preferably at least 10% of its volume or nominal thickness, without substantial damage to the insulating material. By substantially gas impermeable should be understood that the film will restrict gas flow to such an extent that the film will allow a pressure difference, such as 50 kPa, across the film to be maintained for at least 10 minutes, preferably at least 1 hour. Hereby it is possible to at least partially evacuate the enclosure, whereby the enclosure and the insulating material will compress and thereby enable easy fitting of the insulating filling in the cavity of the brick.
A total enclosure of the insulating material further has the advantage that a loose insulating material can be used without risk of insulating material escaping the cavity, any potential dust problems during manufacture etc.
It could be an advantage if the pressure difference is maintained for a significant period, such as at least a week, as the insulating filling could hence be compressed for cost-efficient transport and storage and still be compressed at time of introduction into the cavities of the brick. On the other hand it could be advantageous for the pressure difference to be neutralized quickly, e.g. within a few minutes or shorter, for the insulating filling to expand quickly after being introduced into the cavity. This would eliminate the need for perforating the film to expand the insulating filling in the cavity for securing the insulating filling in the cavity.
The insulating filling may be sized to the corresponding cavity of the brick to provide a loose fit, which will enable easy fitting of the element in the cavity. According to an embodiment, however, the size of the insulating filling is adapted for a tight fit in the corresponding cavity. This is a particularly simple and cost effective way of anchoring the filling in the cavity of the brick. A further advantage is that the insulation and fire properties of the brick are not influenced by any additional adhesive or binder for bonding the insulating filling to the brick. With a tight fit the insulating filling will be held in place in the cavity by friction between the insulating filling and the cavity walls.
The insulating filling may further comprise additional materials, such as organic or inorganic fibres. According to an embodiment the insulating filling comprises mineral fibres, such as glass fibres, stone fibres or slag fibres, which can provide extra strength to the filling.
The insulating filling is adapted to have a first size during installation in the insulated building brick and a second size after installation in the insulated building brick, said sizes being substantially stable and the first size being smaller than the second size. By size should be understood any dimension (length, width, height), which has an impact on the ease of fitting the insulating filling in the cavity of the brick. As an example the insulating filling may be compressed to have a smaller width, if the width of the insulating filling determines whether it fits into the cavity, whereas other dimensions may be unchanged or even increased. As an example the insulating filling may be stretched longer to have a smaller width, to allow easy installation, if the width of the insulating filling determines whether it fits into the cavity, whereas the length has no influence.
A binder may be added to the insulating material of the insulating filling if considered advantageous. The binder may be organic or inorganic. An example of an inorganic binder is water glass, which has good fire properties.
The brick may comprise a single cavity, but according to an embodiment the brick comprises a plurality of cavities, and all cavities are filled with insulating filling. Hereby a high strength brick with high insulation value is provided. To provide high strength the brick should be as massive as possible, whereas to provide good insulation value the brick should be filled with as much insulation material as possible.
The brick could be any kind of building brick made of any kind of material, e.g. burnt clay, concrete, cellular concrete etc. According to an embodiment the structural body is made of mainly lime (CaO) and sand (SiO 2 ), resulting in a so-called sand-lime brick. The production method of these bricks will provide the advantage that curing of the bricks may take place in an autoclave at relatively low temperatures of around 200° C. Thereby it is possible to arrange the insulating filling in the cavity of the brick before curing of the brick, which may facilitate cost efficient production.
The invention also relates to a method for providing a thermally insulated building brick, said method comprising the steps of providing a structural body having at least one cavity, providing an insulating filling comprising an insulating material arranged in a leading-in sheath, and arranging the insulating filling in the cavity. With this method a brick having high insulation value can be produced effectively, as the insulating filling will be easier to install in the cavity due to the leading-in sheath, and further the insulating filling will be protected during installation in the cavity, which might otherwise pose damage to the insulating filling.
The insulating material could be substantially incompressible and the leading-in sheath could be any kind of wrapping of the insulating filling in part or in total to facilitate introduction into the cavities of the brick. For example insulating filling could be provided in roll-form and the leading-in sheath could be a belt to keep the roll form during introduction in the cavity. After introduction the belt could be cut to enable the roll to expand to fit the cavity. According to an embodiment, the insulating material is compressible and the leading-in sheath is a substantially gas impermeable film arranged as an enclosure around the insulating material, and the method comprises the intermediate step of applying reduced pressure to the enclosure. This enables a particularly efficient way of introducing the insulating filling as the filling is compressed during fitting and can subsequently expand to completely fill the cavity.
According to an embodiment the method comprises the further step of at least partly releasing the reduced pressure of the enclosure, whereby the insulating filling will instantly expand to fill the cavity.
According to an embodiment the method comprises the step of providing the insulating material by selecting at least one silica-based thermal insulator from the group consisting of aerogel, fumed silica and precipitated silica, whereby a brick with high thermal insulation value can be achieved.
The brick could have any suitable dimension as would be understood by the skilled person.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail in the following by way of example and with reference to the schematic drawings in which:
FIG. 1 is a perspective view of a hollow building brick;
FIG. 2 is a sectional view of a hollow building brick at insertion of a thermally insulating filling;
FIG. 3 is a cross-sectional view of a thermally insulating filling for a brick;
FIG. 4 is a cross-sectional view of an alternative thermally insulating filling;
FIG. 5 is a top view of the thermally insulating filling;
FIG. 6 a is a side view of the thermally insulating filling;
FIG. 6 b is a side view corresponding to FIG. 6 a , with the thermally insulating filling under compression;
FIG. 7 shows a step during insertion of the thermally insulating filling in a brick;
FIG. 8 shows a step after insertion of the thermally insulating filling in the brick; and
FIG. 9 shows a final step of expansion of the thermally insulating filling in the brick.
DESCRIPTION OF PREFERRED EMBODIMENTS
A building brick 1 is shown in FIG. 1 , which brick 1 comprises a structural body 2 with a cavity 8 . The structural body 2 of the brick according to this simple embodiment is a traditional building brick made of burnt clay. FIG. 2 illustrates a step of inserting a thermally insulating filling 3 in the cavity 8 of the brick 1 . The thermally insulating filling 3 is compressed from a second size 6 (shown in dashed line) to a first size 5 for installation of the filling 3 in the cavity 8 . As can be seen the first size 5 has a smaller dimension d than the dimension D of the cavity 8 .
FIG. 3 illustrates a thermally insulating filling 3 in cross-sectional view. The thermally insulating filling 3 comprises an insulating material, which is arranged in a leading-in sheath. In the present embodiment the leading-in sheath is in the form of a band 7 a wrapped around the insulating material, and holding the insulating material in a compressed state for easy introduction in the cavity. The insulating material could in this embodiment be provided in roll form. After introduction in the cavity the band 7 a could be torn for the thermally insulating filling to expand to fill the cavity (not shown).
An alternative leading-in sheath in the form of an encapsulating film 7 b is shown in the cross-sectional view of FIG. 4 . With an encapsulating film 7 b it is possible to at least partially evacuate the interior of the filling 3 , thereby compressing the filling for easy introduction in the cavity of the brick.
Evacuation of the filling 3 can be done in a number of ways. One simple example is shown in FIG. 5 , which is a top view of a cylindrical thermally insulating filling 3 in an encapsulating film. The encapsulating film has an opening 9 , which can be used for evacuation purposes. Alternatively the encapsulating film 7 b of the thermally insulating filling could be provided with a suitable valve.
Compression of the thermally insulating filling 3 by evacuation is illustrated in the schematic side views of the thermally insulating filling 3 in FIGS. 6 a and 6 b . In FIG. 6 a the thermally insulating filling 3 is shown in the uncompressed state, whereas in 6 b the thermally insulating filling 3 is compressed to a smaller size by means of a suction device 10 connected to the opening 9 . The smaller size is shown in full-drawn line, whereas the uncompressed size is shown in dashed line.
Insertion of the thermally insulating filling 3 is shown in the cross-sectional view of FIG. 7 . In the illustrated example the suction device 10 is still connected to the thermally insulating filling 3 for constant evacuation in order to keep the insulating filling compressed. In this case the suction device 10 may be a suction disc forming part of a transport device for grasping, compressing and inserting the thermally insulating filling 3 in the cavity. When disconnecting the suction device 10 , the compressed thermally insulating filling 3 would expand to fill the cavity.
Alternatively the suction device 10 could be used only for evacuation/compression of the thermally insulating filling 3 , whereupon the opening 9 of the encapsulating film 7 b could be sealed off to maintain compression. In this case it may be necessary to puncture the encapsulating film 7 b , e.g. using a pointed tool 11 as shown in FIGS. 8 and 9 for the thermally insulating filling 3 to expand to fill the cavity of the brick 1 . Alternatively the encapsulating film 7 b or the seal covering the opening 9 , could be gas permeable, so the vacuum inside the thermally insulating filling 3 would be lost in relatively short time, e.g. a few minutes or hours, so the insulating filling 3 would slowly expand to the second size 6 after installation in the cavity.
Although the leading-in sheath will normally have a limited thickness, and hence only a limited influence on the thermal properties of the brick with insulating filling, it is preferred that the sheath is made of a material with low thermal conductivity, or alternatively that the sheath is removed after installation of the insulating filling. | A thermally insulated building brick ( 1 ) and a method for production thereof, wherein the brick comprises a structural body ( 2 ) with at least one cavity ( 8 ) and an insulating filling ( 3 ) arranged in the cavity. To provide a brick with high insulation value suited for mass production, the insulating filling comprises an insulating material arranged in a leading-in sheath. | 4 |
RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/803,281, entitled “Refuse Cart Lifter With An Improved Range Of Rotation” (Attorney Docket 14893US02), filed Mar. 18, 2004, which makes reference to, claims priority to, and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/455,546, entitled “Refuse Collection Cart Lifter With An Improved Range Of Rotation” (Attorney Docket 14893US01), filed Mar. 18, 2003, the complete subject matter of which is hereby incorporated herein by reference in its entirety.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] [Not Applicable]
[MICROFICHE/COPYRIGHT REFERENCE]
[0003] [Not Applicable]
BACKGROUND OF THE INVENTION
[0004] The present invention relates to refuse container lifting devices, and in particular to refuse cart lifting devices. Refuse containers are often quite heavy, and therefore refuse collection vehicles are generally equipped with refuse container lifting devices to assist the vehicle operator when emptying the refuse containers. However, a refuse collection vehicle may encounter several different types of refuse containers on a given collection route, and the differences in these refuse containers often require the use of separate lifting devices. For example, large commercial refuse containers, or dumpsters, are typically emptied by tipping the container over the edge of the vehicle hopper using a variety of lifting devices, including tipper bars and cable and winch arrangements.
[0005] Refuse carts are relatively light refuse receptacles constructed from various plastics and other synthetic materials. Features of refuse carts may include for example hinged covers, locking covers, wheels, and handles in various locations and configurations. Capacities generally range for example from 30 gallons to 95 gallons. Refuse carts typically encountered in residential areas are emptied using a refuse cart lifter capable of engaging the refuse cart, lifting it, and inverting the refuse cart to empty refuse into the vehicle hopper.
[0006] Many prior refuse cart lifters present a wide profile and thus protrude from the refuse collection vehicle so as to interfere with the emptying of commercial dumpsters when they are tipped over the edge of the vehicle hopper. Protruding cart lifters also created a hazard for the rear-loading refuse collection vehicle driver when backing up, and the side-loading refuse collection driver when navigating narrow roadways, such as alleys. Some lifter designs have addressed this problem by locating the lifter off to the side of or even completely beneath the refuse collection vehicle hopper. Others attempted to reduce the profile of the refuse cart lifter to address the lifter protrusion issue.
[0007] Another problem in the refuse cart lifter industry is that cart lifters typically hang down from the refuse collection vehicle, and therefore reduce the vehicle's ground clearance, particularly on uneven ground. Thus, some lifter designs include a retracted position where the lifter faceplate is angled underneath the refuse collection vehicle hopper, rather than hanging straight down.
[0008] Yet another issue involves refuse compaction cycles. Prior cart lifters continuously dump refuse into the portion of the vehicle hopper closest to the refuse cart lifter because these lifters cannot empty the refuse cart a substantial distance into the hopper when dumping. The refuse therefore quickly accumulates near the refuse cart lifter, which requires the vehicle operator to stop collecting carts and compact the refuse to prevent interference with the next lifter dumping cycle. Thus, a lifter that empties refuse carts further into the refuse collection vehicle hopper would decrease the amount of time and energy spent compacting refuse between refuse cart dumping.
[0009] A further issue involves maintenance of the lifter. Elevated hydraulic loads associated with some lifters correspond to increased wear and strain on cart lifter systems. Also, some lifter motor designs are readily susceptible to damage from contaminants present in the hydraulic system and eventually require complex repairs or rebuilding that can typically only be performed at the manufacturer's facility. Many lifters also use bearings that require regular greasing.
[0010] A separate issue involves the effect of varying dimensions associated with lifting points on the refuse carts with respect to lifter engagement. For example, the distance between lifting points on refuse carts is set to industry standards. In practice, however, the distance between lifting points can vary appreciably. If the distance is significantly less than the industry standard, substantial force may be applied to the lifting points by the lifter's engagement mechanism. Such force can damage the refuse cart lifting points and reduce the effective life of the lifter. On the other hand, if the distance is significantly greater than the industry standard, the lifter's engagement mechanism may fail to engage the refuse cart during dumping, resulting in dropped and damaged refuse carts. Thus, a lifter engagement mechanism that can adjust to the varying dimensions between refuse container lifting points would contribute to longer refuse cart and lifter life, while improving the lifter's refuse cart engagement while dumping refuse carts.
[0011] Yet another problem with existing lifters is their limited ability to control the timing of the latch mechanism that engages the refuse container lifting points during dumping. For example, the timing of the operation of a typical sliding latch is dependent on the length of an actuating arm or member. Since the actuating arm or member is rigid and secured to fixed locations on the lifter, significant modifications must be made to the actuating arm or member attachment points if a longer actuating arm or member is used. Therefore, it would be advantageous to provide a means of controlling the timing of the actuation of the latch mechanism that is not dependent on the length of the actuating arm or member.
[0012] A further related problem with many existing lifters is associated with the range of ground to sill height and tailgate angle conditions encountered by refuse collection vehicles on a routine basis. For instance, the phenomenon known as “suck back” refers to the situation where a lifter's latch system engages early in the upward dumping rotation of the lifter and therefore becomes fully extended before the end of a dumping cycle, which causes the latch to retract slightly during the last few degrees of upward dumping rotation. This situation can lead to dropping of the refuse containers into the hopper near the end of the dumping cycle. Conversely, the container may be located such that the lifter's latch system engages late in the upward dumping rotation of the lifter, which can cause difficulty in engaging the refuse container, or damage to the container when the lifter's latch system releases the container before the container reaches the ground. Thus, it would be advantageous to provide a means of controlling the timing of the actuation of the latch mechanism to compensate for varying pick up conditions.
[0013] Another problem involves the mounting height of the lifter. Due to the standard height of the lifting points on refuse containers, the target height for the upper engagement member of a lifter during initial engagement of the refuse cart is approximately 34 inches. However, the angle of the faceplate relative to the refuse cart must also be considered. If the lifter faceplate is at an angle to the refuse cart of approximately eleven degrees or more when the lifter's upper engagement member reaches a height of approximately 34 inches during lifter operation, the lifter faceplate may cause the refuse cart to kick away from the lifter before the lower engagement member engages with the lower lifting point of the refuse cart. Given a fixed lifter arm length, the angle of the faceplate to the refuse cart during initial refuse cart engagement is dependent upon the height at which the lifter is mounted on the refuse collection vehicle. Hence, numerous lifter arm lengths are required to accommodate a range of lifter mounting heights while maintaining the required initial engagement faceplate angle. Providing numerous lifter arm lengths requires additional expense, time and effort to change out. A lifter capable of maintaining the required initial engagement faceplate angle over a range of mounting heights while requiring a minimum of lifter arm length changes is therefore desirable.
[0014] Thus, a need exists in the refuse collection industry for a residential refuse cart lifter that: possesses a slim profile; provides improved ground clearance; decreases the amount of time and energy spent compacting refuse between the emptying of successive refuse carts; provides needed lifting capacity at lower hydraulic pressures; requires little maintenance; is easy to repair or rebuild at the end user's facility; provides a lifter engagement mechanism that can adjust to the varying dimensions between refuse container lifting points; provides a means of controlling the timing of the actuation of the latch mechanism; and is capable of maintaining an acceptable initial engagement faceplate angle over a range of mounting heights while requiring a minimum of lifter arm length changes to do so.
SUMMARY OF THE INVENTION
[0015] The present refuse cart lifter has an improved operating envelope resulting from a wide range of rotation of the lifter faceplate in combination with a unique lifter arm design. This yields a refuse cart lifter that may be capable of being retracted when not in use for increased ground clearance, while also capable of dumping refuse further into the refuse collection vehicle hopper than prior lifters. This added dumping range increases the efficiency of refuse collection because a vehicle operator does not have to operate the vehicle's packing blade as frequently, resulting in savings in time and energy.
[0016] The presently preferred version of the refuse cart lifter utilizes a slim profile motor to rotate a lifting arm and faceplate 210 degrees for the purpose of dumping refuse containers into a receptacle. It is preferable to use a dual rack and single pinion hydraulically actuated unit as the motor due to its thin profile and superior lifting capacity at lower hydraulic pressures. This motor design also is preferable due to its open gear design, which makes it less susceptible to damage from contaminants in the hydraulic fluid system, and for the ease with which the lifter can be repaired or rebuilt at the end users facility. This actuator may based on the design disclosed in U.S. Pat. No. 4,773,812, which is hereby incorporated by reference.
[0017] The present refuse cart lifter may include a faceplate having multiple sets of lifting arm attachment points that allow the faceplate angle relative to the lifting arms to be changed without negatively affecting the operation of the lifter's latch mechanism. The use of alternate lifting arm attachment points reduces the number of lifting arm lengths required to maintain an acceptable initial engagement faceplate angle over a range of mounting heights.
[0018] The faceplate is preferably attached to the motor using two lifting arms having a unique design that is capable of directing the faceplate substantially into the vehicle hopper when used with a motor having a wide range of rotation. This allows the lifter to be more compact in its home (retracted) position and improves ground clearance when mounted on the rear of a rear loading refuse collection vehicle. The faceplate may have one fixed saddle and one moveable latch mechanism. The latch mechanism may be based on the sliding latch design that is disclosed in U.S. Pat. No. 5,308,211 and related patents, which are hereby incorporated by reference, or a cam-driven, spring loaded latch as discussed below. The latter mechanism may accommodate varying dimensions between refuse container lifting points, and provides a means of controlling the timing of the actuation of the latch mechanism.
[0019] The present lifter may also incorporate an adjustable faceplate having multiple sets of attachment points for the lifting arms. This feature may advantageously enable the lifter to be mounted to a refuse collection vehicle over a range of mounting heights while maintaining an operable saddle height and faceplate angle relative to the refuse cart without changing the length of the lifting arms by simply attaching the lifting arms to the faceplate at different sets of attachment points. This feature therefore may save time and money when mounting the same lifter on different vehicles with varying mounting heights.
[0020] Other design features may include the use of composite bearing materials in exposed bearing areas, such as the bearings that form a part of the sliding latch guide, to make the unit more maintenance free by eliminating the need for regular greasing. Also, longer lifting and latch arms may be utilized to allow for mounting the lifter on the side of a side-loading refuse collection vehicle.
[0021] The present lifter faceplate may extend partially underneath the refuse collection vehicle in the retracted position, and therefore may not protrude significantly outward of the refuse cart lifter motor. The slim profile of the lifter motor and the retracted position of the faceplate may function to preclude interference with the dumping of large commercial containers over the lifter. Thin bumpers may also be mounted to the vehicle to protect the lifter as large commercial containers are dumped into the hopper.
[0022] To empty a residential refuse cart into the hopper of the refuse collection vehicle, the lifter commences an emptying cycle. During the emptying cycle, the lifter motor rotates the lifter faceplate from a retracted position partially beneath the vehicle such that a fixed saddle engages the refuse cart. As the lifter continues to rotate, the cart is lifted in a sweeping arc motion towards the hopper. Meanwhile, the latch mechanism engages a lower lifting point on the refuse cart to prevent the loss of the cart into the hopper as the cart is emptied. If using a sliding latch, a sliding latch guide can be incorporated to prevent unwanted movements of the sliding latch during operation, which includes bearings to reduce friction while sliding. At the end of the emptying cycle, the cart is positioned significantly inward of the outer hopper edge.
[0023] An unloading cycle reverses the emptying cycle and the cart is brought back down to street level in a sweeping arc motion. As the cart descends, the sliding latch disengages the lower lifting point on the refuse cart, followed by the disengagement of the upper saddle and upper lifting point on the refuse cart after the cart reaches the ground. The lifter can then be rotated further until the faceplate returns to the retracted position, substantially under the refuse collection vehicle.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0024] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
[0025] FIG. 1 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position;
[0026] FIG. 2 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in an intermediate position;
[0027] FIG. 3 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position;
[0028] FIG. 4 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position;
[0029] FIG. 5 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in an intermediate position;
[0030] FIG. 6 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position;
[0031] FIG. 7 is a front view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position;
[0032] FIG. 8 is a front view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position;
[0033] FIG. 9 is a side view of an exemplary refuse cart adjacent to a refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position;
[0034] FIG. 10 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown engaging the upper lifting point of an adjacent refuse cart;
[0035] FIG. 11 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position engaging the upper and lower lifting points of a refuse cart;
[0036] FIG. 12 is a perspective view of an exemplary refuse cart adjacent to a refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position;
[0037] FIG. 13 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown engaging the upper lifting point of an adjacent refuse cart;
[0038] FIG. 14 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position engaging the upper and lower lifting points of a refuse cart;
[0039] FIG. 15 depicts the rear of a rear-loading refuse collection vehicle showing two lifters in accordance with the present invention incorporating a sliding latch mechanism mounted to the rear of the refuse collection vehicle;
[0040] FIG. 16 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a retracted position and mounted on a rear-loading refuse collection vehicle;
[0041] FIG. 17 is a partially cut away side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a sliding latch mechanism shown in a dumping position and mounted on a rear-loading refuse collection vehicle;
[0042] FIG. 18 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in a retracted position;
[0043] FIG. 19 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in an intermediate position;
[0044] FIG. 20 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in a dumping position;
[0045] FIG. 21 is a side view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in a retracted position;
[0046] FIG. 22 is a front view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in a retracted position;
[0047] FIG. 23 is a top view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism shown in a retracted position;
[0048] FIG. 24 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention incorporating a spring loaded, cam actuated latch mechanism and multiple sets of faceplate mounting holes, the lifter shown in a retracted position;
[0049] FIG. 25 a is a side view of an exemplary refuse cart lifter utilizing the outer set of faceplate mounting holes shown in a retracted position;
[0050] FIG. 25 b is a side view of an exemplary refuse cart lifter utilizing the outer set of faceplate mounting holes shown in an intermediate position;
[0051] FIG. 25 c is a side view of an exemplary refuse cart lifter utilizing the outer set of faceplate mounting holes shown in a dumping position;
[0052] FIG. 26 a is a side view of an exemplary refuse cart lifter utilizing the inner set of faceplate mounting holes shown in a retracted position;
[0053] FIG. 26 b is a side view of an exemplary refuse cart lifter utilizing the inner set of faceplate mounting holes shown in an intermediate position; and
[0054] FIG. 26 c is a side view of an exemplary refuse cart lifter utilizing the inner set of faceplate mounting holes shown in a dumping position.
DETAILED DESCRIPTION OF THE INVENTION
[0055] FIG. 1 depicts a first preferred embodiment of the present refuse cart lifter 50 shown in a retracted position. The motor 60 is affixed to the front side 56 of the baseplate 52 . The motor 60 depicted is a dual rack, single pinion hydraulic actuator capable of 210 degrees of rotation. Those skilled in the art, however, will appreciate that other motors may be adopted for use with the present invention. The rear side 54 of baseplate 52 can be attached to a refuse collection vehicle or a large refuse collection container. Dual lifting arms 76 are attached at a first end 78 of the lifting arms 76 to the rotatable shaft 62 (see FIG. 4 ) of motor 60 . The second end 80 of the lifting arms 76 are attached to the faceplate 64 . In this view, the inner surface 66 of faceplate 64 is clearly visible, as is the saddle 74 .
[0056] The inner surface 84 of a portion of the sliding latch 82 is also seen. The sliding latch 82 is connected to the baseplate 52 with dual latch arms 88 . A first end 90 of the latch arms 88 is pivotally connected to the front side 56 of baseplate 52 . A second end 92 of the latch arms 88 is rigidly connected to the sliding latch 82 . A pair of sliding latch guides 94 which limit undesirable sliding latch 82 movement in relation to faceplate 64 is also depicted.
[0057] FIG. 2 depicts the first preferred embodiment of present refuse cart 50 lifter shown in an intermediate position. In this figure, the motor 60 has rotated the lifting arms 76 and swung faceplate 64 to a position essentially parallel to baseplate 52 . Note that latch arms 88 have also swung upwards with the sliding latch 82 , which has yet to slide in relation to faceplate 64 due to the geometry of the lifting arms 76 in relation to the latch arms 88 . Also shown in this figure is the location of the upper end 70 and the lower end 72 of faceplate 64 .
[0058] FIG. 3 depicts the first embodiment of the present refuse cart 50 lifter shown in a dumping position, which is the extreme opposite of the retracted position depicted in FIG. 1 . In FIG. 3 , the motor 60 has further rotated rotatable shaft 62 and attached lifting arms 76 preferably past a vertical position. The resulting angle of the first end 78 of lifting arms 76 away from the back side 54 of the baseplate 52 (see FIG. 4 ) or towards the hopper if the present refuse cart lifter 50 is mounted on a refuse collection vehicle (see FIG. 17 ), combined with the design of the lifting arms 76 that directs the second end 80 of lifting arms 76 even further away from the back side 54 of the baseplate 52 serves to swing faceplate 64 to a position above and substantially behind baseplate 52 . Lifting arm 76 design directs the second end 80 of lifting arms 76 away from the back side 54 of the baseplate 52 (see FIG. 1 ) by offsetting the second end 80 of lifting arm 76 from lifting arm 76 using, for example, a curve or an angle in lifting arm 76 . This wide range of rotation of motor 60 and unique geometry of lifting arms 76 facilitates the dumping of refuse further into the refuse receptacle or refuse collection vehicle hopper than otherwise possible using existing lifters.
[0059] Latch arms 88 have also swung upwards with the sliding latch 82 . The first ends 90 of latch arms 88 are pivotally attached to the front side 56 of baseplate 52 , while the second ends 92 of latch arms 88 (seen better in FIG. 1 ) are fixedly attached to sliding latch 82 . Latch arms 88 are of a length and geometry calculated to cause the sliding latch 82 to slide away from saddle 74 of faceplate 64 and engage the refuse cart at some point after faceplate 64 moves from the intermediate position depicted in FIG. 2 to the dumping position in FIG. 3 . A sliding latch guide 94 (see FIG. 1 ) prevents undesirable movements of the sliding latch 82 , and includes bearings to reduce the sliding friction resulting from the movement of sliding latch 82 . The point at which sliding latch 82 begins to slide away from saddle 74 of faceplate 64 can be adjusted by varying either the location of the pivotal connection of the latch arms 88 to the front side 56 of the baseplate 52 , or the length and geometry of the latch arms 88 themselves, or both.
[0060] FIGS. 4 through 6 depict side views of the first embodiment of the present refuse cart lifter 50 shown in the retracted, intermediate and dumping positions, respectively. FIG. 4 shows one end of rotatable shaft 62 . In addition, this figure shows that the lower end 72 of faceplate 64 may located below and substantially behind baseplate 52 when the lifter is in the retracted position. The unique geometry of the lifting arms 76 and the latch arms 88 can also be seen. Note the effect of the lift arm geometry as the lift arms 76 are rotated the full 210 degrees to the dumping position in FIG. 6 . Also important is the slim profile depicted in the retracted configuration of FIG. 4 , showing the faceplate 64 , lifting arms 76 , and latch arms 88 located substantially behind the outermost face 61 of motor 60 . This facilitates the emptying of large commercial refuse containers over the refuse cart lifter, thereby enhancing the versatility of the refuse collection vehicle.
[0061] FIG. 5 depicts a side view of the first embodiment of the present refuse cart lifter 50 in an intermediate position. As in FIG. 2 , the faceplate 64 is substantially parallel to baseplate 52 . At this point, the movement of the latch arms 88 has not yet caused sliding latch 82 to slide away from saddle 74 of faceplate 64 .
[0062] FIG. 6 depicts a side view of the first embodiment of the present refuse cart lifter 50 in the dumping position. Here, it can be observed that the relative connection points and geometries of lifting arms 76 and latch arms 88 have caused sliding latch 82 to slide away from saddle 74 of faceplate 64 as the faceplate 64 moved from the intermediate position shown in FIG. 5 to the dumping position in FIG. 6 .
[0063] As discussed in reference to FIG. 3 , the unique geometry of the lifting arms 76 coupled with 210 degrees of lifting arm 76 rotation from the retracted position serve to position the upper end 70 of faceplate 64 above and substantially behind baseplate 52 . This facilitates the dumping of refuse further into the receiving refuse container than otherwise possible with conventional lifters.
[0064] FIG. 7 depicts a front view of the first embodiment of the present refuse cart lifter 50 in the retracted position. This view shows the vertical relation of faceplate 64 to the baseplate 52 , with faceplate 64 positioned well beneath baseplate 52 .
[0065] FIG. 8 depicts a front view of the first embodiment of the present refuse cart lifter 50 in the dumping position. This view shows the sliding latch 82 extended out from the lower end 72 of faceplate 64 , and faceplate 64 positioned above baseplate 52 .
[0066] FIGS. 9 through 11 show a side view of the emptying of a refuse cart using the first embodiment of the present refuse cart lifter 50 . Initially, an operator would position a refuse cart 104 adjacent to refuse cart lifter 50 , as depicted in FIG. 9 (showing a side view of the first embodiment of the present refuse cart lifter 50 in the retracted position). The upper lifting point 106 and lower lifting point 108 of refuse cart 104 are also illustrated.
[0067] Once refuse cart 104 is positioned adjacent to refuse cart lifter 50 , refuse cart lifter 50 would be operated to rotate lifting arms 76 to swing faceplate 64 up such that saddle 74 engages refuse cart upper lifting point 106 as seen in FIG. 10 . FIG. 11 depicts the dumping position of lifter 50 , which is reached after the continued rotation of lifting arms 76 from the intermediate position in FIG. 10 causes the upper end 70 of faceplate 64 to swing over and substantially behind baseplate 52 , thereby dumping refuse from the refuse cart 104 far behind baseplate 52 . In addition, while faceplate 64 is rotating from the intermediate position depicted in FIG. 10 to the emptying position shown here in FIG. 11 , the relative geometries of lifting arms 76 and latch arms 88 cause sliding latch 82 to slide out and away from saddle 74 of faceplate 64 and engage refuse cart lower lifting point 108 . This prevents refuse cart 104 from falling into the refuse collection area when saddle 74 is inverted as seen in FIG. 11 .
[0068] FIGS. 12 through 14 depict the same sequence of events as FIGS. 9 through 11 during the emptying of refuse container 104 , but from a perspective view. Refuse cart lifter 50 is shown in a retracted position adjacent to refuse cart 104 in FIG. 12 . FIG. 13 depicts the refuse cart lifter 50 engaging refuse cart upper lifting point 106 (not visible in this view) after lifting arms 76 have swung faceplate 64 up and away from baseplate 52 . Finally, FIG. 14 shows the refuse cart lifter 50 faceplate 64 swung to the dumping position with both saddle 74 and sliding latch 82 engaging refuse cart 104 at lifting points 106 and 108 , respectively (not visible in this view).
[0069] FIG. 15 depicts dual lifters 50 mounted to a refuse collection vehicle 100 . The refuse hopper 101 is shown, as is lower hopper edge 102 . As discussed previously, when refuse cart lifters 50 are operated to empty a refuse cart 104 (see, e.g., FIG. 12 ), lifting arms 76 will cause faceplate 64 to swing over and substantially inward of lower hopper edge 102 . This can be seen by examining FIGS. 16 and 17 , which depict a refuse cart lifter 50 mounted on a rear-loading refuse collection vehicle 100 .
[0070] FIG. 16 depicts refuse cart lifter 50 shown in a retracted position and attached to a refuse collection vehicle 100 . This figure emphasizes the slim side profile of the lifter 50 , which facilitates the dumping of large commercial containers over the refuse cart lifter 50 when refuse cart lifter 50 is in the retracted position. FIG. 17 depicts the refuse cart lifter 50 in a the dumping position, and offers a cutaway view (represented by jagged lines) of the refuse collection vehicle hopper showing the upper end 70 of faceplate 64 angled over the baseplate 52 and extending substantially inward of lower hopper edge 102 . An embodiment of the present invention could also be readily mounted to a side-loading refuse collection vehicle (not shown). It should be understood that the term “refuse collection vehicle” is intended to be understood broadly to include any type of vehicle for receiving refuse such as, for example, front, rear or side-loading vehicles, dumpsters, intermediate containers, and the like.
[0071] A second embodiment of the present refuse cart lifter 150 is depicted in FIGS. 18 through 23 . FIG. 18 depicts refuse cart lifter 150 positioned in a retracted position. The motor 160 is affixed to the front side 156 of the baseplate 152 . The motor depicted is a dual rack, single pinion hydraulic actuator capable of 210 degrees of rotation. The rear side 154 of baseplate 152 can be attached to a refuse collection vehicle or a large refuse collection container. Dual lifting arms 176 are attached to the rotatable shaft 162 (see FIG. 20 ) of motor 160 at a first end 178 of the lifting arms 176 . The second end 180 (see FIG. 23 ) of lifting arms 176 are attached to faceplate 164 .
[0072] As lifter 150 lifting arms 176 are rotated, attached faceplate 164 swings in a corresponding arc as lifter 150 is either extended (see FIGS. 19 and 20 ) or retracted (see FIG. 18 ), similar to the operation of the first embodiment relating to refuse cart lifter 50 . Unlike the first embodiment of the present lifter 50 that uses a sliding latch 82 , however, lifter 150 utilizes a spring loaded, cam actuated rotating latch 182 .
[0073] FIGS. 18 through 23 illustrate that rotating latch 182 is attached to actuating rod 192 that is itself attached to rotatable actuating arm 187 . Rotatable actuating arm 187 in turn is connected to lifting arm 176 such that actuating arm 187 can rotate in a scissors-like fashion in conjunction with the movement of lifting arm 176 at attachment point 194 . One end of actuating arm 187 tracks cam 198 via cam follower 196 (best seen in FIG. 20 ). The other end of actuating arm 187 is attached to rotating latch spring bar 186 (see FIG. 18 ), which is turn linked to rotating latch actuating rods 192 having springs 184 . Spring tension provided by springs 184 serves to ensure that cam follower 196 stays in contact with cam 198 (see FIG. 20 ). When actuating arm 187 rotates, springs 184 are free to move rotating latch actuating rods 192 , which in turn engages the rotating latches 182 by pivoting rotating latches 182 around latch rod 190 . A refuse container can thus be held between rotating latch 182 and saddle 174 (see FIG. 19 ). However, when lifter 150 is in the dumping position shown in FIG. 20 , the weight of a refuse cart may act against springs 184 and disengage the refuse container. To prevent such disengagement, a positive stop 183 (shown in FIG. 19 ) is located on the outer surface 168 of faceplate 164 to alleviate such action against springs 184 .
[0074] Once the refuse container has been emptied, actuating arm 187 tracks cam 198 as lifting arms 176 are rotated back to a fully or partially retracted position, and rotating latch spring bar 186 opposes springs 184 to move rotating latch actuating rods 192 towards springs 184 . Rotating latches 182 consequently rotate around latch rod 190 and gradually disengage the refuse container as lifter 150 moves into a fully or partially retracted position.
[0075] A third embodiment of the present invention is depicted in FIG. 24 . This embodiment is similar to the second embodiment of the invention in basic structure and operation, but unlike the other embodiments of the present invention, this embodiment employs an adjustable connection between faceplate 265 and lifting arms 276 . This adjustable connection may employ multiple sets of attachment points 300 and 302 on faceplate 265 for connecting lifting arms 276 to faceplate 265 . Thus, the assembled configuration of faceplate 265 with respect to lifting arms 276 is adjustable, which facilitates the mounting of refuse cart lifter 250 at a range of mounting heights without changing lifting arm lengths. While FIG. 24 depicts lifter 250 faceplate 265 as having two sets of attachment points for lifting arms 276 , more attachment points are contemplated. In FIG. 24 , faceplate 265 is depicted attached to lifting arms 276 at a first set of attachment points 300 . The second set of mounting points 302 for lifting arms 276 are not in use.
[0076] It should be understood that while the third embodiment depicts attachment points 300 and 302 on faceplate 265 , the present invention is not so limited. For instance, attachment points 300 and 302 could be located on lifting arms 276 . Similarly, while the third embodiment depicts the use of nuts and bolts to attach faceplate 265 to lifting arms 276 , other means of attachment known to persons of skill in the art, such as clamps, pins, etc., may also be used.
[0077] The detailed operation of lifter 250 is similar to the above description of operation relating to lifter 150 with the exception of adjustable faceplate 265 . For example, FIG. 24 depicts lifter 250 having a spring loaded, cam actuated rotating latch 282 as described with respect to lifter 150 above. Parts of lifter 250 shared with lifter 150 are identified with similar reference numbers that correspond to the numerals used with respect to lifter 150 . Thus, lifter 250 has a baseplate 252 having a rear side 254 and a front side 256 . Motor 260 is attached to baseplate 252 and drives lifting arms 276 , which are in turn attached to faceplate 265 . Faceplate 265 has an attached saddle 274 that, in conjunction with rotating latch 282 , serves to engage and hold refuse cart during the emptying of the cart.
[0078] Rotating latch 282 is attached to actuating rod 292 that is itself attached to rotatable actuating arm 287 . Rotatable actuating arm 287 in turn is connected to lifting arm 276 such that actuating arm 287 can rotate in a scissors-like fashion in conjunction with the movement of lifting arm 276 at attachment point 294 . One end of actuating arm 287 tracks cam 298 via a cam follower 296 (not seen in this view, but similar to the cam follower 196 of the second embodiment of lifter 150 shown in FIG. 22 ). The other end of actuating arm 287 is attached to rotating latch spring bar 286 , which is turn linked to rotating latch actuating rods 292 having springs 284 . Spring tension provided by springs 284 serves to ensure that cam follower 296 stays in contact with cam 298 (not seen in this view). When actuating arm 287 rotates, springs 284 are free to move rotating latch actuating rods 292 , which in turn engages the rotating latch 282 by pivoting rotating latch 282 around latch rod 290 . A refuse container can thus be held between rotating latch 282 and saddle 274 .
[0079] FIGS. 25 a through 26 c illustrate how adjusting faceplate 265 facilitates changing the mounting height of lifter 250 without necessitating the replacement of lifter arms 276 with arms of a different length to compensate for the mounting height difference. Turning to FIG. 25 a , lifting arms 276 of a specific length are attached to adjustable faceplate 265 at a first set of mounting points 300 . In this configuration, lifter 250 is mounted at mounting height B from the substantially level pickup surface 299 and presents a retracted ground clearance height of A when lifter 250 is in the retracted position shown. By way of illustration for comparison with the parameters shown in FIG. 26 a for the same given set of lifter arms 276 , Height A in this example is approximately 17.125 inches when lifter 250 is mounted at a height B of approximately 36 inches.
[0080] In FIG. 25 b , adjustable faceplate 265 is extended to an intermediate position for engaging a refuse container wherein faceplate 265 is substantially perpendicular to a substantially level pickup surface 299 . In this intermediate position, faceplate 265 is substantially parallel to a refuse container sitting on the substantially level pickup surface 299 , and height C of saddle 274 is adequate for proper refuse container engagement and disengagement. In general, the preferred saddle height C is approximately 34 inches. Saddle height C in this example is also approximately 34 inches.
[0081] Finally, FIG. 25 c shows lifter 250 in the extended dumping position with refuse cart 104 , wherein adjustable faceplate 265 is positioned at angle D with respect to the horizontal. By way of illustration for comparison with the parameters shown in FIG. 26 c for the same given set of lifter arms 276 , angle D is approximately 45 degrees. Length E is the distance from the back side 254 of base plate 252 to the forward most portion of refuse cart 104 . In this example, length E is approximately 32.5 inches. Height F represents the distance between the lower most portion of refuse cart 104 and substantially level pickup surface 299 . In this example, height F is approximately 33.75 inches. Finally, height G is the distance between the uppermost portion of refuse container 104 and substantially level pickup surface 299 . In this particular example, height G is approximately 78.875 inches.
[0082] FIGS. 26 a through 26 c correspond to FIGS. 25 a through 25 c , respectively. FIGS. 26 a through 26 c use identical lifting arms 276 to lifting arms 276 used in FIGS. 25 a through 25 c . In FIG. 26 a , adjustable faceplate 265 has been adjusted by attaching the same lifting arms 276 from FIGS. 25 a through 25 c at attachment points 302 instead of attachment points 300 . Lifter 250 mounting height B has been raised to height B′, which, by way of specific example only, is approximately 37.5 inches. Height A then changes to height A′. In this example, A′ is approximately 17 inches.
[0083] By moving the attachment points of lifting arms 276 to set of attachment points 302 , it is possible for lifter 250 to achieve a height C′ of saddle 274 that is substantially the same as height C of saddle 274 in the intermediate position despite increased mounting height B′. This adjustment does not adversely affect the operation of lifter 250 in any significant way.
[0084] For instance, by way of comparison with FIG. 25 c , using the same lifter arms 276 used in FIG. 26 c alters angle D from approximately 45 degrees to approximately 54 degrees. Length E increases from approximately 32.5 inches to 35 inches. Height F slightly decreases from approximately 33.75 inches to 33.25 inches. Finally, height G increases from approximately 78.875 inches in FIG. 25 c to 80.875 inches in FIG. 26 c.
[0085] The adjustable faceplate 265 of lifter 250 discussed above with respect to FIGS. 25 a through 26 c can be mounted over a range of mounting heights. By way of example only, the specific embodiment of lifter 250 depicted in FIGS. 25 a through 26 c using lifting arms 276 of a set length may be capable of operating over a range of mounting heights from a low mounting height B of at least approximately 36 inches to a high mounting height B′ of at least approximately 39.5 inches while maintaining saddle height C at a height adequate for proper refuse container engagement and disengagement. Changes to lifter arm 265 length and configuration will lead to other ranges of mounting heights. For example, substituting a second set of lifter arms 265 that are approximately 2 inches longer than lifting arms 265 in the example discussed in FIGS. 25 a through 26 c will result in a lifter 250 that may be capable of operating over a range of mounting heights from a low mounting height B of at least approximately 37.875 inches to a high mounting height B′ of at least approximately 40.875 inches while maintaining saddle height C at a height adequate for proper refuse container engagement and disengagement. Even longer lifting arms 276 may result in an even higher operable range of lifter 250 mounting heights B. For example, the mounting height may range from a low mounting height B of at least approximately 40 inches to a high mounting height B′ of at least approximately 43 inches while maintaining saddle height C at a height adequate for proper refuse container engagement and disengagement. Those of skill in the art will appreciate, of course, that other lifter arm 265 configurations and attachment points will further alter the operable parameters of lifter 250 .
[0086] The words used above are words of description rather than of limitation. Although preferred embodiments of the invention have been described using specific terms, devices, relative positions, and methods, such description is for illustrative purposes only. It should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.
[0087] For example, the present refuse cart lifter could utilize a single lifting arm or a single latch arm, or various multiples of each or both. Furthermore, the lifter could be mounted to freestanding refuse containers, intermediate containers, rear-loading refuse collection vehicles, or side-loading refuse collection vehicles. Thus, it should be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims. | A lifter is disclosed which allows for an improved operating envelope of the faceplate. The lifter utilizes a motor having 210 degrees of rotation and lifting arms of a unique geometry to rotate a faceplate from a retracted position below and substantially behind the lifter baseplate to a dumping position above and substantially behind a lower hopper edge for the purpose of dumping refuse carts into a refuse collection vehicle. This dumps refuse further into the vehicle hopper, which minimizes the number of packing cycles required on a collection route. A faceplate is attached to the motor using two lifting arms. The faceplate has a fixed upper hook and may be configured with a sliding, retractable lower hooking mechanism or a spring loaded, cam actuated rotating hook mechanism. The faceplate may include multiple sets of attachment points for attaching the lifting arms to facilitate the mounting of the lifter on a refuse collection vehicle over a range of heights without necessitating replacement of the lifting arms. | 1 |
TECHNICAL FIELD
This invention generally relates to improving medical workflow efficiency and asset management in medical service delivery.
BACKGROUND
The medical services industry has sought for several years to utilize technology to improve medical workflow efficiency. Specifically, physicians desire to transition from paper based records to electronic health record systems. At the same time, diagnostic devices are being enhanced to include digital technology and to provide digital communication interfaces for communication with external information systems.
Unfortunately, it has been difficult to achieve the ultimate goal of combining the existing devices and documentation systems into a single integrated system. This ultimate objective is frustrated by a number of factors. Firstly, PC's typically have a limited input/output capability, that is, a limited number of ports of various types required. Laptops and tablet or palmtop computers are often limited in their connections. Furthermore, PC's typically do not have the appropriate software (application software as well as operating system software and device drivers) needed to communicate with the wide variety of medical devices that are in common use. Furthermore, even if there was a PC configured to overcome these problems, the end user would be required to deal with a jumble of wires and interconnections to properly connect to the equipment relating to a particular patient. This is a particularly problematic issue if the PC is a mobile device, intended to travel with the medical professional, in which case the required connections and disconnections become a major inconvenience.
One approach to avoid the inconveniences just mentioned is to use networked communications. In the current state of the art, there are a wide variety of network adapters that can be used to connect multiple medical devices to a network so that data may be exchanged with electronic medical records systems. However, configuration of those network devices is complicated and requires significant technical support. The configurations are generally static in nature (for example, a specific serial port adapter is mapped to a static IP address, and then that static IP address is monitored by a PC to communicate with the device). When medical devices, computers and personnel move around in the healthcare organization, these static relationships need to be reconfigured, resulting in inconvenience to patients and healthcare providers.
Networking errors are common when using static IP addressing, and in a medical environment, those errors can be life threatening. Consider, for example, two ECG devices in different examination rooms, connected to a common network. A healthcare professional configuring a computer to monitor a patient (e.g., a mobile computer connected to the network via wireless network) will have no easy basis to determine which ECG is associated with a given IP address. Although the user could be presented with a list of ECG devices on the network, the time and energy spent in selecting the correct choice slows the workflow, and there is a risk that the wrong ECG device is selected, which can lead to a misdiagnosis and other threats to the patient. What is needed is a device that resolves these issues, provides interfaces to many types of medical devices and can automatically establish the correct network connections between those medical devices and the appropriate computers and applications in a dynamic, mobile environment.
In addition to the inefficiencies in device integration, there also exists a level of inefficiency in the medical arena with respect to asset management and workflow for medical and ancillary staff. Understanding the real time locations of physicians, nurses, staff, patients, devices, and other high value entities would provide tremendous immediate improvement in workflow. In addition to on-the-spot locating abilities, the ability to analyze patterns and problems using long term data for these mobile entities in the office could prove extremely valuable to making medical care more productive, efficient, reliable, safe, and profitable.
SUMMARY OF THE INVENTION
The networked interface appliance, and the system in which it is used, addresses the above needs.
In accordance with one aspect, the invention features an interface appliance which interconnects with a statically interfaced device and a dynamically interfaced devices within a specified area (such as an exam room). The statically interfaced device (such as medical diagnostic devices like electrocardiograms (ECG), spirometers, blood pressure meters, x-ray and video equipment) interfaces with the appliance using existing interface technologies such as Universal Serial Bus (USB) ports, serial ports, infrared, BLUETOOTH®, including IEEE 802.15, or other interface methodologies. The dynamically interfaced device (such as a portable computer being used by physicians to receive data from or control diagnostic equipment, or mobile diagnostic equipment) interfaces with the appliance using an internet protocol network. To establish this internet protocol network connection, a beacon signal is transmitted between the dynamically interfaced device and interface appliance, which includes an identifier unique to the transmitting device. A beacon listener receives the beacon signal, and when a beacon signal is detected, the identifier in the wireless beacon signal is used to establish communication between the interface appliance and the dynamically interfaced device over the internet protocol network, thereafter allowing the interface appliance to communicate with the dynamically interfaced device.
In specific embodiments, the beacon signal is transmitted by the interface appliance, and received by the dynamically interfaced device, and the dynamically interfaced device establishes communication with the interface appliance by transmitting a broadcast message over the internet protocol network, the message incorporating the identifier received from the wireless beacon signal and the internet protocol address of the dynamically interfaced device. The interface appliance receives this broadcast message, and upon identifying that its own identifier is included within the broadcast message, responds with a handshake message to the internet protocol address that originated the broadcast message, so that the interface appliance and the dynamically interfaced device thereafter possess each other's internet protocol addresses for future communication.
In an alternative embodiment, the beacon signal is transmitted by the dynamically interfaced device, and received by the interface appliance, the broadcast message is transmitted by the interface appliance, and the handshake message is transmitted by the dynamically interfaced device. In this embodiment, the handshake message may further identify the attributes of the dynamically interfaced device, enabling the interface appliance to identify possible future communications.
In one specific implementation, the dynamically interfaced device is a PC, mobile computer, palmtop, laptop, or other mobile computing device, utilizing medical diagnostic or record software, and the interface appliance includes interfaces to various medical diagnostic equipment, such that the medical diagnostic or record software may connect to and receive data from the diagnostic equipment as part of analyzing a patient's condition and/or developing a patient care record. Furthermore, the medical diagnostic or record software may control the diagnostic equipment via the interface appliance. In such applications, the interface appliance may also act as a data buffer, using memory within the interface appliance to buffer data received from the medical diagnostic equipment for transmission to the dynamically interfaced device over the internet protocol network, thus improving the reliability of the medical data.
In further implementations, the dynamically interfaced device may be a medical diagnostic device coupled to the Internet protocol network (such as a portable X-ray or portable ECG), and the interface appliance interfaces to the medical diagnostic device to facilitate communication between the medical diagnostic device and other dynamically interfaced devices which connect to the interface appliance in the manner described above. It is also possible that the dynamically interfaced devices interface with each other via the Internet protocol network.
The interface appliance may further include a storage interface for connection to removable storage devices such as secure digital cards (SD cards), flash memory cards, USB flash memory drives, and memory sticks. Data within the storage devices connected to the interface appliance may be made available to dynamically interfaced devices connected thereto. The interface appliance may further use such storage devices to store data received from dynamically and statically interfaced devices for later use.
In the detailed embodiment described below, the interface appliance utilizes an operating system permitting remote access to data from and control of dynamically and statically interfaced devices connected to the interface appliance. In addition, the interface appliance permits access to internal functions thereof via the internet protocol network, facilitating remote support and maintenance. In a related functionality, the interface appliance operating system may include a diagnostic routine for detecting malfunctions of the interface appliance or of devices interfaced thereto, and generating messages over the internet protocol network in the event of detection of such malfunctions.
In the specific embodiment described herein, the wireless beacon signal comprises a combined radio frequency and ultrasonic signal, such as the combined radio frequency and ultrasonic signaling used in the Cricket technology developed at the Massachusetts Institute of Technology. In this embodiment, the dynamically interfaced device and/or the interface appliance utilizes a Cricket listener for identifying nearby beacons and the proximity thereof to the listener. In the event the proximity between the beacon and listener is known, as can be achieved using the Cricket technology, the interface appliance may establish communication with dynamically interfaced devices which meet a certain proximity criterion, such those devices closer than a predetermined distance from the interface appliance.
In a further embodiment, managed assets (such as valuable portable devices, personnel such as medical staff and physicians, and customers or patients) are identified by the interface appliance or by a mobile computing device through the use of wireless beacon signals. For example, such assets may generate wireless beacon signals with unique identifiers, received by the interface appliance. The interface appliance may deliver the identifiers received from the additional managed assets to an asset tracking database. If the asset tracking database receives identifiers from plural interface appliances at plural locations, and each interface appliance is associated with its location, the asset tracking database can provide real time tracking of the managed assets. Furthermore, the asset tracking database may permit analysis of workflow, scheduling, equipment utilization, and intra-office communications, and be used for service billing and payroll time entry.
It will be appreciated that the interface appliance described above may improve existing electronic medical record systems, by permitting automatic proximity-based selection and control of medical diagnostic equipment. A physician or staff member carrying a portable computing device can be automatically connected to the medical data for a patient upon entering the patient's room or approaching the patient, thus improving efficiency.
Furthermore, the asset management and proximity detection functions described above may further simplify workflow and improve security; for example, a portable computing device connected with an interface appliance, can detect through the interface appliance whether a physician or staff member is in the vicinity of the portable computing device. If not, the portable computing device may prevent access until a physician or staff member returns. This can prevent the portable computing device from providing access to patient records to unauthorized persons. Furthermore, because the portable computing device may verify that the physician or staff member logged into the device is present in the same location as the portable computing device, the integrity of the medical records may be improved, by verifying that the person logged into the portable computing device is in its vicinity during activities conducted under that persons login identity.
In a further embodiment, the interface appliance may provide a video interface. The interface may be used to deliver video to the proximity of the appliance, such as television signals, educational video and organizational news reports. Further, the video interface may permit the receipt of video from the proximity of the appliance.
Various features discussed below in relation to one or more of the exemplary embodiments may be incorporated into any of the above-described aspects of the present invention alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of the present invention without limitation to the claimed subject matter.
BRIEF DESCRIPTION OF THE FIGURES
Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which:
FIG. 1 is block diagram of a medical diagnostic environment utilizing an interface appliance in the form of a medical diagnostic gate;
FIGS. 2A-2C are network diagrams illustrating the connectivity of a mobile computing device to a medical diagnostic gate via a network, and illustrating the delivery of a beacon signal from the gate to the device and responsive broadcast, handshake and service request packet exchanges;
FIG. 3A is network diagram illustrating a more complete implementation of the invention in a medical diagnostic environment, including multiple gate devices for each of several local areas, multiple PC/mobile computing devices, and multiple assets (persons, objects), the locations of which are tracked, in which a mobile asset beacon signal is received by a listener at a gate;
FIG. 3B illustrates an embodiment in which the mobile asset provides network-enabled functionality, and initiates a handshake response of to the broadcast signal issued thereto, and FIG. 3C illustrates a subsequent service request to the mobile asset.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
Referring now to FIG. 1 , the present invention will be described in connection with a medical diagnostic environment, in which the interface appliance forms a medical diagnostic gate 10 forming a communications hub for a plurality of medical diagnostic devices. Gate 10 is a network appliance built in a hard case enclosure designed to be located on a desktop, on a wall, within an exam table, or directly interfaced within a device (such as a vital sign monitor (VSM)). In one embodiment, this appliance has a Windows compliant processor board as its backbone, with necessary onboard hardware for 100 mbps Ethernet connectivity to an Internet protocol network and 802.11 (a, b, g and/or n) wireless networking, enabling connectivity to other network connected devices such as a physician PC or other mobile computing device 28 , an electronic medical records (EMR) server 36 , any network-enabled medical equipment such as an x-ray 22 , and the public Internet 30 .
Gate 10 includes 4 universal serial bus (USB) ports, US-232 serial port, Bluetooth® connectivity, and an infra-red emitter and reader, each to permit connectivity to medical diagnostic devices, including a scale 14 (e.g., a Seca Model 882, Tanita Model BF-350 or A&D Model UC-321 P connected via wired or wireless infrared communication), spirometry device 16 (connected via wired communication), ECG device 18 (connected via wired communication), vital signs monitor (VSM) 20 (delivering blood pressure, pulse and temperature signals via wired or wireless infrared communication), a USB camera, and other medical diagnostic or monitoring equipment connectable via USB, RS-232, Bluetooth or infrared. The technology for providing connectivity to a wide variety of devices in this manner is available in products sold by the assignee of the present application in its IQ-mark product line, such as:
IQvitals Mobile Cart
Midmark IQcart™
Midmark IQclassic™
Midmark IQecg™
Midmark IQflex™
Midmark IQholter™
Midmark IQmanager™
Midmark IQspiro™
Midmark IQstress™
Midmark IQvitals™
Midmark IQvitals™ PC.
Gate 10 further includes a VGA video port and S-video port, enabling the delivery of video signals to an in-room monitor (not shown). The outgoing video port on gate 10 allows for display of patient education videos, patient directed history functions, broadcast television, or office productions. EMR server may utilize central software to determine the most appropriate video imagery for a given patient situation. Such software will have the capacity to direct the programs to be displayed locally based on logic that is sensitive to patient age, diagnoses, problem lists, user input, physician directed video, and other considerations.
Gate 10 further includes a secure digital (SD Card) port, a flash media card port, and a memory stick port, providing for storage an retrieval of data, such as data collected from diagnostic monitoring devices.
The surface of the cased enclosure of gate 10 includes light emitting diode lights which display status information regarding the gate 10 , including power status, ‘device connected’, ‘input data stream active’, ‘network linked’ (solid)/'network transmission active' (fast blink). The surface of the gate 10 enclosure may further include a display, such as a single line alphanumeric display LCD display of 16 characters or similar. The display may be used to display an identifier of gate 10 to distinguish it from other gates, or for other status information useful when connecting diagnostic devices to gate 10 .
The internal software of gate 10 incorporates an operating system for managing the functionality of the gate 10 . In one embodiment, this internal software includes an operating system (e.g., Windows XP, XP embedded, Vista or Windows CE) that controls device drivers, memory management, and network functions. When devices are attached to gate 10 via any one of the various ports (USB, Serial, BLUETOOTH®, including IEEE 802.15), gate 10 automatically powers up the device, initiates communications with the external hardware, and informs the network of the device's availability at the specific gate location.
Gate 10 is further equipped with the “Cricket Location Support System” developed at the Massachusetts Institute of Technology and documented in U.S. Pat. No. 6,816,437 to Teller et al. and assigned to the Massachusetts Institute of Technology, the entirety of which is incorporated herein by reference. Cricket technology is further described in the paper entitled “The Cricket Location-Support System” by Priyantha, Chakraborty and Balakrishnan, 6⇄ International Conference on Mobile Computing and Networking (ACM MOBICOM), Boston, Mass. August 2000 and incorporated herein in its entirety.
The Cricket technology utilizes a beacon signal comprising a simultaneous pulse of ultrasound and radiofrequency waves to determine the distance between beacons and listeners with respect to each other. Software, made available from the Massachusetts Institute of Technology as public domain, uses a logic algorithm to accurately determine locations of the beacons through mathematical analysis of the ultrasonic and radiofrequency signal timing.
The beacon component 24 included in gate 10 periodically generates a combined ultrasonic/radiofrequency signal to be utilized in proximity detection by wireless computing devices such as laptop computer 28 , as discussed below with reference to FIGS. 2A to 2C . Each mobile computing device has a USB driven listening device 26 that provides capabilities that will used to detect beacon signals from nearby gate appliances and initiate the network conversation using either wireless or wired network protocols and embedded software as discussed in further detail below.
The Cricket listening component 26 included in gate 10 periodically detects other beacons 24 that are within the range of the listener 26 . Beacons 24 are attached to assets within the medical facility such as a portable X-ray 24 . Beacons 24 utilize small circuit boards that include controlled ultrasound and radiofrequency emitters. Cricket circuit boards are currently publicly available through Crossbow Technology, Inc., 4145 N. First Street, San Jose, Calif. 95134. This device may be condensed to smaller size so that it may be attached to, or carried by, objects or people.
As discussed below, listener component 26 of gate 10 monitor the local environment and relay each discovered object's identifier to the internet protocol network. Software within an asset tracking database server may then, based on a known location of the gate, plot the location of each object in a facility map, and store that data for future analysis. Analysis of each asset's location on a day to day basis may permit workflow improvement.
Gate 10 also connects to electronic medical record software in an EMR server 36 . Specifically, gate 10 periodically generates internet protocol messages directed to EMR server 36 to notify server 36 that gate 10 is on-line and, optionally, to notify server 36 of the current capabilities of the diagnostic equipment connected to gate 10 . In one embodiment, after establishing such communication, gate 10 continuously feeds data from the diagnostic equipment connected to gate 10 , to EMR server 36 so that EMR server 36 may store this information and/or provide a feed of this information to other destinations such as a mobile computing device 28 being used by a physician or staff member visiting the patient or monitoring the patient from a remote location.
Gate 10 may also connect to EMR server 36 to provide real time tracking of assets identified as in the vicinity of gate 10 . One asset that can be tracked is a physician or staff person, or the mobile computing device 28 being carried by a physician or staff person. In response to a physician, staff member or mobile computing device entering the vicinity of the gate 10 , EMR server 36 may automatically load a patient's electronic record on the mobile computing device 28 . Furthermore, EMR server 36 may evaluate whether a physician or staff person is in the same room as mobile device 28 , to automate physician/staff log-in to the mobile device 28 , or lockout the mobile device 28 in the event of the absence of authorized personnel in the vicinity of the wireless computing device. Furthermore, EMR server may log the time spent by a physician or staff with a patient for billing purposes, may log whether there is a ‘witness present’ during sensitive examinations requiring a second staff person present, and may accumulate various additional data to assist with EMR workflow analysis (such as patient waiting and scheduling time). These features may aid in improving physician workflow as well by providing instruction on current location of patients, next patient to be seen, etc.
Gate 10 , when acquiring medical diagnostic data, serves as an electronic data buffer for the acquired data. Internal memory in gate 10 will save the data stream, allowing a controlled data transmission to a client (mobile computing device 28 , EMR server 36 ), that is dynamic in response to the available network speed. Gate 10 can thus improve the data obtained by the EMR or mobile device 28 from the medical diagnostic device by improving accuracy and completeness. Failed data transfers will be stored locally within gate 10 until the communication problem is resolved. When communication is re-established, the gate will continue the transmission using stored data. Local ports on gate 10 , such as the SD slot or memory stick slot, can be used to back up the data should the network fail consistently.
It will be appreciated that mobile computing device 28 may operate in a “thin client” mode in which data is delivered to EMR server, and displays generated at EMR server 36 summarizing that information are presented at mobile device 28 , or mobile computing device 28 may operate in a “thick client” mode in which data is delivered from gate 10 directly to mobile computing device 28 for interpretation and storage within the portable device 28 .
Gate 10 is connectable using secure internet protocol communication 30 , to the intranet of the medical facility and/or (via a router or gateway) to the public Internet. Support staff 32 located within the medical facility's intranet, or at a remote location connected the public Internet, may use the gate 10 's internal internet protocol (IP) address to connect to the operating system within gate 10 , for example in response to a support telephone call placed by a physician over the physician's wireless telephone 34 . The operating system of gate 10 supports log-in to the device for diagnosis of malfunctions and remote correction of internal errors. In addition, the support staff may also perform firmware and driver downloads to gate 10 from a remote location. In addition, the device may perform automatic diagnostics and deliver email or other Internet-compatible messages to support team members in the event of problems, potentially prior to awareness by the end user.
Referring now to FIG. 2A , the interaction of a mobile computing device 28 and a gate 10 can be elaborated. Gate 10 , computing device 28 and EMR server 36 are each connected to an internet protocol network backbone 40 . The connection of gate 10 to network 40 may be wired or wireless, as noted above. Mobile computing device 28 typically is connected wirelessly to network 40 and EMR server 36 is typically connected via 100 Mbps Ethernet to backbone 40 .
An interaction of a mobile computing device 28 and gate 10 is initiated by the delivery of a wireless beacon signal from beacon 24 associated with gate 10 to a listener 26 associated with mobile computing device 28 . Device 28 captures the beacon identifier from the received beacon signal, and issues an internet protocol packet including the beacon identifier and its own identifier. In the event plural beacon signals are received, the identifier from the nearest beacon (as determined using the above-referenced Cricket logic) is used. In the event multiple beacons are seen but at least one beacon lacks location information, the ambiguity needs to be resolved. In one embodiment, the identifiers of each of the beacons (which may be intuitive text names) are presented to the user for the user to select the desired beacon.
In a thin client implementation of the invention, gate 10 initially delivers all medical diagnostic data to EMR server 36 , and mobile computing device receives this data from EMR server 36 by delivering the internet protocol packet 37 to EMR server 36 , so that EMR server 36 may identify mobile computing device 28 as within the vicinity of gate 10 , and begin delivery of medical diagnostic information received from gate 10 to mobile computing device 28 .
In a thick client implementation of the invention, a connection is established from gate 10 directly to mobile computing device 28 . To accomplish this, mobile computing device 28 must learn the IP address of the gate 10 that issued the beacon signal. In this case, the internet protocol packet 37 issued by mobile computing device 28 in FIG. 2A is a broadcast packet, issued to all nodes on the local network, including gate 10 . Gate 10 , upon receipt of this broadcast packet, responds as shown in FIG. 2B by delivering a handshake IP packet 38 identifying the gate 10 and its device attributes (i.e., data streams provided, etc.) This packet is directed to the return address of the broadcast packet issued by mobile computing device 28 , and as such is returned to mobile computing device 28 . When this packet is successfully received in response to a broadcast message, mobile computing device 28 may respond by issuing a service request to gate 10 to begin streaming of medical diagnostic information from gate 10 . Mobile computing device 28 may further issue data access requests to EMR server 36 to retrieve the medical record for the patient in the current proximity of gate 10 and to combine this information with incoming diagnostic data from gate 10 to present on the screen of the mobile computing device.
It will be noted that mobile computing device 28 should properly handle error conditions such as the receipt of multiple responses to a broadcast packet, and the receipt of such responses without the prior transmission of a broadcast packet. Both conditions indicate an address conflict or other malfunction which may be notified to the administrator or otherwise handled appropriately.
Referring now to FIG. 3A , in a more complex implementation of the invention, the computing environment may include a plurality of gates 10 , 10 - 1 , 10 - 2 , 10 - 3 , each associated with its own location. Each gate, however, is assigned a unique identifier and a unique IP address (typically by a dynamic host configuration protocol (DHCP) server), as a consequence of which only one gate will respond to a broadcast message incorporating a beacon signal. Furthermore, plural mobile computing devices 28 move about the mobile computing environment and are dynamically connected with information regarding particular patients as they enter and leave the vicinity of those patients.
Additionally, in the embodiment of FIG. 3A , plural assets 42 - 1 , 42 - 2 and 42 - 3 are associated with beacons 24 , to allow tracking of the location of those assets. Specifically, the beacon 24 attached to an asset 42 - 1 issues a wireless beacon signal which, when in range, is received by the listener device on a gate 10 - 1 . Gate 10 - 1 responds by originating an IP packet 43 incorporating the beacon identifier. This IP packet 43 is delivered to an asset tracking database 44 within EMR server 36 . Within asset tracking database 44 , the gate identifier is used as an index in a first table 46 associating each gate with its physical location, and then this physical location is stored along with the beacon ID for the asset in a second database 48 , so that database 48 accumulates asset tracking data over time, for use in various ways as discussed above.
It will be noted that assets tracked in the manner described above, may include networked communications capabilities. For example, a portable x-ray device such as 22 shown in FIG. 1 , may incorporate networked communication capability which may be accessed. In such a circumstance, the packet 43 issued in FIG. 3A may be a broadcast packet, receivable by the mobile asset 42 . If mobile asset 42 includes a networked communications capability, asset 42 may respond to this broadcast message by delivering a responsive handshake message 45 identifying itself and/or its capabilities. Upon receipt of this responsive message, the gate 10 may then issue a service request 47 to the IP address of the asset 42 - 1 to begin use of its networked communications capability.
It will be appreciated that the functionality described above for connecting to a mobile asset, may also be implemented in a mobile computing device. Specifically, a mobile computing device may listen for a beacon signal from an asset, deliver a responsive broadcast packet 43 , receive a reply message 45 , and issue a service request 47 . In this manner networked communication with diagnostic devices may extend to devices that do not connect through gate 10 for network communication.
The invention has been described herein in substantial detail, however, it is not the Applicant's intention to be limited to such details which are presented for illustrative purposes. Specifically, when introducing elements of the present invention (E.G., the exemplary embodiments(s) thereof), the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
It will be noted that beacon technology other than Cricket may be used consistently with the present invention. Specifically, radiofrequency identification (RF-ID) technology may be used to generate and detect beacon signals. For example, RF-ID operating at 438 MHz at a power level less than 50 mW could be used without substantial interference in a medical environment, and would provide functionality for identifying proximity of mobile assets and mobile computing devices to gates 10 positioned about a medical facility, however, it is presently believed that Cricket offers advantages in its ability to measure proximity and in limiting connectivity to line-of-sight circumstances which may reduce the potential for making incorrect connections.
As various changes could be made in the above-described aspects and exemplary embodiments without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. | A networked interface appliance for use in the medical arena that simplifies the connectivity of medical diagnostic devices to the portable computers in electronic medical record systems (EMR's). The appliance utilizes location support hardware and software to locate and map various tagged assets within the existing environment. The appliance automatically determines the proximity of nearby portable assets and computing devices, and creates network connection to each. Data obtained from a diagnostic device connected to the appliance is buffered and transmitted to portable computing devices connected to the appliance. Using specific IP addressing, support teams can connect to the appliance to diagnose and correct problems remotely using a local area network, wide area network or the Internet. A video port for remotely controlled video display and for local data acquisition is included. Location data from the appliance can be utilized in improving billing algorithms and workflow analysis. Asset management and location mapping of resources are also supported. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for the generation of gases. More particularly, the present invention relates to methods and apparatus for the generation of hydrogen and oxygen by the electrolytic dissociation of water.
2. Description of the Prior Art
It is well known that a gas, such as oxygen, hydrogen or chlorine, may be generated by disassociating a chemical compound into its constituent elements. The prior art describes several devices which utilize electrolytic cells for disassociating such compounds and generating gas. Such electrolytic cells take a variety of forms, but generally include a catalytic anode, a catalytic cathode and an adjacent electrolyte which is in electrical contact with both the anode and the cathode. A d-c voltage is applied across the catalytic electrodes to drive the reaction.
When reactants contact an electrode, they are dissociated into their constituent ionic forms, and the evolved gas is collected. For example, if water is placed in contact with the anode, an oxidation reaction will occur, disassociating the water to produce hydrogen and oxygen ions. The hydrogen ions move to the cathode where a reduction reaction produces hydrogen molecules, and at the anode the oxygen ions combine to form molecular oxygen. Generally, the electrolyte is a solid polymeric ion-exchange membrane.
Gas generators employing electrolytic cells may be used in many applications in place of compressed gas stored in cylinders. Moreover, electrolytic cells make possible the manufacture of inexpensive, compact devices for producing gas at the point of use. An example of an electrolytic cell gas generator is described in Dempsey et al. U.S. Pat. No. 3,870,616, which describes a hydrogen generator having a main water tank supplying water to the anode of an electrolytic cell for dissociation. However, not all the water supplied to the anode is dissociated. In fact, the bulk of the water supplied to the anode is transported with the dissociated hydrogen ions across the ion-exchange membrane into the cathode chamber. Part of this water returns to the anode chamber by diffusion back across the ion-exchange membrane; however, when gas is being actively generated, the rate of protonic pumping by the hydrogen ions is much greater than the diffusion rate of the water back across the membrane so that eventually a build up of water takes place in a accumulator chamber disposed above the cathode chamber. Whenever the water in the accumulator chamber rises above a predetermined level, a solenoid valve is closed to shut off the water supply from the main tank to the anode chamber. Nevertheless, as long as there is an electrical current supplied to the electrolytic cell, the dissociation reaction continues. In order to continue the reaction, and the production of gas, water must be supplied to the anode. However, the only water supplied to the anode chamber comes from the diffusion of water from the cathode chamber back across the ion-exchange membrane. During this period, the dissociation of the water is rate limited by the rate of water diffusing lack across the membrane.
"Drying out" or "breaking down" the membrane is a phenomenon which occurs when the electrolytic cell's demand for water is greater than the supply. The dissociation of water is driven by the current supplied to the electrolytic cell. As the current is increased, the quantity of water dissociated is increased. However, if the supply of water at the anode is not great enough to satisfy the demand of the electrolytic cell, the water molecules which were incorporated into the structure of the membrane during the manufacturing process will become dissociated. This irreversibly "dries out" the membrane, breaking down the polymer structure. As a result the output of the cell is progressively reduced, and the cell eventually becomes inoperable. This phenomenon will also occur if the generator accidentally runs dry, or loses its water through a leak in the system, or if the solenoid valve remains closed indefinitely.
The water contained in an electrolytic cell gas generator can become contaminated with impurities, such as metals, salts, acids, bases, or other electrolytes. Impurities such as these are contained in ordinary tap water. Once entered into the system, these impurities or contaminants are absorbed directly into the ion-exchange membrane, thereby "poisoning" the membrane and reducing the amount of uncontaminated surface area remaining to transport ions. As a result, the output of the cell is progressively reduced until the cell ceases to function entirely. This can be a gradual process or, if the amount of contamination is great enough, the membrane can be poisoned in a matter of minutes. Because these contaminants are invisible to an operator and electrolytic gas cell generators presently cannot detect if contaminated water is present, the ion-exchange membranes of these systems can be destroyed by the errant addition of tap water or other impure water into the generator.
SUMMARY OF THE INVENTION
It is an object of the present invention to address one or more of the foregoing deficiencies in electrolytic gas generators by providing an improved electrolytic gas generator.
One particular object of the present invention is to provide an electrolytic hydrogen and oxygen generator which produces hydrogen and oxygen at rates greater than those attainable in presently available electrolytic hydrogen generators.
Another important object of the present invention is to provide an electrolytic gas generator which is constructed to provide a longer productive lifetime for the ion-exchange membrane.
A further important object of the present invention is to provide a electrolytic cell gas generator which includes various safety features which protect the electrolytic cell from damage due to massive leaks, through the errant addition of impure water, or due to the absence of water from the supply system.
A still further object of the present invention is to provide a electrolytic gas generator having a solid-polymer-electrolyte electrolysis unit wherein the solid-polymer-electrolyte is protected from drying out.
Other objects and advantages of the invention will be apparent from the following detailed description and the accompanying drawings.
In accordance with the present invention, the foregoing objectives are realized by providing an electrolytic hydrogen and oxygen generator comprising an electrolytic cell having a cathode and an anode separated by an electrolyte; an electrical power supply connected to the electrolytic cell for applying a voltage across the cathode and anode; a water reservoir connected to the electrolytic cell for supplying water to the anode side of the cell; a hydrogen-water separator connected to the electrolytic cell for receiving hydrogen and water from the cathode side of the cell and separating the hydrogen from the water; and a water return line connecting the hydrogen-water separator to the water reservoir for returning water from the separator to the water reservoir so that the water is recycled to the anode side of said electrolytic cell. In a preferred embodiment, the water reservoir includes a sensor for producing an electrical signal in response to a drop in the water level in the reservoir to a predetermined level or in response to a predetermined change in the electrical conductivity of the water in the reservoir, and control means responsive to the electrical signal from the sensor for interrupting the supply of electrical power to the electrolytic cell. The preferred embodiment also includes a hydrogen output line for removing the hydrogen from the hydrogen-water separator, the hydrogen output line including a drying tube made of material which selectively adsorbs water vapor from gas flowing through the interior of the tube, and transfers the adsorbed water to the exterior of the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic illustration of an electrolytic-cell hydrogen generator embodying the present invention;
FIG. 2 is an exploded perspective of the electrolytic cell in the hydrogen generator of FIG. 1;
FIG. 3 is an exploded side elevation, partially in section, of the hydrogen-water separator in the generator of FIG. 1;
FIG. 4 is a block diagram of electrical circuits in the hydrogen generator;
FIG. 5 is a simplified schematic diagram of electrical circuits for controlling current supplied to the hydrogen generator cell to obtain a selected level of hydrogen pressure;
FIG. 6 is a simplified schematic diagram of electrical circuits which are used for detecting excessive water conductivity and lack of water in the hydrogen generator cell;
FIG. 7 is a simplified schematic diagram of electrical circuits which are used for detecting a failure of the hydrogen generator to achieve a selected pressure, for example, due to a massive leak in the generator;
FIG. 8 is a detailed schematic diagram of circuits for indicating a selected hydrogen pressure, sensing the actual hydrogen pressure, and shutting down the generator under certain abnormal conditions;
FIG. 9 is a detailed schematic diagram of the circuits for controlling the current supplied to the hydrogen generator cell to obtain a selected level of hydrogen pressure;
FIG. 10 is a detailed schematic diagram of the circuits for detecting excessive water conductivity and lack of water in the hydrogen generator; and
FIG. 11 is a detailed schematic diagram of the circuits for detecting the failure of the hydrogen generator to achieve a selected pressure.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but 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.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and referring first to FIG. 1, there is shown a gas generator which produces hydrogen and oxygen by the electrolysis of deionized, distilled water in an electrolytic cell C. Deionized, distilled water is the only liquid contained in the apparatus, and must be replenished as it is consumed. Gas generators of this type are intended for use in gas chromatography, flame ionization detectors, sulfur monitors, and other equipment requiring a source of pure hydrogen.
Deionized, distilled water for the electrolysis process is stored in reservoirs 1 and 2. The reservoir 1 includes a sensor 3 for simultaneously sensing both the presence and the purity of water in the reservoir, as will be described in more detail below. If the sensor 3 detects either an inadequate water supply or impure water, it produces a signal which automatically interrupts the supply of electrical power to the cell C. This prevents damage to the electrolytic cell because supplying electrical power to the cell without an adequate supply of water, causes dissociation of the water contained within the solid-electrolyte membrane in the cell. This irreversibly "dries out" the membrane, thereby destroying the membrane and requiring replacement. Similarly, if the electrolytic cell were allowed to run with an impure water supply, the membrane would soon become contaminated with impurities. Again this would destroy, and require replacement of, the membrane.
As an additional protective measure the reservoirs 1 and 2 may be provided with a deionizing agent sealed in a porous envelope or bag 4 to alleviate the problem of possible membrane contamination from small quantities of impurities, including metal ions generated in the closed-loop water system.
The reservoirs 1 and 2 are preferably positioned above the electrolytic cell C so that water flows into the cell by gravity. The water levels in the reservoirs remain virtually the same since they are connected in parallel to a common water supply line 5 to the cell. Thus, the water flows from the reservoirs 1 and 2 through respective lines 6 and 7 which converge at a Y connection 8 to the supply line 5. A check valve 9 is provided in the supply line 5 downstream of the connection 8 to prevent the back flow of water into the lines 6 and 7.
A drain line 5a is connected to the water supply line 5 via T connection 5b. This drain line 5a can be used not only to drain the system when desired, but also to connect the system to an auxiliary or larger water supply reservoir for applications where it is desired to have the unit operate continuously for periods longer than can be accommodated by the two reservoirs 1 and 2.
The water enters the water-tight housing of the electrolytic cell C through an inlet port 10. The inlet port 10 leads to an internal conduit 11 which conducts the water to an anode chamber 12, located directly beneath an ion-exchange membrane 14 which serves as the solid electrolyte for the cell. A cathode chamber 13 is formed directly above the membrane 14, and an electrical power supply (not shown in FIG. 1) is connected across the electrodes in the two chambers 12 and 13 so that the water is dissociated into ionic hydrogen and oxygen via electrolysis. The positively charged hydrogen ions are transported across the ion-exchange membrane 14 into the cathode chamber 13 along with water molecules. The negatively charged oxygen ions recombine at the anode to form molecular oxygen within the anode chamber 12.
The oxygen-enriched water exits the anode chamber 12 through an internal conduit 15 leading to an outlet port 16 which communicates with a return conduit 17 to return the oxygen-enriched water to the reservoir 2. The return conduit 17 includes an oxygen vent 18 which separates the oxygen gas from the water by venting the oxygen to the atmosphere. The reservoir 2 preferably includes a similar vent in its cap 19 which vents any oxygen remaining in the water that is returned to this reservoir.
Within the cathode chamber 13, the positively charged hydrogen ions combine to form molecular hydrogen. These hydrogen molecules, along with any water molecules transported across the membrane 14, flow out of the cathode chamber 13 through a conduit 20 into a hydrogen-water separator 21. The water remains at the bottom of the separator 21 where a float valve 22 opens to discharge water into a conduit 23 whenever the water rises above the desired level. This insures that the upper region of the separator 21 remains open for the collection of hydrogen gas. Thus, hydrogen diffuses from the water into the upper region of the separator 21 for collection and further processing.
The water conduit 23 returns the water therein to the reservoir 1 via outlet port 24, return line 25 and a hydrogen vent 26 which separates entrained hydrogen gas from the water by venting the hydrogen to the atmosphere. The cap 27 of the reservoir 1 preferably includes a similar vent which removes any remaining hydrogen from the water that is returned to this reservoir. Pressure for returning water from the separator 21 to the reservoir 1 is provided by the accumulated hydrogen in the separator, which forces water through the conduit 23 whenever the float valve 22 is open.
The hydrogen gas that accumulates in the separator 21 has a certain amount of water vapor entrained therein. This water vapor must be removed from the hydrogen because most uses for the hydrogen require pure hydrogen. Part of the water is removed from the hydrogen gas by passing the gas through a coalescing filter 28 in the upper region of the separator 21. As is well known, a coalescing filter forms a tortuous path which removes liquid droplets from a gas flowing therethrough.
In accordance with a further feature of this invention, the hydrogen is further dried by passing it through a drying tube made of a material which selectively adsorbs water vapor from gas flowing through the interior of the tube, and transfers the adsorbed water to the exterior of the tube. Thus, from the separator 21, the hydrogen passes upwardly through a conduit 30 to a drying coil 31 which removes a substantial portion of the water vapor from the hydrogen gas. The absorbed water then passe through the walls of the tubing and is evaporated from the outside surface of the tubing. Examples of suitable drying coils are described in more detail in U.S. Pat. Nos. 3,735,558 and 4,705,543. Other drying devices, such as a water trap for example, could be used in place of the drying tube.
From the drying coil 31, the hydrogen gas passes into a desiccator chamber 33 filled with a desiccant such as silica gel or a molecular sieve, either of which can be regenerated from time to time rather than being replaced. The partial drying of the hydrogen before it reaches the desiccator chamber 33 extends the intervals at which the desiccant must be regenerated. The gas flows downwardly through the desiccant and exits at the bottom of the chamber 33 through a tube 34.
The release of hydrogen gas from the unit is controlled by a shutoff valve 35 which connects the tube 34 to a hydrogen output port 36. A pressure gauge 37 monitors the hydrogen pressure in the conduit 34 and is mounted on the front panel of the generator to display the pressure reading to the user. A pressure transducer 38 also monitors the hydrogen pressure in the tube 34 and produces a corresponding electrical signal which is used to control the electrical power supplied to the electrolytic cell, as will be described in more detail below.
A preferred embodiment of the electrolytic cell of the present invention is shown in FIG. 2. This cell has a watertight housing 100 which clamps a solid polymeric ion-exchange membrane electrolyte 107 between a catalytic cathode 102 and a catalytic anode 103. These electrodes 102 and 103 preferably have a thickness of at least about 0.020 inch each. Electrical power is supplied to the cathode 102 through two attachment points 102a and 102b at opposite ends thereof, and the anode 103 receives electrical power through two similar attachment points 103a and 103b. The heat generated by resistance is directly related to the distance the current must travel through the resistor. The electrodes in electrolytic cells act as resistors, and thus, heat is generated as a current is passed through them. The heat generated in the electrodes of the present invention is substantially reduced by providing two electrical inputs for each electrode. Gaskets 106, 109 and 110 are provided to insure a water-tight construction for the electrolytic cell. In addition, a gasket 105 is provided between the anode 103 and the base of the housing 100 to electrically insulate the anode 103 from the base of the housing 100. This gasket 105 also has sufficient thermal conductivity to ensure good heat transfer from the electrodes into the housing 100, which serves as a heat sink. The housing 100 in turn is fastened to a metal chassis which also becomes part of the heat sink.
The two gaskets 106 and 109 are preferably laminates having a catalytic screen 101 disposed between two non-conductive annular gaskets. The screen is in electrical contact with the adjacent electrode and functions as a part of that electrode. To ensure that the screens firmly engage the respective electrodes, as well as the solid-electrolyte membrane 107, a pressure disc 108, of the same diameter as the screens, is disposed between the cathode 102 and the uppermost gasket 110 so that when the two housing sections are drawn together, the disc 108 exerts pressure on the screens. Water enters the cell housing 100 through a tee connection 111 connected to the housing by a stem 112, with the other end of the tee leading to a drain port. Water and oxygen are removed from the housing via an outlet 113, and water and hydrogen are removed from the separator 21 via an outlet 114 in the housing 100.
Although the invention has been illustrated with only one electrolytic cell, i.e., one pair of electrodes and one ion-exchange membrane, it will be understood that two or more cells may be stacked on top of each other in a single housing in order to increase the hydrogen-producing capacity of the unit.
FIG. 3 illustrates a preferred embodiment of the hydrogen-water separator 21. The separator is constructed as an elongated, cylindrical vessel attached to the electrolytic cell housing and communicating with the cathode chamber of the electrolytic cell through the inlet port 20. Hydrogen-enriched water enters the separator through the inlet port 20, and the water level gradually rises around a hollow stem 201 fitted into the top of the housing 100. The float valve 22 cooperates with the stem 201 and is constructed from a tube 202 attached to a base 203 which in turn is attached to a hollow float valve body 204 sealed by a top 205. The tube 202 telescopes over the stem 201 having a central bore 206 extending along its axis. The tube 202 has two slots at its upper end to facilitate the flow of water between the main vessel of the separator 21 and the stem 201.
As the level of hydrogen-enriched water rises in the separator, the float assembly valve 22 lifts off the stem 201, thereby opening the top of the stem 201. Hydrogen-enriched water flows through the stem to a conduit within the top of the housing 100 and then on to the main reservoir 1, thereby lowering the water level in the separator 21. When the water level in the separator is sufficiently low, the float valve 22 seats on top of the stem 201, thereby closing the water return line to the reservoir 1.
If the float valve 22 should ever become inoperable, a ball valve 207 at the top of the separator chamber ensures that water never exits the separator 21 into the hydrogen conduit 30. If the water level should ever rise to the position of the ball valve 207, a ball 208 rises into a socket 209, sealing the outlet tube 30. The ball valve 207 protects the rest of the unit from contamination by liquid water, and also protects any sensitive equipment the operator may have connected to the hydrogen outlet port.
The hydrogen-water separator also includes a pressure relief valve 210 connected to a port 211 in the side wall of the main vessel of the separator 21. In the event that the pressure in the hydrogen collection becomes too great, the relief valve 210 will open, relieving the pressure. Accordingly, this valve prevents any accidental increase in pressure in the separator over acceptable limits which could damage the unit, any equipment connected to the unit, or the operator. The relief valve 210 is particularly important in view of the fact that the ball valve 207 can close the only other gas exit from the separator 21.
As discussed above, the ion-exchange membrane utilized in electrolytic cell gas generators is very delicate. For example, a sudden release of pressure in the separator can delaminate the membrane and render it inoperable. The float ball valve 207 included in the hydrogen gas collection chamber will prevent such a sudden loss of gas pressure in the unit. For example, if the outlet valve 35 were to be open to the outside atmosphere without resistance, hydrogen would rush out, rapidly reducing the pressure in the system. However, in the event of such an occurrence, the rapid flow of hydrogen past the ball 208 will lift the ball into the socket 209, sealing the outlet tube 30. This will prevent any damage to the ion-exchange membrane.
Turning now to FIG. 4, there is shown a block diagram of the preferred electrical circuits in the hydrogen generator. To provide a selected pressure of hydrogen gas, the pressure of the hydrogen gas is measured with the pressure transducer 38, and the hydrogen generator cell C is supplied with an amount of electrical current that is regulated in response to the difference between the measured pressure and the desired pressure. The desired pressure is indicated by the reference voltage from the pressure adjust potentiometer 502, and a differential amplifier 503 compares the reference voltage to a pressure-indicating voltage from the pressure transducer 38 to provide a control signal for regulating the electrical current to the cell.
Instead of using the output pressure as the controlling parameter, the hydrogen flow rate in the hydrogen output line could be used as the controlling parameter. This would be desirable for certain applications where a controlled flow rate is more important than a controlled pressure. In this case, the pressure transducer 38 would be replaced with a flow rate sensor, such as by sensing differential pressures in the hydrogen output line.
The preferred method of regulating the current to the cell is pulse width modulation of signals gating a pair of silicon controlled rectifiers. Therefore, a pulse width modulator 504 is responsive to the control signal from the differential amplifier 503 and provides variable-width gate pulses to the SCR circuits 505. To limit the cell current to a safe value, the cell current is sensed by a threshold comparator 506 which provides a signal to inhibit the pulse width modulator 504 when a predetermined maximum cell current is reached.
To ensure that the hydrogen generator operates within guaranteed specifications, the current to the hydrogen-generating cell C is shut off entirely when certain conditions occur. The sensing of these conditions triggers a one-shot 507 that is reset only upon cycling a power switch "off" and then "on". In the usual case appropriate maintenance or servicing would be performed when the power switch is off before it is turned back on. For convenience of circuit design the one-shot shuts off the current to the hydrogen cell by driving the reference voltage from the potentiometer 502 to an extreme minimum value. Alternatively, the one-shot 507 could directly inhibit the SCR circuits 505.
Normally the voltage across the anode and cathode in the hydrogen generator cell C will not exceed a known maximum voltage. To shut off the hydrogen generator when the cell voltage exceeds the maximum voltage, a cell voltage threshold detector 508 supplies a shut-down signal to the one-shot 507.
To generate hydrogen gas and to avoid permanent damage to the solid electrolyte in the hydrogen generator cell C, the solid electrolyte should always be immersed in water. Also, to guarantee that pure hydrogen is generated and to avoid contamination of the solid electrolyte, the water must be deionized and should have a resistivity of at least a certain minimum value such as 100,000 ohm/cm. These conditions are insured by a water quality and level detector 509 that provides a shut-down signal to the one-shot 507 in the absence of a minimum level of high quality water in the hydrogen generator cell C.
When the hydrogen generator is unable to provide hydrogen gas at the desired pressure, a hydrogen leak might be the cause. Therefore, a mass leak detector 510 provides a shutdown signal to the one-shot 507 when the hydrogen pressure fails to increase at a predetermined minimum rate if it has not already reached the desired pressure.
Turning now to FIG. 5, there is shown a simplified diagram of the pulse width modulator 504 and the SCR drive and power control circuits 505. The pulse width modulator 504 includes a resistor 511, a capacitor 512, directional diodes 513 and 514, and a level detector 515. Associated with the pulse width modulator 504 is a transistor 516 and a resistor 517 which are responsive to a source 518 of pulses at the zero crossings in the 60-Hz. or 50-Hz. voltage from the power lines. The transistor 516 applies the pulses to the reference voltage from the potentiometer 502 and the pulses are transferred through the differential amplifier 503 and cause the output of the differential amplifier to go negative and be clamped by diode 513 so that the capacitor 512 is discharged to approximately ground potential through the diode 514 during each zero crossing. The pulses are relatively narrow and therefore during the absence of the pulses the capacitor 512 is charged through resistor 511 up to a value responsive to the difference or between the desired pressure and the measured pressure.
To provide pulses at a 120-Hz. or 100-Hz. rate and at phase angles proportional to the pressure difference, the voltage across the capacitor 512 is applied to a level detector 515 which has a predetermined threshold above ground potential. Pulses from the level detector 515 are applied to the gates of the SCRs 519 and 520 which are wired to the hydrogen generating cell C and a center-tapped secondary of a power transformer 521 in a full-wave rectifier circuit. Since the gating pulses to the SCRs occur at a variable time delay from the zero crossings in the power line voltage, the conduction angle of the SCRs and the current through the cell are adjusted in response to the difference between the desired pressure and the measured pressure.
Turning now to FIG. 6, there is shown a simplified schematic diagram of the water quality and level detector circuits 509 which interrupt the supply of electrical power to the electrolytic cell whenever (1) the water level in the reservoir becomes too low, or (2) impure water is present in the reservoir, e.g., as a result of the addition of tap water rather the deionized distilled water. These circuits include the water probe 3 having a pair of spaced electrodes disposed in the water reservoir 1, an oscillator 531 for energizing the electrodes, a first differential amplifier 532 and a second differential amplifier 533. The first differential amplifier 532 senses the voltage across a resistor 534 which is in series with the water probe 3. The second differential amplifier 533 senses the voltage across the water probe 3. The value of the resistor 534 and the respective gains of the differential amplifiers 532 and 533 are selected so that both of the differential amplifiers provide respective alternating-current output signals that are substantial only when the resistance between the electrodes of the water probe falls within a predetermined range. If the level of the water in the water reservoir 1 falls below the tips of the electrodes in the water probe 3, then an insubstantial amount of current will flow through the resistor 534. In this case only the second differential amplifier 533 will generate a substantial output signal. Conversely, when the resistivity of the water falls below the minimum resistivity, then only the first differential amplifier 532 will generate a substantial output signal.
To indicate the error conditions, the outputs of the two differential amplifiers 532, 533 are wired in a bridge circuit including directional diodes 535, 536, 537, and 538; resistors 539, 540, 541, and 542; and transistors 543 and 544. When both of the amplifiers 532 and 533 generate substantial signals, then the diode bridge is balanced and neither of the transistors 543 and 544 is activated. When the water has a resistivity that is too low, the signal from the first differential amplifier 532 cause the diode 535 and the transistor 543 to conduct, thereby signaling that the water should be changed. When water is absent from between the electrodes of the water probe 3, then the signal from the second differential amplifier 533 causes the diode 538 and the transistor 544 to conduct, thereby signalling that the water level is low.
It will be understood that sensors other than electrodes may be used to sense the "charge water" or "low water" conditions. For example, an optical sensor or a float switch could be used to sense the water level.
Turning now to FIG. 7, there is shown a simplified schematic diagram of the massive leak detector 510. The massive leak detector is operative only when the hydrogen pressure has failed to reach the desired pressure. This condition is detected by a comparator 550 that compares the reference voltage from the pressure adjusting potentiometer 502 to the pressure indicating signal from the pressure transducer 38. The differential amplifier 550 is matched with the differential amplifier 503 of FIG. 5 so that the output signal of the amplifier 550 will be at a positive voltage only when the hydrogen generating cell is energized and the measured pressure has failed to reach the desired pressure. Under these conditions, the hydrogen generating cell should generate a sufficient amount of hydrogen gas to increase the pressure at a substantial rate until the measured pressure reaches the desired pressure.
To determine whether the measured pressure is substantially increasing, the massive leak detector 510 includes a capacitor 551 which is periodically connected by a controlled switch 552 to the output voltage of the pressure transducer 38. The switch 552 is pulsed closed at the prescribed intervals. The increase in the pressure-indicating voltage over the prescribed interval appears as a voltage pulse across a resistor 553 in series with the capacitor 551. If the hydrogen generator is operating properly, then the voltage pulse turns on a transistor 555.
A massive leak is detected when the transistor 555 fails to be turned on within a prescribed time interval whenever the measured pressure is below the desired pressure. For this purpose the output of the comparator 550 charges a capacitor 557 through a resistor 556, and the capacitor 557 is connected to the collector of the transistor 555 to discharge the capacitor when the transistor turns on. The voltage across the capacitor 557 is fed to a shutdown detector that has a predetermined threshold voltage to which the capacitor 557 is charged by the comparator 550 unless the transistor 555 turns on.
When a massive leak is present, the measured pressure will fail to reach the desired pressure and hence the capacitor 557 will be charged. Also, the measured pressure will fail to increase at a rate sufficient to turn the transistor 555 on to discharge the capacitor 557. Therefore, the shutdown detector 558 will assert a signal indicating the presence of the massive leak and fire the one shot 507 (FIG. 4) permanently.
Turning now to FIG. 8, there is shown a detailed schematic diagram of the preferred circuits associated with the pressure-adjusting potentiometer 502, the one-shot 507 and the pressure transducer 38. The electronic circuits are powered by a secondary 560 of the power transformer 521 that is separate from the secondary 561 that supplies current to the hydrogen-generating cell C. The primary of the power transformer 521 is connected to the power lines through a switch 562.
To provide positive (+VCC) and negative (-VCC) supply voltages for the electronic circuits, the secondary coil 560 has a grounded center tap and is connected to a bridge rectifier 563. The positive and negative outputs of the bridge rectifier 563 are shunted to ground through respective electrolytic filter capacitors 564 and 565. In addition, the positive and negative output voltages of the bridge rectifier 563 are regulated by respective positive and negative voltage regulators 566 and 567. The outputs +VCC and -VCC are shunted to ground by respective electrolytic capacitors 568 and 569.
To provide a voltage reference for the pressure transducer 38, the output of the positive voltage regulator 566 is connected through a voltage-dropping resistor 570 to a zener diode 571. The voltage across the zener diode 571 is buffered by an amplifier 572 having its gain set by resistors 573 and 574.
To measure the hydrogen gas pressure, the pressure transducer 38 has a balanced resistive strain gage bridge 575, and the difference voltage across the bridge is amplified by a pair of differential amplifiers 576 and 577 that are wired so as not to amplify common mode signals. The amplifiers work in connection with feedback resistors 578, 579, 580, and 581.
The pressure-adjusting potentiometer 502 is connected through resistors 517 and 583 to the reference voltage from the amplifier 572. The voltage reference, however, is removed from the pressure-adjusting potentiometer 502 when the one-shot 507 is triggered by a shut-down signal. The bistable element of the one-shot is an SCR 584 having a snubbing capacitor 585 and resistor 586. The cathode of the SCR is biased by resistors 587 and 588 to a negative voltage between ground and -VCC. To trigger the SCR, a transistor 589 receives the shut-down signal and is wired as an emitter follower to drive the gate of the SCR through a current-limiting resistor 590 and a shunt resistor 591.
The voltage across the pressure-adjusting potentiometer 502 is also interrupted periodically by pulses at the zero crossings in the power line voltage. The pulse generator circuits 518 include a transistor 516 having its emitter held at a negative voltage by a resistor 593 connected to ground and a resistor 594 connected to -VCC. To turn the transistor 516 on and off at the zero crossings of the power line voltage, the transistor is normally turned off by a negative voltage from either one of two directional diodes 595 and 596 connected to the AC inputs of the bridge rectifier 563. The base of the transistor 516 is connected to these diodes 595 and 596 through a resistor 597, and is also connected to the positive supply +VCC through a resistor 598, and the values of the resistors 597 and 598 are selected so that the transistor 516 is turned on for a short time during each zero crossing. The base and the emitter of the transistor 516 are shunted by a directional diode 599 to prevent the base of the transistor from being reversed biased.
Turning now to FIG. 9 there is shown a detailed schematic diagram of the differential amplifier 503, the pulse width modulator 504, the SCR drive and power control circuits 505, the maximum cell current feedback circuits 506, and the cell over voltage detector 508. The pressure-indicating signal from the pressure transducer (38 in FIG. 8) is applied to the differential amplifier 503 through a low-pass filter including series resistors 610 and 611, and a shunt capacitor 612. The gain of the differential amplifier 503 is set by a feedback resistor 613. The level detector 515 includes a differential amplifier 614 having a threshold set by a voltage divider including resistors 615 and 616. To generate a positive pulse when the threshold is exceeded, the output of the differential amplifier 614 is connected to a capacitor 617 which in turn is connected to a positive feedback resistor 618. The capacitor 617 is also shunted to ground by a clamping diode 619 and a resistor 620 so that positive pulses are generated across the resistor 620.
To drive the gates of the SCRs 519 and 520, the pulses across the resistor 620 are applied to the base of a transistor 621 wired in an emitter-follower configuration. The emitter of the transistor 621 is connected to respective series resistors 622, 623 and shunt resistors 624 and 625 which are in turn connected to the gates of the SCRs.
In order to indicate that the SCRs are being turned on, the collector of the transistor 621 is fed by current through a light-emitting diode 626 having its anode connected to +VCC. A capacitor 628 supplies current for pulses to the SCR gates, and the capacitor 628 and a resistor 627 average these high current pulses to approximately d-c. for the light-emitting diode 626.
To limit the current through the silicon controlled rectifiers to a safe maximum value, the current is sensed by a series resistor 630 having a relatively low resistance. The current through this resistance creates a relatively small negative voltage which is low-pass filtered by a resistor 631 and an electrolytic capacitor 632.
The maximum cell current detector 506 further includes a differential amplifier 633 which compares the voltage across the capacitor 632 to a reference voltage provided by a voltage divider including a resistor 634 and a variable resistor 635. The gain of the amplifier 633 is set by a series resistor 636 and a negative feedback resistor 637. The output of the amplifier 633 is fed back to the threshold-detecting amplifier 614 through a directional diode 638. When the current through the hydrogen-generating cell C is less than a predetermined maximum value set by the variable resistors 635, then the diode 638 will be reverse biased, and the amplifier 633 will have a negligible effect on the threshold-detecting amplifier 614. However, when the current through the hydrogen-generating cell C exceeds the predetermined maximum limit, then the diode 638 is forward biased and the amplifier 633 will inhibit the threshold-detecting amplifier 614. Therefore, when the maximum current limit is exceeded, gate pulses will be applied at maximum phase to hold preset maximum current levels through the hydrogen-generating cell C.
The over voltage detector 508 shuts off the hydrogen-generating cell entirely when the cell voltage exceeds a certain maximum limit. The cell voltage is low-pass filtered by a resistor 640 and an electrolytic capacitor 641. The cell over voltage detector 508 further includes a differential amplifier 642 having a gain set by a series resistor 643 and a negative feedback resistor 644. The desired voltage threshold is provided by a resistor voltage divider including resistors 645 and 646.
The amplifier 642 is connected to the transistor 589 of the one-shot circuit 507 of FIG. 8, through a directional diode 647 and a resistor 648. Therefore, when the cell voltage exceeds the threshold value, the amplifier 642 forward biases the diode 647, and current flows through the diode to turn on the transistor 589 in FIG. 8 to trigger the one-shot (507 in FIG. 8) and shut off the current to the hydrogen-generating cell C.
Turning now to FIG. 10, there is shown a detailed schematic diagram of the water quality and level detector 509. The oscillator 531 includes an integrated circuit 650 that works in connection with capacitors 651, 652, resistors 653, 654 and directional diodes 655 and 656. The signal from the integrated circuit 650 is coupled through a tantalum capacitor 657 to the current-sensing resistor 534. Due to the rather high resistance being sensed, the signal across the water probe 3 is buffered by a follower amplifier 658 before being applied to the amplifiers 532 and 533. The first amplifier 532 works in connection with resistors 659, 660, 661 and 662, and the second amplifier 533 works in connection with a coupling capacitor 663 and resistors 664, 665, and 666.
The outputs of the amplifiers 532, 533 are connected to the diode bridge including the diodes 535 to 538 and the resistors 539 to 542. The midpoints of the diode bridqe are connected to the transistors 543 and 544. To reject noise, the midpoints of the bridge are shunted to ground by resistors 667, 667a and capacitors 668 and 669.
To indicate the "charge water" or "no water" error conditions, the collectors of the transistors 543 and 544 are connected to respective light-emitting diodes 670 and 671 which share a common current-limiting resistor 672. To shut off the current to the hydrogen-generating cell (C in FIG. 9) when either the "change water" or "no water" error is detected, the voltage across the current-limiting resistor 672 is coupled through a capacitor 673 to the voltage reference in the cell over voltage detector 508 of FIG. 9. This is the most convenient method of connecting the water quality detector to the one-shot 507 of FIG. 8.
Turning now to FIG. 11 there is shown a detailed schematic diagram of the massive leak detector 510. The pulse generator 554 includes an integrated circuit 680 working in connection with capacitors 681, 682 and resistors 683 and 684. The controlled switch 552 is preferably an optical coupler. The light-emitting diode of the optical coupler 552 is connected to the output of the integrated circuit 680 through a current-limiting resistor 685. Preferably a directional diode 686 shunts the controlled switch 552 to ensure that the phototransistor of the switch is not reverse biased.
The differential amplifier 550 works in connection with resistors 687, 688 and 689. The amplifier 550 charges the capacitor 557 through a directional diode 690 and the resistor 556. When the output voltage of the amplifier 550 is negative, the capacitor 557 discharges through the resistor 556 and a shunt resistor 691.
The capacitor 551 should have low leakage and is preferably a polycarbonate capacitor.
As shown in FIG. 11, it is preferable to provide an amplifier 692 between the resistor 553 and the transistor 555. The amplifier 692 works in connection with a capacitor 693 and resistors 694, 695 and 696. The output of the amplifier 692 is coupled to the transistor 555 through a network including directional diodes 697 and 698, a capacitor 699 and resistors 700 and 701.
When the measured pressure has been substantially increasing and the electronic switch 552 closes, a relatively small voltage pulse is generated across the current sensing resistor 553 but this voltage pulse is amplified by the amplifier 692 to have a sufficient amplitude to turn on the transistor 555. The transistor 555 will therefore discharge the capacitor 557. The collector of the transistor 555 is connected to the capacitor 557 through a current limiting resistor 702. If, however, the pressure is not substantially increasing and the amplifier 550 has a positive output voltage indicating that the desired pressure has not been reached, then the capacitor 557 will charge up to the threshold of the one-shot (507 of FIG. 8) to shut down the hydrogen-generating cell (C in FIG. 9).
As one feature of the present invention, water is recycled from the hydrogen-water separator to the anode side of the electrolytic cell by returning water from the separator to the water reservoir. This feature permits water to be supplied continuously from the reservoir to the anode chamber, without the need to periodically reverse the movement of water molecules through the solid electrolyte and the attendant danger of drying out and irreversibly damaging the electrolyte. | Apparatus for generating hydrogen by the electrolysis of water comprising an electrolytic cell having a cathode and an anode separated by a solid electrolyte, an electrical power supply connected to the cell for applying a voltage across the cathode and anode, a water reservoir connected to the cell for supplying water to the anode side, a hydrogen-water separator connected to the cell for receiving hydrogen and water from the cathode side and separating the hydrogen from the water, and a water return line connecting the hydrogen-water separator to the water reservoir for returning water to the water reservoir whereby the water is recycled to the anode side. A float valve in the upper region of the hydrogen-water separator closes the hydrogen outlet in response to an increase in the water level in the separator to the level of the hydrogen outlet, to prevent water from entering the hydrogen outlet in the event of a malfunction. A pressure relief valve in the hydrogen-water separator discharges hydrogen from the separator to the atmosphere in response to an increase in the gas pressure in the separator beyond a predetermined level. A sensor in the water reservoir producing an electrical signal in response to a drop in the water level in the reservoir to a predetermined level, or in response to a predetermined change in the electrical conductivity of the water, and control circuitry responds to the electrical signal for interrupting the supply of electrical power to the cell. | 2 |
BACKGROUND
In a typical data storage system management application, various physical and logical aspects of the data storage system may be displayed in a hierarchical manner on a graphical user interface (GUI). In order to re-arrange logical aspects of the data storage system, a typical implementation requires properties fields of the various elements to be textually modified. For example, in order to add a logical unit of storage (LUN) to a storage group, a storage group properties box is opened, and a button is clicked to indicate that a new LUN should be added to that storage group. This would bring up a dialog box asking the user to select a particular LUN from a list of known LUNs to add to that storage group.
SUMMARY
Unfortunately, these conventional data storage system management applications are deficient. In particular, they require a cumbersome procedure to rearrange elements. In contrast, embodiments of the present invention improve upon those conventional data storage system management applications by allowing a Drag & Drop (DnD) method of rearranging logical aspects of the data storage system. In a particular embodiment, the DnD feature is implemented with the aid of a properties file.
In one embodiment, a method is provided, the method including (a) storing a set of drag-and-drop properties associated with an object in a properties file, the properties file being stored on a tangible computer readable medium, and (b) implementing a program in software. The program includes an instantiation of the object and a method for handling DnD features associated with the instantiated object with reference to the set of DnD properties stored in the properties file.
In another embodiment, a method is provided, the method including (a) receiving an indication that a user is attempting to drag a graphical representation of an object, (b) determining the type of the object, (c) determining if the type of the object is identified by a source element in a properties file, the properties file being a text file written in a markup language and the properties file storing one or more source elements, each source element identifying a valid source for a DnDoperation, (d) if the type of the object is identified by a source element in the properties file, allowing the user to drag the graphical representation of the object, and (e) if the type of the object is not identified by a source element in the properties file, forbidding the user from dragging the graphical representation of the object. In another embodiment, computer software for performing this method is provided. Other embodiments are also provided, such as a data structure for a properties file.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention.
FIG. 1 illustrates an example computer window displaying an example object hierarchy in accordance with one embodiment. The figure also displays an example of a DnD operation.
FIG. 2 illustrates an example system for use in practicing an embodiment.
FIG. 3 illustrates an example properties file of one embodiment.
FIG. 4 illustrates an example method for performing a DnD operation in accordance with one embodiment.
FIG. 5 illustrates an example method for developing a software application to perform a DnD operation in accordance with one embodiment.
DETAILED DESCRIPTION
FIG. 1 depicts a window 30 of a data storage system management application displaying an example object hierarchy 32 of the data storage system. For example, a domain is shown in an expanded format, having within it hosts, storage processor A, storage processor B, a physical folder, a LUN folder, a RAID groups folder, and a storage groups folder. The elements with a “+” sign next to them are displayed in a collapsed format, while the elements with a “−” sign next to them are displayed in an expanded format.
As depicted, storage group 1 includes one LUN, LUN 2. Some objects may be dragged in order to alter the logical arrangement of the data storage system. For example, a user may drag LUN 1 onto storage group 1 , as depicted by arrow 34 . This operation would cause LUN 1 to be added to storage group 1 .
FIG. 2 depicts an example system 38 for use in practicing an embodiment. Host 40 is connected to a network 42 . Host 44 and host 46 might also be connected to the network 42 . One or more storage enclosures (SEs) 48 are also connected to the network. SE 48 contains a plurality of disk drives 50 , for example, 240 disks 50 . SE 48 also contains two storage processors 52 , 54 .
Host 40 connects to the network 42 by means of a network interface 56 . Host 40 also contains local storage 58 , a processor 64 (which may include one CPU or multiple CPUs running in parallel), and memory 66 . Local storage 58 stores a properties file 62 , located within a path 60 .
Memory 68 includes a management application 68 , which includes a drag & drop subsystem 70 . Management application 68 runs on processor 64 and accesses storage hierarchy 32 , which is stored in memory 68 . Management application 68 is able to access properties file 62 .
FIG. 3 depicts an example properties file 62 of one embodiment. As depicted, properties file 62 is an XML file, having an introductory XML tag at the beginning. It should be understood, that in other embodiments, properties file 62 could be another type of markup file, such as an SGML file. In yet other embodiments, properties file 62 could be yet another type of file, such as a binary data file.
As depicted in FIG. 3 , properties file 62 includes a header 82 and a footer 84 . Header 82 and footer 84 may represent a drag & drop element, as indicated by the <Dnd> and </Dnd> tags.
Between the header 82 and footer 84 , properties file 62 contains one or more source elements 86 (for example, source elements 86 ( a ), 86 ( b )). It should be understood that in some embodiments, the properties file 62 can contain multiple source elements, while in other embodiments, several properties files 62 are maintained, each properties file 62 including only one source element 86 . Each source element 86 contains a header 88 , one or more body elements 90 , and a footer 92 . Header 88 is a start-tag containing an identification of the element type (in this case “Event” indicating a source element) and an attribute definition 94 defining the SourceKey attribute. In first source element 86 ( a ), SourceKey is defined to be EV_LUN, indicating that the source element represents a LUN. In second source element 86 ( b ), SourceKey is defined to be EV_Host, indicating that the source element represents a Host. The presence of a source element 86 with a particular SourceKey definition in a properties file means that a drag & drop resource corresponding to that SourceKey definition is a valid draggable element. Footer 92 is an end-tag, formally closing the source element in accordance with standard XML.
Body elements 90 , such as target elements 90 ( a - d ), define valid drag & drop elements onto which a source drag & drop element may be dropped. Each target element 90 includes two attribute definitions 96 , 98 . Target definition 96 defines TargetKey to be a particular valid drag & drop target element onto which the source element defined by the SourceKey of the parent source element may be dropped. Action class definition 98 defines ActionClassName to be a reference to an action class to be called when the source element defined by the SourceKey of the parent source element is dropped on the target defined by TargetKey. As depicted, ActionClassName is a fully qualified JAVA method name.
According to properties file 62 as depicted in FIG. 3 , a LUN element is a draggable element, which may be dropped onto a storage group (represented by TargetKey=“EV_Virtual Array”), a RAID group (represented by TargetKey=“EV_RaidGroup”), or another LUN (represented by TargetKey=“EV_LUN”), while a Host element is also a draggable element, which is droppable only on a storage group (represented by TargetKey=“EV_Virtual Array”). When a LUN element is dropped onto a storage group, the JAVA method com.company.product.storagefunctions.AddLUNToStorageGroup is called. When a LUN element is dropped onto a RAID group, the JAVA method com.company.product.storagefunctions.AddLUNToRaidGroup is called. When a LUN element is dropped onto another LUN, the JAVA method com.company.product.storagefunctions.ExpandLUNActions is called. When a Host element is dropped onto a storage group, the JAVA method com.company.product.storagefunctions.AddHostToStorageGroup is called.
FIG. 4 depicts a method 100 performed by a computer, such as host 40 from FIG. 2 , while running storage management application 68 , using drag & drop subsystem 70 . In step 110 , host 40 receives an indication that a user is attempting to drag a graphical representation of an object across a computer screen. For example, the user attempts to drag LUN 1 of object hierarchy 32 of FIG. 1 . It should be understood that the dragged object is a drag & drop object, for example as defined in the JAVA standard java.awt.dnd package as well as in the standard Swing library. The notification may be made by a JAVA watch class, such as the javax.swing.TransferHandler class as is well-understood in the art, although other well-known means of notification may be used as well.
Upon receiving the indication of a drag operation, step 120 is performed. In step 120 , host 40 determines the type of the dragged object. Thus, in the example, the type of the object would be EV_LUN, since it is a representation of a LUN being dragged. Once this is done, in step 130 , it is determined if that object type is identified by a source element 86 of properties file 62 (see FIG. 3 ). If the object type is not identified by a source element 86 in the properties file 62 , then, in step 133 , the user is forbidden from dragging the graphical representation of the object across a computer screen. However, in the current example, since properties file 62 includes the line <Event SourceKey=“EV_LUN”>, in step 135 , the user is permitted to drag the object.
In a continuation of method 100 , the user may attempt to drag the object over another object. Thus, continuing in the above example, the user may attempt to drag LUN 1 over Storage Group 1 . Thus, in step 140 , host 40 receives an indication that the user has dragged the graphical representation of the dragged object over a graphical representation of another object, the other object being another logical or physical unit of a data storage system. Following step 140 , in step 150 host 40 determines the type of the other object over which the first object was dragged. Thus, in this example, the type of the object would be determined to be an EV. VirtualArray, since it is a representation of a storage group.
In step 160 , host 40 determines if the type of the other object is identified by a target element 90 in the properties file 62 nested within a source element 86 which references the object, the target element 90 identifying a valid target for a drag-and-drop operation having a source identified by the corresponding source element 86 . If not, operation proceeds to step 163 , forbidding the user from dropping the first object over the second object. If, however, the proper target element 90 is found within the properties file 62 , then operation proceeds to step 165 , allowing the user to drop the first object over the second object. Thus, in the present example, because the source object is a LUN, host 40 examines source element 86 ( a ) (having SourceKey=“EV_LUN”) for a target element 90 having an attribute definition TaregtKey=“EV_VirtualArray”. Because target element 90 ( a ) has this attribute definition, a storage group is a valid object over which a LUN may be dropped.
In some embodiments, when a first object is dragged over a valid target object, a graphical representation is made on the screen indicating that the target object is a valid target, even if the first object is not actually dropped there. For example, if the target object is displayed on-screen in a collapsed format, when a user hovers the object over the target and the target is determined to be a valid target, the target object may be expanded to be displayed in an expanded format.
Once a user drops the first object on the second object, step 170 may be performed, host 40 extracting a reference to an action function from target element 90 . Thus, in the current example, because the second object corresponds to target element 90 ( a ), the ActionClassName attribute definition from target element 90 ( a ) is extracted, indicating a reference to an action method identified by the JAVA fully qualified name com.company.product.storagefunctions.AddLUNToStorageGroup. Then, in step 180 , host 40 calls the referenced action function. Thus, for example, action function com.company.product.storagefunctions.AddLUNToStorageGroup might cause host 40 to modify the object hierarchy 32 stored in memory to include LUN 1 within storage group 1 and to update window 30 to indicate this change.
In some embodiments, instead of a reference to an action method, a reference is made to an action class. Such an action class is written to implement a standardized JAVA interface. Thus, the interface may define an abstract executeActionClass method which is to be called upon the instantiation of the particular action class that implements the interface.
The method 100 of FIG. 4 may be implemented in software. The software may be stored on a tangible computer-readable medium. A tangible computer-readable medium may include, for example, a magnetic disk, an optical disk, or a non-volatile flash-based memory device. When executed by a computer (e.g., host 40 ), the software causes the method 100 to be performed.
FIG. 5 depicts a method 200 for developing a software application to perform a drag & drop operation in accordance with one embodiment. In step 210 , a programmer stores a set of drag-and-drop properties associated with an object in a properties file 62 , the properties file 62 being stored on a tangible computer readable medium, such as local storage 58 on host 40 . Properties file 62 , in some embodiments, includes multiple sets of drag-and-drop properties associated with multiple objects.
In step 220 , the programmer implements various function in software, such as, for example, JAVA. In sub-step 223 , the programmer defines a class corresponding to the object and writes code causing that class to be instantiated in at least one case. In sub-step 225 , the programmer writes software code (such as, for example, JAVA code) to implement method 100 . This implementation may include writing a DnD transfer handler class, which includes a function for parsing the XML in the properties file 62 as well as functions for determining whether a drag & drop object is draggable or droppable. It also contains code to call the appropriate action method when needed.
Method 200 is an improved method of implementing a drag & drop feature because it allows the draggability and dropability of various objects to be modified without making significant changes to the software code.
While various embodiments of the invention have been particularly shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
For example, while embodiments have been described as operating in a storage system context, the invention is not so limited. Thus, in other embodiments, drag & drop objects may represent objects that do not represent storage devices or other logical elements of a data storage system.
Furthermore, it should be understood that all embodiments which have been described may be combined in all possible combinations with each other, except to the extent that such combinations have been explicitly excluded.
Furthermore, it should be understood that the term “JAVA,” as used in this Specification, refers to the JAVA software platform, version 6.0, as promulgated by Sun Microsystems, Inc. of Santa Clara, Calif. “JAVA” was a registered trademark of Sun Microsystems, Inc. at the time of filing. It should also be understood that all references to JAVA are by way of example only. In fact, another software platform could be used instead of JAVA. | A method is provided, the method including (a) storing a set of drag-and-drop properties associated with an object in a properties file, the properties file being stored on a tangible computer readable medium, and (b) implementing a program in software. The program includes an instantiation of the object and a method for handling drag-and-drop features associated with the instantiated object with reference to the set of drag-and-drop properties stored in the properties file. Software and data structure methods are provided as well. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates to a multiple needle sewing machine or an embroidery machine, and more particularly relates to a needle changing means of the machine.
2. Description of the Prior Art:
A conventional multiple needle sewing machine or an embroidery machine has a block member to which a plurality of needle bars are provided movably in the vertical direction. The aforementioned machine has also a first means for arranging the plural needle bars at equal height, a second means for maintaining the resulting condition after completion of the operation of the first means, and a third means for moving the block member across a feeding line of a work to be sewn upon needle changing. Aforementioned three means are respectively controlled. In other words, each means has a control mechanism therefor. Thus, a conventional machine is rather or comparatively complex in construction.
SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide a multiple needle sewing machine having a needle changing means by which needle change operation may be performed by a single lever transferring action.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is side view of a multiple needle sewing machine in which a side plate is removed,
FIG. 2 is a partial sectional view of a portion of an arm,
FIG. 3 is a perspective view of a needle bar,
FIG. 4 is a cross sectional view along IV--IV line in FIG. 1,
FIG. 5 is a view for showing the relationship between a main shaft and a crank,
FIG. 6 is a portion of a top view of an arm,
FIG. 7 is a front view of a lever for needle bar changing,
FIG. 8 is a side view of the lever of FIG. 7,
FIG. 9 is a rear side view of the arm, and
FIGS. 10, 11 and 12 are views for showing operation upon needle changing by the lever of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 through 12, numeral 1 denotes an overhanging arm having therein a main shaft 2 and a needle bar crank 3 rotable together with the main shaft 2. The main shaft 2 is so constracted that it may be rotated by a driving means such as a motor.
The crank 3 is fixedly connected with a pin 4 which is rotatably connected to an upper end portion of crank rod 5. A guide member 6 is secured to the arm 1 by a screw means 7. On the guiding member 6, there is slidably mounted a sliding member 8 having an axial portion 8a. The axial portion 8a is loosely passed through a lower end portion of the crank rod 5 and is fixedly connected with a crank slide block 9 which is slidably fitted in a vertical groove 1a of the arm 1. The sliding member 8 is also connected having a member 10 with a projection 10a. Thus, the member 10 and the sliding member 8 are moved on the guide member 6 in the vertical direction upon rotation of the main shaft 2.
Three parallel bars 12a, 12' and 12" are arranged in a block member 11 so as to be movable in the vertical direction. Any one of the three needle bars 12, 12' and 12" is brought into engagement with the projection 10a by moving the block member 11 across the feeding line of the work as described later in detail.
Numeral 13 denotes a guide member with a bent portion 13a and is fixed to the arm 1 by a screw means 14. An inner face 13b of the bent portion 13a is so opposed to an inner surface 1b of the arm 1 that the block member 11 may be movable between the inner surfaces 13b and 1b. The leftward movement of the block member 11 in FIG. 2 is ajustable by a screw means 15.
As seen from FIG. 3, the needle bar 12 has a slot 12a, an annular V-groove 12b and a longitudinal groove 12c. The needle bars 12' and 12" have a similar construction to the needle bar 12.
Numeral 16 denotes a plate having three projections 16a, 16b and 16c, and is fixed to the block member 11 by a screw means 17. The projections 16a , 16b and 16c are respectively in engagement with the longitudinal grooves 12c, 12'c and 12"c so as to prevent the rotation of the needle bars 12, 12' and 12".
Numeral 18 denotes a slightly flexible plate having at the lower end portion thereof a slot 18b. The plate 18 is movably connected to the block member 11 by a stepped screw means 19 in the vertical direction. An upper end portion of the plate 18 is bent substantially perpendicular thereto and is divided into three pawl portions 18a, 18a' and 18a".
Between the plates 16 and 18, there is disposed a spring 20 so as to lift the plate 18 in the upward direction. Thus, the three pawl portions 18a, 18a' and 18a" of the plate 18 are respectively in engagement with grooves 12b, 12'b and 12"b of the needle bars. In FIGS. 1 and 2, only the slot 12a of the needle bar 12 is in engagement with the projection 10a of the member 10 so that the needle 51 connected to the needle bar 12 may be used and the grooves 12'b and 12"b of the other needle bars are respectively in engagement with the pawl portions 18a' and 18a" so that needles 51' and 51" respectively connected to the needle bars 12' and 12" may be spaced from a throat plate 52 at a distance while the needle 51 is being in use.
A bracket 21 is fixedly connected to the front side of the arm 1 as seen from FIGS. 6 thru 8 and has an open space 21b in the upward direction. The space 21b is provided at the side wall thereof with three notches 21a, 21a' and 21a". A shaft 22 is rotatably connected to the front side of the arm 1 and is secured with a plate 24 having a cam portion 24a by a screw means 25. Between the plate 24 and the front side of the arm 1, there is inserted a swing plate 23 having a substantially rectangular aperture 23a whose four corners are curved or rounded. The cam portion 24a of the plate 24 is fitted in the rectangular aperture 23a so that the swing plate 23 may be moved together with movement of the plate 24.
An operating lever 26 is provided at an upper end portion with a knob 27 and a lower end portion of the lever 26 is pivotably connected to an ear portion 24b of the plate 24.
A pushing rod 29 passing through the arm 1, is provided at the right end portion with a tongue portion 30 so as to be engageable with the lever 26. At a left portion of the rod 29, there is formed a bore 29a in which a spring 31 is inserted for urging a slider 32 within a slot 32a. A pin 33 is passed through the rod 29 and is in sliding engagement with the slot 32a so that the slider 32 may be movable at a distance (FIG. 8).
At the rear side of the arm 1, a swing member 34 is located and pivoted thereto at a center portion 34a of the member 34 (FIGS. 6 and 9). In FIG. 6, the swing member 34 is urged by a spring 36 disposed between the member 34 and the arm 1 and is rotated in the clockwise direction with the result that the member 34 is brought into engagement with the left end portion of the rod 29.
At a rear projection 1c, there is loosely inserted a shaft 37 to which a lever 38 is fixedly connected by a screw means 39 (FIG. 1), and to which a swing member 40 with a projection 40a is fixedly connected by a screw means 41 (FIGS. 1 and 9). As seen from FIG. 6, the lever 38 has a horizontal portion 38a which is located above the needle bars 12, 12' and 12".
On the arm 1, there is movably supported a shaft 50 opposite end portions of which are respectively connected to the block member 11 and a connecting member to which a screw means 44 is connected. Numeral 43 denotes a rod and opposite end portions thereof are respectively connected to the shaft 50 via screw means 44 and the swing plate 23 by a stepped screw means 46. Numeral 47 denotes a stopper having a horizontal portion connected to the arm 1 by a screw means 48 and a upward portion with adjustable screw means 49. Movement of the shaft 50 is restricted by the screw means 49 (FIGS. 2 and 9).
In operation, when the knob 27 is pushed in the frontward direction or is moved from a solid line position to a phantom line position in FIG. 8, the lever 26 is rotated about the pin 28 in the counter-clockwise direction with the result that the lever 26 is disengaged from the notch 21a". Due to the counterclockwise or frontward movement of the lever 26, the rod 29 is brought into movement against the spring 31 in the frontward direction and then the swing member 34 is rotated in the counterclockwise direction against the spring 36 (FIG. 6).
Upon the counterclockwise rotation of the swing member 34, the projection 40a of the swing member 40 is brought into engagement with the end portion of the slot 34b and is rotated in the clockwise direction. The swing member 40 and the lever 38 are so connected on the common shaft 37 that the lever 38 is then moved in the clockwise direction (FIG. 10). Particularly, as to the lever 38, due to the clockwise rotation thereof, the horizontal portion 38a of the lever 38 is lowered and is brought into engagement with the needle bars 12' and 12". Upon further downward movement of the horizontal portion 38a of the lever 38, the height of the needle bars 12' and 12" is lowered against the pawl portions 18a' and 18a" so as to be equalized to that of the needle bar 12. In detail, slots 12a, 12'a and 12"a are brought into alignment with each other in the horizontal direction (FIGS. 10 and 11).
Next, under this condition wherein slots 12a, 12'a and 12"a are in alignment with each other, the knob 27 is transferred from the solid line position to the phantom line position indicated at 27" (FIG. 7). Upon aforementioned transfer of the knob 27, the knob 27, the lever 26, the plate 24 with the cam portion 24a and the swing plate 23 are rotated in the counter-clockwise direction. Thus, rod 43 connected to the swing plate 23 and the shaft 50 are moved in the rightward direction with the result that the projection 10a of the member 10 is brought into the slot 12a" of the needle bar 12" (FIG. 12).
Upon release of the knob 27 positioned at 27" after engagement of the projection 10a of the member 10 with the slot 12'a of the needle bar 12", the lever 26 is held in the notch 21a" and the block member 11 is unmoved. Simultaneously, the swing member 34 is returned to its original position after clockwise rotation and the lever 38 is lifted to its original position. After upward movement of the lever 38, the needle bars 12 and 12' are moved in the upward direction by upward urging of the spring 20 and are held at a height upon respective engagement of grooves 12b and 12b' with pawl portions 16a and 16a'.
In FIGS. 7 and 12, if the pitch between the needle bars 12 and 12" is indicated by X, the amount of movement of the shaft 50, the rod 43 and the swing member 23 has to be X. However, it is difficult to form the pitch between the needle bars 12 and 12' as X/2 and to form the pitch between the needle bars 12' and 12" as X/2. Therefore, it is possible to generate an error β as to each of aforementioned pitches. Similarly, error α is possible as to the amount of movement of the swing member 23. Such errors α and β can be eliminated by adjusting the screw means 15 and/or 49. | In a multiple needle sewing machine having a plurality of needle bars and a block member to which they are moveably mounted, a lever device can be located at any one of a plurality of positions corresponding to that of a specific needle bar. During transfer of the lever from one position to another, the block member is moved across the feeding line of a workpiece to be sewn and another needle bar corresponding to another lever position is brought into operative connection with a crank. | 3 |
[0001] Applicant claims the benefits of provisional application Ser. No. 61/888,106, filed Oct. 8, 2013. The present invention introduces a novel structure for connecting cylindrical parts having internal, eccentrically positioned parts requiring engagement.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] In a world where mechanization is state-of-the-art, various mechanical parts are necessarily connected with one another to create a path for the flow of energy, for example. Typical among such parts are cylindrical parts which, when connected, create a path for the uninterrupted flow of fluids, electricity, and other such elements.
[0004] For myriad reasons, the connection between cylindrical parts, even such parts which are of identical diameter, can be a difficult task. Not surprisingly, such connections can often be found at the point where access is severely limited and the ability to get a wrench or other tool on a connector is not only difficult, but in some instances, perhaps impossible.
[0005] Overview of the Prior Art
[0006] Joining cylindrical members, such as pipes or cylindrical housings, is usually done in one of three methods: flange connection, that is where a flange is formed or otherwise positioned at the connection point on the cylindrical members to be joined and then the flanges themselves are joined together. Also there may be a threaded connection, and, finally, the use of welds is used where it is safe to do so, and there is no need to get into the cylindrical members for maintenance and repair once they are joined.
[0007] However, if there are internal elements that must be joined, and those elements are not concentric within the cylindrical parts being joined, an obvious problem has been created. The prospect of using a threaded connection is obviously vitiated. Otherwise stated, if there are internal components, the connections of which are eccentric, relative rotation of the cylindrical members to be joined is not feasible, and use of a conventional threaded connection is not possible. In those cases, either a flange connection is used, or the two members are welded.
SUMMARY OF THE INVENTION
[0008] As will become apparent from a reading of the detailed description of the present invention, it is a singular objective of the present invention to provide to industry a very simple and straightforward device for effecting a connection between cylindrical casings, or the like, including internal ports being also interconnected within very restricted and limited space.
[0009] It is a further objective of the present invention, related to the foregoing, to provide an effective seal between cylindrical parts in limited spaces, which seal is capable of being unsealed for maintenance, replacement or repair.
[0010] There are certain situations where the cylindrical members have a restricted outer diameter, such as oil field downhole assemblies, which usually must fit snugly within boreholes or casing, and a conventional external flange is not feasible. In these cases, an internal flange can be used. This type of flange is commonly used for oilfield downhole producing equipment. The disadvantage of such a flange connection is the significant restriction in inner diameter at the neck of the flange.
[0011] If the internal components of the members to be joined have eccentric connections require a greater inside diameter than allowed by the internal flange, one is forced to resort to a welded connection. However, welded connections may not be either feasible, due to temperature sensitivity of the equipment or components inside the housing, or desirable due to the resulting unit being of a greater length than can be easily handled. Welding also changes the metallurgy of the housing material, which can weaken it or make it more vulnerable to corrosion.
[0012] The present invention provides a method to securely join two cylindrical members via a threaded connection, while allowing the eccentric components connections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a cross-section through a typical internal flange connection between downhole components of an electrical centrifugal pump;
[0014] FIG. 2 is a perspective view of the ends of two cylindrical members to be joined, showing the eccentric location of components to be connected during the process;
[0015] FIG. 3 is a perspective side view of the same two cylindrical members in position to be joined;
[0016] FIG. 4 is a side view of the doubly threaded coupling, with a window in the coupling showing the internal threads;
[0017] FIG. 5 is a perspective side view of the doubly threaded coupling, showing the right-hand threads on the inside right surface of the coupling;
[0018] FIG. 6 is a perspective view of the two cylindrical members with the coupling (shown semi-transparent) positioned for joining the two members together;
[0019] FIG. 7 is a perspective view of the two cylindrical members nearly completely joined via the rotation of the doubly threaded coupling;
[0020] FIG. 8 is a perspective view of the two cylindrical members completely joined by the coupling;
[0021] FIG. 9 is a side view of the two cylindrical members partially connected, with a window in the threaded coupling revealing the position of the infernal components;
[0022] FIG. 10 is the same side view as shown in FIG. 9 , with the two cylindrical members completely connected, with a window in the threaded coupling showing the final position of the internal components;
[0023] FIG. 11 is a perspective view of the ends of two cylindrical members to be joined, similar to FIG. 2 , showing the O-ring sealing elements of each of the cylindrical members;
[0024] FIG. 12 is a side view of the doubly threaded coupling for joining the cylindrical members shown in FIG. 9 , with a window in the threaded coupling revealing the position of the internal components;
[0025] FIG. 13 is a side view of the FIG. 11 embodiment showing the two cylindrical members partially connected, with a window in the threaded coupling revealing the position of the internal components;
[0026] FIG. 14 is the same side view as shown in FIG. 13 , with the two cylindrical members completely connected, with a window in the threaded coupling showing the final position of the internal components;
[0027] FIG. 15 is a side view of two cylindrical members to be joined, where the outer diameters of the perspective members are not equal; and,
[0028] FIG. 16 shows the FIG. 15 embodiment fully connected, with a window in the threaded coupling showing the position of the threaded portion of the cylindrical members.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The present invention has a particular, although not exclusive, beneficial use for those in the oil patch. By way of example, there are many situations where cylindrical members to be joined have a restricted outer diameter due to limited space within a borehole or casing, and the use of a conventional external flange connection is not feasible. In these cases, an internal flange can be used. This type of flange, shown in FIG. 1 , is commonly used for oilfield downhole producing equipment. The disadvantage of such a flange connection is the significant restriction in inner diameter at the neck of the flange.
[0030] If the internal components of the cylindrical members to be joined have eccentric connection, offset from the centerline of the cylindrical members, and require a greater internal diameter than allowed by the internal flange, oilfield workers today, until the advent of the present invention, have been forced to resort to a welded connection. However, welded connections may not be either feasible, due to temperature sensitivity of the equipment or components inside the housing, or desirable due to the resulting unit being of a greater length than can be easily handled. Welding also changes the metallurgy of the housing material, which can weaken it or make it to more vulnerable to corrosion.
[0031] FIG. 1 is a representation of a typical internal flange arrangement that is in current use in many production wells. Briefly, cylindrical members 20 and 22 are joined at flanges 24 and 25 by fasteners 26 . Note the great restriction in the diameter of the connecting neck 27 and 29 between the two cylindrical members.
[0032] FIGS. 2 through 10 show, in stark contrast, the current invention. FIG. 2 shows the ends of two cylindrical members, 28 , 30 , to be joined, with the left hand member 28 clearly showing an eccentrically located, male splined shaft 35 and locating dowel 37 , which are to mate with the female splined receptacle 39 and dowel bore 42 , respectively, in the right hand member 30 . Note that each of the two members has a cylindrical extension ( 44 left and 46 on the right) from the face of the member that is somewhat smaller in outer diameter than the rest of the member. The outer surface of these extensions is threaded, with the cylindrical extension 44 on the left member having a left-hand thread 48 , and the cylindrical extension 46 on the right member having a right-hand thread 51 .
[0033] FIG. 3 shows the two members lined up in preparation for joining.
[0034] FIGS. 4 and 5 show an internally threaded female coupling 53 . FIG. 4 shows a side view of the coupling, with a window in the coupling revealing the threads on the left inside surface 54 being left-handed, and those on the right inside surface 55 being right-handed. FIG. 5 is a perspective view of the coupling, showing the right hand female threads 55 on the inner surface of the right hand side.
[0035] Moving to FIG. 6 , the two members 28 , 30 are positioned to be joined with the threaded female coupling 53 (shown semi-transparent) situated between them. The left and right cylindrical members are pushed together, engaging the female threaded coupling 53 . The coupling, in keeping with the invention, is rotated as shown by arrow A in FIG. 7 , thereby engaging the threaded extensions 48 , 51 and pulling the two members together without requiring relative rotation of either member. This allows the splined shaft and locating dowel 37 to travel straight into the female splined receptacle 39 and dowel bore 42 as the members are drawn together by the rotation of the coupling, until the members seat firmly against one another as seen in FIG. 8 .
[0036] Note in FIG. 8 , which shows cylindrical members 28 and 30 firmly connected via female coupling 53 , there remains a gap 54 between the ends of the female coupling 53 and the edges 45 and 47 of the outer housings of cylindrical members 28 and 30 . As the connection between cylindrical members 28 and 30 is made up, as shown in FIG. 7 , the rotation of female coupling 53 draws the two cylindrical members 28 and 30 together, FIG. 9 , until the inner faces of cylindrical extensions 44 and 46 contact and bear on one another, as seen in FIG. 10 . At this point, female coupling 53 is tightened to the desired torque, and the connection is complete, This contact between the cylindrical extensions 44 and 46 occurs before the ends of female coupling 53 contacts the housing edges 45 and 47 , leaving a gap 54 . This is necessary to assure that the threaded connections between the female coupling 53 and the cylindrical extensions 44 and 46 are fully made up and evenly loaded.
[0037] FIGS. 2 through 10 show the basic principle of the current invention. However, in practice, the resulting connection between cylindrical members 28 and 30 will almost always require some mechanism to effect a pressure and fluid entry seal between the external environment and the inside of the joined cylindrical members 28 and 30 . FIGS. 11 and 12 show one commonly employed method to effect such a seal.
[0038] FIG. 11 shows the ends of the two cylindrical members 28 and 30 , to be joined, as shown in FIG. 2 , but with added sealing surfaces 60 and 64 outboard of the cylindrical extensions 44 and 46 . Sealing surfaces 60 and 64 are shown with O-rings 62 and 66 placed in O-ring grooves (not shown) machined into the sealing surfaces of 60 and 64 .
[0039] FIG. 12 shows a side view of the female coupling 53 adapted for the O-ring sealing of the connection between cylindrical members 28 and 30 , with the window in the coupling revealing the threads on the left inside sealing surface 55 being left-handed, and those on the right inside sealing surface 56 being right-handed, and the female sealing surfaces 61 and 65 , which fit snugly over the male sealing surfaces 60 and 64 , effecting a seal with O-rings 62 and 66 .
[0040] The two cylindrical members 28 and 30 , show in FIG. 11 , are joined via the internally threaded coupling 53 in the same manner as is shown in FIGS. 3, 6, 7, 8 , and 10 .
[0041] FIGS. 13 and 14 show the process of making up the connection between cylindrical members 28 and 30 , similar to what is shown in FIGS. 9 and 10 , with cylindrical members 28 and 30 drawn together by the rotation of female coupling 53 until the faces of cylindrical extensions 44 and 46 contact and bear against one another, leaving a gap 54 between female coupling 53 and the housing edges 45 and 47 of cylindrical members 28 and 30 , respectively.
[0042] Although the current invention is particularly well suited for joining cylindrical members with offset internal components, the current invention can just as easily be used to join cylindrical members with concentric components, or bores, in lieu of the more conventional internally flanged or threaded connection. Also, the current invention can be utilized to join cylindrical members of different outside diameters by using a female coupling 57 adapted to the different threaded diameters, as shown in FIGS. 15 and 16 .
[0043] It will be appreciated as well that those skilled in the art, upon reading this detailed description, may think of some variations in structure and form, such variations are within the contemplation of the invention as described and claimed in the following: | A device for the threaded connection of tubular members, particularly as used in the petroleum industry, which provides both the full strength and near full internal diameter of typical oilfield tubular threaded connections, with the ability to securely join two cylindrical members with eccentric internal connections. | 5 |
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention generally relates to semiconductor devices equipped with a test mode and a method for operating the same. More particularly, the present invention relates to a semiconductor device with a built-in measurement circuit that supports examinations of the semiconductor device when the semiconductor device is examined by a test apparatus such as an IC tester in a test mode.
2. Description of Related Art
FIG. 3 shows a conventional semiconductor device. In the semiconductor device shown in FIG. 3, buffer circuits 101 , 102 , 103 , . . . , each having two inverters, are inserted as input circuits between input terminals 1 , 2 , 3 ,. . . and an internal circuit 30 .
As shown in FIG. 3, when input data is applied to the input terminals 1 , 2 , 3 , . . . from a test apparatus such as an IC tester, the input data is supplied to the internal circuit 30 through the buffer circuits 101 , 102 , 103 , . . . , respectively. Therefore, when this type of semiconductor device is examined by using the test apparatus, logic levels to be inputted in the internal circuit need to be measured. For this purpose, it is proposed to provide a measurement circuit that operates in a test mode within the semiconductor device, to thereby measure logic levels that are inputted in the internal circuit. In the semiconductor device shown in FIG. 3, for example, AND circuits 21 , 22 , 23 , . . . , each including a NAND gate and an inverter, are provided as measurement circuits.
The AND circuits are connected to a series of the data input terminals in a chain like manner. More particularly, for example, input data from the second data input terminal 2 is supplied through the buffer circuit 102 to one of two inputs of the second AND circuit 22 . Also, an output from the AND circuit 21 that is connected to the second AND circuit 22 in an immediately proceeding stage is supplied to the other input of the AND circuit 22 . Furthermore, an output of the AND circuit 22 is supplied to one input of the AND circuit 23 , and input data from the third data input terminal 3 is inputted to the other input of the AND circuit 23 . In this manner, the multiple AND circuits are connected in a chain-like manner.
A test mode signal TEST is supplied through a test mode signal input terminal 60 to one input of the AND circuit 21 in the first stage. The test mode signal TEST is at high level in a test mode. Also, an output of one of the AND circuits in the last stage is supplied to one input of a selection circuit 70 . An output of the internal circuit 30 is supplied to the other input of the selection circuit 70 . The selection circuit 70 is controlled by the test mode signal TEST. The selection circuit 70 selects the output of the internal circuit 30 in a normal operation mode, and selects the output of the AND circuit in the last stage in a test mode. An output of the selection circuit 70 is read out through an output terminal 80 by an external device.
It is noted that, in the normal operation mode, the test mode signal TEST is at low level. Therefore, outputs from the AND circuits 21 , 22 , 23 , . . . are at low level without regard to the level of the input data. On the other hand, the test mode signal TEST is at high level in the test mode. Therefore, when input data on input systems other than an input system that is subject to measurement are fixed at high level, and the logic level of input data (for example, input data applied to the data input terminal 1 ) in the input system that is subject to measurement is changed, the logic level inputted in the input system of the internal circuit 30 is accordingly changed. The change is transferred through the AND circuits 21 , 22 , 23 , . . . that are connected in a chain-like manner, and outputted through the selection circuit 70 and then through the output terminal 80 . In this manner, the logic level of an input within the internal circuit 30 can be measured without regard to differences in the specification of the input circuits of the semiconductor device.
SUMMARY OF THE INVENTION
When the buffer circuits are used as input circuits in a manner shown in FIG. 3, a problem occurs when a power supply to a separate system that supplies input data is tuned off. In other words, in such an instance, the data input terminals of the semiconductor device are placed in a high-impedance state, an input to the buffer circuits may have a potential close to an intermediate potential between a power supply potential V DD and a power supply voltage V SS , i.e., a value of (V DD +V SS )/2. Alternatively, an input to the buffer circuits may have a potential close to a value of V DD /2 when a power supply voltage V SS is at a grounding potential. As a result, a drain current may constantly flow through the inverters that form the buffer circuits.
In order to prevent wasteful current from flowing even in the instance described above, some techniques are proposed. For example, an AND circuit 11 shown in FIG. 4 or an OR circuit 91 shown in FIG. 5 is used to form an input circuit instead of the buffer circuit 101 used in the semiconductor device shown in FIG. 3 .
Referring to FIG. 4, the AND circuit 11 includes a NAND gate and an inverter. One of input terminals of the NAND gate is connected to the data input terminal 1 . The other input terminal of the NAND gate is supplied with a control signal C that is internally generated in the semiconductor device. Even when the data input terminal 1 is placed in a high-impedance state, an output of the NAND gate of the AND circuit 11 is always at high level if the control signal C is maintained at low level. Therefore, wasteful current does not flow.
Referring to FIG. 5, the OR circuit 91 includes a NOR gate and an inverter. One of input terminals of the NOR gate is connected to the data input terminal 1 . The other input terminal of the NOR gate is supplied with a control signal C bar that is internally generated in the semiconductor device. Even when the data input terminal 1 is placed in a high-impedance state, an output of the NOR gate of the OR circuit 91 is always at low level if the control signal C bar is maintained at high level. Therefore, wasteful current does not flow.
However, when the semiconductor device having an input circuit that is formed with the AND circuit 11 shown in FIG. 4 is tested, the output of the AND circuit 11 is fixed at low level and does not change even when the logic level on the data input terminal 1 is changed, unless the control signal C is changed to high level. Also, when the semiconductor device having an input circuit that is formed with the OR circuit 91 shown in FIG. 5 is tested, the output of the OR circuit 91 is fixed at high level and does not change even when the logic level on the data input terminal 1 is changed, unless the control signal C bar is changed to low level.
Accordingly, when the AND circuit 11 shown in FIG. 4 or the OR circuit 91 shown in FIG. 5 is inserted in an input system of the semiconductor device having a measurement circuit that uses the AND circuits 21 , 22 , 23 , . . . shown in FIG. 3, the logic level of an input in the input circuit cannot be measured unless the internal control signal is changed.
In view of the above, it would be desired to provide a semiconductor device having an input circuit and a method for operating the same, in which the logic level of an input on the input circuit can be measured by a test apparatus such as an IC tester even when a gate circuit that uses an internally generated control signal is used in a first stage of the input circuit.
A semiconductor device in accordance with one exemplary embodiment of the present invention has an internal circuit in which input data is gated and supplied to the internal circuit according to an internal control signal generated within the semiconductor device. The semiconductor device has N number (N being two or greater integers) of data input terminals for inputting input data, and a test mode input terminal for inputting a test mode signal. An OR device is provided for obtaining a logical sum of the internal control signal and the test mode signal. The semiconductor device also has N number of gate circuits that are supplied with the input data applied to the N data input terminals, respectively. When an output of the OR device is active, those of the N gate circuits responsive to the output of the OR device pass the input data applied to the data input terminals. The internal circuit is supplied with outputs of the N gate circuits. The semiconductor device has a first stage AND device and second through Nth stage AND devices. The first stage AND device has a first input that is supplied with an output of a first one of the N gate circuits and a second input that is supplied with the test mode signal. The second through Nth stage AND devices respectively have first input terminals that are supplied with outputs of second through Nth ones of the N gate circuits, respectively, 25 and second input terminals that are supplied with outputs of the first through (N−1)th stage AND devices, respectively.
The semiconductor device may further include a selection circuit that selects an output of the internal circuit in a normal operation mode and selects an output of the Nth stage AND device in a test mode, and an output terminal that is supplied with an output of the selection circuit.
In the semiconductor device, the internal control signal and an output of the OR device may be active at high level. Alternatively, the internal control signal and an output of the OR device may be active at low level.
By a semiconductor device having the structure described above in accordance with the embodiment of the present invention, even when a gate circuit that uses an internally generated control signal is used in one of the input circuits in the first stage thereof, the operation of the gate circuit can be controlled by using a test mode signal. Therefore, the logic level of an input in the input circuits can be measured by using a test apparatus such as an IC tester.
Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate, by way of example, various features of embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a structure of a semicoductor device in accordance with a first exemplary embodiment of the present invention.
FIG. 2 schematically shows a structure of a semiconductor device in accordance with a second exemplary embodiment of the present invention.
FIG. 3 schematically shows a structure of a semiconductor device including buffer circuits in an input system.
FIG. 4 shows an example of a gate circuit that is inserted in the input system of the semiconductor device.
FIG. 5 shows another example of a gate circuit that is inserted in the input system of the semiconductor device.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a structure of a semiconductor device in accordance with a first exemplary embodiment of the present invention. Referring to FIG. 1, the semiconductor device has a plurality of data input terminals 1 , 2 , 3 , . . . , N. It is noted that FIG. 1 shows only three data input terminals, and fourth through Nth data input terminals are omitted to simplify the illustration. Input data are inputted to the respective data input terminals 1 , 2 , 3 , . . . , N from an external test apparatus. Also, the semiconductor device also has a test mode signal input terminal 60 . A test mode signal TEST that is at high level in a test mode is supplied to the test mode signal input terminal 60 from the external test apparatus.
The semiconductor device of the present embodiment includes AND circuits 11 , 12 , 13 , . . . N as gate circuits that gate the input data. The input data applied to the data input terminals 1 , 2 , 3 , . . . , N are supplied to an internal circuit 30 of the semiconductor device through the AND circuits 11 , 12 , 13 , . . . N that provide logical multiplication of the input data and an internal control signal C. It is noted that FIG. 1 shows only three AND circuits 11 , 12 , 13 as gate circuits, and fourth through Nth AND circuits are omitted to simplify the illustration. Each of the AND circuits 11 , 12 , 13 , . . . . N include a NAND gate and an inverter. Input data is supplied to one of two inputs of each of the NAND gates from the corresponding one of the data input terminals, and an output from an OR circuit 50 is inputted in the other input of each of the NAND gates. The OR circuit 50 includes a NOR gate and an inverter. The internal control signal C that is internally generated in the internal circuit 30 is inputted in one of two inputs of the NOR gate of the OR circuit 50 and the test mode signal TEST is inputted to the other input of the NOR gate of the OR circuit 50 . The OR circuit 50 provides a logical sum of the internal control signal C and the test mode signal TEST.
Even when the internal control signal C is normally at low level in the test mode, the test mode signal TEST is at high level. As a result, the output of the OR circuit 50 is at high level. Therefore, when the logic levels of the data input terminals 1 , 2 , 3 , . . . , N are changed, outputs of the AND circuits 11 , 12 , 13 , . . . . N are accordingly changed.
Furthermore, the semiconductor device includes AND circuits 21 , 22 , 23 , . . . , N as measurement circuits within the semiconductor device.
Each of the AND circuits 21 , 22 , 23 , . . . . N includes a NAND gate and an inverter. It is noted that FIG. 1 shows only three AND circuits 21 , 22 , 23 as measurement circuits within the semiconductor, and fourth through Nth AND circuits are omitted to simplify the illustration.
A first one ( 21 ) of the AND circuits as measurement circuits has a first input that is supplied with an output of a first one ( 11 ) of the AND circuits as gate circuits and a second input that is supplied with the test mode signal. Second one ( 22 ) through Nth AND circuits as measurement circuits have first inputs that are supplied with outputs of the second ( 12 ) through Nth ones of the AND circuits as gate circuits, respectively, and second inputs that are supplied with outputs of immediately preceding ones of the AND circuits as measurement circuits (i.e., the AND circuit 21 through (N−1)th AND circuit), respectively.
In one embodiment, for example, input data from the second data input terminal 2 is supplied through the AND circuit 12 (i.e., second gate circuit) to one of two inputs of the second stage AND circuit 22 . Also, an output from the AND circuit 21 in an immediately proceeding stage is supplied to the other input of the AND circuit 22 . Furthermore, an output of the AND circuit 22 is supplied to one of two inputs of the AND circuit 23 in the next stage, and input data from the third data input terminal 3 is inputted to the other input of the AND circuit 23 . In this manner, the multiple AND circuits are connected to one another in a chain-like manner.
The test mode signal TEST is supplied to one of two inputs of the AND circuit 21 in the first stage. Also, an output of the AND circuit in the measurement circuits in the last stage (i.e., the Nth stage AND circuit) is supplied to one of two inputs of a selection circuit 70 . An output of the internal circuit 30 is inputted to the other input of the selection circuit 70 . The selection circuit 70 is controlled by the test mode signal TEST. The selection circuit 70 selects the output of the internal circuit 30 in a normal operation mode, and selects the output of the AND circuit in the last stage in a test mode. An output of the selection circuit 70 is read out through an output terminal 80 by an external device.
It is noted that, in the normal operation mode, the test mode signal TEST is at low level. Therefore, outputs from the AND circuits 21 , 22 , 23 , . . . , N are at low level without regard to the level of the input data. On the other hand, the test mode signal TEST at high level is provided in the test mode. Therefore, when input data on the input systems other than the input system that is subject to measurement is fixed at high level, and the logic level of input data on the input system that is subject to measurement is changed, the change is transferred through the AND circuits 21 , 22 , 23 , . . . , N that are connected in a chain-like manner and through the selection circuit 70 , and outputted from the output terminal 80 . In this manner, inputted logic levels on the AND circuits 11 , 12 , 13 , . . . , N can be measured without regard to variations in the specification of the input circuits of the semiconductor device.
Next, a second exemplary embodiment of the present invention is described below with reference to FIG. 2 . The second embodiment is different from the first embodiment in that OR circuits are used instead of the AND gates as gate circuits.
The semiconductor device of the second embodiment includes OR circuits 91 , 92 , 93 , . . . N as gate circuits that gate the input data. The input data applied to the data input terminals 1 , 2 , 3 , . . . , N are supplied to an internal circuit 30 of the semiconductor device through the OR circuits 91 , 92 , 93 , . . . N that provide logical sums of the input data and an internal control signal C bar. It is noted that FIG. 2 shows only three OR circuits 91 , 92 , 93 as gate circuits, and fourth through Nth OR circuits are omitted to simplify the illustration. Each of the OR circuits 91 , 92 , 93 , . . . N include a NOR gate and an inverter. Input data is supplied to one of two inputs of each of the NOR gates of the respective OR circuits 91 , 92 , 93 , . . . N from the corresponding one of the data input terminals, and an output from a NOR gate 51 is inputted in the other input of each of the NOR gates of the respective OR circuits 91 , 92 , 93 , . . . N. The internal control signal C bar that is internally generated in the internal circuit 30 is supplied through an inverter 52 to one of two inputs of the NOR gate 51 , and the test mode signal TEST is supplied to the other input of the NOR gate 51 . The inverter 52 inverts the internal control signal C bar to form an internal control signal C. The NOR gate 51 provides a logical sum of the internal control signal C and the test mode signal TEST, inverts its result and outputs the same.
When the internal control signal C bar is normally at high level in a test mode, the test mode signal TEST is at high level, and therefore an output of the NOR gate 51 is at low level. As a result, when logic levels on the data input terminals 1 , 2 , 3 , . . . , N are changed, outputs of the gate circuits 91 , 92 , 93 , . . . , N are accordingly changed.
The semiconductor device of the second embodiment has AND circuits 21 , 22 , 23 , . . . , N, each including a NAND gate and an inverter, a selection circuit 70 , and an output terminal 80 , in a similar manner as the first embodiment. Also, the semiconductor device of the second embodiment measures the logic levels of inputs to the internal circuit 30 in a similar manner conducted in the first embodiment.
It is noted that, in the exemplary embodiments described above, one type of internal control signal is used. However, the present invention is also applicable to other cases in which a plurality of internal control signals are used. In such cases, OR circuits in FIG. 1 or NOR gates 51 and inverters 52 in FIG. 2 may be provided in the same number of the internal control signals, respectively.
In accordance with the present invention, even when a gate circuit that uses an internal control signal is used in one of the input circuits in the first stage thereof, the operation of the gate circuit can be controlled by using a test mode signal. Therefore, the logic level of an input in the input circuits can be measured by using a test apparatus such as an IC tester.
While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | A semiconductor device is provided having an internal circuit in which input data is gated and supplied to the internal circuit according to an internal control signal generated within the semiconductor device. The semiconductor device has N number (N being two or greater integers) of data input terminals for inputting input data, and a test mode input terminal for inputting a test mode signal. An OR device is provided for obtaining a logical sum of the internal control signal and the test mode signal. The semiconductor device also has N number of gate circuits that are supplied with the input data applied to the N data input terminals, respectively. When an output of the OR device is active, those of the N gate circuits responsive to the output of the OR device pass the input data applied to the data input terminals. The internal circuit is supplied with outputs of the N gate circuits. | 6 |
BACKGROUND OF THE INVENTION
This invention concerns a mounting arrangement for a supplementary crop processing device for a harvester and more particularly, a mounting for a bulky, heavy device which is movable selectively between operating and non-operating positions, such as a straw chopper on a combine harvester.
In a typical combine harvester, either so-called conventional or rotary, straw from the separator is discharged downwardly from the hood structure at the rear of the combine. This straw is already somewhat reduced from the threshing and separating operations and, if it is desired to reduce it further, it is passed through a straw chopper.
The most common type of straw chopper consists of a transversely mounted flail rotor associated with a transverse array of fixed shear blades carried in a housing with an upwardly directed inlet opening and supported beneath the combine hood to intercept the flow of straw from the separator. In some harvesting conditions, or to preserve longer straw for some later use, it is desirable to return the straw to the ground without passing it through the straw chopper.
Two principal methods are known for removing the chopper from the path of the straw. U.S. Pat. No. 3,712,309 (Schmitz) discloses a chopper supported on a pair of approximately horizontal rails, one on each side of the combine hood. The straw chopper may be releasably secured in either a rearward operating position or in a forward transport (or inoperative position) in which the straw chopper is removed from the path of the straw flow from the separator. In a second method, embodied, for example, in the German-made John Deere combines model numbers 1065 and 1075, the straw chopper is supported on a linkage permitting it to be pivotably swung from a rearwardly operating position to a forward transport position. In a third approach, Scott (U.S. Pat. No. 4,526,180) inactivates the straw chopper for discharging the straw into a windrow by opening a door in the floor of the chopper casing, allowing the straw to be discharged before reaching the straw chopping rotor. The straw chopper unit, as a whole, remains fixed in relation to the combine hood.
These known methods of inactivating the straw chopper each have their disadvantages and limitations. In the simple slide arrangement of Schmitz, even if the slide could be maintained horizontal (which, with reference to the overall combine design, is generally not convenient), moving the chopper is difficult. Manually moving the chopper or man-handling it along the slides is made difficult by a combination of high frictional forces between the chopper and mating slide members and, if the chopper is not kept perfectly square with the combine, binding or jamming occurs. Given the widths of many modern combines and hence, the relatively large lateral spacing between the support rails of the chopper and the length of the chopper structure engagement with the rails, it is often difficult even for two men to move one of the larger choppers. Introduction of anti-friction devices (rollers or the like) at the sliding surfaces have been proposed, but these would not necessarily overcome the binding or cocking problem, would add to the cost of the chopper, and in some conditions, increase the hazards to the operator in moving the chopper by making it difficult to control on a slope, etc. (unless very sophisticated anti-friction devices were used, giving support and guidance in both horizontal and vertical planes).
The John Deere swinging linkage arrangement potentially costs more to manufacture than a simple slide (as in Schmitz) even if only a simple linkage is used. Use of a simple linkage limits the range of chopper position and attitude in the transport position. The swinging chopper approach requires relatively more sophisticated fastener or latching arrangements for securing the chopper in its two positions, contributing significantly to the potential increase in manufacturing costs compared with the simple slide arrangement.
The apparently simple convertibility of Scott is appealing, requiring only the raising or lowering of the lower front side portion or pan of the casing (58) allowing straw to be dumped straight through the straw chopper casing (15) and onto the ground without being chopped. However, the advantage of maintaining the straw chopper rotor in a fixed position relative to the straw discharge from the combine separator must require some tradeoff in terms of cost of sheet metal deflectors, space consumption, and optimization of feeding the chopper rotor if the rotor is to be effective both in and out of the flow material from the combine separator.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a combine harvester straw chopper mounting which is simple in structure and relatively low in manufacturing cost and which permits one man with moderate effort and improved safety to adjust the chopper fore-and-aft.
In accordance with the invention, a supplementary crop material processing device, such as a straw chopper, is supported on a pair of parallel, spaced-apart rails, which are required to provide only the vertical support for the chopper. Preferably, lateral positional stability and directional control of the straw chopper is maintained or achieved by rotatable drive means engageable between the chopper and the harvester structure and operative, on being rotated, to displace the chopper fore-and-aft on the rails, including moving the chopper between extreme positions of adjustment-operating and inoperative positions, respectively.
In a preferred embodiment of the invention, the drive means comprises a rack and pinion arrangement with the pinion associated with the movable straw chopper and the rack parallel to, or preferably forming part of, the guide rail structure of the harvester. A pinion assembly may comprise a transverse shaft substantially spanning the width of the straw chopper and carrying at each of its opposite ends, a pinion member in the form of an extended pitch sprocket with teeth spaced apart so as to be engageable with a matching series of "notches" (which may be openings, such as slots or holes, for example) in the harvester guide rail structure. The pinion shaft may be shaped in at least one location to be engageable by a tool, such as a wrench, for manually rotating the shaft. Preferably, the pinion sprockets are timed together and fixed non-rotatably to the shaft and, in manufacture and assembly, it is arranged that the corresponding notches forming the rack in the rail structure are in transverse alignment so that once the straw chopper assembly, including the teeth of the pinion sprockets, have been squarely engaged with the supporting guide rails of the harvesting structure, rotation of the pinion shaft will move the opposite sides of the straw chopper structure in unison so that it may be conveniently displaced in either direction along the rails, between opposite extreme positions corresponding to straw chopper operation and straw chopper disengagement.
It is a feature of the invention that the timing together of the twin pinion sprockets and the lateral alignment of the notches of the parallel "racks" formed by the guide rails, automatically maintain directional control of the chopper assembly and keep it square with the guide rails as it is being advanced or retracted along the guide rails. Alignment is maintained whether the straw chopper is moved by means of the drive mechanism (torque applied to the pinion assembly) or whether the chopper assembly is manually displaced along the guide rails. An additional feature of the automatic alignment is that if the ends of the rack portions of the spaced apart parallel guide rails are also in alignment, effective stops are provided at both ends and serve to precisely position the straw chopper in its operating position and in its inactive position, thus facilitating securing the chopper in those respective positions, for example, by the insertion of clamping hardware.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic left-hand side elevation of the rear portion of a self-propelled combine harvester embodying the invention.
FIG. 2 is an enlarged underside left front perspective showing the straw chopper and its support rails with the chopper in a rearward, operating position.
FIG. 3 is a further enlarged cross-sectional view approximately on line 3--3 of FIG. 2 showing the mechanism for slidably adjusting the straw chopper on its support rails.
FIG. 4 is an enlarged partial view, taken on line 4--4 of FIG. 3, with the chopper in its forward position, illustrating the "stop" function of the rack and sprocket.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention is embodied in an otherwise generally conventional self-propelled combine harvester, only the rear portion of which is shown in FIG. 1. The combine body 10 is carried by wheels, including a pair of steerable rear wheels 12 and includes straw walkers 14, a return conveyor 16 beneath the walkers, and a longitudinally reciprocating cleaning shoe including an upper screen or chaffer 18 and a lower screen or sieve 20. The rearward portion of the combine body 10 comprises a hood 22 forming an open bottomed chamber defined by opposite right- and left-hand side walls 24, 26, respectively, and a rear wall 28 providing a cover and protection for some of the combine components, including the straw walkers 14 and containing and directing the flow of straw from the straw walkers downwards, as indicated by arrow 30. A straw chopper assembly 32, generally conventional in terms of overall function and configuration, is carried by and beneath the hood 22 and is powered through a belt drive 34 extending along the left-hand side of the combine body 10. Looking at the combine hood 22 in more detail and referring particularly to FIGS. 2 and 3, the opposite lower edges of the hood side walls 24, 26 lie in a common generally horizontal plane and each side wall is turned inward to form a flange 40, 42, respectively. A pair of rails, right- and left-hand, 44 and 46, respectively, are attached to the respective hood side walls by suitable fasteners 48 and each rail is spaced downward from its side wall flange (40, 42), so as to create a pair of longitudinally extending guide spaces 50, 52. The horizontal flanges 54, 56 of the guide rails each have a series of uniformly spaced rectangular slots 58. In assembly, the foremost pair of slots 60, 62 and the rearmost pair of slots 64, 66 are in transverse alignment, as indicated in the case of the forward slots by the line 68 in FIG. 2. A baffle plate 70, disposed low and somewhat forward of the rear or discharge end of the straw walkers 14, transversely spans the hood 22 and is attached rigidly at its opposite ends to the hood side walls 24, 26.
The chopper assembly 32 need be described only briefly here. Its transverse rotor 80, powered by the belt drive assembly 34 and driven in the direction indicated by arrow 82, is at least partially contained in a casing 84 consisting of opposite end or side walls, right- and left-hand 86 and 88, respectively, and an upright rear wall 90. Partially wrapping the rotor 80 and forming a guide surface for crop material processing by the chopper assembly, is a wrapper or deflector wall 92 ending at a rearward transverse discharge edge 94 and extending upwards partially into the hood chamber to end in a transverse inlet or upper edge 96 which registers with the lower edge 98 of the fixed transverse baffle 70. Thus, with the straw chopper assembly 32 in the rearward, operating position shown in FIG. 1, the rearward or inner surfaces of the inner baffle 70 and the wrapper 92 form a continuous deflecting or guiding surface, directing discharge of straw from the chopper in the general direction indicated by arrow 100.
A vaned straw spreader assembly 110 is supported and extends rearwardly from the rear wall 90 of the straw chopper and is positioned so as to intercept the straw discharge from the chopper, directing it somewhat downwardly and, by virtue of its diverging vanes 111, spreading it over a width greater than that of the combine. The spreader assembly 110 is pivotably attached to the chopper rear wall 90 and braced by adjustable members 112 so that the angle of the spreader assembly 110, relative to the horizontal, can be changed.
The upper edges of the chopper side walls 86, 88 are bent outwards to form a pair of generally horizontal flanges 114, 116 and these flanges are reinforced by support angles 118, 120, attached to the chopper side walls and flanges by spot welding or other suitable means. For supporting the chopper assembly 32 on the hood 22, the double flanges thus formed along the upper edges of the chopper walls are entered into the spaces or channels 50, 52 so that the chopper assembly may be supported by the flanges 54, 56 of the hood guide rails 44, 46 and locked in position by suitable clamping hardware such as the nut and bolt assemblies 122 shown in the drawings.
In each side of the straw chopper assembly 32, adjacent the side wall flanges 114, 116, a pinion assembly support strap 130 is attached by suitable hardware and extends somewhat forward of the straw chopper wrapper 92. A pinion shaft 132 spans the combine hood 22 passing through holes 134 and the support straps 130. The left-hand end of the shaft 132 extends somewhat beyond the hood left-hand side wall 26 and drive surfaces, such as the parallel flats 136 (seen best in FIG. 3), are formed on its free end. A pair of "pinions" 138 are rigidly attached to the shaft 132 at a spacing equal to that of the transverse center spacing of the rows of slots 58 in the guide rails 44, 46. These pinions 138 are in the form of extended pitch sprockets with teeth 140 at relatively wide pitch centers matching the pitch center distance of the arrays of slots 58 in the guide rails 44, 46. The pinions 138 are timed together and the support straps 130 are positioned so that in assembly, the teeth 140 may enter the slots 58 in the guide rails 44, 46 as shown best in FIG. 3. As well as providing the possibility for driving the chopper assembly along its guide rails, the engagement of the pinions 138 with the slots 58 positions the shaft 132 laterally. A safety shield 142 in the form of a flanged disc is rigidly attached to the shaft 132 just outboard of the sprocket 138 on the left-hand side of the hood 22. The shaft 132, with attached sprockets 138 and shield 142 and with the support straps 132 loose on the shaft between the sprockets, comprise a sprocket sub-assembly 144.
In assembly of the straw chopper to the combine, the chopper assembly 32, less the sprocket sub-assembly 144, is positioned and supported by the rails 44 and 46 and moved forward so that when the sprocket sub-assembly 144 is attached to the chopper assembly, by means of attaching the support straps 130 to the side walls 86, 88 of the chopper with appropriate hardware, the opposite sprockets 138, laterally aligned, engage opposite slots 58 in the guide rails 44, 46.
In operation, the chopper assembly 32 is driven to the desired position, either fully rearward in an operating and chopping position as indicated in full line in FIG. 1, or fully forward to a windrowing or disengaged position, as indicated in phantom outline at 32' in FIG. 1. Provision of the flats 136 on the shaft 132 enables the shaft 132 to be rotated conveniently using a standard wrench on the flats 136 and hence, propelling the chopper assembly with the notches or slots 58 of the guide rails and the sprockets 138 functioning as a rack and pinion. Any initial misalignment of the chopper is corrected automatically when the shaft 132 is "torqued" and both sprockets 138 are brought into driving engagement with their respective slots 58. In both positions, the chopper assembly 32 is secured by hardware 122 as shown in FIG. 3.
The length of the arrays of slots 58 in the guide rails 44, 46 is sufficient only to provide drivable movement between the precise operating and disengaged or windrow positions. The corresponding, laterally aligned front and rear pairs of slots (60, 62 and 64, 66) are disposed so that, in either direction, engagement of a sprocket tooth 140 with the underside of a guide rail flange 54 or 56 (as shown in FIG. 4) "stops" the chopper assembly, squarely aligned and with holes in the guide rails substantially aligned for easy insertion of the securing hardware 122. Final maneuvering of the chopper assembly, if required for better hole alignment, is easily done by one person from one side of the combine using a wrench on the flats 136 of the shaft 132. Once the chopper assembly 32 has been properly assembled and aligned and the sprocket sub-assembly 144 is in position with sprockets 138 engaging the slots 58 of the guide rail, the rigid torsional connection between the pair of sprockets 138 provided by their attachment to the shaft 132 provides positive alignment for the chopper whether movement is by wrench on the shaft flats 136, or by sliding it manually on the rails. This latter operation may sometimes be convenient in cases where the chopper is freely movable on the guide rails and, for example, the guide rails slope slightly downward as they do in a forward direction in the present embodiment (as shown in FIG. 1). Sliding may be accomplished with no risk of binding through skewing of the chopper because of the positive aligning effect of the rigid sprocket sub-assembly 144, engaging the slots 58 of the parallel racks 44, 46.
The present invention greatly facilitates the adjustment and handling of a straw chopper supported and slidably movable on guide rails. An operator can simply drive the chopper from one position to another with very much reduced effort while the means of adjustment automatically maintains the alignment of the chopper. Application of the invention to a conventional chopper already carried on guide rails is accomplished cheaply and simply. Addition of the slots (58) to the guide rail (44, 46) makes the rail a dual purpose member-rack as well as supporting guide rail. The straw chopper assembly itself (32) need be modified only by adding mounting holes for the sprocket sub-assembly (144). Addition of the compact sprocket sub-assembly does not significantly increase the bulk of the straw chopper assembly.
In the present embodiment, the straw spreader deflector assembly 110 is carried entirely by the chopper assembly 32. In the operating position of the straw chopper (fully rearward position), the spreader assembly 110 is supported approximately horizontally, its angle being adjustable through the provision of a range of attachment holes for the braces 112. In the forward inoperative or windrow position (32'), the spreader assembly 110 is adjusted downwards, as indicated in phantom outline at 110' in FIG. 1, to allow unobstructed flow of straw from the straw walkers, directly downwards onto the ground for formation of a windrow. | The rear mounted straw chopper of a combine harvester receives the straw discharge from the straw walkers of the combine and discharges chopped straw rearwardly. The chopper is slidably supported on a pair of spaced apart, longitudinally oriented guide rails so that the chopper can be adjusted from a rearward, operating position to a forward, inoperative or windrow position in which straw bypasses the chopper. Movement of the chopper on its guide rails is facilitated by attachment to the straw chopper casing of a transverse shaft and sprocket assembly, the teeth of a pair of sprockets engaging longitudinally spaced openings in the guide rails so that, upon rotation of the shaft, the sprockets and guide rails cooperate in rack and pinion fashion to propel the chopper assembly along the rails while maintaining it in square alignment. The shaft and sprocket assembly may be rotated conveniently by means of a wrench engaging flats on an end of the shaft. | 0 |
REFERENCE TO RELATED APPLICATION
This application claims priority of a Provisional Patent Application filed Jun. 30, 2010, application No. 61/360,065, the contents of which are incorporated herein.
FIELD OF THE INVENTION
The present invention relates to a manually adjustable valve for controlling flow of inducted combustion air into an internal combustion engine.
BACKGROUND OF THE INVENTION
One form of drag racing which has become popular is known as bracket racing. The term “bracket” refers to a window of time that is required for the vehicle to start and complete a prescribed race course, typically a straight quarter mile course. In bracket racing, drag race vehicles are pitted against other such vehicles of generally similar racing abilities because for any given race, vehicles must have race times or alternatively stated, complete the course, in a time interval that is neither less than nor greater than the magnitude of the selected time interval or bracket.
The advantage of this arrangement is that it assures a fairly close race. Otherwise, all other things being equal, the race will be won by that competitor who has devoted more technical resources, and therefore financial resources, to developing a faster race vehicle. Limiting participation of race vehicles to predetermined time brackets both assures a close race, which is of greater interest to spectators, and imposes a limit on otherwise unlimited spending in an effort to become ever faster.
The concept of bracket racing essentially rewards consistency over sheer speed. That is, it becomes desirable to remain within a particular bracket to avoid disqualification in races. At the same time, it is desired to finish the race in an elapsed time period which is the minimum of the predetermined time bracket.
Vehicles for bracket racing have become so developed in their ability to finish races within a particular time bracket that influences such as ambient temperature, humidity, wind speed and direction, and other factors may cause a race vehicle to cover the course too fast and thus be disqualified, or to become slower to the point of being uncompetitive in the selected time bracket. A way of establishing fine control over maximum horsepower would address these problems.
In NASCAR racing, so-called restrictor plates are used to achieve a certain level of parity among race vehicles. While restrictor plates serve their intended purpose in stock car racing situations, they would not be truly useful in bracket constrained drag racing since they are fixed in their levels of control and cannot assure that the race vehicle on which one is placed will actually be limited to any particular elapsed time bracket.
There exists a need in bracket racing to be able to modify engines of race vehicles under closely controlled constraints to enable small adjustments of engine power to suit prevailing conditions in order for a particular race vehicle to qualify for and be competitive within a particular time bracket.
SUMMARY OF THE INVENTION
The present invention provides a compact device which is generally similar to a restrictor plate, but which provides ability to make fine adjustments to the degree of restriction which is achieved.
The novel restrictor device incorporates at least one adjustable restrictor which is movable to achieve infinite increments of adjustment, so that an engine may be tuned such that drag race results are confined to a particular predetermined elapsed time bracket. The adjustable restrictor moves laterally once placed on a typical engine, so that it moves perpendicularly to the flow of inducted air. The adjustable restrictor is compactly enclosed in a surrounding housing. One or more adjustment knobs may project laterally from the housing.
The number of restrictors may be more than one. Illustratively, in a currently preferred embodiment, two restrictors are provided, each restricting or controlling two carburetor bores of a four barrel carburetor for example. In this embodiment, each restrictor is provided with a common control shaft. The shaft may be passed through threaded holes formed in the housing, with the threading being of opposite hand so that the two restrictors are moved in opposite directions by the one control shaft.
It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is an exploded diagrammatic end view of a typical V8 or V6 engine, showing the mounting location of an adjustable restrictor according to an aspect of the invention.
FIG. 2 is an exploded perspective view of an adjustable restrictor according to at least one aspect of the invention.
FIG. 3 is a top plan view of the components of FIG. 2 , with the uppermost component removed to reveal internal positional details, with gate valve elements shown in one position of a range of adjustment positions.
FIG. 4 is a top plan view similar to FIG. 3 , but showing the gate valve elements adjusted to another position of the range of adjustment positions.
FIG. 5 is an exploded perspective detail view of one gate valve element and associated components.
DETAILED DESCRIPTION
Referring first to FIG. 1 , according to at least one aspect of the invention, there is shown an adjustable restrictor device 100 as it would be installed onto the intake manifold 10 of an internal combustion engine 12 . After assembly, the adjustable restrictor device 100 will be sandwiched between the intake manifold 10 and a carburetion device such as a carburetor 14 or fuel injection throttle body (not shown). The adjustable restrictor device 100 may be held in place by fasteners 16 which secure the carburetion device to the intake manifold 10 . Although shown as bolts, the fasteners 16 may comprise studs (not shown) anchored in the intake manifold 10 and cooperating nuts (not shown). After installation, the adjustable restrictor device 100 will be fairly inconspicuous and will add to only a limited degree to the overall height of the engine assembly. After installation, and as will be further detailed hereinafter, the adjustable restrictor device 100 may be utilized to control flow of inducted combustion air into the internal combustion engine 12 .
FIG. 2 shows the principal components of the adjustable restrictor device 100 , which principal components include a base 102 , a cover 104 , and two gate valves or restrictors 106 , 108 . The base 102 and cover 104 collectively form a housing comprising a face surface 110 which is disposed perpendicularly to the direction of combustion air flowing through the housing into the engine, such as the internal combustion engine 12 .
The base 102 and the cover 104 provide two complementing sections which when assembled result in an internal chamber being formed therebetween. The restrictors 106 , 108 are contained within the internal chamber.
The base 102 and cover 104 respectively bear a plurality of openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 , 128 for passing air into the engine. The openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 , 128 are formed in surfaces parallel to the face surface 110 , and further may be disposed in vertical registry with corresponding throttle bores (not shown) formed in the carburetion device. Illustratively, the carburetion device may be a four barreled carburetor (not shown) having four throttle bores. The openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 , 128 may each have an axis such as the axis 131 which coincides with the openings of the carburetor. It may be stressed at this point that the face surface 110 is important only in that it provides semantic basis for a hypothetical plane which passes through the adjustable restrictor 100 and is perpendicular to the flow of air through the various openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 , 128 .
After assembly, the base 102 and cover 104 seal the induction passage established by the carburetion device and intake manifold from ambient air, so that characteristics of air and fuel flow are not altered during passage from the carburetion device to the intake manifold. The role of the adjustable restrictor device 100 is to selectively increase and decrease maximum air and fuel flow so as to selectively limit maximum power which may be developed by the engine.
Increasing and decreasing air and fuel flow, which will be referred to subsequently as throttling, is accomplished by adjusting position of the restrictors 106 , 108 so as to selectively partially obstruct the effective surface area of the openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 , 128 . Although the restrictors may be moved in other directions if desired, results are obtained efficiently by moving the restrictors 106 , 108 perpendicularly to the direction of combustion air flowing through the adjustable restrictor device 100 , or alternatively stated, the restrictors 106 , 108 , which are supported by the housing and fully enclosed therein., are each disposed to move in a direction generally parallel to the face surface 110 of the housing.
The restrictor 106 may have gently rounded shallow troughs 172 , 174 formed therein. The restrictor 108 may have comparable troughs 175 , 177 .
The restrictors 106 , 108 may be disposed to move in mutual opposition to one another in the directions indicated by the arrows 128 , 130 in the following way. Each restrictor 106 or 108 may be controlled by a control shaft which may comprise a first control shaft section 132 and a second control shaft section 134 . The control shaft may have external threading sections 136 , 138 respectively, which external threading sections 136 , 138 cooperate with corresponding threaded holes 140 , 142 formed in the base 102 . The control shaft sections 132 , 134 are joined together, for example by welding, adhering, rivets, threaded fasteners, or other means (not shown) after inserting each control shaft section 132 or 134 into place from opposite sides of the housing. After the control shaft section 134 is passed through a hole 175 , and the control shaft section 132 is passed through a corresponding hole (not visible in the view of FIG. 2 ) from the opposite side of the housing, the tips of the two control shaft sections 132 , 134 may be welded together using the opening 180 for welding access. Alternatively the control shaft utilized may merely be a single rod with portions of thread of opposite pitch.
The resultant single control shaft is rotatably supported on the housing in an orientation such that it may move the restrictors 106 , 108 in opposite directions (such as indicated by the arrows 128 , 130 ) parallel to the face surface 110 of the cover 104 when rotated by either end (e.g., the section 132 or the section 134 ). Further rotation exerts a force on the respective restrictor 106 or 108 and moves the restrictor 106 or 108 to a new position. When supported in a threaded hole such as the threaded 140 or 142 , it follows that rotation of the enlarged head 144 or 146 will cause the control shaft to move helically.
The effect of moving the restrictors 106 , 108 to new positions is illustrated in FIGS. 3 and 4 . In FIG. 3 , the restrictors 106 , 108 are shown at the outer limits of travel such that the openings 120 , 122 , 124 , 126 are fully exposed to air flow. It should be appreciated that the control shaft (the welded control shaft sections 132 , 134 ) remains at a generally constant or unmoved location on the housing, and the restrictors 106 , 108 move laterally along the control shaft as they traverse the threaded portions 136 , 138 .
As seen in FIG. 4 , the control shaft may be rotated to adjust the restrictors 106 , 108 to new positions in which the openings 120 , 122 , 124 , 126 are partially obstructed. As depicted in FIG. 4 , this movement leaves a gap to the left of the restrictor 106 and a gap to the right of the restrictor 108 through which gaps the control shaft becomes revealed.
For convenience of operation, the control shaft projects to the exterior of the housing so as to be accessible for movement from the exterior thereof. The control shaft 134 may be grasped and rotated by hand using either of respective enlarged knurled heads 144 , 146 .
The control shaft also may perform the function of repeatably resetting the restrictors 106 , 108 . For example, the restrictors 106 , 108 may be adjusted to the fully obstructed position, and then adjusted by rotating the control shaft by a predetermined definite number of turns. The user may monitor ambient weather conditions such as barometric pressure, humidity, temperature, wind speed and direction, and the like, and may make adjustments to the initial setting established by the predetermined number of turns of the control shaft. The results may be noted, with degree of fine control due to weather conditions being factored in to modify the initial setting in subsequent racing.
The restrictors 106 , 108 may be arranged to move in mutual opposition to one another. That is, as the restrictor 106 is adjusted from the position shown in FIG. 3 to the position shown in FIG. 4 , the restrictor 108 moves similarly but in an opposite direction of travel. With the threading sections 136 , 138 each being of opposite hand to the other, each of the threading sections 136 , 138 controlling one restrictor 106 or 108 , either enlarged knurled head 144 or 146 may be grasped by one hand and rotated with the fingers. Thus the restrictors 106 , 108 may be moved in opposite directions despite one direction of rotation of their respective control shaft. Similar adjustments may be made by rotating either of the enlarged knurled heads 144 or 146 . Because the control shaft projects from the housing at opposite sides of the housing, each of the enlarged knurled heads 144 or 146 is located on one side of the adjustable restrictor assembly 100 . This affords the convenience of being able to adjust the restrictors 106 , 108 from different locations. Although the present application discloses an embodiment utilizing two knurled heads 144 , 146 , it should be appreciated that the present invention may be operated by a single knurled head.
It will be apparent from examining FIG. 2 that bolt holes 148 , 150 , 152 , 154 formed in the cover 104 are generally coaxial with bolt holes 156 , 158 , 160 , 162 formed in the base 102 . These bolt holes 148 , 150 , 152 , 154 , 156 , 158 , 160 , 162 may be located and dimensioned so as to cooperate with the bolt pattern established by the fasteners 16 (see FIG. 1 ), and may for example, duplicate the function of similar fasteners originally provided by the manufacturer of the engine 12 to mount the carburetion device to the intake manifold 10 .
FIG. 5 shows a feature for immobilizing a restrictor such as the restrictor 106 in a selected position of adjustment. A small spring 164 may be arranged to impose force on a block 166 . The small spring 164 may seat at one end against a threaded set screw 168 which is inserted into the restrictor 106 to contain the spring 164 and at the other end, against an end surface of the block 166 . The block 166 is forced by the spring to make contact with the adjusting screw threads 136 (not shown in FIG. 5 ) imposing forces which act to pin the threaded shaft 132 (also not shown in FIG. 5 ) in place so that adjustment of the restrictor is preserved.
The present invention may be modified in many ways to similar effect. For example, whereas the cover 104 and the base 102 are shown as having four openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 respectively, the number and configuration of these openings 112 , 114 , 116 , 118 , 120 , 122 , 124 , 126 may be varied to suit conditions for each engine or to suit manufacturing convenience. For example, pairs of openings such as the openings 112 , 114 may be made to communicate or alternatively stated, may be siamesed.
The number of restrictors such as the restrictors 106 , 108 may be increased or decreased. For example, each opening 112 , 114 , 116 , 118 may be provided with an individual restrictor (not shown) if desired. Restrictors may be yoked together and adjusted by only one control shaft (this option is not shown).
The housing may be formed as a pocket open at only one end, with a suitable restrictor or restrictors inserted through the open end if desired (this option is not shown).
The control shaft arrangement may be modified to include traveling nuts (not shown) which propel the respective restrictors such as the restrictors 106 , 108 by interference. A singular control shaft may be replaced by plural control shafts (not shown, each control shaft controlling a different restrictor. For example, the restrictors 106 , 108 each have an opening such as the opening 170 for receiving the tip of a control shaft such as the control shaft 134 . Such an opening may be modified to enclose and entrap an enlarged terminal so that the associated restrictor is subjected to pulling forces when the control shaft is rotated in one direction and subjected to pushing forces when the control shaft is rotated in the other direction.
Components of the adjustable restrictor device 100 shown coupled to the base 102 may be coupled to the cover 104 where feasible.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible. | An adjustable restrictor device for controlling flow of induction air into an engine. The restrictor device may comprise a generally flat compact housing which is installed between a carburetor and intake manifold of an engine. The housing may have throughbores to allow air flow, which coincide in location to carburetor bores. The restrictor device may have two individual restrictors enclosed therein, each movable to positions which progressively obstruct and open the throughbores to control flow of inducted air. Each restrictor may be manually controlled in common by a rotatable control shaft. Threading of the knobs may be opposite handed, thereby enabling the restrictors to move similarly in effect as to controlling air flow but in opposite directions. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to contrast or imaging agents useful in vivo for studies and diagnosis of the gastrointestinal tract. The agents are zeolite materials enclosing a paramagnetic ion such as trivalent gadolinium. The loaded zeolites are particularly suitable for oral administration and function well as magnetic resonance imaging contrast or image brightening agents in the upper gastrointestinal tract.
2. Description of Related Art
The availability of sophisticated methods such as MRI and CT has contributed to the increased use of imaging technology in therapy and diagnostic studies. Gastrointestinal tract imaging is a particular area of interest because currently used imaging agents generally provide poor imaging, resulting in visualization of little more than gross blockages or anatomical abnormalities.
Barium sulfate and paramagnetic iron oxide are agents traditionally used for gastrointestinal studies. The latter material has become popular because of the paramagnetic properties of Fe 2 O 3 which is suited for MRI studies, but it has many disadvantages. These include black bowel, side effects of diarrhea and, from an analytical standpoint most important, the presence of artifacts arising from clumping. When paramagnetic iron concentrates, it may become ferromagnetic, drastically altering its imaging properties. Even when images are obtained, the signal is black, making it difficult to distinguish imaged from nonimaged areas.
The development of imaging contrast agents, particularly for gastrointestinal tract studies has been slow. Historically, the most popular agent has been superparamagnetic iron oxide for magnetic imaging, due to its nonbiodegradability. Although good contrast effects have been achieved in some MR studies in the small bowel, increasing occurrence of blurring and `metal` artifacts in the distal part of the bowel has been recorded (1). In other studies with superparamagnetic iron oxide, good resolution of the head and tail of the pancreas, anterior margins of the kidneys and para-aortic region has been shown in human patients. Some patients experienced episodes of diarrhea (2).
Magnetic imaging is particularly useful for the study and diagnosis of tumors or inflammatory abdominal diseases. Paramagnetic species represented by gadolinium seem to be potentially agents for these studies, the metal itself cannot be used in humans because of its toxic properties. Nevertheless, diethylenetriamine penta-acetic acid (DTPA) complexes of trivalent gadolinium have less toxicity than the uncomplexed salt and have been tested in human patients. Opacification of the gastrointestinal tract has been reported, but less than 60% of the magnetic resonance scans showed improved delineation of abdominal pathologies. Furthermore, nearly 40% of the patients reported diarrhea and meteorism (3).
Encapsulation of solid paramagnetic complexes in sulfonated ion-exchange resins for use in abdominal imaging has been suggested. It has been speculated that such encapsulation in acid-stable materials would prevent significant demetallation which otherwise occurs in the stomach when image contrasting agents are orally administered for gastrointestinal tract imaging (4).
Superparamagnetic iron oxide has been coated onto a polymer carrier matrix and evaluated as an oral contrast medium for MRI. Generally good images were obtained in the region of the small bowel, except the duodenum, but the useful concentration range appeared to be fairly narrow since some concentrations caused an artifact in the stomach after ingestion of the agent (I).
There is clearly a need for orally effective, well-tolerated agents that can be used in humans for imaging studies. In particular, an MRI imaging agent applicable to gastrointestinal tract studies would be useful for visualizing the anatomy of the intestinal tract and particularly to differentiate normal and pathological states, such as tumors. An effective, orally deliverable paramagnetic imaging contrast agent devoid of the common side effects currently encountered with the presently used GI imaging agents would represent a significant improvement over the iron and gadolinium complexes described. These compounds have several problems, including toxicity and lack of good image quality. Even with reports of improved compositions such as carrier complexes and matrices, some areas of the intestine are inadequately visualized with these materials and side effects still exist. For example, although trivalent gadolinium is an excellent paramagnetic MRI contrast species, its toxicity limits use in humans to its DTPA complex, which itself may exhibit toxicity.
A solution to many of the problems inherent in the use of presently used agents of choice in imaging the gastrointestinal tract has been discovered. A nontoxic zeolite carrier that preferentially binds paramagnetic metal ions within a lattice-like structure has been shown to have little toxicity and to exhibit excellent imaging properties. Furthermore, many of the problems associated with the use of superparamagnetic iron oxide are eliminated, including metal imaging and patient side effects such as diarrhea.
SUMMARY OF THE INVENTION
The present invention is a method of contrast imaging in humans or animals utilizing a zeolite-enclosed paramagnetic metal ion. The paramagnetic ion is preferentially bound by the zeolite. Preparations of paramagnetic metal ions enclosed in a zeolite are orally administrable and nontoxic. In a preferred embodiment, trivalent gadolinium is enclosed in CaA or NaX to form CaGdA or NaGdX.
Generally, the invention is an imaging method which involves administering a paramagnetic ion enclosed in zeolite. Most often the method will be used in humans but of course it could be used in animals, for example, in veterinary practice for diagnosis of gastrointestinal abnormalities. The amount of paramagnetic ion enclosed within the zeolite is enough to be effective as a contrast or imaging brightening agent. A particularly useful feature of this invention is the brightness of the areas imaged with zeolite enclosed paramagnetic ions. This contrasts with images obtained with superparamagnetic iron oxide which develop as dark or deep gray areas. Brightly imaged areas are preferred over dark contrast for visualizing the anatomy of the area and for detecting pathologies because delineation is increased.
Zeolite-enclosed paramagnetic ions are particularly useful for imaging studies in human beings and have many advantages over superparamagnetic iron oxide. Superparamagnetic iron tends to clump in the gastrointestinal tract causing a conversion from paramagnetic to ferromagnetic properties. Additionally, superparamagnetic iron oxide administered in the quantities necessary for satisfactory imaging causes unpleasant side effects in human beings, including diarrhea and meteorism. Such effects have not been observed with zeolite-enclosed trivalent gadolinium. The invention also overcomes the problems associated with toxicity of some of the paramagnetic metals considered most useful for MRI studies, for example trivalent gadolinium. Toxicity of trivalent gadolinium has been reduced by combining it with dimethyltetraaminopenta-acidic acid to form complex that exhibits less toxicity than the gadolinium salt. However, some studies with gadolinium DTPA indicate problems similar to those encountered with super paramagnetic iron oxide such as side effects of diarrhea and meteorism. In addition, the toxicity of the complex has not been fully determined. Toxicity has not been observed with the use of zeolite-enclosed gadolinium This may be due to relatively tight binding of the metal ion within the zeolite.
Although the invention has been illustrated with trivalent gadolinium and divalent manganese, other ion species that ion exchange with a zeolite could be used. Examples include tetravalent vanadium, trivalent vanadium, divalent copper, divalent nickel, trivalent chromium, divalent cobalt, divalent iron, trivalent iron and trivalent cobalt. Any of a variety of salts of these species may be used, including chlorides, acetates, nitrates and the like. These examples are not intended to be limiting and other species capable of ion exchanging include members of the lanthanide series of elements and the rare earth elements.
There are numerous zeolites that can be used for the entrapment of paramagnetic ions and are therefore useful for the practice of the invention. For example, the synthetic zeolites type A, type X, type Y or ZSM-5 zeolite are particularly useful (5,6). There are many types of zeolites, differing in chemical composition, cavity diameter or natural occurrence, such as the mordenite class of zeolites. Shapes of these substances are to some extent derived from the linkages of secondary building units forming the typical three-dimensional framework of the molecules. The shapes may then have an effect on ion exchange ability, selectivity in restricting the passage of molecules based on size, and absorption properties.
Materials similar to zeolites may be used to enclose metal ions useful for imaging. Molecular sieves, for example, are structurally similar to zeolites. Zeolite building blocks are Si +4 and Al +4 tetrahedra linked through common oxygen atoms extending in an infinite 3-dimensional network. When isomorphic atoms are substituted for aluminum or silicon (e.g., gallium, germanium or phosphorus) synthetic zeolites, more commonly known as molecular sieves are created. Use of molecular sieves that possess ion exchange properties may be used analogously to zeolites.
Ion exchange properties of the zeolite are particularly important in preferential binding of certain ions, particularly metal ions of the transition metal series. The amount of metal ion actually enclosed within the zeolite will depend on the characteristics of the particular zeolite type used, as well as the presence of other positively charged ions. Thus, for example, if calcium zeolite type A is mixed with a gadolinium salt and allowed to equilibrate over a period of time, the final exchange product will contain both positively charged gadolinium and calcium ions. It has been found that these zeolites, however, will preferentially exchange with the transition metal series so that there are greater concentrations of the transition metal ions than the ions from group 1 or group 2 elements. At any rate, the preferential binding of paramagnetic ions such as Gd +3 and Mn +2 is sufficient to give excellent MRI imaging properties when the paramagnetic zeolite entrapped ion is used for imaging studies.
Zeolite enclosed paramagnetic ions are particularly useful for MRI studies of the gastrointestinal tract, especially since pharmaceutically acceptable preparations of these materials can be administered enterically, for example, by nasogastric tube to either an animal or a human being. Oral administration is preferred for most applications involving studies or treatment of humans.
Detection of the zeolite enclosed paramagnetic ion after administration is most preferably performed by magnetic resonance imaging, although conventional radiographic imaging and CT may also be employed similar to methods used with BaSO 4 and gastrographin imaging. High Z (atomic weight) metals like gadolinium may also be detected by monochromatic x-ray sources, for example, K-edge imaging.
In a most preferred method of practice, the invention is used for gastrointestinal tract imaging. A pharmaceutically acceptable formulation including zeolite enclosed trivalent gadolinium is administered, preferably orally, to a human or animal and detected by magnetic resonance imaging. The trivalent gadolinium may be enclosed within calcium type A zeolite or sodium type X zeolite or any other suitable zeolite. The zeolite is prepared in a pharmaceutical carrier.
The zeolite enclosed metal ion compounds of this invention may be combined with pharmaceutically acceptable formulating agents, dispersing agents and fillers. Powders, granules, capsules, coated tablets, syrupy preparations and aqueous suspensions may be utilized for oral preparations. Formulating agents employed may be either solid or liquid, including but not limited to such solids as calcium phosphate, calcium carbonate, dextrose, sucrose, dextrin, sucrose ester, starch, sorbitol, mannitol, crystalline cellulose, talc, kaolin, synthetic aluminum silicate, carboxymethyl cellulose, methylcellulose, cellulose acetate phthalate, alginates, polyvinyl pyrrolidone, polyvinyl alcohol, gum arabic, tragacanth gum, gelatin, bentonite, agar powder, shellac, Tween 80, carrageenans and psyllium. Modified zeolite materials having residual charges or modifying groups might also be used which may be adsorbed to various carrier matrices such as clay. Examples of liquids suitable as suspending fluids include water, isotonic salt solution, ethanol, propylene glycol, polyethylene glycol, glycerol, Hartman's solution and Ringer's solution. A preferred liquid for suspension is EZpaque supernatant which is readily obtained from EZpaque after removing BaSO 4 , either by centrifugation or filtration.
Administration is most preferably oral because of better patient acceptance in that form but administration may also be enteric, vaginal, anal or by direct introduction into the gastrointestinal tract at any point such as by introduction through tubes accessing the alimentary canal. Examples of nonoral use include retrograde pelvic studies and investigations to define vaginal contents. Flavor enhancers may be added to oral preparations, including taste masking substances such as sweeteners and citrus flavors. Other additives, including color, preservatives, bulk or antifoam agents may also be included in the formulation.
The invention may also be used in conjunction with magnetic resonance imaging of body surfaces. For example, artificial limbs must be custom fitted to leg, arm, hand or foot amputees. Present methods are time-consuming and rendered difficult because photographs show only skin surface while x-ray indicates only dense material such as bone. MRI could show both bone and skin and therefore facilitate design of a prosthetic device which must be customized to the remaining member of the body. Zeoliteenclosed trivalent gadolinium would be ideal for this purpose. The crystalline material would be powdered sufficiently to be conveniently applied to a skin surface, preferably as an aerosol which could be either a dry powder or a suspension in a suitable fluid, for example water or alcohol. The skin is preferably first treated with an agent that promotes adherence of the powder to the surface, for example, tincture of benzoin. Other applications envisioned are imaging of the foot, useful in customizing footwear for abnormal or injured feet. Surface imaging could also be used in connection with inanimate surfaces, for example some metal surfaces. In some cases, especially where high resolution was desired, uniform application would be important so that surface roughness reflected the surface examined rather than an artifact of uneven application.
The invention may also be used to evaluate lung ventilation. An aerosol of suitably small particles, in the nanometer range, would be inhaled by the patient prior to MRI scans to determine lung ventilation.
The zeolite enclosed ionic species of this invention will typically be formulated as suspensions or dispersions, preferably in EZ dispersant (available from E-ZM Company) or used as the supernatant from pharmacy-purchased suspensions of BaSO 4 under the trade name of EZpaque) at a low weight to volume ratio. For oral administration this is preferably approximately -%. Higher concentrations of the zeolite composition may be prepared as suspensions; however, for MR imaging purposes, image intensity decreases markedly above weight ratios of 1%. The 1% suspensions in EZpaque supernatant appear to be stable indefinitely.
A marked advantage of calcium gadolinium enclosed in type A zeolite is the relatively low concentration that may be employed in a dispersing medium. For example, a one percent concentration of calcium gadolinium type A zeolite administered orally is effective in producing excellent images for MRI studies, although higher weight percent concentrations may be utilized in accordance with the form of the preparation. In contrast, when barium sulfate is used in the same dispersing medium, concentrations of up to 40-50% by weight are required and precipitation is often a problem.
A most preferred paramagnetic ion useful for GI studies of this sort is trivalent gadolinium, however, other metal ions as listed above can be used. Excellent results have also been obtained using zeolite enclosed divalent manganese.
It will be appreciated by those of skill in the art that there will always be present within the zeolite not only the paramagnetic ion which is used for the imaging, but also a second ion with which the paramagnetic ion was exchanged. The type of second ion will depend on the zeolite compound used in the preparation. For example, calcium zeolite, calcium type A zeolite, sodium zeolite or other salts formed from first and second group elements may be used. Alternatively, the parent zeolite could be exchanged with protons, alkali or alkaline earth metal ions, transition or rare earth metal ions prior or subsequent to entrapment of a paramagnetic ion. It should be further understood that a zeolite enclosing a paramagnetic ion may contain other ligands such as hydroxyl ion, chloride ion or water depending on the method of preparation. Any or all of these species may affect the properties of the enclosed ions. The presence of any one or a number of these may alter or attenuate the pharmacological effects of the zeolite enclosed paramagnetic ion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an MRI scan of the gastrointestinal tract of a rabbit taken after two administrations by NG tube of a 1% suspension of CaGdA at 12 hr and 4 hr before MRI scanning. Panel IA illustrates the effect of the presence of CaGdA in the stomach. Panel 1B indicates delineation of the jejunum region of the intestine in the presence of CaGdA.
FIG. 2 is an MRI scan of the gastrointestinal tract of a dog taken after administration by NG tube of a 1 % suspension of CaGdA. Panels A and B are scans taken 1 hr after administration. Panels C and D are scans taken 3 hr after administration.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following examples illustrate preferred embodiments of the practice of the invention. It should be understood that these examples are intended to be illustrative of the invention and in no way limiting.
EXAMPLE 1
Preparation of Zeolite-enclosed Trivalent Gadolinium
Calcium zeolite (calcium A), 10 g, was mixed with 2 g of GdCl 3 ·6H 2 O in approximately 100 ml deionized water and stirred at 30° C. for 18 hr. The resulting zeolite suspension was suction filtered and washed extensively with deionized water until negative for chloride ion by silver nitrate test. The resulting CaGdA gave a negative test for free Gd +3 using the colorimetric indicator, xylenol orange. The zeolite was dried in a vacuum oven overnight at 50° C. The resulting sample contained 3.24% trivalent gadolinium by weight. Analogous procedures using NaA, NaX or NaY yielded the percent weight compositions shown in Table 1. MnCl 2 used in place of GdCl 3 formed MnNaX when exchanged into NaX.
TABLE 1______________________________________Compound Weight percent metal______________________________________GdNaA 6.18GdCaA 3.24GdNaX 6.19GdNaY 3.11MnNaX 5.59______________________________________
Various zeolites were suspended in EZ dispersant at the indicated weight percent and image intensity data recorded as shown in Table 2.
TABLE 2______________________________________Compound Intensity.sup.1 Std. Deviation % sol'n*______________________________________GdNaY 1061.43 29.76 1 382.19 12.42 0.1 259.49 8.45 0.01 228.97 8.55 0.001 187.65 7.67 0.0001GdNaX 454.08 19.91 1 1273.13 36.84 0.1 349.54 13.93 0.01 219.17 10.84 0.001 64.49 10.77 0.0001GdNaA 365.06 12.51 1 1522.71 29.67 0.1 391.05 8.90 0.01 237.03 9.37 0.001 193.79 8.39 0.0001GdCaA 408.25 47.06 1 772.24 27.09 0.1 280.11 10.38 0.01 230.06 7.69 0.001 200.32 8.56 0.0001MnNaX 34.57 6.50 1 1312.48 29.02 0.1 453.10 16.17 0.01 257.36 6.90 0.001 185.37 8.66 0.0001______________________________________ .sup.1 Mean value *All sample zeolites suspended in EZpaque supernatant at the indicated wt %.
EXAMPLE 2
Gastrointestinal Imaging in the Rabbit
1 g of CaGdA was suspended in 99 ml dispersing medium prepared from E-Zpaque™ supernatant obtained by centrifugation of the BaSO 4 . Approximately 200-300 cc was introduced into the stomach of a rabbit using a pediatric nasogastric (NG) tube at 12 hr and 4 hr prior to MRI. MRI scans were obtained periodically using a conventional T 1 weighed sequence. FIG. 1 is an MRI scan 4 hr after the last administration. CaGdA was detected in the stomach, as indicated by the bright region in Panel A. 12 hr after administration the majority of the CaGdA had passed into the intestine and, as shown in Panel B, was concentrated in the jejunum region.
EXAMPLE 3
Gastrointestinal Imaging in the Dog
Experimental protocol as described in Example 2 was followed in imaging the gastrointestinal tract of a dog, except that approximately 500 cc of 1% suspension of CaGdA was administered via NG tube. FIG. 2A is an MRI scan taken 1 hour after administration. FIG. 2B is an MRI scan taken 3 hours after administration.
PROPHETIC EXAMPLE 4
The present example outlines the procedure contemplated by the Applicants to be useful for the successful imaging of fistulas.
MRI Fistulagrams
A human patient will have been diagnosed as having a fistula. Generally, indications of infection should not be present as injection of fluid into the fistula might cause delocalization of an infection. In appropriate cases, the fistula will be injected with a suspension of 1% GdNaX in a suitable vehicle such as EZpaque supernatant. 5-15 cc injections will be used, depending on the size of the fistula. Imaging will then be performed using standard MRI procedures in order to visualize extent and location of fistulous tracts.
PROPHETIC EXAMPLE 5
The present example outlines the procedure contemplated by the Applicants to be useful for the successful imaging of the gastrointestinal tract in pediatric practice.
MRI Imaging in Pediatric Patients
Young patients generally do not tolerate hyperosmolic iodinated agents currently in use. The following procedure would be used in this group of patients. The patient is administered 100-150 cc of a 1% solution of GdNaX in EZpaque supernatant or other suitable vehicle via a pediatric NG tube. The administered suspension must not be hyperosmolar. Images are obtained immediately after administration using standard MRI imaging procedures.
PROPHETIC EXAMPLE 6
The present example outlines the procedure contemplated by the Applicants to be useful for the successful imaging of surfaces to which prosthetic devices are to be fitted.
MRI of Amputated Human Long Limb Members
The limb to which a prosthetic device is to be fitted is prepared for attachment of a prosthetic device by surgical procedures as medically indicated to provide a suitable attachment surface. The surface is then coated with a material such as benzoin that will facilitate adherence of an applied powder to the surface. Zeolite-enclosed gadolinium, prepared as described in Example i, is sufficiently to allow easy dispersion in a liquid or as an aerosol, washed extensively in water until the wash is free of gadolinium as determined by testing with xylenol orange, and then applied to the skin surface. Application is with an aerosol, either as a dry powder or as a suspension in a suspending agent such as alcohol or water. After the surface is coated with a fine layer of powder, images are obtained by standard magnetic imaging procedures. The resulting images are used to design custom matings for the artificial limb.
PROPHETIC EXAMPLE 7
The present example outlines the procedure contemplated by the Applicants to be useful for the successful imaging of the lungs in evaluating lung ventilation.
Lung Ventilation Evaluation
Zeolite-enclosed gadolinium is prepared as described in Example 1. After drying, the solid is ground to approximately nanometer range. From this an aerosol in a compatible inhalant is prepared. The aerosol is administered and imaging performed using standard MRI imaging procedures.
The present invention has been described in terms of particular embodiments found by the inventors to comprise preferred modes of practice of the invention. It will be appreciated by those of skill in the art that in light of the present disclosure numerous modifications and changes can be made in the particular embodiments exemplified without departing from the intended scope of the invention. For example, any of a number of zeolites or molecular sieves could be used as the enclosing matrix and any of a number of cationic species could be present within the zeolite, some of which could be used to modify effects of the enclosed ion of interest, for example, trivalent gadolinium in imaging studies. These and obvious related modifications are contemplated to be within the scope of the claims.
REFERENCES
The references listed below are incorporated herein by reference to the extent they supplement, explain, provide a background for or teach methodology, techniques and/or compositions employed herein.
1. Lonnemark, M., Hemmingsson, A., Bach-Gansmo, T., Ericsson, A., Oksendal, A. Nyman, R. and Moxnes, A., Acta Radiol. 30, 193-196 (1989).
2. Hahn, P.F., Staark, D.D., Lewis, J.M., Saini, S., Elizondo, G., Weissleder, R., Fretz, C.J. and Ferrucci, J.T., Radiology 175, 695-700 (1990).
3. Claussen, Von C., Kornmesser, W., Laniado, M., Kaminsky, S., Hamm, B. and Felix, R., ROFO 148, 683-689 (1989).
4. Braybrook, H.H. and Hall, L.D., Drug. Des. Deliv. 4, 93-95 (1989).
5. Breck, D.W., Zeolite Molecular Sieves, Krieger Publishing Company, Malabar, FL, 1984.
6. Rankel, L.A. and Valyocaik, E.W., U.S. Pat. No. 4,388,285, Jun. 14, 1983. | The invention relates to a method of using zeolite enclosed paramagnetic ions as image brightening or image contrast agents. In particular, zeolite enclosed trivalent gadolinium is useful in MRI studies of the entire gastrointestinal tract, providing excellent images. Zeolite-enclosed gadolinium complexes may be conveniently administered in oral preparations without side effects of diarrhea. Other transition metal ions, including divalent manganese may be enclosed in any suitable zeolite which has ion exchange properties sufficient to exchange the selected metal. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a polymer powder based on polyamide or on copolyamides, preferably nylon-12, which comprises phosphonate-containing flame retardant, to a process for producing this powder, and also to moldings produced by a layer-by-layer process which selectively melts regions or selectively binds them to one another, from this powder.
[0003] 2. Discussion of the Background
[0004] Very recently, a requirement has arisen for the rapid production of prototypes. Selective laser sintering is a process particularly well suited to rapid prototyping. In this process, polymer powders in a chamber are selectively irradiated briefly with a laser beam, resulting in melting of the particles of powder on which the laser beam falls. The molten particles fuse and solidify again to give a solid mass. Three-dimensional bodies, including those of complex shape, can be produced simply and rapidly by this process, by repeatedly applying fresh layers and irradiating these.
[0005] The process of laser sintering (rapid prototyping) to realize moldings made from pulverulent polymers is described in detail in patent specifications U.S. Pat. No. 6,136,948 and WO 96/06881 (both DTM Corporation). A wide variety of polymers and copolymers is claimed for this application, e.g. polyacetate, polypropylene, polyethylene, ionomers, and polyamide.
[0006] Nylon-12 powder (PA 12) has proven particularly successful in industry for laser sintering to produce moldings, in particular to produce engineering components. The parts manufactured from PA 12 powder meet the high requirements demanded with regard to mechanical loading, thus having properties particularly close to those of the mass-production parts subsequently produced by extrusion or injection molding.
[0007] A PA 12 powder with good suitability here has a median particle size (d 50 ) of from 50 to 150 μm, and is obtained as in DE 19708946 or as in DE 4421454, for example. It is preferable here to use a nylon-12 powder whose melting point is from 185 to 189° C., whose enthalpy of fusion is 112 J/g, and whose freezing point is from 138 to 143° C., as described in EP 0911142.
[0008] Other processes with good suitability are the SIB process, as described in WO 01/38061, or a process as described in EP 1015214. The two processes operate using infrared heating over an area to melt the powder, and selectivity is achieved in the first process by applying an inhibitor, and in the second process by way of a mask. Another process which has found wide acceptance in the market is 3D printing, as in EP 0431924, where the moldings are produced by curing of a binder applied selectively to the powder layer. Another process is described in DE 10311438, in which the energy required for melting is introduced by way of a microwave generator, and selectivity is achieved by applying a susceptor.
[0009] For these processes, use may be made of pulverulent substrates, in particular polymers or copolymers, preferably selected from polyester, polyvinyl chloride, polyacetal, polypropylene, polyethylene, polystyrene, polycarbonate, poly(N-methylmethacrylimide) (PMMI), polymethyl methacrylate (PMMA), ionomer, polyamide, copolyester, copolyamides, terpolymers, acrylonitrile-butadiene-styrene copolymers (ABS), or a mixture of these.
[0010] Although the known polymer powders intrinsically have good properties, moldings produced using these powders still have some disadvantages. A particular disadvantage with the polymer powders currently used is their high flammability and combustibility. This currently inhibits the use of processes described above in short runs in aircraft construction, for example.
SUMMARY OF THE INVENTION
[0011] It was therefore an object of the present invention to provide a polymer powder which can be used in one of the processes described above to produce parts of lower flammability. In particular, the intention here is to achieve the Underwriters Laboratories (UL®) V-0 classification; wherein a V-0 classification means that burning stops within 10 seconds on a vertical specimen, and no drips are allowed; a V-1 classification means that burning stops within 30 seconds on a vertical specimen, and no drips allowed; and a V-2 classification means that burning stops within 30 seconds on a vertical specimen, and drips of flaming particles are allowed.
[0012] Surprisingly, it has now been found that addition of phosphonate-containing flame retardants to polymers can produce polymer powders which can be used in layer-by-layer processes in which regions are melted or selectively bound, to produce moldings which achieve markedly better UL® classification than moldings composed of conventional polymer powders. For example, this method can achieve UL® V-0 classification. It is particularly advantageous if the mechanical properties of the components are simultaneously retained.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention therefore provides a polymer powder for processing in a layer-by-layer process in which regions are selectively melted or bound to one another, wherein the powder comprises at least one polymer and at least one phosphonate-containing flame retardant.
[0014] The present invention also provides a process for producing polymer powder of the invention, which comprises mixing at least one polymer powder in the presence of a solvent in which the phosphonate-containing flame retardant has at least low solubility, and then removing the dispersion medium/solvent. The melting points of the flame retardants used must, of course, be above room temperature.
[0015] The present invention also provides moldings produced by a layer-by-layer process in which regions are selectively melted or selectively bound to one another, wherein the moldings comprise phosphonate-containing flame retardant and at least one polymer.
[0016] The polymer powder of the invention has the advantage that it can be used in a layer-by-layer process in which regions are selectively melted or selectively bound to one another to produce moldings which have low flammability and combustibility. Moldings which achieve UL® V-0 classification are therefore obtainable. Addition of flame retardant mostly impairs the mechanical properties of the moldings. Nevertheless, the moldings of the invention retain good tensile strain at break and an only slightly reduced modulus of elasticity, when compared with moldings composed of material to which no flame retardant has been added. This opens up application sectors which were inaccessible hitherto for reasons of poor combustibility classification.
[0017] The polymer powder of the invention is described below, as is a process for its production, but there is no intention that the invention be restricted thereto.
[0018] A feature of the polymer powder of the invention for processing in a layer-by-layer process in which regions are selectively melted or selectively bound to one another is that the powder comprises at least one polymer or copolymer and at least one phosphonate-containing flame retardant.
[0019] A polyamide preferably present in the polymer powder of the invention is a polyamide which has at least 8 carbon atoms per carbonamide group. The polymer powder of the invention preferably comprises at least one polyamide which contains 10 or more carbon atoms per carbonamide group. The polymer powder particularly preferably comprises at least one polyamide selected from nylon-6,12 (PA 612), nylon-11 (PA 11), and nylon-12 (PA 12).
[0020] The polymer powder of the invention preferably comprises polyamide with a median particle size of from 10 to 250 μm, preferably from 45 to 100 μm, and particularly preferably from 50 to 80 μm.
[0021] A polymer powder particularly suitable for laser sintering is a nylon-12 powder whose melting point is from 185 to 189° C., preferably from 186 to 188° C., whose enthalpy of fusion is 112±17 J/g, preferably from 100 to 125 J/g, and whose freezing point is from 133 to 148° C., preferably from 139 to 143° C. The process for the production of the polyamide powder on which the polymer powders of the invention are based is well-known, and in the case of PA 12 may be found by way of example in the publications DE 2906647, DE 3510687, DE 3510691, and DE 4421454, which are incorporated by way of reference in the disclosure content of the present invention. The polyamide pellets required may be purchased from various producers, and by way of example nylon-12 pellets are supplied as VESTAMID® by Degussa AG.
[0022] For the processes which do not use a laser, a copolymer powder has particularly good suitability, in particular a copolyamide powder.
[0023] The polymer powder of the invention preferably comprises, based on the entirety of the components present in the powder, from 1 to 30% by weight of at least one phosphonate-containing flame retardant, preferably from 5 to 20% by weight of a phosphonate-containing flame retardant, particularly preferably from 8 to 15% by weight of a phosphonate-containing flame retardant, and very particularly preferably from 10 to 12% by weight of a phosphonate-containing flame retardant.
[0024] If the content of the phosphonate-containing flame retardant is below 1% by weight based on the entirety of the components present in the powder, there is a marked reduction in the desired effect of low flammability and low combustibility. If the content of the phosphonate-containing flame retardant is above 30% by weight, based on the entirety of the components present in the powder, the mechanical properties of the moldings produced from these powders become markedly poorer, the modulus of elasticity for example.
[0025] The phosphonate-containing flame retardant present in the polymer powder of the invention is preferably Antiblaze 1045, which is commercially available and can be purchased from Rhodia.
[0026] For applying the powders to the layer to be processed it is advantageous if the phosphonate-containing flame retardant encapsulates the polymer grains, this being achievable by wet-mixing of polymer dispersions in a solvent in which the phosphonate-containing flame retardant has at least low solubility, because the resultant treated particles have particularly good distribution of the flame retardant. However, it is also possible to use powders with phosphonate-based flame retardant incorporated by compounding in bulk, with subsequent use of low-temperature milling to give powder. Suitable flow aids, such as fumed aluminum oxide, fumed silicon dioxide, or fumed titanium dioxide, may be added to the resultant powder.
[0027] Polymer powder of the invention may therefore comprise these, or else other, auxiliaries, and/or filler. By way of example, these auxiliaries may be the abovementioned flow aids, e.g. fumed silicon dioxide or else precipitated silicas. By way of example, fumed silicon dioxide is supplied with the product name Aerosil® with various specifications by Degussa AG. Polymer powder of the invention preferably comprises less than 3% by weight, with preference from 0.001 to 2% by weight, and very particularly preferably from 0.05 to 1% by weight, of these auxiliaries, based on the entirety of the polyamides present. By way of example, the fillers may be glass particles, metal particles, or ceramic particles, e.g. solid or hollow glass beads, steel shot, granulated metal, or else color pigments, e.g. transition metal oxides.
[0028] The median grain size of the filler particles here are preferably smaller than or approximately equal to that of the particles of the polyamides. The median grain size d 50 of the fillers should preferably not exceed the median grain size d 50 of the polyamides by more than 20%, with preference 15%, and with very particular preference 5%. A particular limitation on the particle size results from the permissible overall height or, respectively, layer thickness in the layer-by-layer apparatus.
[0029] Polymer powder of the invention preferably comprises less than 75% by weight, with preference from 0.001 to 70% by weight, particularly preferably from 0.05 to 50% by weight, and very particularly preferably from 0.1 to 25% by weight, of these fillers, based on the entirety of the components present.
[0030] If the stated maximum limits for auxiliaries and/or fillers are exceeded, depending on the filler or auxiliary used, there can be marked impairment of mechanical properties of moldings produced from these polymer powders.
[0031] The polymer powders of the invention can be produced simply, preferably by the process of the invention for producing polymer powder of the invention, by mixing at least one polyamide with at least one phosphonate-containing flame retardant, preferably by incorporation through wet-mixing. By way of example, a polymer powder obtained by reprecipitation or by milling may be dissolved or suspended in an organic solvent and mixed with the phosphonate-containing flame retardant, or else the polymer powder may be mixed in bulk with phosphonate-containing flame retardant. In the case of operation in a solvent, the phosphonate-containing flame retardant is preferably present in solution, or at least to some extent in solution, in a solvent when mixed with a solvent which comprises the polymer, whereupon either this solvent may comprise the dissolved polymer and the polymer powder is obtained by precipitation of the polymers from the flame-retardant-containing solvent, or the solvent may comprise the suspended pulverulent polymer and the polymer powder is obtained by removing the solvent.
[0032] In the simplest embodiment of the process of the invention, a very wide variety of known methods may be used to achieve a fine-particle mixture. For example, the mixing method may be wet-mixing in low-speed assemblies—e.g. paddle driers or circulating screw mixers (known as Nautamixers)—or by dispersion of the phosphonate-containing flame retardant and of the polymer powder in an organic solvent, followed by distillative removal of the solvent. In this procedure it is advantageous if the organic solvent dissolves the phosphonate-containing flame retardant, at least at low concentration, because the flame retardant can encapsulate the polyamide grains during the drying process. Examples of solvent suitable for this variant are lower alcohols having from 1-3 carbon atoms, and ethanol may preferably be used as solvent.
[0033] In one of these first variants of the process of the invention, the polyamide powder may be a polyamide powder intrinsically suitable as a laser sintering powder, phosphonate-containing flame retardant simply being admixed thereto. For this, it is advantageous for at least the flame retardant to be at least to some extent dissolved or heated, in order to reduce viscosity. In another embodiment, the polyamide grains may also be in suspended form.
[0034] In another variant of the process, the phosphonate-containing flame retardant is mixed with a, preferably molten, polyamide through incorporation by compounding, and the resultant flame-retardant-containing polyamide is processed by (low-temperature) grinding or reprecipitation to give laser sintering powder. The compounding process usually gives pellets which are then processed to give polymer powder. This conversion process may take place via milling or reprecipitation, for example. The process variant in which the flame retardant is incorporated by compounding has the advantage, when compared with the pure mixing process, of achieving more homogenous distribution of the phosphonate-containing flame retardant in the polymer powder.
[0035] In this instance, a suitable flow aid will be added to the precipitated or low-temperature-ground powder to improve flow behavior, examples being fumed aluminum oxide, fumed silicon dioxide, or fumed titanium dioxide.
[0036] In another preferred process variant, the phosphonate-containing flame retardant is admixed with an ethanolic solution of the polymer before the process of precipitation of the polymer has been completed. By way of example, DE 3510687 and DE 2906647 describe this precipitation process. This process may be used by way of example to precipitate nylon-12 from an ethanolic solution via controlled cooling, following a suitable temperature profile. Reference is made to DE 3510687 or DE 2906647 for a detailed description of the precipitation process.
[0037] The person skilled in the art may use this process variant in a modified form for a broad range of polymers, polymer and solvent being selected here in such a way that the polymer dissolves in the solvent at an elevated temperature, and that the polymer precipitates from the solvent at a lower temperature and/or on removal of the solvent. The corresponding laser sintering polymer powders of the invention are obtained by adding phosphonate-containing flame retardant to this solution, and then drying.
[0038] The phosphonate-containing flame retardant used may preferably comprise a phosphonate containing cyclic ester structures, e.g. Antiblaze 1045®, this being a commercially available product which can be purchased from Rhodia.
[0039] To improve processibility, or for further modification of the polymer powder, this may receive additions of inorganic color pigments, e.g. transition metal oxides, stabilizers, e.g. phenols, in particular sterically hindered phenols, flow aids, e.g. fumed silicas, or else filler particles. The amount of these substances added to the polymer powder, based on the total weight of components in the polymer powder, is preferably such as to comply with the concentrations stated for fillers and/or auxiliaries for the polymer powder of the invention.
[0040] The present invention also provides processes for producing moldings by selective laser sintering, by using polymer powders of the invention, which comprise polymers and phosphonate-containing flame retardants. The present invention in particular provides a process for producing moldings by a layer-by-layer process which selectively melts or selectively binds parts of a phosphonate-containing precipitation powder based on a nylon-12 whose melting point is from 185 to 189° C., whose enthalpy of fusion is 112±17 J/g, and whose freezing point is from 136 to 145° C., the use of which is described in U.S. 6,245,281.
[0041] These processes are well-known, and are based on the selective sintering of polymer particles, layers of polymer particles being briefly exposed to laser light with resultant binding between the polymer particles exposed to the laser light. Three-dimensional objects are produced by successive sintering of layers of polymer particles. By way of example, details of the selective laser sintering process are found in the publications U.S. Pat. No. 6,136,948 and WO 96/06881.
[0042] The moldings of the invention, produced by selective laser sintering, comprise a phosphonate-containing flame retardant and polymer. The moldings of the invention preferably comprise at least one polyamide which contains at least 8 carbon atoms per carbonamide group. Moldings of the invention very particularly preferably comprise at least one nylon-6,12, nylon-11, and/or one nylon-12, and at least one phosphonate-containing flame retardant.
[0043] Other processes with good suitability are the SIB process, as described in WO 01/38061, or a process as described in EP 1015214. The two processes operate using infrared heating over an area to melt the powder, and selectivity is achieved in the first process by applying an inhibitor, and in the second process by way of a mask. Another process which has found wide acceptance in the market is 3D printing, as in EP 0431924, where the moldings are produced by curing of a binder applied selectively to the powder layer. Another process is described in DE 10311438, in which the energy required for melting is introduced by way of a microwave generator, and selectivity is achieved by applying a susceptor.
[0044] For these processes, use may be made of pulverulent substrates, in particular polymers or copolymers, preferably selected from polyester, polyvinyl chloride, polyacetal, polypropylene, polyethylene, polystyrene, polycarbonate, poly(N-methylmethacrylimide) (PMMI), polymethyl methacrylate (PMMA), ionomer, polyamide, copolyester, copolyamides, terpolymers, acrylonitrile-butadiene-styrene copolymers (ABS), or a mixture of these.
[0045] The flame retardant present in the molding of the invention is preferably a cyclic organic phosphonate containing ester structures. It contains from 10 to 25% of phosphorus, particularly preferably from 18 to 22%. An example of a flame retardant of this type is Antiblaze 1045 from Rhodia.
[0046] The molding of the invention preferably comprises, based on the entirety of the components present in the molding, from 1 to 50% by weight of phosphonate-based flame retardants, preferably from 5 to 30% by weight, particularly preferably from 8 to 20% by weight, and very particularly preferably from 10 to 12% by weight.
[0047] The moldings may also comprise fillers and/or auxiliaries, e.g. heat stabilizers and/or antioxidants, e.g. sterically hindered phenol derivatives. Examples of fillers are glass particles, ceramic particles, and also metal particles, e.g. iron shot, or corresponding hollow beads. The moldings of the invention preferably comprise glass particles, very particularly preferably glass beads. Moldings of the invention preferably comprise less than 3% by weight, with preference from 0.001 to 2% by weight, and very particularly preferably from 0.05 to 1% by weight, of these auxiliaries, based on the entirety of the components present. Moldings of the invention also preferably comprise less than 75% by weight, with preference from 0.001 to 70% by weight, particularly preferably from 0.05 to 50% by weight, and very particularly preferably from 0.5 to 25% by weight, of these fillers, based on the entirety of the components present.
[0048] The examples below are intended to describe the polymer powder of the invention and its use, without restricting the invention to the examples.
[0049] The BET surface area determination carried out in the examples below complied with DIN66131. Bulk density was determined using an apparatus to DIN53466. A Malvern Mastersizer S, version 2.18, was used to obtain the laser scattering values.
[0050] Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only, and are not intended to be limiting unless otherwise specified.
EXAMPLES
Example 1.
[heading-0051] Incorporation of Antiblaze™ 1045 by Reprecipitation.
[0052] 40 kg of unregulated PA 12 prepared by hydrolytic polymerization (the preparation of this type of polyamide being described by way of example in DE 2152194, DE 2545267, or DE 3510690) with a relative solution viscosity η rel . of 1.61 (in acidified m-cresol) and with an end group content of 72 mmol/kg COOH and 68 mmol/kg NH2 are heated to 145° C. with 0.3 kg of IRGANOX® 1098 and 4.44 kg of Antiblaze™ 1045, and also 350 L of ethanol, denatured with 2-butanone and 1% water content, within 5 hours in a 0.8 m 3 stirred tank (diameter=90 cm, height=170 cm), and held for 1 hour at this temperature, with stirring (blade stirrer, diameter=42 cm, rotation rate=91 rpm). The jacket temperature was then reduced to 120° C., and the internal temperature was brought to 120° C. at a cooling rate of 45 K/h, at the same stirrer rotation rate. From this juncture onward, with the same cooling rate, the jacket temperature was maintained below the internal temperature by from 2 K to 3 K. Using the same cooling rate, the internal temperature was decreased to 117° C., and was then held constant for 60 minutes. The internal temperature was then brought to 111° C., using a cooling rate of 40 K/h. At this temperature, the precipitation began and was detectable through evolution of heat. After 25 minutes, the internal temperature decreased, indicating the end of the precipitation. The suspension is cooled to 75° C. and then transferred to a paddle drier. The ethanol is removed therefrom by distillation at 70° C. and 400 mbar with the stirrer system running, and the residue was then further dried at 20 mbar and 85° C. for 3 hours. A sieve analysis was carried out on the resultant product and gave the following result.
TABLE 1 Sieve analysis of product produced in Example 1 Particle Size, μm % by wt. <32 μm: 8% <40 μm: 17% <50 μm: 46% <63 μm: 85% <80 μm: 95% <100 μm: 100% BET: 6.8 m 2 /g Bulk density: 430 g/L Laser diffraction: d(10%): 44 μm, d(50%): 69 μm, d(90%): 97 μm.
Example 2.
[heading-0053] Incorporation of Antiblaze™ 1045 by Compounding and Reprecipitation
[0054] 40 kg of regulated PA 12 (L1600) prepared by hydrolytic polymerization, with a relative solution viscosity η rel . of 1.61 (in acidified m-cresol) and with an end group content of 106 mmol/kg of COOH and 8 mmol/kg of NH 2 are extruded at 225° C. in a twin-screw compounder (Bersttorf ZE 25) with 0.3 kg of IRGANOX® 245 and 4.44 kg of Antiblaze® 1045, and strand-pelletized. This compounded material was then heated with 350 L of ethanol, denatured with 2-butanone and 1% water content, within 5 hours in a 0.8 m 3 stirred tank (diameter=90 cm, height=170 cm), and held for 1 hour at this temperature, with stirring (blade stirrer, diameter=42 cm, rotation rate=91 rpm). The jacket temperature was then reduced to 120° C., and the internal temperature was brought to 120° C. at a cooling rate of 45 K/h, at the same stirrer rotation rate. From this juncture onward, with the same cooling rate, the jacket temperature was maintained below the internal temperature by from 2 K to 3 K. Using the same cooling rate, the internal temperature was decreased to 117° C., and then held constant for 60 minutes. The internal temperature was then decreased to 111° C., using a cooling rate of 40 K/h. At this temperature, the precipitation began and was detectable through evolution of heat. After 25 minutes, the internal temperature decreased, indicating the end of the precipitation. The suspension was cooled to 75° C. and then transferred to a paddle drier. The ethanol was removed therefrom by distillation at 70° C. and 400 mbar with the stirrer system running, and the residue was then further dried at 20 mbar and 85° C. for 3 hours. A sieve analysis was carried out on the resultant product and gave the following result:
BET: 7.3 m 2 /g Bulk density: 418 g/L Laser diffraction: d(10%): 36 μm, d(50%): 59 μm, d(90%): 78 μm.
Example 3.
[heading-0058] Incorporation of Antiblaze™ 1045 in Ethanolic Suspension
[0059] The procedure is as described in Example 1, but the flame retardant was not added initially, but 4.44 kg of Antiblaze™ 1045 were added at 75° C. only after the precipitation of the freshly precipitated suspension in the paddle drier. Drying and further work-up takes place as described in Example 1.
BET: 5.3 m 2 /g Bulk density: 433 g/L Laser diffraction: d(10%): 40 μm, d(50%): 61 μm, d(90%): 79 μm.
Example 4.
[heading-0063] Incorporation of Antiblaze™ 1045 in Ethanolic Suspension
[0064] The procedure is as described in Example 3, but 4.7 kg of Antiblaze™ 1045 were added at 75° C. to the freshly precipitated suspension in the paddle drier, and drying was completed as described in Example 1.
BET: 5.1 m 2 /g Bulk density: 422 g/L Laser diffraction: d(10%): 45 μm, d(50%): 65 μm, d(90%): 84 μm.
Example 5.
[heading-0068] Incorporation of Antiblaze™ 1045 in Ethanolic Suspension
[0069] The procedure is as described in Example 3, but 4.21 kg of Antiblaze™ 1045 were added at 75° C. to the freshly precipitated suspension in the paddle drier, and drying was completed as described in Example 1.
BET: 5.6 m 2 /g Bulk density: 437 g/L Laser diffraction: d(01%): 42 μm, d(50%): 55 μm, d(90%): 81 μm.
Example 6.
[heading-0073] Incorporation of Antiblaze™ 1045 within a Dry Blend
[0074] 4444 g of (10% by weight) of Antiblaze™ 1045 were mixed in a dry-blend process utilizing a Schugi Flexomix mixer at 3000 rpm with 40 kg of nylon-12 powder produced as in DE 2906647 with a median grain diameter d 50 of 53 μm (laser diffraction) and with a bulk density to DIN 53466 of 443 g/L. This is a vertical tube of diameter 100 mm in which there is a moving rotor with spray nozzles. For this process, it is preferable to heat the flame-retardant additive in order to reduce the viscosity.
Example 7.
[heading-0075] Incorporation of Antiblaze™ 1045 within a Dry Blend
[0076] 4444 g of (10% by weight) of Antiblaze™ 1045 were mixed in a dry-blend process utilizing a Schugi Flexomix mixer at 3000 rpm with 40 kg of copolyamide powder (Vestamelt 470) prepared as in DE 2906647 with a median grain diameter d 50 of 78 μm (laser diffraction) and with a bulk density to DIN 53466 of 423 g/L. This is a vertical tube of diameter 100 mm in which there is a moving rotor with spray nozzles. For this process, it is preferable to heat the flame-retardant additive in order to reduce the viscosity.
BET: 2.2 m 2 /g Bulk density: 423 g/L Laser diffraction: d(10%): 38 μm, d(50%): 78 μm, d(90%): 122 μm.
Comparative Example 1.
[0080] 40 kg of unregulated PA 12 prepared by hydrolytic polymerization, with a relative solution viscosity η rel . of 1.61 (in acidified m-cresol) and with an end group content of 72 mmol/kg of COOH and 68 mmol/kg of NH 2 were brought to 145° C. with 0.3 kg of IRGANOX® 1098 in 350 ml of ethanol, denatured with 2-butanone and 1% water content, within a period of 5 hours in a 0.8 m 3 stirred tank (diameter=90 cm, height=170 cm), and held for 1 hour at this temperature, with stirring (blade stirrer, diameter=42 cm, rotation rate=91 rpm). The jacket temperature was then reduced to 120° C., and the internal temperature was brought to 120° C. at a cooling rate of 45 K/h, at the same stirrer rotation rate. From this juncture onward, with the same cooling rate, the jacket temperature was maintained below the internal temperature by from 2 K to 3 K. Using the same cooling rate, the internal temperature was decreased to 117° C., and then held constant for 60 minutes. The internal temperature was then decreased to 111° C., using a cooling rate of 40 K/h. At this temperature, the precipitation began and was detectable through evolution of heat. After 25 minutes, the internal temperature fell, indicating the end of the precipitation. The suspension was cooled to 75° C. and then transferred to a paddle drier. The ethanol was removed therefrom by distillation at 70° C. and 400 mbar with the stirrer system running, and the residue was then further dried at 20 mbar and 85° C. for 3 hours.
BET: 6.9 m 2 /g Bulk density: 429 g/L Laser diffraction: d(10%): 42 μm, d(50%): 69 μm, d(90%): 91 μm.
Further Processing
[0085] All of the specimens from Examples 1 to 7 were treated for 1 minute with 0.1% by weight of Aerosil 200 in a CM50 D Mixaco mixer, at 150 rpm. These powders were then used on an EOSINT P360 laser sintering system to construct dumbbell specimens to ISO 3167, and also fire-protection test specimens of 80×3.2×10 mm (length=width=height). A tensile test to EN ISO 527 was used to determine (Table 2) mechanical values on the components. Density was determined by a simplified internal method. For this, the tensiles produced to ISO 3167 (multipurpose test specimen) were measured, and from these measurements the volume was calculated, the weight of the tensile specimens was determined and density was calculated from volume and weight.
TABLE 2 UL ® Classification of the Specimens from Examples 1-7 Parts composed from powders produced as described in UL Modulus of Thickness, Example No. Classification elasticity, N/mm 2 mm Example 1 a V-0 1588 3.9 Example 2 b V-0 1711 4.0 Example 3 c V-0 1501 4.0 Example 4 d V-0 1454 4.1 Example 5 e V-2 1673 3.7 Example 6 f V-0 1632 3.9 Example 7 g V-0 1207 3.8 Comparative Example 1 Unclassified 1601 3.6 a Reprecipitation. b Compounding and reprecipitation or milling. c Suspension 10%. d Suspension 15%. e Suspension 5%. f Dry Blend, Copolyamide.
[0086] As can be seen in Table 2, the incorporation of phosphonate-containing flame retardant by mixing achieves the improvement described in the following. Starting at a concentration of 10% of the phosphonate-containing flame retardant, a UL® V-0 classification is achieved. The components become only slightly thicker, but this can be corrected by reducing the amount of energy introduced by the laser.
[0087] The priority document of the present application, DE Application 10334497.7, filed Jul. 29, 2003, is incorporated herein by reference.
[0088] Obviously, numerous modifications and variations on the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | The present invention relates to a polymer powder composed of polyamide or of copolyamides, which also comprises flame retardant, in particular phosphonates, to a layer-by-layer process which selectively melts regions or selectively binds them, and also to moldings produced from this polymer powder. Compared with conventional products, the moldings constructed using the powder of the invention exhibit marked advantages in flammability and combustibility and drop behavior, particularly with respect to UL® (Underwriters Laboratories) classification. Furthermore, moldings produced from polymer powder of the invention have adequately good mechanical properties when compared with moldings based on polymer powders without flame retardant, in particular in terms of modulus of elasticity and tensile strain at break. In addition, these moldings also have a density close to that of injection moldings. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to intrusion detection systems and particularly to safety systems used on industrial machines. This improvement relates to means for presetting an acceptable obstruction.
2. Description of the Prior Art
Intrusion detection systems employing light beams are well known and typified in U.S. Pat. Nos. 4,249,074 and 3,970,846. These systems employ light beam sources and photodetectors to create a screen, and then monitor the beams (photodetector output) to detect an intrusion. In U.S. Pat. No. 4,249,074 a system is proposed which detects an impermissible intrusion, such as an operator's hand, by counting the number of consecutive beams which are interrupted. However, a need exists for the system which allows a specific obstruction (i.e. work bench) or detects the absence of an obstruction (i.e. feed stock).
SUMMARY OF THE INVENTION
The present invention employs a plurality of spaced light beam sources and corresponding photodetectors to form a light screen. A programmed microprocessor and memory circuitry senses the photodetector outputs, during a sequential scan, and stores information in memory on the location of an allowed obstruction by storing information on the location of initially blocked beams. During operation of the equipment, when changes occur in the size or the position of the obstruction, the system uses a programmed microprocessor to compare blocked beams to the stored information to analyze this change and to detect an impermissible intrusion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of the light screen concept showing an obstruction blocking certain light beams.
FIG. 2 is a block diagram of the circuitry controlling the emission of the light beams.
FIG. 3 is a block diagram of the circuitry controlling the reception and analysis of the light beams.
FIG. 4 is a flow diagram of the programming of the microprocessor.
While the invention will be described in connection with a preferred embodiment, it will be understood that it is not the intent to limit the invention to that embodiment. On the contrary, it is the intent to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIG. 1 there is shown a representation of a light screen for detecting intrusions, the generation and utilization of which is well known in the art. A plurality of light emitting (typically infrared) sources are positioned in spaced relation along the emitter side of an opening of a machine, and photodetectors are similarly positioned along the receiver side of the opening to receive the emitted light beams. Each photodetector is paired to a light emitting source to define a channel therebetween. When an obstruction is positioned between the emitting unit and the receiving unit, channels will be blocked and no signal will be present at the photodetector in the receiving unit.
The novel improvement of the present invention records the initial position of a permissible obstruction. When the obstruction pattern changes or moves, this system monitors such change and determines whether there is an impermissible intrusion or other event which requires a shut down of machinery or operator alert. By holding the initial obstructed pattern in a microprocessor memory, the change in blocked light beam channels is analyzed by the microprocessor programming to determine if the allowable obstruction was removed or repositioned, or if the detected change indicates a dangerous condition.
The electrical hardware of the present invention is shown in block diagram form in FIGS. 2 and 3. The light emitter circuit receives a synchronizing infrared signal generated at the receiver unit and then sequentially activates the infrared transmitter for each channel at regular intervals determined by the clock. The receiver unit likewise begins with the sync signal and sequentially monitors each channel receiver synchronously with the emitter unit. This monitoring is under control of the microprocessor and EPROM memory (FIG. 3) which is used to establish an allowable channel obstruction pattern, to analyze any change, and to operate the relay circuitry (to shut down the equipment) when a change in the sensed obstruction is not permissible. An external switch is used to instruct the microprocessor to select the mode of operation: "Reset", to set the allowable obstruction; or "Run", to monitor the light screen and analyze any change during operation of the machinery.
The software program for the microprocessor is physically located in the EPROM and is shown as a flow diagram in FIG. 4. Once a sync signal initiates the scan of the photodetector outputs, this decisional logic causes the circuit to monitor and test the channels. The position on the key switch determines the mode of operation: whether the location of an obstruction is being recorded as allowable ("Reset" mode) or whether the location of blocked beams is being tested against the recorded obstruction ("Run" mode).
As depicted in FIG. 4, when in the Reset mode the channels are examined sequentially; and if a channel is blocked, information on the location of that blocked channel is stored in a memory (Auto Blank Register). If the channel is not blocked then the corresponding register memory is cleared. This testing and storing of blocked locations continues until all channels are examined, whereupon the system is ready to be placed in the "Run" mode.
When the key switch is set to Run, then each channel is similarly checked for blockage. But in this mode, if the channel is determined to be blocked, then the Auto Blank Register is checked to see if it is an allowable obstruction. If it is not an allowable obstruction, then a violation is declared, causing the relays to shut down the equipment or an alert to be sounded.
In a further mode of operation, once the microprocessor has detected and stored the location of blocked channels, the software manipulates the stored data to (1) detect the removal of the obstruction (the system detects no blockage on channels originally stored as blocked) and (2) detect the movement of an obstruction (the detected blocked channels are the same in number and relative position as the stored locations of blocked channels even though they are in a different absolute location.) This mode of operation is the same as the previously described "Run" mode, except that when a blocked channel is found which is not an "Auto Blank" channel, the system completes scanning all channels and then performs an additional analysis: (1) if all "Auto Blank" channels are unblocked then the obstruction has been removed; and (2) if the blocked channels are the same in number but shifted so the relative position is the same, then the obstruction has moved. This additional logic is added to the logic of FIG. 4, and the programming required to implement these steps is well within the capabilities of those skilled in the art.
From the foregoing description, it will be apparent that modifications can be made to the apparatus and method for using same without departing from the teachings of the present invention. Accordingly, the scope of the invention is only to the limited as necessitated by the accompanying claims. | The present invention employs a plurality of spaced light beam sources and corresponding photodetectors to form a light screen. A programmed microprocessor and memory circuitry senses the photodetector output and stores information on the position of an allowed obstruction. During operation of the equipment, the microprocessor repeatedly senses the photodetector output to determine which channels are blocked. When dangerous changes occur in the size, position or presence of an obstruction, the system alerts the operator or stops the equipment. | 6 |
PRIORITY
[0001] This application claims priority under 35 U.S.C. §119(a) to Korean Patent Applications filed in the Korean Intellectual Property Office on Apr. 19, 2006 and assigned Ser. No. 2006-35239; filed in the Korean Intellectual Property Office on Nov. 13, 2006 and assigned Ser. No. 2006-111903; and filed in the Korean Intellectual Property Office on Nov. 14, 2006 and assigned Ser. No. 2006-112350, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a multi-hop relay Broadband Wireless Access (BWA) communication system, and in particular, to an apparatus and method for providing synchronization channels to Mobile Stations (MSs) and Relay Stations (RSs) and eliminating near-far interference between a direct service and a relay service in a multi-hop relay BWA communication system.
[0004] 2. Description of the Related Art
[0005] One of the most critical requirements for deployment of a 4 th Generation (4G) communication system is to build a self-configurable wireless network. The self-configurable wireless network refers to a wireless network configured in an autonomous or distributed manner without control of a central system to provide mobile communication services. For the 4G communication system, cells of very small radiuses are defined for the purpose of enabling high-speed communications and accommodating a larger number of calls. Hence, a conventional centralized wireless network design is not viable. Rather, the wireless network should be built to be under distributed control and to actively cope with an environmental change like addition of new Base Stations (BSs). As a result, the 4G communication system requires the self-configurable wireless network.
[0006] For real deployment of the self-configurable wireless network, techniques used for an ad hoc network should be introduced to a wireless access communication system. Such a major example is a multi-hop relay BWA communication system configured by applying a multi-hop relay scheme used for the ad hoc network to a BWA network with fixed BSs.
[0007] In general, since a BS and an MS communicate with each other via a direct link, a highly reliable radio link can be established easily between them in the BWA communication system. However, due to the BSs being fixed, the configuration of a wireless network is not flexible, making it difficult to provide an efficient service in a radio environment experiencing a fluctuating traffic distribution and a great change in the number of required calls.
[0008] The above drawback can be overcome by a relay service that delivers data over multiple hops via a plurality of neighbor MSs or neighbor RSs. The use of the multi-hop relay scheme facilitates fast network reconfiguration adaptive to an environmental change and renders the overall wireless network operation efficient. Also, a radio channel in a better channel status can be provided to an MS by installing an RS between the BS and the MS and thus establishing a multi-hop relay path via the RS. In this way, high-speed data channels can be provided to MSs in a shadowing area or an area where communications with the BS are unavailable. Cell coverage can also be expanded.
[0009] FIG. 1 illustrates service provisioning in a typical multi-hop relay BWA communication system.
[0010] In FIG. 1 , in the multi-hop relay BWA communication system, MSs 140 to 170 (MS 1 to MS 4 ) can receive the BWA services through a BS 100 , a primary RS (RS 1 ) 110 , and secondary RSs (RS 2 ) 120 and 130 .
[0011] MS 1 and MS 2 within the service area 101 of the BS 100 communicate with the BS 100 via direct links L 1 . MS 2 , which is located at the cell boundary of the BS 100 and thus placed in a poor channel state, can receive a higher-speed data channel via an RS-MS link L 2 between MS 2 and RS 2 130 than via the direct link L 1 .
[0012] MS 3 and MS 4 outside the service area 101 of the BS 100 communicate with the BS 100 via RS-MS links L 3 provided by RSI 110 . The communication links between the BS 100 and MS 3 and MS 4 via RS 1 110 expand the cell coverage. MS 4 , which is located at the cell boundary of RS 1 110 and thus placed in a poor channel state, can increase its transmission capacity using an RS-MS link L 4 between MS 4 and RS 2 120 .
[0013] As described above, when an MS is in a poor channel state at a cell boundary of a BS or in a shadowing area suffering from a severe shielding effect due to, for example, buildings, the BWA communication system enables the MS to communicate with the BS by providing a better-quality radio channel to the MS via an RS. In other words, the BS can provide high-speed data channels to the cell boundary and the shadowing area and expand its coverage area by the multi-hop relay scheme. The RSs 110 , 120 and 130 are classified into RS 1 (RS 110 ) that expands cell coverage and RS 2 (the RSs 120 and 130 ) that increases capacity according to their relay capabilities.
[0014] Typically, transmission/reception is carried out between a BS and an MS in frames having the configuration illustrated in FIG. 2 in the BWA communication system. FIG. 2 illustrates a Time Division Duplex (TDD) frame structure compliant with Institute of Electrical and Electronics Engineers (IEEE) 802.16, for data transmission/reception between the BS and the MS.
[0015] In FIG. 2 , a TDD frame 200 is divided into a DownLink (DL) subframe 210 and an UpLink (UL) subframe 220 with a guard region called Transmit/receive Transition Gap (TTG) in between. A guard region called Receive/transmit Transition Gap (RTG) is interposed between TDD frames.
[0016] The DL subframe 210 includes a preamble and a common control channel in mandatory slots. The MSs within the service area of the BS acquire synchronization and control information from the preamble and the common control channel.
[0017] As described above, the BWA communication system provides services to the MSs or RSs outside the cell coverage of the BS or in a shadowing area by use of the RSs. In order to ensure backward compatibility for the MSs, communications are conducted in frames configured as illustrated in FIG. 2 . That is, an RS operates in the same manner as an MS during initial access and negotiates a relay operation with the BS so that BS can provide a relay service to MSs in frames having the configuration of FIG. 2 . Because the RS provides the relay service using the same frame configuration as the BS, it has difficulty in concurrently communicating with the BS and the MSs over one frequency band in one frame. To avert a Radio Frequency (RF) isolation problem caused by the frame configuration illustrated in FIG. 2 , the frames are configured as illustrated in FIG. 3 so that transmission to and reception from the RS occur in parallel in time.
[0018] FIG. 3 illustrates a TDD frame structure in a conventional multi-hop relay BWA communication system.
[0019] In FIG. 3 , a DL subframe 300 is divided into a first area 301 and a second area 303 , and a UL subframe 310 is divided into a first area 311 and a second area 313 . For the RS operation transitions, the first areas 301 and 311 are distinguished from the second areas 311 and 313 in time division. The lengths of the first areas 301 and 311 and the lengths of the second areas 311 and 313 are fixed or adaptively adjusted according to a cell environment.
[0020] The BWA communication system provides a direct link service in the first areas 301 and 311 and a relay link service in the second areas 303 and 313 . Hence, the BS provides a synchronization channel, a control channel, and a traffic channel to an MS connected to it by a direct link in the first areas 301 and 311 and a synchronization channel, a control channel, and a traffic channel to an RS in the second areas 303 and 313 .
[0021] Since the RS may move as illustrated in FIG. 4 , the BWA communication system should consider the mobility of the RS.
[0022] FIG. 4 illustrates movement of the RS in the conventional multi-hop relay BWA communication system.
[0023] In FIG. 4 , being located in a vehicle such as a bus or a train, RS 1 420 has mobility. Hence, the BWA communication system should provide a synchronization channel to RS 1 420 for synchronization and cell search, taking into account its mobility.
[0024] In the case of the frame configuration illustrated in FIG. 3 , the lengths of the first and second areas 301 and 303 of the DL subframe 300 may vary depending on a cell environment. The resulting change in the position of the synchronization channel at the start of the second area 303 imposes overhead because RS 1 420 should locate the synchronization channels of the neighbor BSs. Increased interference between neighbor cells due to the power boost of synchronization channels, transmission of information about the neighbor BSs, and search for the synchronization channel of each neighbor BS add to the RS overhead.
[0025] Without providing the synchronization channels, RS 2 's 120 and 130 , as illustrated in FIG. 1 , provide the relay service in conjunction with the BS by multiple communications in the cell. In this case, an MS experiences near-far interference because of the power difference between a signal received from BS 100 or the RS 1 110 and a signal received from the RS 2 120 or 130 , as illustrated in FIG. 5 .
[0026] FIG. 5 illustrates a signal flow for a relay service from an RS in the conventional multi-hop relay BWA communication system.
[0027] In FIG. 5 , within the cell area of a BS 500 , a first MS 530 (MS 1 ) in a good channel status receives a service from the BS 500 via a direct link and a second MS 520 (MS 2 ) in a poor channel status receives the service via RS 2 510 .
[0028] Although BS 500 and RS 2 510 perform multiple communications using orthogonal resources in the same time area, a BS link signal is overlaid with an RS link signal in the air. Thus, MS 1 may undergo near-far interference as it receives a stronger interference signal from the nearby RS 2 510 than a signal from BS 510 . The near-far interference may also occur to the uplink as RS 2 510 receives a stronger interference signal from MS 1 than a signal from MS 2 .
SUMMARY OF THE INVENTION
[0029] An aspect of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, one aspect of the present invention is to provide an apparatus and method for efficiently supporting cell search and synchronization according to the mobility of an RS in a multi-hop relay BWA communication system.
[0030] Another aspect of the present invention is to provide an apparatus and method for efficiently supporting cell search and synchronization according to the mobility of an RS by providing synchronization channels in a multi-hop relay BWA communication system.
[0031] A further aspect of the present invention is to provide an apparatus and method for reducing near-far interference caused by multiple communications within a cell in a multi-hop relay BWA communication system.
[0032] Still another aspect of the present invention is to provide an apparatus and method for eliminating near-far interference between relay communications and direct communications in a cell by time-multiplexing the relay communications and the direct communications in a multi-hop relay BWA communication system.
[0033] Yet another aspect of the present invention is to provide a method for configuring a frame so as to provide synchronization channels and eliminate near-far interference and an apparatus supporting the same in a multi-hop relay BWA communication system.
[0034] According to an aspect of the present invention, there is provided a method for configuring a subframe in order to support a relay service in a multi-hop relay (BWA) communication system. The method includes configuring at least one of a BS-MS link subframe, a primary RS-MS link subframe, and a BS-secondary RS link subframe is configured in a first period of the subframe, the BS-MS link subframe being a subframe for a link between a BS and an MS, the primary RS-MS link subframe being a subframe for a link between a primary RS that provides a synchronization channel; and configuring an MS, and the BS-secondary RS link subframe being a subframe for a link between the BS and a secondary RS that does not provide a synchronization channel, and at least one of a BS-primary RS link subframe, an RS-RS link subframe, and a secondary RS-MS link subframe is configured in a second period of the subframe, the BS-primary RS link subframe being a subframe for a link between the BS and the primary RS, an RS-RS link subframe being a subframe for a link between an RS and another RS, and a secondary RS-MS link subframe being a subframe for a link between the secondary RS and an MS.
[0035] According to another aspect of the present invention, there is provided a method for configuring a downlink subframe in order to support a relay service in a multi-hop relay (BWA) communication system. The method includes configuring a BS-MS link subframe and an RS-MS link subframe are provided in a first period of the downlink subframe, the BS-MS link subframe being a subframe for a link between a BS and an MS and the RS-MS link subframe being a subframe for a link between an RS and an MS; configuring a 1 st group RS-2 nd group next-hop RS link subframe is configured in a second period of the downlink subframe, the 1 st group RS-2 nd group next-hop RS link subframe being a subframe for a link between an RS of a first group including odd-hop RSs and a next-hop RS of a second group including even-hop RSs; and configuring a BS-1-hop RS link subframe and a 2 nd group RS-1 st group next-hop RS link subframe are configured in a third period of the downlink subframe, the BS-1-hop RS link subframe being a subframe for a link between the BS and a 1-hop RS and the 2 nd group RS-1 st group next-hop RS link subframe being a subframe for a link between an RS of the second group and a next-hop RS of the first group.
[0036] According to another aspect of the present invention, there is provided a method for configuring a downlink subframe in order to support a relay service in a multi-hop relay BWA communication system. The method includes configuring a BS-MS link subframe and an RS-MS link subframe are configured in a first period of the downlink subframe, the BS-MS link subframe being a subframe for a link between a BS and an MS and the RS-MS link subframe being a subframe for a link between an RS and an MS; configuring a BS-1-hop RS link subframe and a 2 nd group RS-1 st group next-hop RS link subframe are configured in a second period of the downlink subframe, the BS-1-hop RS link subframe being a subframe for a link between the BS and a 1-hop RS and the 2 nd group RS-1 st group next-hop RS link subframe being a subframe for a link between an RS of a second group including even-hop RSs and a next-hop RS of a first group including odd-hop RSs and configuring a 1 st group RS-2 nd group next-hop RS link subframe is configured in a third period of the downlink subframe, the 1 st group RS-2 nd group next-hop RS link subframe being a subframe for a link between an RS of the first group and a next-hop RS of the second group.
[0037] According to still another aspect of the present invention, there is provided a method for configuring an uplink subframe in a multi-hop relay BWA communication system. The method includes configuring an MS-BS link subframe and an MS-RS link subframe are configured in a first period of the uplink subframe, the MS-BS link subframe being a subframe for a link between an MS and a BS and the MS-RS link subframe being a subframe for a link between an MS and an RS; configuring a 2 nd group RS-1 st group previous-hop RS link subframe is configured in a second period of the uplink subframe, the 2 nd group RS-1 st group previous-hop RS link subframe being a subframe for a link between an RS of a second group including even-hop RSs and a previous-hop RS of a first group including odd-hop RSs; and configuring a 1-hop RS-BS link subframe and a 1 st group RS-2 nd group previous-hop RS link subframe is configured in a third period of the uplink subframe, the 1-hop RS-BS link subframe being a subframe for a link between a 1-hop RS and the BS and the 1 st group RS-2 nd group previous-hop RS link subframe being a subframe for a link between an RS of the first group and a previous-hop RS of the second group.
[0038] According to yet another aspect of the present invention, there is provided a method for configuring an uplink subframe in a multi-hop relay BWA communication system. The method includes configuring an MS-BS link subframe and an MS-RS link subframe are configured in a first period of the uplink subframe, the MS-BS link subframe being a subframe for a link between an MS and a BS and the MS-RS link subframe being a subframe for a link between an MS and an RS: configuring a 1-hop RS-BS link subframe and a 1 st group RS-2 nd group previous-hop RS link subframe is configured in a second period of the uplink subframe, the 1-hop RS-BS link subframe being a subframe for a link between a 1-hop RS and the BS and the 1 st group RS-2 nd group previous-hop RS link subframe being a subframe for a link between an RS of a first group including odd-hop RSs and a previous-hop RS of a second group including even-hop RSs; and configuring a 2 nd group RS-1 st group previous-hop RS link subframe is configured in a third period of the uplink subframe, the 2 nd group RS-1 st group previous-hop RS link subframe being a subframe for a link between an RS of the second group and a previous-hop RS of the first group.
[0039] According to yet another aspect of the present invention, there is provided a method of a BS in a multi-hop relay BWA communication system. The method includes the BS allocating resources to a first period and a second period of a subframe, the first period being for communicating with at least one of an MS and a secondary RS that does not provide a synchronization channel and the second period being for communicating with a primary RS that provides a synchronization channel; communicating with the at least one of the MS and the secondary RS in the first period of the subframe; and communicating with the primary RS in the second period of the subframe.
[0040] According to still another aspect of the present invention, there is provided a method of an RS that provides a synchronization channel in a multi-hop relay BWA communication system. The method includes the RS setting a first period and a second period according to control information received from an upper node, the first period being for communicating with an MS and the second period being for communicating with at least one of the upper node and a lower RS; communicating with the MS in the first period; and communicating with the at least one of the upper node and the lower RS in the second period.
[0041] According to still another aspect of the present invention, there is provided a method of an RS that does not provide a synchronization channel in a multi-hop relay BWA communication system. The method includes the RS setting a first period and a second period according to control information received from an upper node, the first period being for communicating with the upper node and the second period being for communicating with an MS; communicating with the upper node in the first period; and communicating with the MS in the second period.
[0042] According to still yet another aspect of the present invention, there is provided an apparatus of a BS in a multi-hop relay BWA communication system. The apparatus includes a timing controller for providing a timing signal for transmission and reception according to a subframe configuration in which a first period and a second period are defined, the first period being for communicating with at least one of an MS and a secondary RS that doest not provide a synchronization channel and the second period being for communicating with a primary RS that provides a synchronization channel; a transmitter for generating one of a first period signal and a second period signal according to the timing signal and transmits the generated signal; and a receiver for receiving one of the first period signal and the second period signal according to the timing signal and recovers the received signal.
[0043] According to still yet another aspect of the present invention, there is provided an apparatus of an RS that provides a synchronization channel in a multi-hop relay BWA communication system. The apparatus includes a timing controller for providing a timing signal for transmission and reception according to a subframe configuration in which a first period and a second period are defined, the first period being for communicating with at least one of an MS and a secondary RS that doest not provide a synchronization channel and the second period being for communicating with an upper node; a transmitter for generating one of a first period signal and a second period signal according to the timing signal and transmits the generated signal; and a receiver for receiving one of the first period signal and the second period signal according to the timing signal and recovers the received signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:
[0045] FIG. 1 illustrates a signal flow for a relay service in a typical multi-hop relay BWA communication system;
[0046] FIG. 2 illustrates a frame structure in a typical IEEE 802.16 system;
[0047] FIG. 3 illustrates a frame structure in a conventional multi-hop relay BWA communication system;
[0048] FIG. 4 illustrates an RS movement in the conventional multi-hop relay BWA communication system;
[0049] FIG. 5 illustrates a signal flow for a relay service from an RS in the conventional multi-hop relay BWA communication system;
[0050] FIG. 6 illustrates a frame structure with synchronization channels in a multi-hop relay BWA communication system according to the present invention;
[0051] FIG. 7 illustrates a frame structure in the multi-hop relay BWA communication system according to the present invention;
[0052] FIG. 8 is a diagram illustrating the transmission and reception timings of signals in accordance with the frame structure illustrated in FIG. 7 ;
[0053] FIG. 9 illustrates a frame structure in the multi-hop relay BWA communication system according to the present invention;
[0054] FIG. 10 illustrates a configuration of the multi-hop relay BWA communication system according to the present invention;
[0055] FIG. 11 illustrates a DL subframe structure in the multi-hop relay BWA communication system according to the present invention;
[0056] FIG. 12 illustrates the positions of synchronization channels in the DL subframe illustrated in FIG. 11 in the multi-hop relay BWA communication system according to the present invention;
[0057] FIG. 13 illustrates a DL subframe structure in the multi-hop relay BWA communication system according to the present invention;
[0058] FIG. 14 illustrates the positions of synchronization channels in the DL subframe illustrated in FIG. 13 in the multi-hop relay BWA communication system according to the present invention;
[0059] FIG. 15 illustrates a UL subframe structure in the multi-hop relay BWA communication system according to the present invention;
[0060] FIG. 16 illustrates a UL subframe structure in the multi-hop relay BWA communication system according to the present invention;
[0061] FIG. 17 is a flow diagram illustrating a process of a BS in the multi-hop relay BWA communication system according to the present invention;
[0062] FIG. 18 is a flow diagram illustrating a process of a RS 1 in the multi-hop relay BWA communication system according to the present invention;
[0063] FIG. 19 is a flow diagram illustrating a process of a RS 2 in the multi-hop relay BWA communication system according to the present invention;
[0064] FIG. 20 is a flow diagram illustrating a process of an MS in the multi-hop relay BWA communication system according to the present invention; and
[0065] FIG. 21 is a block diagram of the BS in the multi-hop relay BWA communication system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] Preferred embodiments of the present invention will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.
[0067] The present invention provides a technique for providing a synchronization channel to support the mobility of an RS and eliminating near-far interference caused by multiple communications within a cell in a multi-hop relay BWA communication system. The following description will be made in the context of a Time Division Duplex (TDD)-Orthogonal Frequency Division Multiple Access (OFDM) wireless communication system, while the present invention is also applicable to a communication system using any other multiple access scheme or any other division duplex scheme.
[0068] The term “primary RS” or “RS 1 ” is defined as an RS that expands cell coverage and the term “secondary RS” or “RS 2 ” is defined as an RS that increases capacity. Therefore, the RS 1 provides a synchronization channel, a control channel, and traffic channels to the MSs or the RSs outside the cell area of a BS, whereas the RS 2 provides unicast control and traffic channels to the MSs in a poor channel status though located in the cell area of the BS.
[0069] While it is described herein that a subframe is configured in compliance with the IEEE 802.16 standard for communications between a BS and an RS, it is obviously to be understood that an advanced technology with novel functionalities and usages is also applicable. The same holds true for communications with an upper RS (or superordinated RS) and a lower RS.
[0070] FIG. 6 illustrates a frame structure that provides synchronization channels to the MSs and the RSs in a multi-hop relay BWA communication system according to the present invention.
[0071] In FIG. 6 , a frame is composed of a DL subframe 610 and a UL subframe 620 . The DL subframe 610 includes time-multiplexed first and second areas 611 and 613 , and the UL subframe 620 includes time-multiplexed first and second areas 621 and 623 . The lengths of the first areas 611 and 621 and the lengths of the second areas 621 and 623 may be fixed or vary depending on a cell environment.
[0072] A BS communicates with an MS connected to it via a direct link in the first areas 611 and 621 , and communicates with an RS in the second areas 613 and 623 . As the lengths of the first areas 611 and 621 and the second areas 613 and 623 may vary dynamically according to the cell environment as mentioned above, the BS allocates synchronization channels at the start of the first area 611 and at the end of the second area 613 so that the MS and the RS can acquire synchronization. The BS also allocates ranging channels at the start of the first area 621 and the end of the second area 623 , for ranging from MSs. The positions of the ranging channels (or ranging slots) in the UL subframe 620 may be indicated by a control channel rather than they are fixed.
[0073] To facilitate synchronization and cell search, the BS provides the MS with a synchronization channel (referred to as BS synchronization channel) in the form of a preamble and the RS with a synchronization channel (referred to as RS synchronization channel) in the form of a postamble. As the synchronization channels reside at the start and end of the DL subframe 610 , the MS and the RS can acquire synchronization information and neighbor BS information from the fixed synchronization channels. The RS synchronization channel can further be used for interference measurement.
[0074] Multiple communications take place among the BS, RS 1 , RS 2 and MSs in the multi-hop relay BWA communication system.
[0075] Since the BS and RS 2 provide a service to the MSs within the service area of the BS, they use orthogonal resources to avoid interference between two links, i.e. a BS-MS link and an RS 2 -MS link. When a plurality of RS 2 's exist in the cell, the orthogonal resources allocated to the RS 2 can be reused among them by spatial multiplexing.
[0076] Therefore, the BS-MS link signal is distinguished from the RS 2 -MS link signal in the frequency domain, but they overlap each other in the time domain. When the BS and RS 2 communicate with the MSs at the same time, near-far interference occurs.
[0077] In this context, the same time resources are not allocated to the BS-MS link and the RS 2 -MS link as illustrated in FIG. 7 . Specifically, the BWA communication system allocates predetermined resources of the second areas 613 and 623 to the RS 2 -MS link.
[0078] FIG. 7 illustrates a frame structure in the multi-hop relay BWA communication system according to the present invention. According to the frame structure, a frame is so configured that resources are allocated to the RS 1 and the RS 2 in frequency division.
[0079] In FIG. 7 , each frame is composed of a DL subframe 720 and a UL subframe 730 . The DL subframe 720 includes a time-multiplexed first and second areas 721 and 723 , and the UL subframe 730 includes time-multiplexed first and second areas 731 and 733 . The lengths of the first areas 721 and 731 and the lengths of the second areas 723 and 733 are fixed or dynamically vary depending on a cell environment.
[0080] In an RS 2 frame 710 , the RS 2 communicates with the BS in the first areas 721 and 731 and communicates with an MS in predetermined parts 711 and 713 of the second areas 723 and 733 . If a plurality of RS 2 's exist, the second areas 723 and 733 are reused among them by spatial division multiplexing. The RS 1 provides a transparent relay service to an MS in the first areas 721 and 731 and communicates with the BS in the second areas 723 and 733 .
[0081] When a frame is configured by the spatial multiplexing and the time multiplexing as described above, the transmission and reception of the BS, RS 1 , RS 2 , and the MSs are in the relationship illustrated in FIG. 8 .
[0082] FIG. 8 is a diagram illustrating the transmission and reception timings of signals in accordance with the frame structure illustrated in FIG. 7 .
[0083] In FIG. 8 , in the DL subframe 720 , a BS 800 sends a synchronization channel, a control channel, and a traffic burst to an RS 2 820 or an MS 830 connected to the BS 800 via a direct link in the first area 721 and then sends a control channel, a traffic burst, and a synchronization channel to an RS 1 810 in the second area 723 . The BS 800 provides the MS 830 and the RSs 810 and 820 with a BS synchronization channel and an RS synchronization channel at the start of the first area 721 and at the end of the second area 723 , respectively.
[0084] The RS 1 810 sends a synchronization channel, a control channel, and a traffic burst to the RS 2 820 or the MS 830 connected to the RS 1 810 via a relay link in the first area 721 . Then, the RS 1 810 receives the synchronization channel, the control channel, and the traffic burst from the BS 800 in the second area 723 .
[0085] The RS 2 820 receives the control channel and the traffic burst needed for the relay service from the BS 800 in the first area 721 . Then, the RS 2 820 sends the traffic burst to the MS 830 connected to the RS 2 via a relay link in the predetermined part 711 of the second area 723 .
[0086] The MS 830 receives the synchronization channel, the control channel, and the traffic burst from the BS 800 or the RS 1 810 in the first area 721 . Then, the MS 830 receives a signal from the RS 1 810 or the RS 2 820 in the second area 723 . Particularly, the MS 830 receives the traffic burst from RS 2 820 in the part of the second area 723 .
[0087] To avoid near-far interference, the second areas 723 and 733 are allocated to a RS 2 -MS link and a BS-RS 1 link by frequency division. In another embodiment of the present invention, the second areas 723 and 733 are allocated to the RS 2 -MS link and the BS-RS 1 link by time division.
[0088] FIG. 9 illustrates a frame structure in the multi-hop relay BWA communication system according to the present invention. A BS frame 700 and an RS 2 frame 710 are shown.
[0089] In FIG. 9 , each of the frames 700 and 710 is composed of the DL subframe 720 and the UL subframe 730 . The DL subframe 720 includes the time-multiplexed first and second areas 721 and 723 , and the UL subframe 730 includes the time-multiplexed first and second areas 731 and 733 . The second areas 723 and 733 are divided into the RS 2 -MS areas 900 and 920 and BS-RS 1 areas 910 and 930 . The BS provides the RS 1 with an RS synchronization channel taking the form of a postamble at a fixed position. Therefore, the RS 2 -MS areas 900 and 920 precede the BS-RS 1 areas 910 and 930 in the second areas 723 and 733 .
[0090] The BS communicates with the RS 2 or an MS in the first areas 721 and 731 and communicates with RS 1 in the second areas 723 and 733 . Notably, the BS leaves the RS 2 -MS areas 900 and 920 empty in the second areas 723 and 733 to avoid intra-cell interference. Accordingly, the BS communicates with RS 1 in the BS-RS 1 areas 910 and 930 .
[0091] For RS 1 , the BS provides the RS synchronization channel and a ranging channel at the ends of the BS-RS 1 areas 910 and 930 .
[0092] In the RS frame 710 , RS 2 communicates with the BS in the first areas 721 and 731 and then communicates with an MS in the RS 2 -MS areas 900 and 920 of the second areas 723 and 733 . Notably, the RS 2 does not use the BS-RS 1 areas 910 and 930 to avoid the intra-cell interference.
[0093] The above description has been made in the context of a two-hop multi-hop relay BWA communication system. The BWA communication system may be configured so that an MS communicates with a BS over multiple hops, as illustrated in FIG. 10 .
[0094] FIG. 10 illustrates a configuration of the multi-hop relay BWA communication system according to the present invention.
[0095] In FIG. 10 , a BS 1001 communicates with an MS 1019 via relay links established by a plurality of RSs 1011 , 1013 , 1015 , and 1017 .
[0096] The RSs 1011 , 1013 , 1015 , and 1017 can be grouped into a 1 st group and a 2 nd group. For example, if the BS 1001 is set as a 0-hop RS, the 1 st group is an even-hop group including the BS 1001 , a 2-hop RS 1013 , a 4-hop RS, and other even-hop RSs and the 2 nd group is an odd-hop group including a 1-hop RS 1011 , a 3-hop RS 1015 , and other odd-hop RSs.
[0097] If the BS 1001 is not classified as the 0-hop RS, the 1 st group is an odd-hop group including the 1-hop RS 1011 , the 3-hop RS 1015 , and other odd-hop RSs and the 2 nd group is an even-hop group including the 2-hop RS 1013 , the 4-hop RS, and the other even-hop RSs.
[0098] When the multi-hop links are grouped into the first and second groups in this way, communications are carried out in frames having the configurations illustrated in FIGS. 11 to 16 in the BWA communication system. The following description is made on the assumption that the 1 st group is the odd-hop group and the second area illustrated in FIG. 6 is further divided into second and third areas.
[0099] A DL subframe has the configuration illustrated in FIG. 11 or FIG. 13 in the BWA communication system.
[0100] FIG. 11 illustrates a DL subframe structure in the multi-hop relay BWA communication system according to the present invention.
[0101] Referring to FIG. 11 , each DL subframe 1100 includes a time-multiplexed first, second, and third areas 1101 , 1103 , and 1105 , respectively.
[0102] In a BS subframe 1110 , the BS sends the downlink subframes to an MS within its service area in the first and second areas 1101 and 1103 . To avoid interference between the MS and an RS, null data can be filled in the second area 1103 , instead of the downlink subframe. The BS provides the MS with a preamble as a synchronization channel at the start of the first area 1101 . The BS sends a downlink subframe to a 1-hop RS of the 1 st group in the third area 1105 . The BS provides the 1-hop RS with a postamble as a synchronization channel at the end of the third area 1105 .
[0103] In a 1 st group RS subframe 1120 , a 1 st group RS sends a downlink subframe to an MS within its service area in the first area 1101 . The 1 st group RS provides the MS with a synchronization channel in the form of a preamble at the start of the first area 1101 . The 1 st group RS sends a downlink subframe to a next-hop RS of the 2 nd group in the second area 1103 . The 1 st group RS provides the next-hop RS with a synchronization channel in the form of a postamble at the end of the second area 1103 . The 1 st group RS receives a downlink subframe from a previous-hop RS of the 2 nd group in the third area 1105 . If the 1 st group RS is the 1-hop RS, the 1 st group RS receives the downlink subframe from the BS in the third area 1105 . A TTG is interposed between the second area 1103 and the third area 1105 , for an operation transition of the 1 st group RS. Hence, the 1 st group RS sends the synchronization channel to the 2 nd group RS using resources of the second area 1103 before the TTG
[0104] In a 2 nd group RS subframe 1130 , a 2 nd group RS sends a downlink subframe to an MS within its service area in the first area 1101 . The 2 nd group RS provides the MS with a synchronization channel in the form of a preamble at the start of the first area 1101 . The 2 nd group RS receives a downlink subframe from a previous-hop RS of the 1 st group in the second area 1103 . The 2 nd group RS sends a downlink subframe to a next-hop RS of the 1 st group in the third area 1105 . The 2 nd group RS provides the next-hop RS with a synchronization channel in the form of a postamble at the end of the third area 1105 . For operation transitions of the 2 nd group RS, a TTG is interposed between the first area 1101 and the second area and an RTG intervenes between the second area 1103 and the third area 1105 .
[0105] While not shown, if the 1 st group RS is a last-hop RS, the 1 st group RS sends the downlink subframes to the MSs within its service area in the first and second areas 1101 and 1103 . To avoid interference between the MSs and the RS, the second area 1103 may have null data. Then, the last-hop RS receives a downlink subframe from a previous-hop RS of the 2 nd group in the third area 1105 .
[0106] If the last-hop RS is a 2 nd group RS, the 1 st group RS sends the downlink subframes to the MSs within its service area in the first and third areas 1101 and 1105 . To avoid interference between the MSs and the RS, the third area 1105 may have null data. The last-hop RS receives a downlink subframe from a previous-hop RS of the 1 st group in the second area 1103 .
[0107] In accordance with the DL frame structure illustrated in FIG. 11 , the subframes of the first, second, and third areas of the DL subframe can be configured in compliance with IEEE 802.16 standards, as illustrated in FIG. 12 .
[0108] FIG. 12 illustrates the positions of synchronization channels in the DL subframe illustrated in FIG. 11 in the multi-hop relay BWA communication system according to the present invention.
[0109] In FIG. 12 , a DL subframe 1200 includes time-multiplexed first, second, and third areas 1201 , 1203 , and 1205 , respectively.
[0110] A BS subframe 1210 carries a synchronization channel, a control channel, and a DL burst to an MS within the service area of the BS. The BS positions the synchronization channel for the MS in the form of a preamble at the start of the first area 1201 . If the BS uses the second area 1203 , the BS frame 1210 includes a DL burst in the second area 1203 . The third area 1205 has a control channel, a DL burst, and a synchronization channel for the 1-hop RS. Thus, the BS provides the 1-hop RS with the synchronization channel in the form of a postamble at the end of the third area 1205 .
[0111] In a 1 st group RS subframe 1220 , the first area 1201 carries a synchronization channel, a control channel, and a DL burst to an MS within the service area of the 1 st group RS. The 1 st group RS provides the MS with the synchronization channel in the form of a preamble at the start of the first area 1201 . The second area 1203 has a control channel, a DL burst, and a synchronization channel for the next-hop RS of the 2 nd group. Thus, the 1 st group RS provides the next-hop RS with the synchronization channel in the form of a postamble at the end of the second area 1203 . The 1 st group RS receives a downlink subframe from a previous-hop RS or the BS in the third area 1205 .
[0112] In a 2 nd group RS frame 1230 , the first area 1201 includes a synchronization channel, a control channel, and a DL burst for an MS within the service area of the 2 nd group RS. That is, the 2 nd group RS provides the synchronization channel for the MS in the form of a preamble at the start of the first area 1201 . The third area 1205 carries a synchronization channel, a control channel, and a DL burst for a next-hop RS of the 1 st group. That is, the 2 nd group RS provides the next-hop 1 st group RS with a synchronization channel in the form of a postamble at the end of the third area 1205 . The 2 nd group RS receive a downlink subframe from a previous-hop RS in the second area 1203 .
[0113] FIG. 13 illustrates a DL subframe structure in the multi-hop relay BWA communication system according to the present invention.
[0114] In FIG. 13 , each DL subframe 1300 includes a time-multiplexed first, second, and third areas 1301 , 1303 , and 1305 .
[0115] In a BS subframe 1310 , the BS sends the downlink subframes to the MSs within its service area in the first and third areas 1301 and 1305 . To avoid interference between the MSs and an RS, null data can be filled in the third area 1305 , instead of the downlink subframe. The BS provides a preamble as a synchronization channel at the start of the first area 1301 , for the MSs. The BS sends a downlink subframe to a 1-hop RS of the 1 st group in the second area 1303 . The BS provides the 1-hop RS with a postamble as a synchronization channel at the end of the second area 1303 . Since an RTG exists between the second area 1303 and the third area 1305 in a 1 st group RS subframe 1320 , the BS sends the synchronization channel to the 1-hop RS before the RTG in the second area 1303 .
[0116] In the 1 st group RS subframe 1320 , a 1 st group RS sends a downlink subframe to an MS within its service area in the first area 1301 . The 1 st group RS provides the MS with a synchronization channel in the form of a preamble at the start of the first area 1301 . The 1 st group RS receives a downlink subframe from a previous-hop RS of the 2 nd group in the second area 1303 . If the 1 st group RS is the 1-hop RS, the 1 st group RS receives the downlink subframe from the BS in the second area 1303 . The 1 st group RS sends a downlink subframe to a next-hop RS of the 2 nd group in the third area 1305 . The 1 st group RS provides the next-hop RS with a synchronization channel in the form of a postamble at the end of the third area 1305 . For operation transitions of the 1 st group RS, a TTG is interposed between the first area 1301 and the second area 1303 and an RTG exists between the second area 1303 and the third area 1305 in the 1 st group RS subframe 1320 .
[0117] In a 2 nd group RS subframe 1330 , a 2 nd group RS sends a downlink subframe to an MS within its service area in the first area 1301 . The 2 nd group RS provides the MS with a synchronization channel in the form of a preamble at the start of the first area 1301 . The 2 nd group RS sends a downlink subframe to a next-hop RS of the 1 st group in the second area 1303 . The 2 nd group RS provides the next-hop RS with a synchronization channel in the form of a postamble at the end of the second area 1303 . The 2 nd group RS receives a downlink subframe from a previous-hop RS of the 1 st group in the third area 1305 .
[0118] While not shown, if a last-hop RS belongs to the 1 st group, the last-hop RS sends the downlink subframes to the MSs within its service area in the first and third areas 1301 and 1305 . To avoid interference between the MSs and the RS, the third area 1305 may have null data. The last-hop RS receives a downlink subframe from a previous-hop RS of the 2 nd group in the second area 1303 .
[0119] If the last-hop RS is a 2 nd group RS, the last-hop RS sends the downlink subframes to the MSs within its service area in the first and second areas 1301 and 1303 . To avoid interference between the MSs and the RS, the second area 1303 may have null data. The last-hop RS receives a downlink subframe from a previous-hop RS of the 1 st group in the third area 1305 .
[0120] In accordance with the DL frame structure illustrated in FIG. 13 , the subframes of the first, second and third areas in the DL subframe can configured in compliance with IEEE 802.16 standards, as illustrated in FIG. 14 .
[0121] FIG. 14 illustrates the positions of synchronization channels in the DL subframe illustrated in FIG. 13 in the multi-hop relay BWA communication system according to the present invention
[0122] In FIG. 14 , a DL subframe 1400 includes a time-multiplexed first, second, and third areas 1401 , 1403 , and 1405 .
[0123] A BS subframe 1410 carries a synchronization channel, a control channel, and a DL burst to an MS within the service area of the BS. That is, the BS positions the synchronization channel for the MS in the form of a preamble at the start of the first area 1401 . If the BS uses the third area 1405 , the BS subframe 1410 includes a downlink burst in the third area 1405 . The second area 1403 of the BS subframe 1410 has a control channel, a DL burst, and a synchronization channel for the 1-hop RS. Thus, the BS provides the 1-hop RS with the synchronization channel in the form of a postamble at the end of the second area 1403 .
[0124] In a 1 st group RS subframe 1420 , the first area 1401 carries a synchronization channel, a control channel, and a DL burst to an MS within the service area of the 1 st group RS. The 1 st group RS provides the MS with the synchronization channel in the form of a preamble at the start of the first area 1401 . The third area 1405 has a control channel, a DL burst, and a synchronization channel for the next-hop RS of the 2 nd group. Thus, the 1 st group RS provides the next-hop RS with the synchronization channel in the form of a postamble at the end of the third area 1405 . The 1 st group RS receives a downlink subframe from a previous-hop RS or the BS in the second area 1403 .
[0125] In a 2 nd group RS subframe 1430 , the first area 1401 includes a synchronization channel, a control channel, and a DL burst for an MS within the service area of the 2 nd group RS. That is, the 2 nd group RS provides the synchronization channel to the MS in the form of a preamble at the start of the first area 1401 . The second area 1403 carries a synchronization channel, a control channel, and a DL burst for a next-hop RS of the 1 st group. The 2 nd group RS provides the synchronization channel to the next-hop 1 st group RS in the form of a postamble at the end of the second area 1403 . The 2 nd group RS receive a downlink subframe from a previous-hop RS in the third area 1405 .
[0126] The BWA communication system configures a UL subframe as illustrated in FIG. 15 or FIG. 16 .
[0127] FIG. 15 illustrates a UL subframe structure in the multi-hop relay BWA communication system according to the present invention.
[0128] In FIG. 15 , each UL subframe 1500 includes a time-multiplexed first, second, and third areas 1501 , 1503 and 1505 .
[0129] In a BS subframe 1510 , the BS receives the uplink subframes from the MSs within its service area in the first and second areas 1501 and 1503 . To avoid interference between the MSs and an RS, null data can be filled in the second area 1503 , instead of the uplink subframe. The BS receives an uplink subframe from a 1-hop RS of the 1 st group in the third area 1505 .
[0130] In 1 st group RS subframes 1520 and 1540 , a 1 st group RS receives an uplink subframe from an MS within its service area in the first area 1501 . The 1 st group RS receives an uplink subframe from a next-hop RS of the 2 nd group in the second area 1503 . For example, a 1-hop RS of the first group receives an uplink subframe from a 2-hop RS of the second group. A 3-hop RS of the first group receives an uplink subframe from a 4-hop RS of the second group. The 1 st group RS sends an uplink subframe to a previous-hop RS of the second group in the third area 1505 . If the 1 st group RS is the 1-hop RS, the 1 st group RS sends an uplink subframe to the BS in the third area 1505 . For an operation transition of the 1 st group RS, an RTG is interposed between the second area 1503 and the third area 1505 .
[0131] In a 2 nd group RS frame 1530 , a 2 nd group RS receives an uplink subframe from an MS within its service area in the first area 1501 . The 2 nd group RS sends an uplink subframe to a previous-hop RS of the 1 st group in the second area 1503 . The 2 nd group RS receives an uplink subframe from a next-hop RS of the 1 st group in the third area 1505 . For operation transitions of the 2 nd group RS, an RTG exists between the first area 1501 and the second area 1503 and a TTG is interposed between the second area 1503 and the third area 1505 .
[0132] While not shown, if a last-hop RS belongs to the first group, the last-hop RS receives the uplink subframes from the MSs within its service area in the first and second areas 1501 and 1503 . To avoid interference between the MSs and the RS, the second area 1503 may have null data. The last-hop RS sends an uplink subframe to a previous-hop RS of the 2 nd group in the third area 1505 .
[0133] If the last-hop RS is a 2 nd group RS, it receives uplink subframes from the MSs within its service area in the first and third areas 1501 and 1505 . To avoid interference between the MSs and the RS, the third area 1505 may have null data. The last-hop RS sends an uplink subframe to a previous-hop RS of the 1 st group in the second area 1503 .
[0134] FIG. 16 illustrates a UL subframe structure in the multi-hop relay BWA communication system according to the present invention.
[0135] In FIG. 16 , each UL subframe 1600 includes a time-multiplexed first, second, and third areas 1601 , 1603 , and 1605 , respectively.
[0136] In a BS subframe 1610 , the BS receives the uplink subframes from the MSs within its service area in the first and third areas 1601 and 1605 . To avoid interference between an MS and an RS, null data can be filled in the third area 1605 , instead of the UL subframe. The BS receives an uplink subframe from a 1-hop RS of the 1 st group in the second area 1603 .
[0137] In 1 st group RS subframes 1620 and 1640 , a 1 st group RS receives an uplink subframe from an MS within its service area in the first area 1601 . The 1 st group RS sends an uplink subframe to a previous-hop RS of the second group in the second area 1603 . If the 1 st group RS is a 1-hop RS, the 1 st group RS sends an uplink subframe to the BS in the second area 1603 . In the third area 1605 , the 1 st group RS receives an uplink subframe from a next-hop RS of the 2 nd group. For operation transitions of the 1 st group RS, an RTG is interposed between the first area 1601 and the second area 1603 and a TTG exists between the second area 1603 and the third area 1605 .
[0138] In a 2 nd group RS frame 1630 , a 2 nd group RS receives an uplink subframe from an MS within its service area in the first area 1601 . The 2 nd group RS receives an uplink subframe from a next-hop RS of the 1 st group in the second area 1603 and sends an uplink subframe to a previous-hop RS of the 1 st group in the third area 1605 .
[0139] While not shown, if a last-hop RS belongs to the first group, the last-hop RS receives the uplink subframes from the MSs within its service area in the first and third areas 1601 and 1605 . To avoid interference between the MSs and the RS, the third area 1605 may have null data. The last-hop RS sends an uplink subframe to a previous-hop RS of the 2 nd group in the second area 1603 .
[0140] If the last-hop RS is a 2 nd group RS, the last-hop RS receives the uplink subframes from the MSs within its service area in the first and second areas 1601 and 1603 . To avoid interference between the MSs and the RS, the second area 1603 may have null data. The last-hop RS sends an uplink subframe to a previous-hop RS of the 1 st group in the third area 1605 .
[0141] The BWA communication system may configure a frame by combining the DL subframe illustrated in FIG. 11 and the UL subframe illustrated in FIG. 15 or FIG. 16 . On the other hand, the BWA communication system may configure a frame by combining the DL subframe illustrated in FIG. 13 and the UL subframe illustrated in FIG. 15 or FIG. 16 .
[0142] As described above, the BS sends a synchronization channel to the MSs and the 1-hop RSs according to a frame configuration in the BWA communication system. The 1 st group RSs send synchronization channels to the MSs and the 2 nd group RSs according to the frame configuration. The 2 nd group RSs provide synchronization channels to the MSs and the next-hop RSs of the first group according to the frame configuration.
[0143] The BS, the 1 st group RSs, and the 2 nd group RSs send the synchronization channels in every frame or in every predetermined number of frames. Alternatively, they may include the synchronization channels in frames indicated by a control signal. The control signal contains a Frame Control Header (FCH), a MAP, and a Downlink Channel Descriptor (DCD).
[0144] Now a description will be made of operations of the BS, RS 1 , RS 2 , and the MS to communicate using the frame configurations described above in the BWA communication system.
[0145] FIG. 17 is a flow diagram illustrating a process of the BS in the multi-hop relay BWA communication system according to the present invention.
[0146] In FIG. 17 , the BS defines a direct-link area and a relay-link area in each of the DL and UL subframes in step 1701 . For example, if the BWA communication system spans two hops, a first area for the direct link and a second area for the relay link are defined in each of the DL and UL subframes. If the BWA communication system spans three hops, a first area for the direct link and second and third areas for the relay link are defined in each of the DL and UL subframes.
[0147] In step 1703 , the BS communicates with an MS and RS 2 within its service area in the direct-link area. The BS provides a BS synchronization channel to the MS at the start of the direct-link area. For example, if a frame has the configuration illustrated in FIG. 6 , FIG. 7 , or FIG. 9 , the BS communicates with the MS in the first areas.
[0148] If the DL subframe and the UL subframe have the configurations illustrated in FIG. 11 and FIG. 15 , respectively, the BS communicates with the MS in the first areas or the second areas. If the DL subframe and the UL subframe have the configurations illustrated in FIG. 13 and FIG. 16 , respectively, the BS communicates with the MS in the first areas or the third areas.
[0149] The BS communicates with a 1-hop RS in the relay-link area in step 1705 . For the 1-hop RS, the BS provides an RS synchronization channel at the end of the relay-link area.
[0150] For example, if the frame has the configuration illustrated in FIG. 6 , FIG. 7 or FIG. 9 , the BS communicates with the 1-hop RS in the second areas. Thus, the BS provides the synchronization channel to the 1-hop RS at the end of the second area of the DL subframe.
[0151] If the DL subframe and the UL subframe have the configurations illustrated in FIG. 11 and FIG. 15 , respectively, the BS communicates with the 1-hop RS in the third areas. Thus, the BS provides the synchronization channel to the 1-hop RS at the end of the third area of the DL subframe.
[0152] If the DL subframe and the UL subframe have the configurations illustrated in FIG. 13 and FIG. 16 , respectively, the BS communicates with the 1-hop RS in the second areas. Thus, the BS provides the synchronization channel to the 1-hop RS at the end of the second area of the DL subframe.
[0153] Then, the BS ends the process.
[0154] FIG. 18 is a flow diagram illustrating a process of the RS 1 in the multi-hop relay BWA communication system according to the present invention.
[0155] In FIG. 18 , the RS 1 checks the subframe configuration information, i.e. configuration information about direct-link areas and relay-link areas in the DL and UL subframes received from the BS or an upper RS in step 1801 . If a frame has the configuration illustrated in FIG. 6 , FIG. 7 , or FIG. 9 , the RS 1 checks the configuration information concerning the first and second areas.
[0156] If a DL subframe has the configuration illustrated in FIG. 11 or FIG. 13 and a UL subframe has the configuration illustrated in FIG. 15 or FIG. 16 , the RS 1 checks configuration information about the first, second, and third areas.
[0157] In step 1803 , the RS 1 communicates with an MS or a RS 2 within its service area in the first areas for the direct link. For the MS, the RS 1 provides a synchronization channel at the start of the first area in the DL subframe.
[0158] The RS 1 communicates with the BS or multi-hop RSs in the relay-link areas in step 1805 . For the lower RSs, RS 1 provide a synchronization channel at the end of an area for communicating with the lower RSs in the DL subframe. If the frame has the configuration illustrated in FIG. 6 , FIG. 7 , or FIG. 9 , RS 1 communicates with the BS in the second areas.
[0159] If the DL subframe and the UL subframe of the frame have the configurations illustrated in FIG. 11 and FIG. 15 , respectively, the RS 1 communicates with the lower RSs in the second areas and communicates with the BS or the upper RSs in the third areas. The RS 1 provides the synchronization channel to the lower RSs at the end of the second area in the DL subframe.
[0160] If the DL subframe and the UL subframe of the frame have the configurations illustrated in FIG. 13 and FIG. 16 , respectively, the RS 1 communicates with the lower RSs in the third areas and communicates with the BS or the upper RSs in the second areas. The RS 1 provides the synchronization channel for the lower RSs at the end of the third area in the DL subframe.
[0161] Then the RS 1 ends the process.
[0162] FIG. 19 is a flow diagram illustrating an operation of the RS 2 in the multi-hop relay BWA communication system according to the present invention.
[0163] In FIG. 19 , the RS 2 checks the control information and the subframe configuration information formed according to its relay capability, received from the BS in step 1901 . For example, if a frame is configured as illustrated in FIG. 7 or FIG. 9 , the RS 2 checks the information tconcerning the first and second areas and the RS 2 -MS link areas of the second areas.
[0164] In step 1903 , the RS 2 communicates with the BS in the first area. The RS 2 then communicates with an MS that receives a relay service via the RS 2 in the second area in step 1905 .
[0165] For example, the RS 2 receives a signal from the BS in the first area and sends a signal to the MS in the second area of a DL subframe. In a UL subframe, the RS 2 sends a signal to the BS in the first area and receives a signal from the MS in the second area.
[0166] Then the RS 2 ends the process.
[0167] FIG. 20 is a flow diagram illustrating an operation of the MS in the multi-hop relay BWA communication system according to the present invention.
[0168] In FIG. 20 , the MS communicates with the BS or the RS 1 in the first area in step 2001 .
[0169] In step 2003 , the MS communicates with RS 2 in the second area. For example, in a DL subframe, the MS receives a signal from the BS or RS 1 in the first area and receives a signal from the RS 2 in the second area. In a UL subframe, the MS sends a signal to the BS or RS 1 in the first area and a signal to the RS 2 in the second area.
[0170] Then the MS ends the process.
[0171] It has been described above that each single-directional subframe is divided into the first and second areas or the first, second, and third areas which are time-division-multiplexed in a TDD system. In another exemplary embodiment of the present invention, the single-directional subframe is divided into first and second areas or first, second, and third areas which are frequency-division-multiplexed in a Frequency Division Duplex (FDD) system. In the FDD system, the DL subframe and the UL subframe are sent/received simultaneously in different frequency bands.
[0172] A description will now be made of the structures of the BS and an RS for providing a relay service in the BWA communication system. Because the BS and the RS have the same configuration, their structures will be described, taking a BS configuration illustrated in FIG. 21 . The following description is made with the appreciation that signal transmission and reception are carried out using a single transceiver in the BS and the RS.
[0173] FIG. 21 is a block diagram of the BS in the multi-hop relay BWA communication system according to the present invention.
[0174] In FIG. 21 , the BS includes a transmitter 2101 , a receiver 2103 , a timing controller 2105 , and an RF switch 2107 .
[0175] The transmitter 2101 has a frame generator 2109 , a resource mapper 2111 , a modulator 2113 , and a Digital-to-Analog Converter (DAC) 2115 .
[0176] In operation, the frame generator 2109 configures a DL subframe to send synchronization channels, control channels, and traffic bursts to an MS and a lower RS within the service area of the BS under the timing controller 2105 . Notably, the frame generator 2109 provides a synchronization channel for the MS at the start of a subframe for the MS and a synchronization channel for the lower RS at the end of a subframe for the lower RS in the DL subframe.
[0177] If the BWA communication system spans two hops, the frame generator 2109 configures a subframe to be sent to the MS or the RS 2 in a first area of the DL subframe. Then the frame generator 2109 configures a subframe to be sent to a 1-hop RS in a second area of the DL subframe. The frame generator 2109 positions the synchronization channels at the start of the subframe in the first area and at the end of the subframe in the second area.
[0178] If the BWA communication system spans three or more hops, the frame generator 2109 configures a subframe to be sent to the MS or RS 2 in a first area or first and second areas of the DL subframe. Then, the frame generator 2109 configures a subframe to be sent to the 1-hop RS in a third area of the DL subframe. The frame generator 2109 positions the synchronization channels at the start of the subframe in the first area and at the end of the subframe in the third area.
[0179] The resource mapper 2111 maps the subframes received from the frame generator 2109 to bursts for links corresponding to the subframes.
[0180] The modulator 2113 modulates the mapped subframes in a predetermined modulation scheme.
[0181] The DAC 2115 converts the modulated digital signal to an analog signal and provides the analog signal to the RF switch 2107 .
[0182] The receiver 2103 includes an Analog-to-Digital Converter (ADC) 2117 , a demodulator 2119 , a resource demapper 2121 , and a frame extractor 2123 .
[0183] The ADC 2117 converts an analog signal received through the RF switch 2107 to a digital signal. The demodulator 2119 demodulates the digital signal in a predetermined demodulation scheme.
[0184] The resource demapper 2121 extracts subframes from link bursts received from the demodulator. The frame extractor 2123 extracts a subframe destined for the BS from the subframes.
[0185] The RF switch 2107 switches signals to be sent to or received from the MS, RS 1 , and RS 2 to the transmitter 2101 and the receiver 2103 under the control of the timing controller 2105 .
[0186] The timing controller 2105 controls transmission and reception timings at which the BS communicates with the MS and the lower RS according to a frame configuration.
[0187] The configuration of the RS 1 will be described with reference to FIG. 21 .
[0188] In FIG. 21 , the RS 1 includes the transmitter 2101 , the receiver 2103 , the timing controller 2105 , and the RF switch 2107 .
[0189] The transmitter 2101 has the frame generator 2109 , the resource mapper 2111 , the modulator 2113 , and the DAC 2115 .
[0190] In operation, the frame generator 2109 configures a DL subframe to send synchronization channels, control channels, and traffic bursts to an MS and a lower RS within the service area of the RS 1 under the timing controller 2105 . Notably, the frame generator 2109 provides a synchronization channel for the MS at the start of a subframe for the MS and a synchronization channel for the lower RS at the end of a subframe for the lower RS in the DL subframe.
[0191] The frame generator 2109 also generates a UL subframe in which to communicate with the BS or an upper RS.
[0192] The resource mapper 2111 maps the subframes received from the frame generator 2109 to bursts for links corresponding to the subframes.
[0193] The modulator 2113 modulates the mapped subframes in a predetermined modulation scheme.
[0194] The DAC 2115 converts the modulated digital signal to an analog signal and provides the analog signal to the RF switch 2107 .
[0195] The receiver 2103 includes the ADC 2117 , the demodulator 2119 , the resource demapper 2121 , and the frame extractor 2123 .
[0196] The ADC 2117 converts an analog signal received through the RF switch 2107 to a digital signal. The demodulator 2119 demodulates the digital signal in a predetermined demodulation scheme.
[0197] The resource demapper 2121 extracts subframes from link bursts received from the demodulator. The frame extractor 2123 extracts a subframe destined for the BS from the subframes.
[0198] The RF switch 2107 switches signals to be sent to or received from the BS, the MS, the lower RS, and the upper RS to the transmitter 2101 and the receiver 2103 under the control of the timing controller 2105 .
[0199] The timing controller 2105 controls transmission and reception timings at which the RS 1 communicates with the BS, the MS, the lower RS, and the upper RS according to a frame configuration.
[0200] As described above, the multi-hop relay BWA communication system provides synchronization channels to the MSs and the RSs. Therefore, the RSs facilitate synchronization and cell search. Also, time multiplexing between a relay service and a direct service within a cell eliminates near-far interference between them.
[0201] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | An apparatus and method for configuring a subframe to support a relay service in a multi-hop relay BWA communication system are provided. The apparatus includes at least one of a BS-MS link subframe, a primary RS-MS link subframe, and a BS-secondary RS link subframe are configured in a first period of the subframe, and at least one of a BS-primary RS link subframe, an RS-RS link subframe, and a secondary RS-MS link subframe is configured in a second period of the subframe. | 7 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 11/555,291 entitled “DOCUMENT CLUSTERING BASED ON COHESIVE TERMS” filed Nov. 1, 2006 which is incorporated herein by reference in its entirety
TRADEMARKS
[0002] IBM® is a registered trademark of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names used herein may be registered trademarks, trademarks or product names of International Business Machines Corporation or other companies.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates to document clustering, and particularly to document clustering based on cohesion terms.
[0005] 2. Description of Background
[0006] Before our invention, businesses have systematically increased the leverage gained from enterprise data through technologies such as relational database management systems and techniques such as data warehousing. Additionally, it is conjectured that the amount of knowledge encoded in electronic text far surpasses that available in data alone. However, the ability to take advantage of this wealth of knowledge is just beginning to meet the challenge. One important step in achieving this potential has been to structure the inherently unstructured information in meaningful ways. A well-established first step in gaining understanding is to segment examples into meaningful categories.
[0007] Previous attempts to automatically create categorizations in unstructured data have relied on algorithms created for structured data sets. Such approaches convert text examples into numeric vectors of features, sometimes using latent semantic indexing and principle component analysis to reduce dimensionality, and then cluster the data using well-established clustering techniques such as k-means or Expectation Maximization (EM). These approaches attempt to maximize intra-cluster similarity while minimizing inter-cluster similarity.
[0008] The problem with approaches of this kind is that they often produce categories that are inexplicable to human interpretation. The fact that a group of documents shares a degree of similarity across an artificial feature space does not insure that the documents in that category taken together construct an easily understood concept. This has led to the problem of cluster naming, to which no practical solution has been found.
SUMMARY OF THE INVENTION
[0009] The shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method (and storage medium that includes instructions for causing a computer to implement the method) for document categorization. The method includes identifying terms occurring in a collection of documents, and determining a cohesion score for each of the terms. The cohesion score is a function of a cosine difference between each of the documents containing the term and a centroid of all the documents containing the term. The method further includes sorting the terms based on the cohesion scores. The method also includes creating categories based on the cohesion scores of the terms, wherein each of the categories includes only documents (i) containing a selected one of the terms and (ii) that have not already been assigned to a category. The method still further includes moving each of the documents to a category of a nearest centroid, thereby refining the categories.
[0010] System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
[0011] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features, refer to the description and to the drawings.
[0012] As a result of the summarized invention, technically we have achieved a solution where the creation of taxonomies from cohesion terms is easier for a user to interpret than standard statistical approaches. By creating categories that can be described succinctly with a single word or phrase, the prior cluster-naming problem that plagues most other approaches is avoided. This provides an important practical method for quickly understanding the content of a large number of short text documents in any domain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0014] FIG. 1 illustrates one example of a flow chart for a cohesion term taxonomy;
[0015] FIG. 2 illustrates one example of a flow chart for creation of the categories iteratively; and
[0016] FIG. 3 illustrates one example of a user interface for the cohesion term taxonomy.
[0017] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Turning now to the drawings in greater detail, it will be seen that in FIG. 1 there is flow chart illustrating a cohesion term taxonomy, which is applicable to any situation where it is desirable to create a taxonomy across a set of distinct documents. At a block 10 , a minimum category size (M), an uncategorized document size (U), and maximum number of categories (C) is given. At a block 12 , a dictionary (D) of frequently used words/phrases (terms) in a text data set (T) is identified. At a block 14 , the occurrences of dictionary terms in documents of data set T are counted. At a block 16 , the cohesion of each term is a score, which is determined from the sum of the absolute cosine difference between each document containing the term and the centroid of all documents containing the term. At a block 18 , the cohesion scores are normalized by taking into account the size of each term document set. At a block 20 , terms are sorted in order of decreasing cohesion score. At a block 22 , categories are created iteratively. At a block 24 , the resulting categorizations are refined by running one iteration of a k-means algorithm on the set of categories created at block 22 . (i.e., a centroid is created for each category and each document is moved to the category of the closest centroid).
[0019] The k-means algorithm is a well known algorithm that clusters objects based on attributes into k partitions. It is a variation of the expectation-maximization algorithm that seeks to determine the k means of data generated from gaussian distributions. It assumes that the object attributes form a vector space. It also seeks to achieve is to minimize total intra-cluster variance, or, the function:
[0000]
V
=
∑
i
=
1
k
∑
j
∈
S
i
x
j
-
μ
i
2
[0000] where there are k clusters S i , i=1, 2, . . . , k and μ i is the centroid or mean point of all the points x j εS i . The algorithm starts by partitioning the input points into k initial sets, and then calculates the mean point, or centroid, of each set. It constructs a new partition by associating each point with the closest centroid. Then the centroids are recalculated for the new clusters, and algorithm repeated by alternate application of these two steps until convergence.
[0020] Turning also to FIG. 2 , the creation of the categories iteratively is illustrated by a flow chart. At a block 26 , the most cohesion term in the list not yet used is selected. At a block 28 , if the number of uncategorized documents that contain the selected term is greater than the minimum category size, M, then create a category, at a block 29 , consisting of all documents that contain this term still uncategorized. Otherwise stop at a block 31 . At a block 30 , if the number of uncategorized documents remaining is less than U, then STOP (block 31 ). At a block 32 , if the number of categories created is greater than C, then stop (block 31 ). Repeat these steps until a stop criterion is met or no more dictionary terms remain.
[0021] The dictionary, D is identified at block 12 by representing each document as a vector of weighted frequencies of the document features (i.e., words and phrases), and then using a term-weighting scheme. This scheme emphasizes words with high frequency in a document, and normalizes each document vector to have unit Euclidean norm. For example, if a document were the sentence, “We have no bananas, we have no bananas today,” and the dictionary consisted of only two terms, “bananas” and “today”, then the unnormalized document vector would be {2 1} (i.e., to indicate two bananas and
[0000]
[
2
/
5
·
1
/
5
]
.
[0022] The words and phrases that make up the document feature space are determined by first counting which words occur most frequently (i.e., in the most documents) in the text. A standard “stop word” list is used to eliminate words such as “and”, “but”, and “the”. The top N words are retained in the first pass, where the value of N may vary depending on the length of the documents, the number of documents and the number of categories to be created. Typically N=2000 is sufficient for 10000 short documents of around 200 words to be divided into 30 categories. After selecting the words in the first pass, a second pass is made to count the frequency of the phrases that occur using these words. A phrase is considered to be a sequence of two words occurring in order with out intervening non-stop words. This is repeated so as to keep only the N most frequent words and phrases. This becomes the feature space. A third pass through the data indexes the documents by their feature occurrences. The user may edit this feature space as desired to improve clustering performance. This includes adding in particular words and phrases the user deems to be important, such as named entities like “International Business Machines”. Stemming is usually also incorporated to create a default synonym table that the user may also edit.
[0023] The occurrences of dictionary terms are counted at block 14 by creating a Sparse Matrix of word occurrences in documents after the third pass through. This matrix records how often each dictionary term occurs in each document.
[0024] The cohesion of each term are defined at block 16 by defining the cosine distance between any two document vectors (i.e., the cosine distance metric) as:
[0000]
cos
(
X
·
Y
)
=
X
·
Y
X
·
Y
[0025] The set of documents that match a given term can be represented by a centroid (i.e., average) vector, of all such documents. If the set of documents that match a given term (i.e., the matching set) is defined is represented by, T, then the cohesion of this set is defined to be:
[0000]
cohesion
(
T
,
n
)
=
∑
x
∈
T
cos
(
centroid
(
T
)
,
x
)
T
n
[0026] where T is a text data set containing the documents and n is a normalization parameter.
[0027] The cohesion scores are normalized at block 18 by taking into account the size of each term document set. The normalization parameter allows the user to compare terms that have different amounts of data. Typically small matching set terms would have an advantage if the normalization parameter, n, were set to 1.0. To adjust for this fact the value of n can be adjusted downward to allow larger matching set terms to be ranked higher if desired. A typical value of n=0.9 is one that seems to work well in many application areas.
[0028] The dictionary terms are sorted at block 20 in order of decreasing matching set cohesion. Some terms may be eliminated from this list if the matching set size is deemed to small to get an accurate measure of cohesion.
[0029] Categories are created iteratively at block 22 . Starting with the first term in cohesion order, create mutually exclusive (single membership) categories. The first category contains all documents that contain the most cohesion term. The second category contains all documents that do not contain the most cohesion term, but do contain the second most cohesion term. The third category contains all documents not in the first two categories that contain the third most cohesion term. This category creation method continues until one of the following stopping criteria is met:
[0030] 1. The number of uncategorized documents is less than the minimum threshold, U.
[0031] 2. The number of categories is greater than the maximum threshold, C.
[0032] 3. No more dictionary terms remain to create categories with.
[0000] A lower bound is set on the smallest size of an acceptable category. Thus any term that would create a category of size smaller than this threshold (because most of its documents are already contained in previous categories) is skipped.
[0033] The resulting categorizations are refined at block 24 by creating a centroid for each category (i.e., an average document vector of all documents contained in the category). Each document is then moved into the category of the centroid it is “nearest” to, using the cosine distance metric. This membership “adjustment” tends to place those documents that could belong to more than one category in the category that is most representative of their overall content. The purpose of this refinement is to properly position those documents that contain more than one of the cohesion terms used in the category creation phase.
[0034] It will be appreciated that some of the cohesion terms may be excluded from consideration as category definitions, because they do not lead to useful categories. The level of granularity may be set (i.e., the number of categories) by adjusting the threshold U (i.e., the number of uncategorized documents) or n (i.e., the normalization for size). Further, an alternative to normalizing for category size is to specify a minimum category size and then sample all categories to that size when calculating both the centroid and the cohesion values.
[0035] The k-means clustering described above may create categories that are difficult to interpret by a human being. Typically, cluster-naming approaches attempt to address this issue by adding more and more terms to a name to capture the complex concept that is being modeled by a centroid. Unfortunately, this approach puts the onus on the human interpreter to make sense of what the list of words means and how it relates to the entire set of examples contained in the category. In the present exemplary embodiment, a categorization that is easier to comprehend is to be used. This alternative of putting such documents in more than one category (i.e., multiple membership) is less desirable because it increases the average size of each category and defeats the purpose of summarization via the divide and conquer strategy inherent in a document clustering. Creating multiple copies of documents that match more than one category would be multiplying instead of dividing. Once the clusters are created, they are named with the single term that was used to create each cluster in the first place, thus avoiding the complex name problem associated with k-means clusters. This does not eliminate the need for taxonomy visualization and editing by an analyst, it does however make the process much less cumbersome by creating categories that are (for the most part) fairly easy to comprehend immediately. This is believed to cut the time required to edit each taxonomy by about half (i.e., from around 30 minutes to around 15 minutes per forum).
[0036] computer help desk problem tickets. The initial categorization created by our approach is illustrated in Table 1 below.
[0000] TABLE 1 Class Name Class Size Percentage print 824 12.33% Miscellaneous 689 10.31% install 394 5.89% quick_fix 376 5.63% print_install 289 4.32% note 254 3.80% file 221 3.31% lotus_note 180 2.69% email 153 2.29% customer_install 122 1.83% afs 118 1.77% address_book 117 1.75% adsm 110 1.65% note_email 107 1.60% network 103 1.54% print_unable 102 1.53% password 101 1.51% database 96 1.44% email_database 95 1.42% afs_password 92 1.38% connect_network 88 1.32% note_id 88 1.32% drive 82 1.23% server_connection 78 1.17% afs_quota 74 1.11% install_configure 72 1.08% reboot_system 70 1.05% calendar 68 1.02% personal_address 64 0.96% ip_address 63 0.94% netscape 63 0.94% data_directory 62 0.93% calendar_profile 61 0.91% forward_email 60 0.90% location_document 59 0.88% configure 56 0.84% email_template 54 0.81% email_server 54 0.81% send_email 53 0.79% reset 52 0.78% card 50 0.75% command_line 44 0.66% reset_afs 41 0.61% home_page 41 0.61% hard 40 0.60% id 38 0.57% afs_userid 38 0.57% softdist 35 0.52% internet_email 34 0.51% proxy 33 0.49% vm_session 32 0.48% driver 32 0.48% ring 30 0.45% file_system 30 0.45% netdoor 28 0.42% template 27 0.40% lan 27 0.40% monitor 27 0.40% admin 25 0.37% copy_file 24 0.36% socks 24 0.36% swap 23 0.34% mouse 19 0.28% www 19 0.28% think_pad 18 0.27% modem 18 0.27% apps 15 0.22% serial_number 8 0.12% Total 6684.0 100.00%
The “Miscellaneous” category includes all of the uncategorized documents from the algorithm. These are those documents that did not match any of the cohesion terms before the stopping criteria were met.
[0037] In the next step the user selects any categories that are not suitable and also requests that fewer overall categories be created. Turning to FIG. 3 , the user interface for this interaction is illustrated.
[0038] The selected terms are removed from consideration as possible cohesion terms. Further the n parameter is decreased from the default of “0.9” to a lower “0.85” thus giving a greater advantage in the selection process to more frequent terms. The result of applying these changes and rerunning the algorithm is illustrated in Table 2 below.
[0000] TABLE 2 Class Name Class Size Percentage Miscellaneous 1027 15.37% print 862 12.90% install 449 6.72% quick_fix 414 6.19% email 389 5.82% print_install 295 4.41% file 270 4.04% server 225 3.37% lotus 216 3.23% address_book 190 2.84% afs_password 127 1.90% customer_install 121 1.81% id 114 1.71% email_database 112 1.68% network 111 1.66% password 107 1.60% afs 104 1.56% database 99 1.48% adsm 95 1.42% connect_network 90 1.35% data_directory 81 1.21% quota_increase 75 1.12% hard_drive 74 1.11% server_connection 73 1.09% install_configure 69 1.03% calendar 69 1.03% configure 63 0.94% calendar_profile 60 0.90% ip_address 60 0.90% email_template 58 0.87% location_document 54 0.81% reset 53 0.79% file_open 50 0.75% afs_account 42 0.63% template 39 0.58% driver 38 0.57% vm_session 35 0.52% dialer 34 0.51% common 33 0.49% network_connection 32 0.48% softdist 32 0.48% ring 28 0.42% tcp_ip 27 0.40% respond 24 0.36% certificate 23 0.34% home_page 23 0.34% request_afs 18 0.27% Total 6684.0 100.00%
The user's request for “fewer classes” requires an adjustment to the allowable size of the uncategorized documents (i.e., the Miscellaneous category) to increase from 10% to 15%. This adjustment in conjunction with the smaller n parameter tends to create a higher level (i.e., more general) set of categories that are more in line with what the user desires. Another iteration, decreasing the normalization parameter to 0.8 and allowing the size of the miscellaneous class to grow to 20% creates the taxonomy shown in Table 3 below.
[0000] TABLE 3 Class Name Class Size Percentage Miscellaneous 1395 20.87% print 890 13.32% email 568 8.50% note 481 7.20% install 479 7.17% quick_fix 452 6.76% print_install 298 4.46% server 283 4.23% lotus_note 269 4.02% address_book 181 2.71% afs 163 2.44% password 150 2.24% password_reset 148 2.21% connect_network 127 1.90% database 115 1.72% customer_install 100 1.50% address 91 1.36% configure 80 1.20% adsm 78 1.17% quota_increase 75 1.12% install_configure 73 1.09% reset 64 0.96% request_customer 58 0.87% vos 39 0.58% register_adsm 27 0.40% Total 6684.0 100.00%
After each iteration of the algorithm the categories become somewhat more general, while still retaining much the same flavor.
[0039] Implementation as a computer program, written in the Java programming language and executed with the Java virtual machine is illustrated in the Example below, and includes actual Java code along with explanatory annotations.
EXAMPLE
[0040] public class IntuitiveClustering extends TextClustering implements ActionListener {
[0000]
float wcohesion[ ] = null;
String tempName = null;
public float granularity = 0.9F;
public HashSet badTerms = new HashSet( );
TextClustering tc = null;
public transient JDialog jd = null;
transient JRadioButton more = new JRadioButton(Translate.simpleText(“More
Classes”));
transient JRadioButton less = new JRadioButton(Translate.simpleText(“Fewer
Classes”));
transient JRadioButton same = new JRadioButton(Translate.simpleText(“Same”),true);
transient JList values = null;
transient JButton Done,Cancel;
public boolean ok = true;
public IntuitiveClustering(TextClustering t) {
super( );
tc = t;
if (!Util.getParameter(“granularity”).equals(“”))
granularity = Util.atof(Util.getParameter(“granularity”));
}
public void update(float g, String a[ ]) {
for (int i=0; i<a.length; i++) badTerms.add(a[i]);
granularity = g;
wcohesion = null;
run( );
}
public void promptForUpdate(Frame f, String title) {
jd = new JDialog(f,true);
JPanel buttons = new JPanel( );
buttons.setLayout(new FlowLayout( ));
if (clusterNames==null) clusterNames = tc.clusterNames;
values = new com.ibm.nls.JList(clusterNames);
JScrollPane jp = new JScrollPane(values);
jp.setPreferredSize(newDimension(500,400));
Done = new JButton(“OK”);
Cancel = new JButton(“Cancel”);
Done.addActionListener(this);
Cancel.addActionListener(this);
buttons.add(Done);
buttons.add(Cancel);
ButtonGroup bg = new ButtonGroup( );
bg.add(more);
bg.add(less);
bg.add(same);
FlowLayout fl = new FlowLayout( );
fl.setHgap(15);
JPanel jp2 = new JPanel(fl);
jp2.add(more);
jp2.add(less);
jp2.add(same);
jd.setTitle(title);
jd.getContentPane( ).setLayout(new BorderLayout(10,10));
jd.getContentPane( ).add(“North”,jp);
jd.getContentPane( ).add(“Center”,jp2);
jd.getContentPane( ).add(“South”,buttons);
jd.pack( );
jd.show( );
}
public void actionPerformed(ActionEvent evt) {
if (Done==evt.getSource( )) {
if (more.isSelected( )) granularity = granularity + 0.05F;
if (less.isSelected( )) granularity = granularity − 0.05F;
int v[ ] = values.getSelectedIndices( );
for (int i=0; i<v.length; i++) {
badTerms.add(clusterNames[v[i]]);
if (Util.getParameter(“append”).equals(“yes”)) {
try {
PrintWriter pw = Util.openAppendFile(“stop Words.txt”);
pw.println(clusterNames[v[i]]);
pw.close( );
} catch (Exception e) { };
}
}
ok = true;
jd.dispose( );
}
if (Cancel==evt.getSource( )) {
ok = false;
jd.dispose( );
}
}
public void run( ) {
System.out.println(“granularity = ” + granularity);
float ff[ ] = ClusterView.getDataMeans(tc);
float f[ ] = wordCohesion(tc,ff);
int order[ ] = Index.run(f);
int membership[ ] = new int[tc.ndata];
for (int i=0; i<tc.ndata; i++) membership[i] = −1;
order = Util.reverse(order);
StringVector sv = new StringVector( );
HashSet h = new HashSet( );
for (int i=0; i<order.length; i++) {
if (badTerms.contains(tc.attribNames[order[i]])) {
System.out.println(“bad term: ” + tc.attribNames[order[i]]);
continue;
}
StringVector subterms = new StringVector(tc.attribNames[order[i]],“_”);
if (badTerms.contains(subterms.myElementAt(0))) continue;
if (subterms.size( )>1 && badTerms.contains(subterms.myElementAt(1)))
continue;
float matches = 0.0F;
if (f[order[i]]==0) break;
MyIntVector docs = getMatches(order[i], tc);
for (int j=0; j<docs.size( ); j++)
if (h.contains(docs.elementAt(j)))
matches++;
if (matches/docs.size( )>=0.9F) ;
// System.out.println(“eliminating ” + tc.attribNames[order[i]] + “ as a
duplicate”);
else {
int count = 0;
for (int j=0; j<docs.size( ); j++)
if (!h.contains(docs.elementAt(j)))
count++;
if ((tc.ndata-h.size( ))/100.0>count) continue; //min size of class is 1% of
remaining data
if (count<3) continue;
for (int j=0; j<docs.size( ); j++) {
if (!h.contains(docs.elementAt(j))) {
h.add(docs.elementAt(j));
membership[docs.myElementAt(j)] = sv.size( );
}
}
sv.addElement(tc.attribNames[order[i]]);
}
//System.out.println(“h.size( ) = ” + h.size( ));
if (h.size( )>tc.ndata*Math.min(granularity,0.95)) {
System.out.println(“breaking because granularity = ” + granularity);
break;
}
if (sv.size( )==200) break;
}
for (int i=0; i<tc.ndata; i++)
if (membership[i]==−1) membership[i] = sv.size( );
sv.addElement(“Miscellaneous”);
clusterNames = sv.getStringArray( );
nclusters = clusterNames.length;
input_length = tc.input_length;
ndata = tc.ndata;
example = tc.example;
attribNames = tc.attribNames;
pointNumber = tc.pointNumber;
computeMembership(membership);
classify( );
//mergePhraseSimilar( );
//classify( );
//refine clustering with one step of KMeans
moveToNearestCentroid( );
}
public void moveToNearestCentroid( ) {
TextClustering tc = this;
float ss[ ] = new float[tc.nclusters];
for (int i=0; i<ss.length; i++)
ss[i] = (float)Math.sqrt(Util.dotProduct(tc.centroids[i],tc.centroids[i]));
short nextMembership[ ] = new short[tc.ndata];
for (int i=0; i<tc.ndata; i++) {
SmallMatrixRow smr = ClusterManipulation.getSmallRow(tc.example,i);
int c = AccuracyMetric.getNearestCluster(tc,smr,ss);
if (tc.clusterNames[tc.smembership[i]].equals(EAdvisor.miscClassName))
nextMembership[i] = tc.smembership[i];
else
nextMembership[i] = (short)c;
}
tc.computeMembership(nextMembership);
tc.classify( );
}
public float[ ] wordCohesion(TextClustering tc, float overallRelev[ ]) {
float result[ ] = new float[tc.attribNames.length];
for (int i=0; i<result.length; i++) {
MyIntVector docs = getMatches(i, tc);
result[i] = getAvgDistance(tc,docs.makeArray( ));
}
wcohesion = result;
return(result);
}
public MyIntVector getMatches(int a, TextClustering k) {
MyIntVector result = new MyIntVector( );
SmallSparseMatrix ssm = (SmallSparseMatrix)k.example;
for (int i=0; i<k.ndata; i++) {
SmallMatrixRow smr = ssm.getSmallRow(i);
for (int j=0; j<smr.positions.length; j++) {
if (smr.positions[j]==a) {
result.addElement(i);
break;
}
}
}
return(result);
}
public float getAvgDistance(KMeans tc, int textDocuments[ ]) {
if (textDocuments.length==0) return(0.0F);
float result = 0.0F;
float centroid[ ] = Util.emptyFloat(tc.input_length);
for (int i=0; i<textDocuments.length; i++) {
SmallMatrixRow
smr
=
ClusterManipulation.getSmallRow(tc.example,textDocuments[i]);
for (int j=0; j<smr.positions.length; j++) {
if (smr.positions[j] > −1) {
centroid[smr.positions[j]]+= smr.multiplier;
}
}
}
float ss = (float)Math.sqrt(Util.dotProduct(centroid,centroid));
for (int i=0; i<textDocuments.length; i++)
result+=
Math.abs(SmallSparseMatrix.cosDistance(ClusterManipulation.getSmallRow(tc.example
,textDocuments[i]), centroid, ss));
float size = (float)Math.pow(textDocuments.length,granularity);
return(result/size);
}
[0041] The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
[0042] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
[0043] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
[0044] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0045] While the preferred embodiment to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. | A method and a storage medium, that includes instructions for causing a computer to implement the method, for document categorization is presented. The method includes identifying terms occurring in a collection of documents, and determining a cohesion score for each of the terms. The cohesion score is a function of a cosine difference between each of the documents containing the term and a centroid of all the documents containing the term. The method further includes sorting the terms based on the cohesion scores. The method also includes creating categories based on the cohesion scores of the terms, wherein each of the categories includes only documents (i) containing a selected one of the terms and (ii) that have not already been assigned to a category. The method still further includes moving each of the documents to a category of a nearest centroid, thereby refining the categories. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/903,501 (now U.S. Pat. No. 9,469,893), which is itself a continuation-in-part of U.S. patent application Ser. No. 12/838,004. The parent applications listed the same named inventors.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was developed at the National High Magnetic Field Laboratory in Tallahassee, Fla. The research has been funded in part by National Science Foundation Contract No. DMR-0654118.
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of metallurgy. More specifically, the invention comprises a method for achieving accelerated age hardening in superalloys made of nickel, chromium, and molybdenum by the addition of rhenium. The invention allows a greatly accelerated age-hardening process, while substantially reducing the risk of over-aging.
[0006] 2. Description of the Related Art
[0007] Age hardening (also known as “precipitation hardening”) is used to produce various alloys with desirable properties. The process is used to mechanically strengthen malleable materials for structural applications. In addition to steels, precipitation hardening is commonly used for aluminum, titanium, and nickel alloys. The process produces fine particles of impurity phases, which act as barriers to the motion of crystallographic lattice dislocations.
[0008] Precipitation in solids can produce many different sizes of particles, which have radically different strengthening effects as demonstrated by the following equation:
[0000] Δσ=2/(π E ) −1/2 (λ apb /b ) 1/2 r 1/2 f 1/2
[0000] where E is the Young's modulus, λ apb is the anti-phase inter facial energy, b is the Burger's vector, r is the size of the precipitates, and f is the volume fraction. Both r and f can be related to l, the distance between the precipitates. If the volume fraction is held constant, then one observes an optimized value for the size of the precipitates (r) at which the material reaches a maximum strength.
[0009] The optimal size of the precipitates formed depends upon the thermo-mechanical history of the alloy being hardened. In the prior art, alloys must be kept at elevated temperature for several hours to allow precipitation to take place. Thus, conventional precipitation hardening requires a substantial amount of energy (The large amount of time required is why the process is also referred to as “age hardening”).
[0010] On the other hand, if the process and alloys are altered so that the precipitates can form in a relatively short period of time, the temporal window for achieving an optimal result usually becomes very narrow. It is then easy to “over-age” the alloy. When a material is over-aged (held at the elevated temperature for too long), then both the size of the precipitates and the distance between the precipitates become too large and the Orowan process operates. At certain values for l and for r, the strength or hardness drops significantly to a value governed by a rule-of-mixture.
[0011] An example of a prior art nickel alloy that can be age hardened quickly is IN738LC. This is a nickel based alloy that can be age-hardened in less than 5 minutes at 850° C. Optimum hardness is obtained in about 80 seconds. On the other hand, the hardness will be substantially reduced if the process is carried forward for an additional 40 seconds. In fact, the window of effective age-hardening for this alloy is only about 60 seconds.
[0012] One may generally slate that the prior art discloses: (1) nickel alloys that can be age-hardened using a process that takes several hours and that are not very sensitive to over-aging (extending the process for an additional 10 hours or more does not significantly reduce the hardness), and (2) nickel alloys that have been altered to age harden very quickly, but which are very sensitive to over-aging (suffering reduced hardness if the aging window is inadvertently extended by as little as 40 seconds). A more useful nickel alloy would be one which (1) age hardens quickly, and (2) is not very sensitive to over aging.
[0013] The prior art also discloses accelerating the formation of precipitates in age-hardening by deforming the materials in order to increase the dislocation densities (which enhances the diffusion along the dislocation). In selected alloys, it is in fact essential to deform the alloy before the age-hardening process is applied. Unfortunately, deformation processes are also energy-intensive and therefore expensive. This approach does not represent the desired overall reduction in the amount of energy required for hardening.
[0014] The present invention uses a master alloy of nickel, molybdenum, and chromium (Ni—Mo—Cr). The inventors have discovered that the addition of rhenium to this master alloy in the right ratios and under the right conditions produces an unexpected and highly advantageous alteration in the alloy's age-hardening properties. As explained in detail in the descriptive sections to follow, the hardening properties found in the inventive composition and process result from the formation of long-range-ordered (“LRO”) precipitates of Ni 2 (Mo, Cr, Re). The prior art discloses various combinations of the elements, but fails to disclose or suggest the inventive process.
[0015] For example, U.S. Pat. No. 4,119,458 to Moore teaches alloys of nickel, chromium, and rhenium. Molybdenum is also disclosed in Moore, though the implied percentage of molybdenum is less than 8% by weight. The master alloy in Moore contains nickel, aluminum, vanadium, and cobalt. The Moore invention is directed to solving the problem of reaction between the molten metal and the crucible surrounding it during a re-melting process in order to form a regular secondary eutectic reaction. Moore does not teach age-hardening and in fact the compositions disclosed in Moore are not able to achieve the performance of the present invention since they do not contain enough Mo-like elements to form Ni 2 Mo-ordered precipitates.
[0016] Another example from the prior art is the article “Comparative Corrosion Behavior of Ni—Mo and Ni—Mo—Cr Alloy for Applications in Reducing Environments,” published in the Journal of Material Science, 2006, 41, 8359-8362 (written by Tawancy). The Tawancy article teaches the addition of chromium to enhance corrosion resistance by the delay of Ni 4 Mo precipitates. It does not suggest the inventive formulation or process related to age-hardening.
[0017] In summary, the prior art fails to disclose a Ni—Mo—Cr alloy that can be age-hardened rapidly while displaying resistance to over-aging. The present invention provides a precipitation hardening process which can be completed more rapidly than the known prior art, and which has a relatively broad time window for optimal results. The present invention achieves these results without requiring the use of mechanical deformation.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention comprises a process or strategy for age hardening nickel based alloys to create desirable properties. The inventive process introduces isolated atom nucleation sites to accelerate the nucleation rate by approximately 36 times, thereby permitting age hardening to occur in significantly less time and with significantly less energy expenditure. Further, the inventive process provides a very broad time window for the optimum result, reducing the risk of over-aging.
[0019] The inventive composition adds rhenium to a master alloy of Ni—Mo—Cr. By using a suitable fraction for each constituent, along with a suitable age-hardening process, the invention forms long-range-ordered Ni 2 (Mo, Cr, Re) precipitates and thereby produces a dramatic increase in the age hardening rate without a corresponding reduction in the breadth of the age hardening window.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 is a plot of hardness versus aging time at a temperature of 873 K.
[0021] FIG. 2 is a plot of hardness versus aging time at a temperature of 923 K, comparing one of the inventive alloys to a prior art alloy.
[0022] FIG. 3 is a plot of hardness versus aging time for three alloys made according to the present inventive process. The three alloys were deformed to different strain (41 %, 62%, and 69%) before the aging.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention uses alloys made of Cr—Ni—Mo—Re, which are formulated to allow a very different age hardening process from the prior art alloys. The alloys thus formulated can be age hardened in as little as 5 minutes. The same alloy shows stable mechanical properties without over-aging even after a prolonged aging period (up to 500 hours). Thus, the “window” of optimal time for age hardening is quite broad.
[0024] The new allow was based on a Ni—Mo—Cr alloy, to which rhenium was added. The Ni—Mo—Cr alloy has a face centered cubic structure above about 1123 K with short-range-ordered (SRO) domains. Long-range-ordered (LRO) domains of A 2 B form below 1123 K after a prolonged aging time. The alloys are strengthened by aging when LRO precipitates form. The formation of LRO is beneficial to the alloy's mechanical properties.
[0025] The prior art approach to accelerating age hardening uses cold deformation before the heating process. When a sample of Ni—Mo—Cr is 40% cold worked and then heated to 923 K, 2 hours of hardening time is required to provide a strength equivalent to prior art samples aged to 24 hours. Although the cold work is effective in shortening the aging time by a factor of 12, it is still desirable to shorten the time even further to reduce the cost. In addition, cold deformation complicates the fabrication procedure and may embrittle the materials by inducing the A 3 B type phase.
[0026] Other researchers have tried to accelerate the age hardening process by adding more Mo elements or reducing Cr content. However, over-aging, which is partially due to a formation of stable, but brittle Ni 3 Mo phase, is more likely in such a Ni based alloy if the Cr content is too low or the Mo content is too high. Low Cr content also reduces the corrosion resistance of the materials.
[0027] Although a Ni—Cr—Mo alloy has excellent properties, one would expect it to have a shorter aging time, higher strength, and greater stability at high temperature without formation of phases that embrittle the material. The inventors ultimately decided to add rhenium (Re) to the prior art, allowing approximately the following percentages by weight: Mo:20-30%, Cr:5-10%, Re:3-10%, Ni:60-70%.
[0028] Unlike the prior art, the percentage of Mo in the present invention must be equal to or greater that 20% by weight. This Mo fraction is needed to ensure the formation of A 2 B precipitates. Rhenium was selected as an effective alloy element for several reasons. First, rhenium was used to promote formation of a regular eutectic product in Ni alloys. Exemplary alloys include the following (all by weight):
[0000] TABLE ONE Ni Re Co Cr W Al V Ta C 64.5 6.7 4 3.95 3.2 5.5 5.55 6.5 0.29 63.62 6.2 3.3 4.4 3.2 5.3 5.4 9.1 0.48
In the present invention, the percentage of molybdenum is quite important and it cannot be less than 20% by weight.
[0029] In the inventive formulations, rhenium was selected because it has a relatively large atomic diameter (0.27 nm), a high melting point (3459 K), a high modulus of elasticity (329 GPa) and a large negative energy for formation of A2B type of precipitates by combination of rhenium with Ni and Mo. The large atomic diameter and high melting point elements diffuse relatively slowly so that the kinetics of the precipitate growth will be sluggish and the alloy can be used for long periods without over-aging. The high modulus enhances the strength of the alloy. The large negative energy assists formation of A2B precipitates (in particular Ni2(Mo, Cr, Re)). When the rhenium participates in the precipitation process, the large atomic diameter also results in more distortion in the lattice of the matrix and accelerates the nucleation of the precipitates.
[0030] Our experimental results demonstrate that the addition of rhenium increases the Young's modulus and storage modulus by 10-20% and enhances the stability of the materials during aging. At the same time, the Re accelerates the LRO precipitation hardening by almost 36 times. The magnitude of the acceleration in the LRO precipitation process was quite surprising. FIG. 1 shows a plot of hardness versus the length of aging (note that the X-axis is logarithmic). The hardness of a sample annealed at 1473 K is about 200 HV (IHV=1 Kg/mm 2 =9.8 MPa). Aging at 873 K for 1 minute increases hardness by 25%. In the selected area diffraction patterns, samples aged at 873 K for 1 minute show both the diffused SRO and LRO (A 2 B type) diffraction spots. However, the intensity of the LRO reflections is much stronger than SRO, indicating that the volume fractions of the LRO domains are larger than the SRO ones.
[0031] FIG. 2 shows a comparison of age hardening of the new alloy versus age hardening of a prior art material which is typically subjected to age hardening (such as HAYNES 242, which is a well-known Ni—Mo—Cr alloy). The reader will observe the dramatic reduction in aging time for the rhenium-containing alloy.
[0032] For the new alloy, the A 2 B type LRO domain sizes appear to be about 1-5 nm for materials aged at 873 K (600 degrees Celsius) for 4 minute, as shown in FIG. 4 . These domain sizes in the inventive materials are about 5 crystallographic unit cell sizes when one views the sample in the-[001] orientation of the matrix. Therefore, the addition of rhenium reduces the age-hardening time by acceleration of the A 2 B type LRO precipitate formations with initial size, r, of a few nanometers, where A is Ni and/or Re and B is Mo and/or Re. The beneficial effect of the rhenium addition could be explained by the location of the Re in the materials under the following possibilities: (i) Re accelerates the precipitation by formation of (Ni,Re) 2 Mo; (ii) Re accelerates the formation of the Ni 2 Mo precipitates which exist in its absence but Re will not occupy any sites in the precipitates; (iii) the Re, combining with Ni and Mo, forms nuclei of Ni 2 (Mo,Re), where the addition of Re merely increases the supersaturation of the solute atoms for formation of the LRO precipitate of Ni 2 (Mo,Re); (iv) the Re, combining with Ni and Mo, forms nuclei of Ni 2 (Mo n Re m ), where the addition of Re not only increases the supersaturation of the solute atoms for formation of the LRO precipitate but also occupies an ordered position in B sites of A 2 B type precipitates; or (v) Re and Ni form ordered clusters acting as nucleation site for Ni 2 (Mo, Re) nucleations, i.e., Re forms nuclei of precipitates at an earlier stage than would occur in its absence. To elucidate the impact of Re, i.e., how the Re atoms accelerate the aging we closely examined the atomistic structures of the materials in Z-contrast images in combination with our calculations.
[0033] Our Z-contract imagines demonstrate that Re atoms occupy the site B in the A 2 B precipitates. Therefore, its behavior is similar to Mo in the LRO domains and, (i) and (ii) can be excluded. Although an Re atom occupies the Mo position in the ordered domains, the Z-contrast images show that the Re atom forms no clusters in the Mo positions. Therefore, Re atoms act as neither a cluster nor ordered domains within the B sites in A 2 B to form Ni 2 (Mo n Re m ) for acceleration of the nucleation of the LRO domains. Therefore, no evidence for explanation (iii) can be found in our experimental data.
[0034] Close examinations of the HRTEM images demonstrate that most of the SRO and LRO atoms are in the same locations, indicating that LRO occurs in the same location of the SRO. Thus, the Re additions link the SRO and LRO. Z-contrast image shows that the Re atoms stay within the LRO domains close to Ni 2 Mo-type crystallographic structures. The isolated Re atoms act individually to combine with Ni atoms in acceleration the nucleation of the LRO domains. Therefore, the possible explanations are (iv) and (v) in the preceding paragraph.
[0035] Calculations demonstrate that the formation energies for Ni 2 Mo and Ni 2 Re are −0.127 and −0.141 ev/atom, respectively, making the explanation in scenario (v) more plausible than the rest. This fact indicates that nucleation of Ni 2 Re reduces the system energy even at the early state of age hardening. It appears that the Re atoms act as nuclei for early nucleation of the LRO domains by formation of Ni 2 Re and then Mo diffuses into the domains to form Ni 2 (Re, Mo), thereby accelerating the age-hardening process, accelerated the age hardening process. Thus, it appears that the Re atoms should occupy the Mo positions in the ordered domains in the final products observed by various microscopy technologies.
[0036] Further increasing the aging time from 1 to 4 minutes hardens the material by approximately an additional 25% (resulting from the perfection of the LRO). At this time the material almost reaches its maximum hardness without deformation. The domain sizes of the LRO grow up to 10 nm. A slight increase or reduction in aging time does not change the size of the domain's significantly. It is quite surprising that the LRO domains rich in both Mo and Re can form in such a short time and have such a significant impact on the hardness of the materials.
[0037] Without the Re additions, the LRO domains homogenously nucleate from different locations from the SRO domains and therefore the LRO kinetic is sluggish. Consequently, the prior art alloy requires about 144 minutes to reach the hardness values achieved by the alloy with Re additions in about 4 minutes, as shown in FIG. 2 .
[0038] The short aging time of the new alloy indicates that the inventive precipitate-hardened alloy can be produced in an energy efficient manner compared with other alloys. The high strength, high modulus, and thermal stability demonstrate that the alloy can substitute various existing Ni-based alloys with superior properties.
[0039] After only 4 minutes, the increase in hardness levels out. Thereafter, increasing the aging time to 4 hours at 873 K results in no significant change of the LRO domains compared with those formed when the aging time is only 4 minutes. Even after 529 hours of aging, the hardness shows no sign of decreasing (indicating that over-aging does not occur in this interval). The alloy produced using the present inventive process is thereby seen to be resistant to over-aging.
[0040] Therefore, a minimum aging time of under 5 minutes and preferably close to 4 minutes is best in terms of energy efficiency. However extended aging times of 15 minutes, 50 minutes, or longer can be used without fear of overaging. No significant coarsening of the LRO domains is seen even with very long aging times.
[0041] Some users will naturally elect to extend the aging time beyond 4 minutes in order to ensure that near-maximum hardness is achieved, particularly for large components where the temperature in different portions may vary. Using the inventive alloys, this may be safely done without fear of over-aging some portions of the component.
[0042] In practical applications, some users hope that the new alloys can also be processed by existing heat treatment protocol, such as long aging time. This can be achieved by deformation in the invented alloy. Cold work significantly changes the ordering kinetics and consequently the age-hardening behavior of the new nickel-based superalloy. FIG. 3 shows the hardness values of samples which were annealed at 1473 K. (1200° C.) for 8 hours, then deformed to 41%, 62%, and 69%. Following the cold work, the samples were aged at 873 K. (600° C.) from 36 minutes to over 529 hours. The reader will observe four distinct stages in the precipitation hardening process.
[0043] In the first stage (from roughly 36 minutes to 2.4 hours) little age-hardening was observed. Therefore, deformation increases the entropy of the system and makes the SRO partially disappear. In this incubation stage, the age-hardening process operates by nucleation of new LRO domains and requires a longer time in the deformed samples than annealed ones. In the second stage (roughly from 2.4 hours to 4 hours), the hardness values ramp up to 530 HV for 41%, 589 HV for 62%, and 609 HV for 69% deformation strains respectively. A high degree of LRO occurs in this stage. Therefore, the hardening behavior of the cold-worked samples is markedly different from that of the un-worked annealed ones. The hardening is delayed from 4 minutes to about 4 hours at the aging temperature of 873 K (600° C.). This is a remarkable result, as it demonstrates that for this type of alloy cold work decelerates the aging process, by a factor of 60, and users can process the alloys as the prior art alloys.
[0044] The hardness increases shown in the plots are accompanied by comparable increases in strength, thanks to the presence of the LRO. The ultimate tensile strength and yield strength are respectively 1795 MPa and 1780 MPa for samples worked to 69% strain and then aged to 873 K. (600° C.) for 4 hours. The ultimate tensile strength and yield strength for cold worked samples are 1641 MPa and 1500 MPa respectively.
[0045] In the third stage of aging, the hardness values reach plateaus when aging times are between 4 hours and 50 hours. In the final stage when samples were aged from 50 hours to 529 hours, samples show a continuing decrease in hardness with increasing time. When the aging time reaches 529 hours, the hardness decreases to levels approximating the levels before aging began. The LRO domains, which have the chemistry of Ni 2 (Mo, Re) are highly developed. The interfaces between precipitates and the matrix are very sharp. In comparison with samples aged at 873K (600° C.) for 4 hours, not only are the LRO reflections intensified but also the size of the precipitates increased. This relates to the over-aging of the materials. The over-aging is not seen in annealed samples aged up to 529 hours.
[0046] Thus, the reader will understand that the formulation of the rhenium containing alloy—with the possible addition of strain hardening—allows a greatly enhanced mechanical strength.
[0047] The preceding descriptions contain considerable detail regarding the inventive process. However, these descriptions are properly viewed as defining the preferred embodiments, rather than the scope of the entire invention itself. Thus, the scope of the invention should be fixed by the following claims rather than by the examples given. | This document describes a process/strategy for age hardening nickel based alloys to create desirable properties with reduced energy expenditure. The inventive process introduces isolated atom nucleation sites to accelerate the nucleation rate by approximately 36 times, thereby permitting age hardening to occur in significantly less time and with significantly less energy expenditure. | 2 |
RELATED APPLICATION(S)
This patent arises from a continuation of U.S. application Ser. No. 12/589,702, entitled “SIMULCAST RESOLUTION IN CONTENT MATCHING SYSTEMS” and filed on Oct. 26, 2009, and claims priority from British Application No. GB0820055.2, entitled “SIMULCAST RESOLUTION IN CONTENT MATCHING SYSTEMS” and filed on Oct. 31, 2008. U.S. application Ser. No. 12/589,702 and British Application No. GB0820055.2 are hereby incorporated by reference in their entireties.
FIELD OF THE DISCLOSURE
The present invention relates to systems and methods for measuring the presence of an audience of a media presentation, in particular to systems and methods using content matching technologies.
BACKGROUND
Apparatuses and methods for measuring the audience of a media presentation, such as a television or a radio program, are well-known in the industry. The knowledge of the size and composition of audiences to television or radio broadcasts associated to certain environments, for example in a home, is of paramount importance for the broadcasting industry in order to value the advertising space included in broadcasts.
The group of viewers cooperating in a television audience survey is called a “panel”, while each viewer participating in the panel is called a “panel member”. Audience metering apparatuses cooperate with associated media rendering devices or display systems used by panel members for watching television broadcasts at their respective viewing locations. Such metering apparatuses have three main goals, namely: a) determining the content being shown on their associated media devices; b) identifying the broadcast source (e.g. television channel or other audio or video broadcast stream) and the content distribution platform (e.g., analogue terrestrial transmission, digital terrestrial transmission, analogue satellite transmission, cable TV, IPTV, etc.); and c) registering the presence of one or more panel members so that the exposure to the content, broadcast source and platform can be accounted for, so as to produce audience data.
Audience metering systems typically include a set-top box connected to the media device (traditionally a TV set). In order to identify the content, broadcast source and the platform of the viewed program, these metering systems may use one or more different methods available, such as tuner frequency measurement, or recognition of embedded video or audio codes, Service Information, image feature recognition, watermarking, and signatures, amongst others.
In the case of the signature recognition, many systems have been proposed which, essentially, include a metering device that derives signatures continuously either from the audio or video output (or both simultaneously) of the TV set or display device, and store the signatures together with an associated time stamp. The stored signatures generated by the metering devices are later transmitted by modem or any other telecommunications means to a remotely located central base (or station), where they are processed in order to identify all content shown on the monitored TV set or display device
This function may be achieved by means of content identification technology comprising a set of techniques and methods that can recognize an unknown segment of audio or video material among a plurality of reference segments generated from known broadcast sources. Persons skilled in the art will acknowledge the existence of methods and algorithms used for content identification by means of the generation and recognition of signatures. Audio and/or video signals are converted into signatures that characterize the media content being analyzed. A pattern correlation engine is then used to identify an unknown piece of content by scanning its signatures against a large set of previously-generated reference signatures. The content being displayed is then determined by analyzing correlation values according to appropriate algorithms in order to provide a wide range of media measurement and monitoring services, of which the most widely used is “Broadcast Identification” (i.e. recognizing a broadcast source being watched on a TV set; in the case of television audience measurement, for example, the broadcast source is typically a television channel).
It may happen, however, that two or more different broadcast sources comprise identical content during certain periods of time. This type of event is known as simulcast transmission, and is characterized by the fact that the scanning engine will find two or more reference signatures matching the signature of the unknown piece of content, generating an ambiguous situation in which the audience measurement system cannot unequivocally assign the content to one broadcast source.
In the case of content matching systems coupled with a source detection metering system, such as the one proposed by Wheeler et al. (U.S. Pat. No. 6,675,383), an approach has been implemented to solve the problem. If the audience metering device can identify the broadcast platform associated to the source providing the signal to the TV set or media rendering device during the simulcast period, the scanning process considers only the reference matching signatures originated on broadcast sources transmitted in the identified platform. This can eventually reduce or even eliminate the ambiguity, except for the case in which the simulcast involves two or more broadcast sources transmitted on the same platform (e.g., two analogue terrestrial channels or two digital satellite channels).
Another approach involves the detection of auxiliary codes or any other type of metadata present in the broadcast signal that could eventually identify the content and/or broadcast source viewed by the panel member(s), as proposed, for example, by Neuhauser et al. (International Patent Publication No. 2004/062282), where audio data is identified based on both a signature characterizing the audio data and additional data obtained from the audio data (as, for example, a source identification code). However, people skilled in the art know that if the codes or metadata are present in the broadcasting signals received by the panel members, code detection is used as the main audience measurement method, and the generation of signatures is usually implemented as a second option when the codes or the metadata streams are not detectable or not present, as proposed by Thomas et al. in U.S. Pat. No. 5,481,294, which describes a household metering apparatus which records ancillary codes or extracts program signatures from the programs if no ancillary codes are found in the broadcast signal. As a general rule, content matching methods are used when the audience measurement system cannot rely upon the full availability of codes or metadata.
A third approach, as suggested by Williams et al. in U.S. Pat. No. 5,945,988, may involve the use of known audience data from the monitored panel member(s) in order to enhance the identification of an audio sample. This solution, however, can only provide a best guess based on historical data.
Finally, the case of simulcast transmission has been addressed by Lee et al. and described in International Patent Publication No. 2005/006768. However, the solution described therein is for the specific case wherein the signatures are generated based on a Cycle Redundancy Check (CRC) or recognition of other predetermined data packet portions of a digital broadcast signal. This method, therefore, cannot solve the problem in the case of analogue broadcast signals, or in the case of audience measurement systems that generate signatures based on time-domain or frequency-domain features of a digital audio or video signal, which might be received remotely having been transmitted through the air from a presenting device (such as a television) as an audio wave or as an electromagnetic wave.
There is, therefore, a need to solve the problem faced by content matching technologies in simulcast cases where complementary information provided from a platform detector is not available or is not sufficient to identify a broadcast source, or broadcast source recognition by means of auxiliary codes or other type of metadata is not feasible.
SUMMARY
The present invention is defined in the claims of this patent.
An audience measurement system generates signatures of unknown pieces of content being viewed by the panel members. The signatures of the unknown pieces of content are stored and transmitted to a central processing site, where they are compared with reference signatures for their identification.
The signatures of the unknown content may be obtained remotely from a media presenting device, such as a television or radio, from an audio wave or an electromagnetic wave passing through the air. Alternatively, the signatures may be obtained directly from the audio or video components (or both) of a broadcast signal from the electrical output of the media presenting device.
A scanning engine finds matches between the signatures of the unknown and known content, and stores consecutive matches so as to build tracking segments, which are strings of matches that indicate a full coincidence between the unknown content and one or more known pieces of content for a certain period of time.
In accordance with yet another aspect of the invention, when the signatures of more than one known piece of content match the signatures of the unknown content, the system associates the unknown content to the known piece of content with the longest tracking segment.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, by referring to the enclosed figures of drawing, wherein:
FIG. 1 is a schematic representation of a typical content matching.
FIG. 1A is a schematic representation of components of FIG. 1 .
FIG. 2 is an illustration of a sequence of viewing segments detected by a meter and its corresponding signatures; a stream of reference signatures to which the former are compared; a resulting tracking segment; and a broadcast source attribution.
FIG. 3 depicts combinations of a simulcast transmission with viewing sessions of different lengths.
FIG. 4 is a table with the simulcast resolution factor for different viewing segment lengths.
FIG. 4A is a table showing the results of an implementation of a method and system according to the present invention.
FIG. 5 (which comprises FIGS. 5A and 5B ) is a flowchart of the operations performed by a program used to implement the rule of the longest segment.
DETAILED DESCRIPTION
In a typical audience measurement system 1 (see FIG. 1 ) a metering apparatus 2 (called “Meter”) is used to measure the viewing activity of one or more members of a household with regards to a predefined media presenting device 3 .
An individual metering apparatus 2 is shown in more detail in FIG. 1A . Each metering apparatus 2 (of a plurality of metering apparatuses in the measurement system 1 ) obtains data concerning a broadcast, which is being received from one of a plurality of broadcast sources 50 and accessed on media presenting device 3 by a user. As shown in FIG. 1A , the depicted metering apparatus 2 comprises an audio transducer 2 a that receivers an audio signal (transmitted from the media presenting device 3 as sound through the air). The audio signal is converted into an electrical signal from which a signature is generated corresponding to the unknown content being viewed on multimedia presenting device 3 . Alternatively, the metering apparatus 2 may be directly connected to a video or audio electrical output of the media presenting device 3 .
Each metering apparatus 2 stores and transmits those generated signatures to a central processing site 4 . The transmission may take place over a telephone line, internet connection (wireless or LAN), cellular network or any other communications network providing support for transfer of data. The metering apparatus' signatures of unknown content 5 are then compared to reference signatures 6 by means of a scanning engine 7 at the central processing site 4 that outputs the corresponding matches 8 .
A “viewing session” is defined as a period of time when the multimedia presenting device 3 is on, and a panel member has registered his or her presence. An example of such a system is described in the applicant's co-pending International Patent Application, published under No. 2008/072094, which is herein incorporated by reference. FIG. 2 shows a schematic diagram of a metered viewing session. In the example shown in FIG. 2 , a viewing session 10 starting at a time t 1 and ending at a time t 2 is represented. Each viewing session, in turn, is divided into “viewing segments” ( 21 , 22 , 23 24 25 in the figure), i.e. a period of time wherein the same broadcast source is tuned into at the multimedia presenting device 3 . The minimum length of time that is considered by the audience measurement system 1 as a viewing session is called “persistence threshold” and its value is defined during the system set up process. A value of fifteen seconds is used in most countries, and will be assumed in the description that follows.
In the case of content matching systems, each metering device 2 generates signatures 30 of the content present during the viewing segments, and the signatures 30 are then sent to a central processing site 4 for identification. The signatures 30 of the viewing segments are compared to the “reference signatures” 40 , i.e., the signatures of all the possible broadcast sources 50 that can be viewed by the monitored media presenting device. For each broadcast source 50 , therefore, a stream of signatures is stored in a file in the system's database. A scanning engine 7 compares the signatures 30 of the viewing segments with the reference signatures 40 of each broadcast source 50 , and outputs corresponding matches. In the case of the present invention, each match between a meter signature and a reference signature of any broadcast source is stored in memory during the process. A string of consecutive matches between the meter signatures and the signatures of each broadcast source is called a “tracking segment” 60 , which is also stored and used by the system to identify the broadcast source of the viewed content. In the example shown in FIG. 2 , the matching engine outputs a tracking segment corresponding to broadcast source A during t 1 and t 2 (viewing segment 21 ), a tracking segment corresponding to broadcast source B between t 3 and t 4 (viewing segment 22 ), and a tracking segment corresponding to broadcast source C between t 5 and t 6 (viewing segment 23 ).
In the case of simulcast, two or more tracking segments can be associated to a same viewing segment. In the example shown in FIG. 2 , during viewing segment 24 the scanning engine 7 outputs two tracking segments of different time lengths: a longer one 61 corresponding to broadcast source A and a shorter one 62 corresponding to broadcast source B. During t 7 and t 8 the two broadcast sources where transmitting different content and during t 8 and t 9 the simulcast situation took place. The scanning engine 7 assigns the viewing segment to the broadcast source with the longest tracking segment, as this segment contains extra information that allows the system to identify the viewed broadcast source based on the non-simulcast matched signatures. In this case, the information prior to the simulcast situations is used to identify the broadcast source. Another example of multicast is given in the case of segment viewing segment 25 , where the scanner outputs two tracking segments, both starting at the same time t 10 : a shorter one 63 corresponding to broadcast source A and a longer one 64 corresponding to broadcast source B. The simulcast situation, in the example, corresponds to the time period between t 10 and t 11 . As in the previous example, the scanning engine 7 assigns the viewing segment to the broadcast source with the longest tracking segment (broadcast source B in the example) as this segment contains information about the viewing session during the non-simulcast period that followed between t 11 and t 12 .
In order to determine which of several tracking segments during a simulcast corresponds to the viewing segments the method of the current invention makes a decision based on the “rule of the longest tracking segment” explained in the previous examples. The method is further described in what follows.
Broadcasting environments are characterized by two different types of simulcast behavior: “permanent simulcast”, and “scattered simulcast”. Permanent simulcast is characterized by two or more broadcast sources broadcast exactly the same content throughout the day. Scattered simulcast is characterized by two or more broadcast sources alternately broadcast the same content or different content during certain periods of time. By way of example, scattered simulcast happens when local or regional broadcast sources broadcast throughout the day the same content (usually national networks), but introducing local content during the commercial breaks or other predefined periods of time. The “rule of the longest segment” addresses the case of scattered simulcast, where the simulcast period of two or more broadcast sources is preceded or followed by a period of time during which the content is different for each broadcast source. Other examples of scattered simulcast include the case in which the same film or portions of the same film are available simultaneously from more than one broadcast source. It is important to note that time-shift environments like those offered by contemporary broadcast platforms may produce virtual simulcast situations where a consumer can choose the same piece of content that is available from different broadcast sources at different times, or even from libraries offering pieces of content on an “on-demand” basis. In all these situations, the task of a content matching engine that needs to identify the content being consumed in a measured television set faces a much higher probability of finding identical pieces of content broadcast from several sources at different times or modes. The present invention provides a solution to the problem of maximizing the probability of correctly identifying the correct broadcast source from which such content is being consumed. For this purpose, the matching engine is programmed in such a way that whenever two or more candidates are found for any unknown viewing segment, the longest tracking segment is chosen.
An example of application of the present invention follows. FIG. 3 represents a typical case of syndicated transmissions, wherein two or more broadcast sources transmit a program in simulcast for a predefined length of time 70 (fifteen minutes in the example), inserting their own commercial breaks 80 for another predefined length of time (four minutes for commercial breaks 80 in the example shown in FIG. 3 ). A diagram is shown that describes the possibility of solving simulcast situations, given different viewing segment durations, and assuming a “persistence threshold” 90 of fifteen seconds. In the first case, one minute duration 91 is assumed for the viewing segment. Under these conditions, a total of sixty three viewing segments one every fifteen seconds could overlap with the simulcast period of fifteen minutes. Of those sixty three segments, fifty seven would fall entirely within the simulcast period, rendering it impossible for the matching engine to determine the identity of the viewed broadcast source. In turn, six out of these sixty three one-minute segments would include signatures of non-simulcast content, allowing the identification of the viewed broadcast source by means of the corresponding tracking segments.
The same analysis is repeated for viewing segment lengths of two, three and four minutes ( 92 , 93 and 94 respectively in FIG. 3 ), and is valid for any viewing segment shorter than the simulcast period. The total number of segments that could include a portion of simulcast (Total Simulcast Segments) is given by the formula:
TSS
=
ST
+
VSL
-
PT
PT
Where,
TSS: Total Simulcast segments
ST: Simulcast Time (seconds) ( 70 in FIG. 3 )
VSL: Viewing Segment Length (seconds) ( 91 , 92 , 93 and 94 in FIG. 3 )
PT: Persistence threshold (seconds) ( 90 in FIG. 3 )
The number of segments that include a non-simulcast portion, and can be therefore identified through the signatures of the non-simulcast content (Solved Simulcast Segments), is given by the formula:
TSS
=
2
*
(
VSL
-
PT
)
PT
Where,
SSS: Solved Simulcast Segments
VSL: Viewing Segment Length (seconds)
PT: Persistence threshold (seconds)
Given the above formulas, the Simulcast Resolution Factor (SRF) of the rule of the longest tracking segment is:
SRF
=
SSS
TSS
=
2
*
(
VSL
-
PT
)
(
ST
+
VSL
-
PT
)
FIG. 4 shows a table with the SRF value for viewing segment lengths ranging from one to fifteen minutes (length of the simulcast transmission period) in the first column. The second column shows the average Simulcast Resolution Factor for the given ranges and a persistence time of fifteen seconds. The third column indicates the percentage of simulcast segments resolved by the rule of the longest tracking segment for viewing segment length.
By way of example, FIG. 4A shows a table with the results of the implementation of a system and method according to the present invention in a television market. The first column includes four different viewing segment length ranges. The second column indicates the corresponding share of total viewing time for those viewing segment length ranges. The third column shows the average resolution factors corresponding to those ranges using the rule of the longest segment described in the present invention. The fourth column indicates the percentage of total simulcast viewing time that is solved in each case. As can be seen in the example of FIG. 4A , in a television environment with viewing patterns similar to the ones provided in FIG. 4 , about 90.9% of the total simulcast viewing time in such circumstances can be correctly identified by applying the present invention.
More generally, the longer the viewing segments the higher the probability of identifying the correct source using the present invention, since the probability of encountering a different part, either at the head or at the tail of the segment, becomes correspondingly higher. Since most media consumption of broadcast content tends to happen in segments a few minutes long, the present invention contributes to reducing the impact of simulcast situations in the accuracy of the output data. The remainder of segments that do not converge to a single broadcast source (more likely to be short segments) may be then determined by some other method, if available.
FIG. 5 shows a process 100 according to an exemplary embodiment of the invention to implement the rule of the longest tracking segment. The process 100 is executed for each sampled viewing segment wherein the broadcast source needs to be identified. The process 100 is executed as a computer program comprising executable program instructions in a processor, such as scanning engine 7 . The process 100 begins at block 101 of FIG. 5 , at which the viewing segment's signatures generated by a metering device located in a household are loaded. At block 102 , a file containing the reference signatures of a broadcast source relevant to the metered household is loaded. The total amount of files to be loaded will be determined by the location of the household (signals availability, i.e., terrestrial, satellite and cable networks) and the receiving devices (possibility to decode the aforementioned available signals). Once the meter and reference signatures have been loaded, the process starts a search process 103 .
Assuming that each signature of each viewing segment is both time stamped and numbered, the program sets in block 104 a counter at n=0 for each new viewing segment to be analyzed. In block 105 the program gets the signature indicated by the counter, until the end of the viewing segment is reached, as indicated in block 111 . At block 106 the process compares the previously loaded reference signatures of a certain Broadcast Source N searching for a match between viewing segment's signature n and any reference signature of Broadcast Source N. If the viewing segment has been previously identified as live viewing (by a system process not included in the program described in FIG. 5 ), the timestamp of the viewing segment's signature n is taken into account, and the search is limited to a range given by the time of occurrence of the signature plus/minus (+/−) a predefined time tolerance (e.g., 15 seconds), given the fact that the reference signatures are also time stamped in a synchronized way. If, however, the viewing segment has been previously identified as time-shifted viewing (by a system process not included in the program described in FIG. 5 ), the file loaded in block 102 should include the reference signatures of Broadcast Source N for a predefined amount of days (for example, current day plus previous day, plus last week, plus last months, etc).
If a match is found (block 107 ) the process proceeds to block 108 to check if the reference signature that matches the viewing segment's signature is synchronous with the previous matched reference signature (i.e., the time interval between the two signatures in the viewing segment is exactly the same as the one between the two corresponding matching signatures in the reference signatures file). If so (or always in the case of the first signature of each viewing segment), the process stores the matching signature appending it to the previously saved signatures, creating in this way a Tracking Segment for Broadcast Source N (block 109 ). The process then increments the signature counter (block 110 ) and repeats the matching process for the next signature until the end of the viewing segment is reached (block 111 ). When this happens the process compares in block 112 the time length value of the Tracking Segment N saved in block 110 (that is given by the difference between the time stamps of the last and first matched signatures) with the persistence threshold value that has been previously defined. If the time length is greater or equal than the persistence threshold, the process at block 113 stores the Tracking Segment for Broadcast Source N for later comparison with Tracking Segments from other broadcast sources, increments the Reference Signatures counter (block 114 ), checks the existence of new Reference Signature to be matched (block 115 ), loads the Reference Signatures for the new broadcast source (block 102 ), and starts a new search (block 103 ) comparing the signatures of the viewing segment with the reference signatures of Broadcast Source N+1. If at block 112 the time length of the Tracking Segment is lower than the persistence threshold, the Tracking Segment is discarded, and the process proceeds to block 114 , already described.
When the end of the Reference Signatures is reached at block 115 , the process starts a comparison process of all the Tracking Segments stored at block 113 . At block 117 , the process compares the time length of the stored Tracking Segments, searching the one with the longest duration. If, at block 118 , the process finds that no single Tracking Segment is longer than the others, it cannot identify the Viewing Segment under analysis and outputs a corresponding message (“Assign by means of an alternative method” at block 119 in the example shown in FIG. 5 , assuming that yet another method is used in these cases). If at block 118 the longest Tracking Segment is found, the process identifies the Broadcast Source having said longest tracking segment at block 120 . The process then assigns the Viewing Segment to the Broadcast Source identified in the previous step, and outputs the result (Longest TrackSeg=“Broadcast Source N” at block 121 in the example).
Once a Viewing Segment has been assigned to a broadcast source, the process restarts at block 100 , loads the signatures of a new Viewing Segment (block 101 ), and repeats the search, matching and comparison steps until all the viewing segments generated by the metering device are processed.
Without prejudice to the underlying principle of the invention, the details and embodiments may vary, also significantly, with respect to what has been described and shown by way of example only, without departing from the scope of the invention as defined by the annexed claims.
It will be apparent to those skilled in the art that the present invention may be advantageously applied in various processes involving identifications of broadcast sources, in a variety of media formats, including television and radio programs broadcast via a variety of communication means, like cable networks, satellite networks, Internet links, etc. | Example methods disclosed herein to identify media sources comprise obtaining monitored signatures generated from monitored media, comparing the monitored signatures with reference signatures generated from reference media provided by a plurality of reference sources, determining tracking segments associated with respective ones of the reference sources, each tracking segment representing sequences of matches between the monitored signatures and respective reference signatures for a respective one of the reference sources, and evaluating time lengths of the tracking segments to identify which reference source in the plurality of reference sources provided the monitored media. | 7 |
RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. § 119 or 365 to Great Britain, Application No. 0712878.8, filed Jul. 3, 2007. The entire teachings of the above application are incorporated herein by reference.
TECHNICAL FIELD
[0002] This invention relates to a communication system and method.
BACKGROUND
[0003] Voice over internet protocol (“VoIP”) communication systems allow the user of a device, such as a personal computer, to make calls across a computer network such as the Internet. These systems are beneficial to the user as they are often of significantly lower cost than fixed line or mobile networks. This may particularly be the case for long distance calls. To use VoIP, the user must install and execute client software on their device. The client software provides the VoIP connections as well as other functions such as registration and authentication. In addition to voice communication, the client may also provide video calling and instant messaging (“IM”).
[0004] One type of VoIP communication system uses a peer-to-peer (“P2P”) topology built on proprietary protocols. To access the peer-to-peer system, the user must execute P2P client software provided by a P2P software provider on their PC, and register with the P2P system. When the user registers with the P2P system the client software is provided with a digital certificate from a server. Once the client software has been provided with the certificate, communication can subsequently be set up and routed between users of the P2P system without the further use of a server. In particular, the users can establish their own communication routes through the P2P system based on the exchange of one or more digital certificates (or user identity certificates, “UIC”), which enable access to the P2P system. The exchange of the digital certificates between users provides proof of the user's identities and that they are suitably authorised and authenticated in the P2P system. Therefore, the presentation of digital certificates provides trust in the identity of the user. It is therefore a characteristic of peer-to-peer communication that the communication is not routed using a server but directly from end-user to end-user. Further details on such a P2P system are disclosed in WO 2005/009019.
[0005] One of the advantages of VoIP communication systems, compared to the public switched telephone network (“PSTN”), is that supplementary information can be provided about the users of the VoIP communication system. This supplementary information can take the form of presence information and a “mood message”.
[0006] Presence information is an indication of the current status of a user of the system. More specifically, presence information is displayed in the user interface of the client for each of the contacts that the user has stored, and allows the user to view a best guess regarding the current status of the contacts in the system. Example presence states that may be displayed include “online”, “offline”, “away”, “not available” and “do not disturb”. The use of presence states provides a user with a best guess regarding the current status of a contact before attempting to communicate with the contact. For example, if the user is not online, and therefore unable to be contacted, then this is indicated to the user before attempting to make a call. Similarly, if a contact is busy and unlikely to answer, then this may also be communicated in advance via the presence state. This is a considerable advantage over PSTN systems, which do not provide any prior information on the probable state of a user. The only option in PSTN systems is to dial a number and wait and see if it is answered.
[0007] Mood messages are short text strings that are composed by the users to distribute information about themselves to their contacts and supplement their presence status. The mood message of a contact is generally displayed next to the contact's name and presence status in the client. Mood messages are useful for a number of reasons. For example, a mood message can be used to give more information or a reason for a particular presence status, e.g. if a user is offline, the mood message may say “On holiday”, thereby explaining why the user is offline. Similarly, if a user's presence state is set to “do not disturb”, the mood message may say “Busy working. Only contact me if urgent”. Mood messages are also useful for users that travel frequently, as a VoIP system can be accessed from anywhere in the world, but this is not reflected in the presence states. Therefore, it is useful for a user to show a mood message such as “In London” next to their presence state.
[0008] One popular use for mood messages is to utilise the mood message as a means to easily share links to multimedia content on the internet. For example, users can include a hyperlink to a particular webpage that has some interesting multimedia content (such as a video, picture or audio recording) in the mood message, so that all the user's contacts can see the hyperlink and click on the hyperlink to visit the webpage.
SUMMARY
[0009] The multimedia content at the website linked in the mood message can serve to stimulate conversation over the VoIP communication system. However, this relies on the contacts of the user with the mood message actually clicking on the hyperlink and viewing the webpage. This can be a problem, as a mere hyperlink does not generally encourage other users to view the media.
[0010] There is therefore a need for a technique to address the aforementioned problems and provide for the efficient sharing and display of multimedia content by the users.
[0011] According to one aspect of the present invention there is provided a method of accessing content at a user terminal connected to a communication network and executing a communication client, comprising: said client displaying a list of contacts associated with a user of said client; said client retrieving a message from said communication network, wherein said message is related to a further user represented by one of said contacts displayed in said list of contacts, said message comprising a reference to content stored in a storage means accessible by said communication network; said client initiating a call to said further user over the communication network responsive to a user of said client selecting said one of said contacts in said list of contacts; and responsive to initiating said call, said client establishing communication with said storage means using said reference, accessing the content and displaying the content at said user terminal.
[0012] In one embodiment, said content is a video. In another embodiment, said content is an audio recording.
[0013] Preferably, the method further comprises the step of said client muting said content responsive to said further user answering said call. Preferably, the method further comprises the step of downloading the list of contacts from a network element. Preferably, said step of retrieving the message comprises communicating with a further client executed at a user terminal of the further user. Preferably, said message is a mood message created by said further user.
[0014] Preferably, said step of displaying the content at said user terminal comprises said client executing media player means at said user terminal, wherein said content is displayed to said user using said media player means. Preferably, said media player means is embedded within said client. Preferably, said media player means comprises user-operable controls for controlling playback and setting audio properties of said content.
[0015] Preferably, the method further comprises the step of ascertaining whether said reference to said content is listed in a database prior to displaying said content. Preferably, if said reference to said content is listed in said database, said user terminal does not display said content. Preferably, said reference is a network address of said content. Preferably, said network address is a uniform resource identifier.
[0016] Preferably, said communication network is a packet based communication network. In one embodiment, said client is a voice over internet protocol communication client. Preferably, said voice over internet protocol communication client is a peer-to-peer communication client. In another embodiment, said client is an instant messaging communication client.
[0017] In one embodiment, said user terminal is a personal computer. In another embodiment, said user terminal is a mobile device.
[0018] According to another aspect of the present invention there is provided a computer program product comprising program code means which when executed by a computer implement the steps according to the above-defined method of accessing content at a user terminal.
[0019] According to another aspect of the present invention there is provided a method of accessing content at a user terminal connected to a communication network and executing a communication client, comprising: said client displaying a list of contacts associated with a user of said client; said client retrieving a message from said communication network, wherein said message is related to a further user represented by one of said contacts displayed in said list of contacts, said message comprising a reference to content stored in a storage means accessible by said communication network; said client receiving a communication request initiated by said further user over the communication network; and responsive to receiving said communication request, said client establishing communication with said storage means using said reference, accessing the content and displaying the content at said user terminal.
[0020] Preferably, said communication request is an incoming call.
[0021] According to another aspect of the present invention there is provided a computer program product comprising program code means which when executed by a computer implement the steps according to the above-defined method of accessing content at a user terminal.
[0022] According to another aspect of the present invention there is provided a user terminal comprising: communication means for communicating with a communication network; display means; and processing means arranged to execute a communication client, wherein said client is configured to: display a list of contacts associated with a user of said client on said display means; retrieve a message from said communication network, wherein said message is related to a further user represented by one of said contacts displayed in said list of contacts, said message comprising a reference to content stored in a storage means accessible by said communication network; initiate a call to said further user over the communication network responsive to a user of said client selecting said one of said contacts in said list of contacts; and, responsive to initiating said call, establish communication with said storage means using said reference, access the content and display the content on said display means.
[0023] According to another aspect of the present invention there is provided a user terminal comprising: communication means for communicating with a communication network; display means; and processing means arranged to execute a communication client, wherein said client is configured to: display a list of contacts associated with a user of said client on said display means; retrieve a message from said communication network, wherein said message is related to a further user represented by one of said contacts displayed in said list of contacts, said message comprising a reference to content stored in a storage means accessible by said communication network; receive a communication request initiated by said further user over the communication network; and, responsive to receiving said communication request, establish communication with said storage means using said reference, access the content and display the content at said user terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] For a better understanding of the present invention and to show how the same may be put into effect, reference will now be made, by way of example, to the following drawings in which:
[0025] FIG. 1 shows a P2P communication system;
[0026] FIG. 2 shows a user interface of a client executed on a user terminal;
[0027] FIG. 3 shows a detailed view of a user terminal executing a client;
[0028] FIGS. 4A to 4C show user interfaces for entering a mood message in a client;
[0029] FIG. 5A shows a user interface for adding a multimedia mood message;
[0030] FIG. 5B shows a user interface for selecting a video to add to a mood message;
[0031] FIG. 6A shows multimedia mood message data;
[0032] FIGS. 6B and 6C shows a user interface containing a multimedia mood message;
[0033] FIG. 7 shows a client user interface comprising a contact with a multimedia mood message;
[0034] FIGS. 8A to 8D show client user interfaces in which a video ringback is displayed;
[0035] FIGS. 9A to 9B show client user interfaces in which a video ringback can be paused;
[0036] FIGS. 10A to 10C show client user interfaces with control options for a video ringback;
[0037] FIG. 11 shows a client user interface with options displayed following the end of a video;
[0038] FIG. 12 shows a client user interface with a message displayed if a video ringback affects call quality;
[0039] FIG. 13 shows a client user interface with a resized video;
[0040] FIG. 14 shows a client user interface for an unavailable video; and
[0041] FIG. 15 shows a client user interface displaying a video during an incoming call.
DETAILED DESCRIPTION
[0042] Reference is first made to FIG. 1 , which illustrates a P2P communication system 100 . Note that whilst this illustrative embodiment is described with reference to a P2P communication system, other types of communication system could also be used, such as instant messaging systems and other, non-P2P, VoIP systems. A first user of the P2P communication system (denoted “User A” 102 ) operates a user terminal 104 , which is shown connected to a network 106 , such as the Internet. The user terminal 104 may be, for example, a personal computer (“PC”), personal digital assistant (“PDA”), a mobile phone, a gaming device or other embedded device able to connect to the network 106 . The user device is arranged to receive information from and output information to a user of the device. In a preferred embodiment of the invention the user device comprises a display such as a screen and a keyboard and mouse. The user device 104 is connected to the network 106 via a network interface 108 such as a modem, and the connection between the user terminal 104 and the network interface 108 may be via a cable (wired) connection or a wireless connection.
[0043] The user terminal 104 is running a client 110 , provided by the P2P software provider. The client 110 is a software program executed on a local processor in the user terminal 104 . The user terminal 104 is also connected to a handset 112 , which comprises a speaker and microphone to enable the user to listen and speak in a voice call. The microphone and speaker does not necessarily have to be in the form of a handset, but can be in the form of a headphone or earphone with an integrated microphone, or as a separate loudspeaker and microphone independently connected to the user terminal 104 .
[0044] An example of a user interface 200 of the client 110 executed on the user terminal 104 of User A 102 is shown illustrated in FIG. 2 . The client user interface 200 displays the username 202 of User A 102 in the P2P system, and User A can set his own presence state (that will be seen by other users) using a drop down list by selecting icon 204 .
[0045] The client user interface 200 comprises a tab 206 labelled “contacts”, and when this tab is selected the contacts stored by the user in a contact list are displayed. In the example user interface in FIG. 2 , five contacts of other users of the P2P system (User B to F) are shown listed in contact list 208 . Each of these contacts have authorised the user of the client 110 to view their contact details and online presence and mood message information. Each contact in the contact list has a presence status icon associated with it. For example, the presence status icon for User B 210 indicates that User B is “online”, the presence icon for User C 212 indicates that User C is “not available”, the presence icon for User D 214 indicates that User D's state is “do not disturb”, the presence icon for User E 216 indicates User E is “away”, and the presence icon for User F 218 indicates that User F is “offline”. Further presence indications can also be included. Next to the names of the contacts in pane 208 are the mood messages 220 of the contacts.
[0046] The contact list for the users (e.g. the contact list 208 for User A) is stored in a contact server 113 shown in FIG. 1 . When the client 110 first logs into the P2P system the contact server 113 is contacted, and the contact list is downloaded to the user terminal 104 . This allows the user to log into the P2P system from any terminal and still access the same contact list. The contact server is also used to store the user's own mood message (e.g. the mood message of User A 102 ) and a picture selected to represent the user (known as an avatar). This information can be downloaded to the client 110 , and allows this information to consistent for the user when logging on from different terminals. The client 110 also periodically communicates with the contact server 113 in order to obtain any changes to the information on the contacts in the contact list, or to update the stored contact list with any new contacts that have been added. Presence information is not stored centrally in the contact server. Rather, the client 110 periodically requests the presence information for each of the contacts in the contact list 208 directly over the P2P system. Similarly, the current mood message for each of the contacts, as well as a picture (avatar) that has been chosen to represent the contact, are also retrieved by the client 110 directly from the clients of each of the contacts over the P2P system.
[0047] Calls to the P2P users in the contact list may be initiated over the P2P system by selecting the contact and clicking on a “call” button 222 using a pointing device such as a mouse. Alternatively, the call may be initiated by typing in the P2P identity of a contact in the field 224 . Referring again to FIG. 1 , the call set-up is performed using proprietary protocols, and the route over the Internet 106 between the calling user and called user is determined by the peer-to-peer system without the use of servers. In FIG. 1 , an illustrative route is shown between the caller User A ( 102 ) and the called party, User B ( 114 ), via other peers ( 116 , 118 , 120 ) of the P2P system. It will be understood that this route is merely an example, and that the call may be routed via fewer or more peers.
[0048] Following authentication through the presentation of digital certificates (to prove that the users are genuine subscribers of the P2P system—described in more detail in WO 2005/009019), the call can be made using VoIP. The client 110 performs the encoding and decoding of VoIP packets. VoIP packets from the user terminal 104 are transmitted into the Internet 106 via the network interface 108 , and routed to the computer terminal 122 of User B 114 , via a network interface 123 . A client 124 (similar to the client 110 ) running on the user terminal 122 of User B 114 decodes the VoIP packets to produce an audio signal that can be heard by User B using the handset 126 . Conversely, when User B 114 talks into handset 126 , the client 124 executed on user terminal 122 encodes the audio signals into VoIP packets and transmits them across the Internet 106 to the user terminal 104 . The client 110 executed on user terminal 104 decodes the VoIP packets from User B 114 , and produces an audio signal that can be heard by the user of the handset 112 .
[0049] The VoIP packets for the P2P call described above are passed across the Internet 106 only, and the PSTN network is not involved. Furthermore, due to the P2P nature of the system, the actual voice calls between users of the P2P system can be made with no servers being used. This has the advantages that the system scales easily and maintains a high voice quality, and the call can be made free to the users.
[0050] FIG. 3 illustrates a detailed view of the user terminal ( 104 ) on which is executed client 110 . The user terminal 10 comprises a central processing unit (“CPU”) 302 , to which is connected a display 304 such as a screen, an input device such as a keyboard 306 , a pointing device such as a mouse 308 , a speaker 310 and a microphone 312 . The speaker 310 and microphone 312 may be integrated into a handset 112 or headset, or may be separate. The CPU 302 is connected to a network interface 108 as shown in FIG. 1 .
[0051] FIG. 3 also illustrates an operating system (“OS”) 314 executed on the CPU 302 . Running on top of the OS 314 is a software stack 316 for the client 112 . The software stack shows a protocol layer 322 , a client engine layer 320 and a client user interface layer (“UI”) 318 . Each layer is responsible for specific functions. Because each layer usually communicates with two other layers, they are regarded as being arranged in a stack as shown in FIG. 3 . The operating system 314 manages the hardware resources of the computer and handles data being transmitted to and from the network via the network interface 108 . The client protocol layer 322 of the client software communicates with the operating system 314 and manages the connections over the P2P system. Processes requiring higher level processing are passed to the client engine layer 320 , which handles the processing required for the user to make and receive calls over the P2P system. The client engine 320 also communicates with the client user interface layer 318 . The client engine 320 may be arranged to control the client user interface layer 318 to present information to the user via the user interface of the client (as shown in FIG. 2 ) and to receive information from the user via the user interface. The control of the client user interface 318 will be explained in more detail hereinafter.
[0052] Reference is now made to FIGS. 4A to 4C , which illustrate the known user interface for entering a mood message into a client. FIG. 4A shows a portion of the client user interface for User A 102 (as shown in FIG. 2 ) that is used by User A to set his mood message. The panel 402 is shown when User A uses the pointing device 308 of the user terminal 104 to select the field displaying his username (labelled 202 in FIG. 2 ) in the client user interface ( 200 in FIG. 2 ). Panel 402 displays the username 202 and presence icon 204 for User A (as in FIG. 2 ). In addition, panel 402 also displays an avatar 404 that User A has selected to represent himself, and a text-entry box 406 in which User A can enter a mood message.
[0053] When User A uses the pointing device 308 of the user terminal 104 to select the text-entry box 406 , the panel shown in FIG. 4B is displayed. The text-entry box 406 is displayed in a different colour, and a cursor 408 is present in the text-entry box 406 to indicate to the user that text may be typed.
[0054] After User A has typed a mood message into text-entry box 406 , then the panel 402 is of the form shown in FIG. 4C . In this example, User A has typed the text message “This is a sample text message” 410 and has also typed a webpage address “http://www.skype.com” 412 , which is automatically hyperlinked by the client 112 such that the address 412 becomes a clickable link in the UI, whereby if the user clicks the link using the pointing device 308 , the user terminal 104 executes a web-browser program that navigates to the webpage address and displays the webpage to the user on the display device 304 .
[0055] The mood message that was typed by User A is transmitted to the contact server 113 and stored in User A's data record. In alternative embodiments, the mood message data is not transmitted immediately to the contact server 113 , but is sent with the next periodic update message from the client 110 to the contact server 113 . In addition, the mood message of User A 102 is also periodically communicated to each of User A's contacts over the P2P system when this is retrieved by the contacts.
[0056] Reference is now made to FIG. 5A , which illustrates the UI for adding a multimedia mood message. In the following embodiment, a video is incorporated into a user's mood message. However, it will be appreciated that the same technique may be used for incorporating other types of media into mood messages, such as images and sound recordings.
[0057] FIG. 5A shows a portion of the client UI for User A 102 similar to that shown in FIG. 4A . Panel 502 comprises a mood message entry area 504 which displays a different message to that in FIG. 4A . In particular, the message invites the user to enter a text message or to add a video into their mood message, and has a hyperlink embedded for the word “video” 506 . The user therefore not only has the option to write a text message, but also to add a video to their mood message. Note that in alternative embodiments, other types of media (such as still images or audio) may also be added to mood messages. In this instance, the hyperlink in FIG. 5A is changed accordingly, for example to read “video or photo”.
[0058] If the user uses the pointing device to click in the mood message entry area 504 (but not on the word “video”) then a cursor is shown as in FIG. 4B , and the user can type a text message, as in FIG. 4C , which is then distributed to the contacts of User A as described previously.
[0059] If the user uses the pointing device to click on the word “video”, then the user begins the process for selecting a video for insertion into the mood message.
[0060] In preferred embodiments, the selection of a video is made by the user through the presentation of a UI showing a selection of available videos, which is displayed to the user responsive to the user clicking on the word “video”. An example of such a video selection UI 508 is illustrated in FIG. 5B . The UI 508 can be considered to comprise two separate elements. The first element is the frame of the UI 508 , comprising tabs ( 510 , 512 , 514 ), navigation buttons 516 , search field 518 , mood message preview area 520 and control buttons ( 522 , 524 ). The second element is a pane 526 which shows different information for each of the tabs ( 510 , 512 , 514 ). Specifically, pane 526 displays representations of the available videos.
[0061] The information for the above-two elements in UI 508 is fetched from different sources. Firstly, the information relating to the frame of the UI is fetched from a content directory 127 . The content directory 127 is shown in FIG. 1 connected to the network 106 . The client 110 is arranged to communicate with the content directory 127 and retrieve the information to allow the client 110 to present the UI 508 to the user. In particular, the client 110 needs to fetch the information regarding the tabs ( 510 , 512 , 514 ). Specifically, information is needed on the number of tabs (three are shown in FIG. 5B , but more or less tabs may be shown—for example if there is only a single content provider then no distinct tabs are required), the titles of the tabs, and the address of where the information to populate pane 526 for each tab is located. Preferably, this address is in the form of a webpage uniform resource locator (“URL”).
[0062] Once the information regarding the frame of UI 508 has been retrieved from the content directory 127 , the information for pane 526 is retrieved from a content provider. FIG. 1 illustrates three separate content providers ( 128 , 130 , 132 ) connected to network 106 . In this exemplary embodiment, these three content providers ( 128 , 130 , 132 ) respectively provide the information displayed for the three tabs ( 510 , 512 , 514 ) of UI 508 . The content providers ( 128 , 130 , 132 ) provide the information that populates pane 526 and also provide the actual video data. Preferably, the content providers are third parties, and separate from the P2P software provider. Note that the media content that is made available by the content provider can be provided by individual users uploading the media to the content provider.
[0063] In the example shown in FIG. 5B , the UI 508 shows the content for tab 510 , labelled “Partner 1 ”. The client uses the address obtained from the content directory 127 for tab 510 to access content provider 128 in order to display the information for this tab. More specifically, the address from the content directory 127 is a URL of a webpage provided by the content provider 128 , and the client downloads this webpage (in the form of hypertext mark-up language (“HTML”)) over the network 106 and displays the webpage in pane 526 . If the user uses the pointing device to select a different tab, such as 512 or 514 , then the address provided by the content directory 127 for the selected tab is used to fetch the information to be displayed for this tab.
[0064] The purpose of the information shown in pane 526 is to provide the user with a selection of videos that are available to be included in the user's mood message. Pane 526 displays a plurality of thumbnail images (e.g. thumbnail 528 ) representing each video and a title (e.g. title 530 ) for each video. The thumbnail image for a video is a small image of a single frame from the video. The thumbnail for each video is generated from the video file itself (e.g. it can be the first frame of the video, or a frame a predetermined time or percentage into the video). Preferably, a list of categories 532 is displayed to allow the user to view a sub-set of the available videos. Furthermore, the user can search the videos by keywords using the search field 518 .
[0065] Preferably, the content directory 127 is provided by the P2P software provider. This allows the P2P software provider to present a portal to several content providers ( 128 , 130 , 132 ) that are able to provide videos to the users, thereby avoiding the requirement for the P2P software provider to host and/or stream its own videos. The content directory 127 can be updated to add or remove content providers as required.
[0066] When UI 508 is displayed on the users terminal 104 , the user can use the pointing device to browse the available videos from the different content providers (by using the different tabs 510 - 514 , the categories 532 and the search field 518 ). When a user sees a video that he is interested in, he clicks the thumbnail to view a preview of the video. When the user has chosen a video, he can select the “save mood message” button 522 to save the video to his mood message.
[0067] In an alternative embodiment, the user can also add a video to his mood message without using the video selection UI. For example, the user can copy and paste a URL of a video on a webpage directly into his mood message (e.g. into the field illustrated in FIG. 4B ). The client detects that this URL is linking to a video (or other type of media), and automatically generates the required multimedia mood message data (described with reference to FIG. 6A below) in order for the video mood message to be created for this video. In some embodiments, the client can also check that the video URL is from an approved partner (e.g. one of the content providers 128 , 130 , 132 ).
[0068] In a further alternative embodiment, the user can additionally add a video to his mood message by selecting a control displayed on the webpage of a content provider in association with a particular video. For example, the webpage of a content provider ( 128 , 130 , 132 ) can display videos that can be viewed by a user using a web-browser. The webpage displays an “add to mood” button in proximity with the videos, such that if the button is activated by the user, then data regarding the video is passed to the client to allow the client to generate the required mood message data. Therefore, the client can create a multimedia mood message in the same way as described previously, but without using the video selection UI.
[0069] In yet further embodiments, the user can also add videos from a webpage, even if the webpage is not from a content provider that displays a specific “add to mood” button as part of the webpage itself. The P2P software provider can provide plug-in software for the web-browser program that detects that the webpage being viewed contains an embedded video, and overlays an “add to mood” button in proximity to the video in the webpage. If the user selects the button, then data is passed to the client that allows the client to generate the multimedia mood message data in the same way as described above. In preferred embodiments, the client can check that the webpage is from an approved partner (e.g. one of the content providers 128 , 130 , 132 ) before permitting the video to be included in a mood message.
[0070] Further details regarding the process by which the user creates a multimedia mood message is the subject of a co-pending patent application entitled “Multimedia Mood Messages” by the same applicant (identified by attorney reference number 313765.GB), and is not discussed further here.
[0071] Once the multimedia mood message has been chosen by the user, the client generates mood message data to enable the mood message to be displayed in the client and passed to the contacts of the user. The mood message data 602 that is generated by the client is illustrated in FIG. 6A . The mood message data 602 that is generated and stored by the client comprises two main parts. The first part is a media object 604 , which contains the data related to the media (e.g. the video). The second part of the mood message data 602 is a text comment 606 that the user has typed to accompany the video (if present).
[0072] The media object 604 comprises several data items. A media type field 608 defines the type of media (e.g. video, photo, audio etc.) A media title field 610 includes the title of the media. A content provider identity 612 is used to identify which content provider the media originated from (e.g. 128 , 130 or 132 in FIG. 1 ). A content provider uniform resource identifier (“URI”) 614 provides an address of where further information may be found regarding the content provider (e.g. the address of the content provider webpage). A media URI 616 is the address of where the media is stored, and this is the address from where the media is streamed when it is played. The thumbnail image for the media is stored in the media object at 618 . Preferably, the thumbnail image is provided by the content provider.
[0073] The multimedia mood message then appears to the user in the client UI as shown in FIGS. 6B and 6C . FIG. 6B shows the same panel 502 of the client UI as illustrated in FIG. 5A . However, the panel 502 now includes the thumbnail image 620 for the video selected by the user (this is read from the thumbnail image 618 in the media object 604 ). The user also has the option to add a text comment at this stage to accompany the video (if this was not done previously, or if the user wishes to amend a previously entered comment). This is achieved by the user clicking in the text-entry region 622 and typing. FIG. 6C illustrates the case where the user has typed a message 624 in region 622 .
[0074] Therefore, at this stage, the user (in this case User A) has selected a video to be included in his mood message, and generated corresponding multimedia mood message data 602 . The next stage is for the multimedia mood message to be passed to User A's contacts.
[0075] Referring again to FIG. 1 , the video mood message data 602 as shown in FIG. 6A is transmitted from the client 110 to the clients of the contacts of User A over the P2P system. According to one embodiment, the multimedia mood message data 602 for User A is retrieved periodically by the contacts of User A 102 . For example, the client 124 of User B 114 (who is a contact of User A) may periodically request mood message information from each of its contacts, thereby requesting the mood message information from User A. The multimedia mood message information is transmitted from User A to User B responsive to such a request. In an alternative embodiment, the multimedia mood message data 602 is transmitted to each of the contacts of User A as soon as the mood message is created or changed (i.e. it is pushed to the contacts immediately). In a further alternative embodiment, the multimedia mood message data 602 is pushed to the contacts at periodic intervals.
[0076] As User B 114 is a contact of User A, the multimedia mood message data 602 is provided to the client 124 of User B over the P2P system. The multimedia mood message data must be processed by the client 124 before the mood message is displayed to User B. The client 124 reads the mood message data 602 and analyses the media object 604 . For example, the client 124 will read the media type field 608 to determine the type of media referred to in the media object 604 (e.g. a video in this example). The client will also extract the thumbnail 618 so that it may be displayed in the UI of the client 124 next to the contact entry for User A. The media URI 616 is extracted and hyperlinked to the thumbnail image in the client UI. The media title 610 is also read for display in the client UI.
[0077] The result of the multimedia mood message data 602 being displayed in User B's client is illustrated in FIG. 7 . FIG. 7 shows the client UI 700 for User B with the contact for User A 702 expanded. The contact for User A 702 shows User A's name 704 , presence state 706 , avatar 708 , and buttons for initiating an IM chat 710 or voice call 712 with User A. Next to the contact 702 for User A is displayed a thumbnail image 714 of the video chosen by User A for his mood message. The thumbnail image 714 is extracted from the thumbnail field 618 of the multimedia mood message data 602 . The thumbnail image 714 also has a play button 716 overlaid on it, to indicate to the user that the video can be played by clicking on the thumbnail image 714 . If User B uses his pointing device to place a pointer over the thumbnail image 714 , then the text comment provided with the video (if any) is displayed. Alternatively, if no text comment has been provided, the title of the video is displayed.
[0078] As mentioned previously, a problem with User A 102 sharing multimedia content in a mood message is that it relies on User B 114 actively selecting to view the video in the mood message (by activating the play button 716 ). To counter this, a system and method is utilised whereby the video from User A's mood message is automatically displayed to a contact of User A (e.g. User B) whenever that contact attempts to establish a call with User A. More specifically, during the time between the call being initiated by the contact and the time at which User A answers the call, the video is played to the contact. This technique can be referred to as a “video ringback”.
[0079] Reference is now made to FIGS. 8A to 8D , which illustrate the process by which a video ringback is displayed to User B 114 when he is calling User A 102 . In this example, User A 102 has created a video mood message, and the mood message data has been passed to User B 114 , such that the video mood message is displayed in User B's client UI 700 , next to User A's name (as illustrated in FIG. 7 ). User B 114 initiates a call with User A 102 , by selecting the call button 712 in the client UI 700 (or alternatively using call button 718 ). The client 124 of User B 114 then attempts to establish a connection with the client 110 of User A 102 over the network 106 in order to set up a voice call.
[0080] In addition, the client 124 of User B 114 also detects that the contact being called (User A in this example) has a video mood message. In response to detecting this, the client attempts to start a video ringback. The client 124 reads the mood message data 602 , and specifically the media URI 616 . The client uses the media URI 616 to contact the location at the content provider ( 128 , 130 , 132 ) where the video is stored, and initiate streaming of the video to the client 124 of User B 114 .
[0081] The UI 700 of the client 124 of User B at the beginning of this process is shown illustrated in FIG. 8A . Compared to FIG. 7 , the UI shown in FIG. 8A now displays a call tab 802 (indicating the name of the person being called) instead of the contact list tab. Shown in the call tab 802 is a contact card 804 for the user being called (User A 102 ). The contact card 804 comprises the name of the callee 806 , their presence state 808 and avatar 810 , as well as further control buttons 812 that are out of the scope of this description.
[0082] Below the contact card is an embedded video player 814 . In FIG. 8A , the client 124 is loading the video from User A's mood message (using the media URI 616 ), and this is reflected in the image displayed in the embedded video player 814 . The status of the call to User A 102 is shown at 816 . In FIG. 8A , User A has not yet answered the call, and the status is “connecting”.
[0083] When the video located at the media URI 616 has been loaded, the video is played back to User B 114 , whilst he is waiting for User A 102 to answer the call. This is illustrated in FIG. 8B , which shows the client UI 700 as in FIG. 8A , except that the video from User A's mood message is now being played to User B in the embedded video player 814 .
[0084] Preferably, the client 124 of User B 114 initially plays an audible ringing tone to User B 114 whilst the video begins to be played back, in order to indicate to the user that the call is waiting to be answered. After the ringing tone has been played for a predetermined period of time (e.g. 3 seconds), the ringing tone is faded out, and the sound that accompanies the video is faded in.
[0085] When User A 102 answers the call, the video playback is muted, so that the sound of the video is not playing over the top of User A's voice. This is shown in FIG. 8C . The embedded video player 814 is showing a message 818 over the top of the video to indicate to User B 114 that the video has been muted. The playback of the video (minus the sound) continues behind the message 818 . The status 816 now shows that the call is connected, and displays the duration of the call.
[0086] If User B 114 wishes to unmute the video, so that he can continue to hear the sound of the video even after User A has answered the call, then this can be achieved by User B moving the cursor with the pointing device over the embedded video player in order to display a control bar 820 , as shown in FIG. 8D . More detail on the operation of the control bar 820 is described below with reference to FIG. 10A to 10C . The control bar 820 comprises a volume control button 822 , and activation of this button by User B 114 allows the volume to be restored, so that the sound of the video can be heard.
[0087] In alternative embodiments, the client pauses the content responsive to User A answering the call, rather than the content being muted. In this case, the message 818 displayed over the video in FIG. 8C indicates that the video is paused. The playback of the video can be resumed by the user by selecting a play button on the control bar 820 , as described in more detail with reference to FIG. 10A to 10C , below.
[0088] Therefore, the above-described process ensures that a video shared by User A 102 in his mood message is seen by his contacts, due to it being played automatically to them during a time when otherwise only a normal ringing tone would be heard.
[0089] When User B 114 first makes a call to User A 102 , he may be surprised by the video that begins playing automatically. It is therefore preferable to provide a way for the video to be rapidly paused by the user, if it is inappropriate for it to be played. This is illustrated in FIGS. 9A and 9B . When the video is being played to User B 114 whilst waiting for User A 102 to answer the call, if the cursor is brought anywhere over the embedded video player 814 then a message 824 is displayed to User B 114 indicating that the video can be paused by clicking on the playing video. This therefore gives the user a large region to click on with the pointing device, allowing the user to rapidly pause the video if required.
[0090] The result of the user clicking on the video with the pointing device is shown in FIG. 9B . The playback of the video has been paused, which is indicated to the user with message 826 . The control bar 820 is displayed to the user to allow him to resume playback if desired.
[0091] Reference is now made to FIG. 10A to 10C , which illustrate in more detail the functions of the control bar 820 . At any point after the video has been initially paused by clicking on the video (as described above with reference to FIGS. 9A and 9B ) or during a call, if the cursor is placed over the embedded video player 814 , then the control bar 820 is displayed at the bottom of the video.
[0092] The control bar 820 comprises a play/pause button 828 , a progress bar 830 , a volume button 822 and a menu button 832 . The play/pause button toggles between playing and pausing the video, and the symbol shown on the button changes accordingly, depending on the current state of the video (i.e. whether it is currently playing or paused). When the volume button 822 is activated, a volume slider is shown to allow the user to change the volume, or the sound can be muted. When the video is either paused, muted, or both, a message is shown overlaid on the video. FIG. 10B shows an example of this for the case where the video is both paused and muted, as reflected in message 834 .
[0093] FIG. 10C shows the options that are presented to User B 114 when the menu button 832 is selected. The first option is a “chat about this” 836 option. If the “chat about this” option 836 is activated, a dialogue box is opened that displays to User B a list of all his contacts. User B can select from this list the contacts with which he wishes to initiate an IM chat conversation. When he has selected the contacts, an IM chat session is established with these contacts, and the video from the embedded video player 814 is automatically inserted into the beginning of the IM chat conversation.
[0094] The second option is a “add to my mood” option 838 . If this option is selected, then the video that is shown in the embedded video player 814 (i.e. video from User A's mood message) is added to User B's mood message.
[0095] The third option is a “more info” option 840 . The “more info” option provides the user with more information regarding the video. Preferably, this is provided by the client 124 executing a web browser and navigating to a webpage of the content provider, the address of which was provided in the content provider URI 614 field of the mood message data 602 .
[0096] The fourth option is an “auto-play video” option 842 . Preferably, this option is enabled by default. When enabled, this option allows videos that are in a callee's mood message to be played automatically when a call is made to the callee (as described with reference to FIGS. 8A to 8D ). If this option is disabled, then the video is not played automatically on making the call, but instead a static frame of the video is shown with the control bar 820 below it, allowing the video to be played if desired. Furthermore, the client 124 preferably monitors the user behaviour, so that if the user pauses the ringback video a predetermined number of times consecutively, then the client will pop-up a message to the user, suggesting that the “auto-play video” option be disabled.
[0097] In further embodiments, the menu button 832 can also present a fifth option (not shown in FIG. 10C ). The fifth option allows the user to report problematic content to the content provider. If this option is selected, then a web browser program is executed on the user's terminal, which navigates to a webpage comprising a form which the user can fill out to report a problem with the content (e.g. copyrighted material, unsuitable subject-matter, etc). The information entered in this form is provided to the content provider, who can choose to remove the video in response thereto.
[0098] Reference is now made to FIG. 11 , which shows the client UI 700 when the video has completed playing. Two buttons are displayed to the user, overlaid over the video. The first is a “play again” button 844 that allows the user to playback the video from the start. Activation of the play/pause button 828 also has the same effect. The second button is a “chat about this” button 846 , which has the same function as selecting the “chat about this” option 836 from the menu button 832 as described above. Playback of the video to the user has requirements both in terms of processing power (i.e. CPU resources) and on the network connection of the user's terminal (i.e. bandwidth resources). As a result of this, it can sometimes be found that playback of the video after the called user has answered can affect the quality of the call. The client monitors the CPU usage, bandwidth, and/or call quality, and if it is determined that the video is detrimentally affecting these aspects, then the video playback is stopped. This is reported to the user as shown in FIG. 12 , using message 848 .
[0099] Furthermore, during a call, User B 114 may need to use controls related to the voice call, such as adjusting sound settings, placing the call on hold or muting his microphone. The controls require space on the call tab 802 . If any of these controls are activated and there is insufficient room to accommodate the controls, then the video is paused and reduced in size as shown in FIG. 13 . In this example, the user has opened an audio settings panel 850 , and this has resulted in the size of the video being reduced accordingly.
[0100] If the client 124 is unable to play the video from the media URI 616 provided by User A's mood message (e.g. due to the video being removed, or a network failure), then an error message is shown to the user. This is illustrated in FIG. 14 , where the embedded video player 814 shows a “video unavailable” message.
[0101] In preferred embodiments, before the video is displayed to User B, the client 124 will perform a check to ensure that the media URI 616 included in the mood message does not relate to a video that has been “blacklisted”. A video may be blacklisted if, for example, it is found to infringe copyright or contains offensive material. Referring to FIG. 1 , a blacklist advertiser 134 is shown connected to network 106 , and connected to the blacklist advertiser is a blacklist database 136 . Note that the blacklist database can be a centralised database or a distributed P2P database. If any videos are “blacklisted”, then the address (i.e. media URI) of the video is stored in the blacklist DB 136 . When a user attempts to access a given media URI, the client first sends a message to the blacklist advertiser 134 containing the media URI. The blacklist advertiser 134 compares the media URI sent by the client with those listed in the blacklist DB 136 .
[0102] If the media URI matches one listed in the blacklist DB 136 , then blacklist advertiser 134 sends a message to the client indicating that the video has been blacklisted. In response to this the client does not display the media, but instead displays a notification of the problem. Conversely, if the media URI 616 is not listed in the blacklist DB 136 , then the blacklist advertiser 134 sends a message to indicate to the client that the media can be displayed to the user.
[0103] In preferred embodiments, in addition to the video in User A's mood message being played to User B when User B is waiting for User A to answer a call, if User B also has a video mood message, then this video can be displayed to User A as part of the incoming call alert. In other words, if both the users have video mood messages, then the video of User A is displayed to User B, and the video of User B is displayed to User A. This is illustrated with reference to FIG. 15 .
[0104] FIG. 15 shows the client UI 200 for User A 102 (as shown in FIG. 2 ). However, in contrast to FIG. 2 , a call is being made from User B 114 to User A 102 . This causes a call tab 1502 to be shown (rather than the contacts tab 206 of FIG. 2 ). The call tab comprises the contact card 1504 of the user calling User A, which displays the callers name 1506 , presence state 1510 and avatar 1510 . A status field 1512 indicates that this is an incoming call from User B. An embedded video player 1514 displays the video from User B's mood message.
[0105] The video in the embedded video player 1514 is displayed by the client 110 using the media URI from User B's mood message to stream the video from the content provider ( 128 , 130 , 132 ), in the same manner as described above with reference to FIGS. 8A to 8D . When User A 102 answers the call, the video displayed to User A in the embedded video player 1514 is muted (in a similar manner to FIG. 8C ) but the video continues to play.
[0106] User A has the same controls over the video shown when there is an incoming call as described above for User B when placing a call. In particular, the same control bar and menu options are available as described above with reference to FIG. 10A to 10C .
[0107] Therefore, the above described system and method ensures that multimedia content shared by users is shown to their contacts in two ways. Firstly, a caller is shown the multimedia content of the called user when he is waiting for the called user to answer the call. Secondly, the called user is shown the multimedia content of the caller when the incoming call is displayed in the client.
[0108] While this invention has been particularly shown and described with reference to preferred embodiments, it will be understood to those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as defined by the appendant claims. | A method of accessing content at a user terminal connected to a communication network and executing a communication client. The method comprises: the client displaying a list of contacts associated with a user of the client; the client retrieving a message from the communication network, wherein the message is related to a further user represented by one of the contacts displayed in the list of contacts, the message comprising a reference to content stored in a storage means accessible by the communication network; the client initiating a call to the further user over the communication network responsive to a user of the client selecting the one of the contacts in the list of contacts; and responsive to initiating the call, the client establishing communication with the storage means using the reference, accessing the content and displaying the content at the user terminal. | 7 |
CROSS-REFERENCE
[0001] This application is the U.S. National Stage patent application of International Application No. PCT/US2007/79086, filed on Sep. 20, 2007, which claims the benefit under 35 U.S.C. Section 119 (e) of U.S. Provisional Patent Application Ser. No. 60/845,885 filed on Sep. 20, 2006 entitled “New Method for the Detection of Chromosomal Inversions” by Susan M. Bailey et al., and of Provisional Patent Application Ser. No. 60/873,149 filed on Dec. 6, 2006 entitled “New Method for the Detection of Chromosomal Inversions (2)” by Susan M. Bailey et al., which applications are hereby incorporated by reference herein for all that they disclose and teach.
FIELD OF THE INVENTION
[0002] The present invention relates generally to detection of chromosomal aberrations and, more particularly, to chromosome-specific chromatid painting for detection of inversions.
BACKGROUND OF THE INVENTION
[0003] Analysis of cancer cells has led to the discovery of more than 500 tumor-specific chromosome aberrations. Detailed analysis of the breakpoints involved in these structural chromosomal rearrangements has been instrumental in the discovery of many cancer-related genes. Of all possible types of structural chromosome anomalies, inversions, which represent a reversal of orientation of a DNA segment within a chromosome, are found comparatively rarely among the known tumor-specific aberrations. Inversions can have genetic effects similar to the easily detected translocations between different chromosomes seen in cancer. Both can result in effects such as disrupting regulatory sequences that control gene expression or creating genetic rearrangements like gene fusions. Inversions form through the same mechanism as translocations, the misrepair of DNA double-strand breaks. Thus, it might be expected that translocations and inversions should be found in comparable numbers. One possible explanation for the discrepancy is that standard karyotype analyses are relatively insensitive to the detection of inversions and consequently have largely failed to find many tumor-specific chromosome aberrations of this type.
[0004] New approaches to measuring incorrect rejoining of radiation-induced DNA double-strand breaks in human cells has led to the conclusion that radiation produces at least ten times the number of chromosomal rearrangements than can now be observed cytogenetically, the vast majority of which are intra-chromosomal (that is, small interstitial deletions and inversions). To the extent that radiation is representative of other mechanisms of creating inversions, it appears likely that their significance has been underestimated and underappreciated in many diseases in addition to cancer.
[0005] In addition to cancer cytogenetics (the study of chromosomes and how changes in chromosome structure and number can lead to the loss of regulation and control of cell proliferation, and orderly differentiation of cells in tissues), chromosome analysis is widely used in prenatal screening as well as the diagnosis of congenital abnormalities, learning difficulties, impaired fertility, and sexual development problems.
[0006] The two methods frequently used for detection of gross cytogenetic aberrations such as translocations are whole chromosome painting by fluorescence in situ hybridization (FISH), and G- or R-banding. The sequence does not have to be known for either technique. Both chromatids of a chromosome are indiscriminately targeted by these techniques. Whole-chromosome-specific-FISH painting consists of using DNA, highly enriched for sequences unique to a particular chromosome, labeled with a reporter molecule, such as a fluorochrome, and hybridizing it to metaphase chromosome spreads. At the same time, hybridization of any labeled repetitive sequences (common to all chromosomes) that may be present are blocked by competitive hybridization to unlabeled repetitive DNA. In this manner, stable aberrations such as translocations can be observed. FISH and the combinatorial derivatives of FISH, such as Spectral Karyotyping, are generally limited by their ability to detect only breaks, interchanges and numerical aberrations. Giemsa-banding, also known as G-banding, or similar approaches such as R- or Q-banding, is suitable only for detecting changes in banding patterns caused by chromosome inversions when the inversion involves a segment of the chromosome large enough to produce a recognizable change in the pattern of banding. While it may be possible with difficulty to detect an inversion with breakpoints near the midpoints of adjacent dark and light bands, many larger disruptions involving regions containing more than two or three bands might not always produce a recognizable change in these light/dark patterns of banding. Band lengths of fully condensed human mitotic chromosomes average ˜10 7 base pairs.
[0007] A chromatid is a replicated chromosome consisting of two identical parts that will be divided equally between daughter cells at mitoses when two new cells are created from one as cell populations grow. At mitosis, then, each chromosome consists of two identical chromatids and each of these consists of a linear, double-stranded DNA molecule. A strand of DNA is basically a phosphate deoxyribose polymer, each with one of four purine or pyrimidine base residues (A, T, G, or C) attached. Beginning with the first sugar there is a phosphate group at the 5′ position and a hydroxyl group at the 3′ position. This hydroxyl group is in turn joined to the next sugar at the 5′ position and the alternating chain continues until the other end of the linear strand where there is a 3′ hydroxyl group. The strands are associated by hydrogen bonding and are thus not covalently joined. The hydrogen bonding between the two strands occurs only between certain bases; that is, A with T and C with G. This results in what is known as complementary base pairing between the two opposite strands.
[0008] The genome of a cell must be replicated prior to the process of cell division in order to provide the same genetic information contained in the parent cell to each of the two new daughter cells. Before this replication, each chromosome consists of one double stranded DNA molecule, with one strand complementary to the other. During replication the complementary single strands of the chromosome are effectively separated, with each one becoming the basic part of a new chromatid. If one of these parental strands is oriented in the 5′→3′ direction along its length with respect to some arbitrary reference direction, then the 5′→3′ direction of the complementary strand will be oriented in the opposite direction. After replication the new synthesized strands each will likewise be complementary to its respective parental strand. The 5′→3′ direction of single strands within a double stranded DNA molecule is sometimes referred to as the polarity of the strand.
[0009] An inversion is an abnormality in chromosome structure that can result from, effectively, two double-stranded breaks occurring at different points along a portion of the chromosome, and rather than the breaks becoming rejoined in their original condition by cellular DNA repair processes, they occasionally rejoin incorrectly in such a way that this interstitial portion of the chromosome becomes effectively rotated through 180° after a “misrejoining” among the broken ends. Importantly, this misrejoining must occur in such a way as to maintain the same 5′→3′ polarity of the strands of the chromosome and that of the inverted segment. While the backbone polarity is maintained, the DNA sequence of the nitrogenous bases within the segment is reversed.
[0010] Chromosome ‘paints’ are mixtures of fluorescent DNA probes, or other types of molecular markers, highly enriched in sequences unique to a particular chromosome that allow a specific chromosome to be identified based on accepted cytogenetic practices that render the chromosome visible using a fluorescent microscope. Such probes can be purchased from a number of vendors.
[0011] The first complete draft of the human genome was made in 2000, and refinements have been made to the database since then. The GenBank database is made available to the public by the National Center for Biotechnology Information (NCBI) of the National Library of Medicine of the National Institutes of Health. Most of the DNA sequences have been ordered into contiguous sequences called contigs.
[0012] The CO-FISH technique, developed in the 1990s, permits fluorescent probes to be specifically targeted to sites on either chromatid, but not both. To date, this technique has been used almost entirely for detection of highly repetitive DNA which consists of a series of DNA sequences repeated over and over again, up to thousands of times and which contains few, if any, genes. Such regions are commonly found at sites on a chromosome involved in the mechanics of genome partitioning such as centromeres and telomeres. In “Strand-Specific Fluorescence in situ Hybridization: The CO-FISH Family” by S. M. Bailey et al., Cytogenet. Genome Res. 107: 11-14 (2004), chromosome organization is studied using strand-specific FISH (fluorescent or fluorescence in situ hybridization) [CO-FISH; Chromosome Orientation-FISH] which involves removal of newly replicated strands from the DNA of metaphase (mitotic) chromosomes, resulting in single-stranded target DNA. Each newly replicated double helix contains one parental DNA strand plus a newly synthesized strand, and it is this newly synthesized strand that is removed. When labeled single-stranded probes are hybridized to such targets, the resulting strand-specific hybridization is capable of providing previously unattainable cytogenetic information. Hybridization is a process in which two complementary nucleic acid sequences anneal by base pairing. In the context of FISH, “in situ” refers to hybridization of a nucleic acid sequence probe to the DNA of chromosomes, where the chromosomes are in cells that are attached to a glass microscope slide.
[0013] For example, it is known that mammalian telomeric DNA consists of tandem repeats of the (TTAGGG) sequence, oriented 5′ to 3′ towards the termini of all vertebrate chromosomes. Thus, CO-FISH with a suitable telomere probe reveals the absolute 5′ to 3′ orientation of DNA sequences relative to the chromosome's pter →qter direction (end of p or short arm of the chromosome to the end of the q or long arm of the chromosome).
[0014] The removal of the newly replicated strands using the CO-FISH procedure leaves the original (parental) strands largely intact. Thus, for the purposes of subsequent hybridization reactions, the two sister chromatids of a chromosome are rendered single stranded, and complementary to one another. The ability of CO-FISH to restrict hybridization of single-stranded probes to only one of the two sister chromatids means that it can also be used for inversion detection. Because an inversion reverses the orientation of the DNA sequences within the inversion region, it becomes visible as a jump or switch in probe signal from one chromatid to its sister chromatid. Such a switch can readily be detected when compared to a reference probe outside of the inverted region.
SUMMARY OF THE INVENTION
[0015] Therefore, it is an object of the present invention to provide a sensitive method for the detection of chromosomal inversions.
[0016] Still another object of the invention is to provide a probe kit for the sensitive detection of chromosomal inversions.
[0017] Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
[0018] To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the method for detecting inversions in a selected mitotic chromosome, hereof, includes the steps of: generating a pair of single-stranded sister chromatids from said selected chromosome, each sister chromatid having a length of DNA and a series of target DNA sequences that span a portion of the length of the DNA of the chromatid; generating a plurality of non-repetitive probes, wherein each of the probes is single-stranded, unique and identical to at least a portion of a target DNA sequence, each of the probes having at least one label, thereby permitting detection thereof; hybridizing the probes to the sister chromatids; and detecting the hybridized probes; whereby if no inversion exists, all of the probes will hybridize to one of the sister chromatids, and whereby if an inversion exists, at least one of the probes will hybridize to the other sister chromatid at the same location as the inversion.
[0019] In another aspect of the present invention and in accordance with its objects and purposes, the method for detecting inversions in a selected mitotic chromosome, hereof, includes the steps of: generating a pair of single-stranded sister chromatids from said selected chromosome, each sister chromatid having a length of DNA and a series of target DNA sequences that span a portion of the length of the DNA of the chromatid; generating a plurality of non-repetitive probes, wherein each of the probes is single-stranded, unique and complementary to at least a portion of a target DNA sequence, each of the probes having at least one label, thereby permitting detection thereof; hybridizing the probes to the sister chromatids; and detecting the hybridized probes; whereby if no inversion exists, all of the probes will hybridize to one of the sister chromatids, and whereby if an inversion exists, at least one of the probes will hybridize to the other sister chromatid at the same location as the inversion.
[0020] In yet another aspect of the present invention and in accordance with its objects and purposes, the kit for detecting inversions in a selected mitotic chromosome, hereof, includes a plurality of non-repetitive probes, wherein each of the probes in the plurality of probes is single-stranded, unique and identical to at least a portion of a target DNA sequence of a chromatid of the chromosome, each of the probes having at least one label, thereby permitting detection thereof.
[0021] In still another aspect of the present invention and in accordance with its objects and purposes, the kit for detecting inversions in a selected mitotic chromosome, hereof, includes a plurality of non-repetitive probes, wherein each of the probes in the plurality of probes is single-stranded, unique and complementary to at least a portion of a target DNA sequence of a chromatid of the chromosome, each of the probes having at least one label, thereby permitting detection thereof.
[0022] Benefits and advantages of the present invention include, but are not limited to, providing a sensitive method for detecting chromosomal inversions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated in and form a part of the specification, illustrate an embodiment of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
[0024] FIG. 1A is a schematic representation of an embodiment of the present method where one DNA strand of each chromatid in a chromosome is removed using the CO-FISH or another procedure, and one of the two resulting single-stranded chromatids is painted, while FIG. 1B is a schematic representation illustrating the same procedure as described in FIG. 1A hereof, but for a chromosome having an inversion.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Briefly, the present invention includes a method for detecting inversions in chromosomes using hybridizing probes for painting one chromatid in order to refine the process of chromosome painting to generate additional information; that is, instead of painting an entire chromosome, probes are developed for painting either chromatid.
[0026] If the 5′→3′ base ordering of either of the sister chromatids is known, the DNA sequence for the sister chromatid can be determined since the sequences are complementary and therefore different in terms of annealing (hydrogen bonding process, also known as base pairing) to fluorescent or other marker probes. The paint on one chromatid technique of the present invention uses CO-FISH (See, e.g., S. M. Bailey et al, supra.) to destroy newly replicated strands in both chromatids. It differs from existing CO-FISH technology in that its object is to hybridize multiple probes to a chromatid so as to give the visual impression upon detection of having painted a large portion of the entire chromatid. This may be accomplished by selecting unique DNA sequences, such as are often found in the exons of genes, for use as probes. Genome databases provide large segments of contiguous DNA sequences that can be investigated for suitability as directional targets/probes, and provide a mechanism for determining orientation relative to other targets/probes and for checking these sequences for uniqueness (occurring once in the genome) by performing what is known as a blast n (blast) search.
[0027] An embodiment of the method of the present invention is performed as follows:
[0028] (1) Large, contiguous DNA sequences (contigs) that are unique to specific chosen chromosomes and therefore to the chromatids to be used as targets from which probes are designed, are identified using genomic databases.
[0029] (2) These sequences are checked for uniqueness (presence only on one specific chromatid), by performing a blast search, which defines the nucleotide sequence database. Both the actual sequences as input, and their complements are compared to the entire genomic database point-for-point, base-by-base, and matching sequences are returned in order of their percentage homology, from highest to lowest; that is, completely-matched sequences located on alternate chromosomes in the same genome are identified and eliminated.
[0030] (3) Analysis of database to determine adequacy of coverage which is defined as the ability of a fluorescent probe set to completely cover a specified chromatid from end to end. Full (100%) coverage would be hybridization to every base, but is clearly not useful for the present method because there are many sequences that are not unique in a chromosome. It is believed by the inventors that the coverage of chromosome-specific unique sequences will allow coverage of unique target sequences where detectable probes are spaced at 1 Mbp intervals along the length of the chromatids, excluding large repetitive regions such as centromeres and telomeres. Coverage of gene-rich regions may be increased in other embodiments of the invention. (4) Synthesizing and labeling suitable probes, as will be described in detail in the EXAMPLES.
[0031] (5) Generating single-stranded sister chromatids in accordance with CO-FISH or another suitable procedure (See, e.g., S. M. Bailey et al., supra, and U.S. Pat. No. 6,107,030 for “Determining Orientation And Direction Of DNA Sequences” which issued to Edwin H. Goodwin and Julianne Meyne on Aug. 22, 2000, the teachings of which patent are hereby incorporated by reference herein.).
[0032] (6) Hybridizing the single-stranded probes to the single-stranded chromatids, as will be described in the EXAMPLES.
[0033] (7) Detecting the single-stranded fluorescent probes hybridized to one chromatid and not the other. Detection of such probes hybridized to chromosome 19p has been achieved. Although high background was observed, probe hybridization appears to be specific.
[0034] (8) Developing chromatid paints (mixtures of probes complementary to the same chromatid), as will be described in the EXAMPLES.
[0035] Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. In the FIGURE, similar structure will be identified using identical reference characters. A metaphase chromosome consists of 2 linear, double-stranded DNA molecules. This form of the DNA is a packaging mechanism that is used to distribute two identical copies of the DNA molecule during cell division. Turning now to FIG. 1A , a schematic representation of one embodiment of the present method is illustrated. Chromosome (i) shows the untouched chromosome after replication, while chromosome (ii) illustrates the newly replicated DNA strand of each chromatid in the chromosome having been removed using CO-FISH or another procedure, leaving the separated parental chromatid strands oriented in opposite directions.
[0036] Chromosome (iii) shows the resulting chromatids after having been exposed to the directional probes of the present invention described hereinbelow, and illustrates the situation where there are no detectable inversions present since upon investigation with a fluorescent microscope in the case of fluorescent probes having been used, no probes appear on the second chromatid.
[0037] FIG. 1B is a schematic representation illustrating the same procedure as described in FIG. 1A hereof, but for a chromosome having an inversion. It should be mentioned that the identical chromatid probe mixture would be used to generate the results in both FIGS. 1A and 1B . As may be observed from FIG. 1B , the molecules are not identical in the newly replicated DNA strands; that is, there is an inversion present which is not observed in chromosomes (i) and (ii) until the chromatids are painted using the directional probes of the present invention and examined using a fluorescent microscope, as an example, when fluorescent probes have been used [chromosome (iii)]. The inverted portion of the first chromatid is not painted, while only the complementary portion appears on the second chromatid as a painted section and is portrayed in the opposite (inverted orientation) by the arrowheads.
[0038] Synthetic oligomers (oligonucleotides, or oligos), are widely used as probes in molecular biology and cytogenetics. In cytogenetic research, a probe allows the chromosomal locations of DNA target sequences to be determined. An oligomer is a single strand of DNA, RNA or PNA (peptide nucleic acid). To generate probes, a label must be attached to the oligomer. For use in chromosome analysis, the label is often a fluorescent molecule in order that the probe can be visualized using fluorescence microscopy. A common labeling procedure utilizes an enzyme called terminal deoxynucleotidal transferase, also known as terminal transferase. This enzyme is a template-independent DNA polymerase that adds deoxynucleotides to the 3′ end of DNA oligomers. To label a probe, a polymerization reaction is prepared with terminal transferase, the oligomer, and a deoxynucleotide triphosphate that has a fluorophore (fluorescent molecule) coupled to it. During the polymerization reaction, terminal transferase adds one or more fluorescently labeled deoxynucleotides to the 3′ end of the oligomer.
[0039] Oligos can also be labeled directly during commercial synthesis on either their 5′ or 3′ ends with fluorescent molecules, fluorescent particles or molecules such as biotin which are readily detectable using secondary reagents such as avidin to which a fluorescent molecule has been attached.
[0040] Having generally described the invention, the following EXAMPLES provide additional detail:
Example 1
Selection of Sequences
[0041] As stated hereinabove, identification of large contiguous DNA sequences (contigs) that are unique to specific chromosomes to be used as targets is achieved by database analysis of publicly available genomic DNA sequences. Within these contigs, shorter sequences ˜40-50 bases long were selected for use as probes and then checked for uniqueness to one specific chromatid by performing a blast search. Sequences 20-90 bases long are anticipated to be useful in the practice of the present invention. Commercially available software programs such as Array Designer are linked to this database function.
[0042] The database is analyzed to determine the ability of a fluorescent probe set to cover a specified chromatid. It is believed by the inventors that coverage of chromosome-specific unique sequences using detectable probes spaced at 1 Mbp intervals along the length of the chromatids, excluding large repetitive regions such as centromeres and telomeres should be adequate to detect a large number of heretofore undetectable inversions. Increased coverage is expected to improve detection.
Example 2
Preparation of Probes
1. Generating Sequence Specific DNA:
[0043] (a) By PCR:
[0044] Sequence-specific genomic DNA suitable for locus-specific probes was obtained by amplifying specific targets in the genome using PCR. It should be pointed out that DNA complementary to the specific targets may also be used. The size of the PCR product was specified from 7.5 to 9.5 kbp. Primer pairs separated by the desired target size were generated by using 10 kbp DNA sequence segments at approximately 1 Mbp intervals. As primers were identified they were verified using blast (GenBank) to assure that the primer sequence was unique to chromosome 19p. Primer sequences found to anneal to additional human chromosomes were excluded from further consideration. If no primer pairs resulted from a 10 kbp sequence, then the next contiguous 10 kbp was screened.
[0045] Microgram quantities of pure genomic DNA were prepared from normal human fibroblasts using Qiagen's DNAeasy columns according to manufacturer's recommendations. Polymerase Chain Reaction (PCR) was performed using Stratagene EXL polymerase. The PCR product was examined by gel electrophoresis, and if multiple bands were observed PCR was repeated with upward annealing temperature adjustments until a single band was obtained. PCR products of the expected size were routinely obtained using EXL polymerase, with several micrograms of PCR product being routinely produced. The PCR products are the size predicted by genome analysis.
[0046] (b) By Oligo Tiling and Commercial Synthesis:
[0047] Array designer 4 software from PREMIER Biosoft International was used to develop a tiled array covering exon 3 of the mucin gene located on chromosome 19p. For the present purpose, a tiled array is defined as a series of ordered, short, individual DNA sequences that are complementary to a corresponding larger contiguous target DNA sequence. The program provides a number of variable parameters. The exon DNA sequence was copied from the NCBI database, pasted into the software, and queried to produce a tiled array. The array consisted of a series of non-overlapping sequences, each 48-52 nucleotides long that were separated by 5 intervening bases. The software checked all sequences for homology elsewhere in the genome using a built in blast search function. 189 oligos were prepared by a commercial vendor. The probe regions corresponded to tiled sequences identified by Array Designer, and were chosen to cover about 10 kbp.
2. Labeling Probes:
[0048] (a) PCR:
[0049] Four of the chromosome 19-specific PCR products were chosen for linear DNA amplification. These were at 1 Mbp intervals starting at 1 Mbp from the end of the 19p chromosome. Approximately 0.5 μg PCR DNA was used for the linear DNA amplification template. The templates that will be used to cerate probes using the linear amplification process are the double-stranded PCR products that were chosen from the genomic database to be spaced at 1 Mbp intervals along the chromosome. These four products, although separated by great distances on the chromosomes can be oriented 5′→3′ based on the information from the genome database that they are all in the same contig. In order to generate a probe to one parental strand and not the other, primers were chosen that were from the same parental strand. In actual practice this was done during primer design, those primers designated as forward primers were all on the same strand with respect to a given contig sequence, and reverse primers were all on the complementary strand. Only single primers were used in linear DNA amplification reactions to produce labeled single-stranded DNA probes. The DNA amplification conditions were virtually identical to PCR conditions using genomic DNA in which the PCR template was synthesized except that the reactions now contained AlexaFluor 594-5-dUTP in an approximately 1:4 molar ratio with dTTP. In side-by-side comparisons of linear DNA amplification reactions with or without labeled nucleotides, similar bands were obtained on electrophoretic gels and similar amounts were determined spectrophometrically. The yield of these reactions has reproducibly been several micrograms. It should be mentioned that other labeled nucleotides may also be used to prepare the probes of the present invention.
[0050] An 8.5 kbp PCR product was used as a template for linear DNA amplification. Only single primers were used. For FISH, probe lengths of 300-500 bases have been shown to produce better results than longer or shorter probes. Commercially available Hae III is a restriction endonuclease having a four by recognition sequence that on average cuts once every 256 bp, and has been reported to digest both single-stranded and double stranded DNA (See, e.g., Reference 1.). It has been found that Hae III not only cuts single-stranded DNA, but reduces it to the desired size for FISH.
[0051] (b) Using Terminal Transferase:
[0052] This procedure labels 35 picomoles of single-stranded oligomer using the enzyme terminal transferase to add one or more fluorescent nucleotides to the 3′ ends of the oligomer molecules. The oligomer typically is single-stranded DNA that has been made synthetically such that it has a sequence complementary to the chromosomal sequence we wish to detect. An example of a labeling reaction is as follows: The dry as purchased oligomer was dissolved in distilled water. A reaction mixture is prepared consisting of distilled water sufficient to give a final volume of 20 microliters, concentrated reaction buffer to give a 1× final concentration, and 35 pico moles of oligomer. To this reaction mixture are added 2.5 mM CoCl 2 , 0.1 mM fluorescently labeled nucleotide triphosphate, and 50 units of terminal transferase, or other suitable enzyme, where the amounts given are final concentrations and can be adjusted to give satisfactory results. The reaction mixture is incubated at 37° C. for a period of time typically 7 to 9 min. 25 mM of EDTA is added to stop the reaction immediately after 7-9 min. of incubation, and the volume is adjusted to 100 microliters by adding distilled water.
Example 3
CO-FISH Using Probes Generated by PCR
[0053] CO-FISH has been described in detail previously, and was used here with some modification. Primary human dermal fibroblasts (catalog #C-004-5C, sold by Cascade Biologics) were subcultured into medium containing 5′-bromo-2′-deoxyuridine (Sigma) at a final concentration of 10 −5 M and collected ˜24 hours later (one cell cycle). Colcemid (0.1 μg/ml; Gibco) was added for the final four hours to accumulate mitotic cells. Cultures were trypsinized (Trypsin-EDTA; Gibco) and cells suspended in 75 mM KCl hypotonic solution at 37° C. for 15 min. before fixation in fresh 3:1 methanol/acetic acid. Fixed cells were dropped onto cold, wet glass microscope slides and allowed to dry slowly in a humid environment.
[0054] Prior to hybridization of the labeled, single-stranded 19p oligomer probe cocktails, slides were aged and treated with 0.5 mg/ml RNase A for 10 min at 37° C. [5], then stained with 0.5 μg/ml Hoechst 33258 (Sigma) in 2×SSC (saline sodium citrate; 1×SSC is 0.15 M NaCl, 0.015 M sodium citrate) for 15 min. at room temperature. Slides were then exposed to 365-nm UV light generated by a Stratalinker 1800 UV irradiator for 25-30 min. Enzymatic digestion of the BrdU-substituted DNA strands with 3 U/μl (U?) of Exonuclease III (Promega) in buffer supplied by the manufacturer (50 mM Tris-HCl, 5 mM MgCl 2 , and 5 mM dithiothreitol, pH 8.0) was allowed to proceed for 10 min at room temperature. An additional denaturation in 70% formamide, 2×SSC at 70° C. for various times was performed, followed by dehydration in a cold ethanol series (70%, 85%, 100%).
Example 4
Hybridization
[0055] A probe hybridization mixture containing 50% formamide, 10% 2×SSC and 10% dextran sulfate, 1% COT1 DNA to block repetitive sequences, and labeled, single-stranded pooled probe [˜100 ng each] was denatured at 65° C. for 1 min. and applied to slides prepared for CO-FISH (as above). Following an overnight hybridization at 37° C. in a moist chamber, slides were washed at 42° C., three minutes each, in: 1) 50% formamide/2×SSC (two washes); 2) 2×SSC (two washes); 3) PN Buffer (Phosphate NP-40); and 4) PN Buffer at room temperature for 5 min., then mounted in a glycerol solution containing 1 mg/ml of the antifade compound p-phenylenediamine HCl and 0.1 μg/ml 4′,6-diamidino-2-phenylindole (DAPI). It should be mentioned that when probes are generated by the PCR method described hereinabove, inevitably there are repetitive sequences in them. Such sequences are labeled and bind to multiple places on many chromosomes which is undesirable. COT 1 DNA is composed of unlabeled DNA from repetitive sequences. During hybridization, COT 1 DNA competes with and, in effect, blocks hybridization from the labeled repetitive sequences in the probe.
Example 5
Detection
[0056] Individual metaphase spreads are examined with a fluorescence microscope and images captured using a CCD camera. On selected slides, a direct-labeled (FITC), a 19q arm-specific DNA paint probe was hybridized as per manufacturer's instructions (Q-BIOgene) to verify that probes were in fact hybridizing to chromosome 19.
Example 6
Results
[0057] Using both strategies to produce probes, PCR and tiled oligos produced similar results. Red fluorescence from chromosome 19 was observed on single chromatids using an epifluorescent microscope. Although there was significant background signal associated with other chromosomes, the presence of the signal confirmed that the probes had incorporated at least one molecule of AlexaFluor 594-5 dUTP, and were capable of being detected. It is expected that non-specific background staining can be reduced by increasing the stringency of hybridization and adding subsequent wash steps. Other fluorescent or non-fluorescent labels, either singly or in combination, may be incorporated into probes using the same methodology.
Example 7
Generation of Paints
[0058] Developing paints is achieved by performing the same operation multiple times along the length of a contig at the stated 1 Mbp interval and then increasing the coverage as desired. Adjacent contigs have an information gap between them. In the databases the contigs are presented with a hypothesized orientation. In order to develop a chromatid paint these orientations must be confirmed. Therefore when probes have been developed for two adjacent contigs, they will be labeled with different fluorochromes. Metaphase chromosomes from multiple normal individuals will be used for CO-FISH. If the two colors are found on the same chromatid in all individuals, the database is correct and assembly of the paint components can continue. If the colors are found on opposite chromosomes from all individuals, the orientation of the contig is reversed from its published orientation. If this is the situation, a new probe set may be prepared using sequences complementary to the unique sequences chosen previously, and paint assembly can continue again with the correctly oriented probes.
[0059] The visual effect of a chromatid paint is to make the two sister chromatids of a mitotic chromosome appear different, and distinguishable, from one another. As an example, the probes of a chromatid paint might be labeled with fluorescein, a green-fluorescing dye, and total DNA stained with propidium iodide, a red-fluorescing DNA-binding dye. In this case, one chromatid would fluoresce red and the other yellow (green plus red appears yellow). If the chromatid paint is applied to a chromosome that has an inversion, label within the inverted region appears on the opposite chromatid producing a distinctive pattern.
[0060] The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | A method and a kit for the identification of chromosomal inversions is described. Chromosomal inversions are difficult to detect unless they are quite large. The improved ability to detect chromosomal inversions is important to a number of medical applications, such as cancer and birth defects, as examples. Reporter species are attached to oligonucleotide strands designed such that they may hybridize to portions of only one of a pair of single-stranded sister chromatids prepared by the CO-FISH procedure, as an example. If an inversion has occurred, these marker probes will be detected on the sister chromatid at the same location as the inversion on the first chromatid. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. application Ser. No. 10/248,368 filed on Jan. 14, 2003, which is a continuation of U.S. application Ser. No. 09/574,600 filed on May 19, 2000, now U.S. Pat. No. 6,517,281. These prior applications are incorporated herein by reference in their entirety.
BACKGROUND OF INVENTION
Spinner spreaders for particulate material are well known in the art, both for agricultural application, lawn care, and road maintenance application. Typically, such spreaders are mounted onto a truck body, truck chassis, trailer, or slid into a truck's dump body. The spreader includes a material storage bin(s), a conveyor system(s) and rotating spinner(s). The conveyor transfers material from the storage bin(s) to the spinner(s). The spinner(s) broadcast the material across the field, lawn, or road. Usually a single spinner or a pair of laterally spaced spinners are provided, with a material divider plate positioned above the spinner(s) to direct the material from the discharge end of the conveyor(s) onto the spinner(s). A wide range of spinner diameters are in use with a general understanding that the amount of material to be spread and the size of the broadcast area are proportional to the diameter of the spinners.
Recently, a new technology has emerged known as variable rate technology. Unlike the past when it was desirable to apply a constant rate of material per acre or lane mile, variable rate technology advances the benefits of varying rates while moving across the field, lawn, or roadway. As it relates to agriculture, it is now desirable to apply different rates of a material in different grids of the same field in order to obtain optimum pH and/or fertility values over the entire field. As for roadways, it is now common practice, for example, to apply a varying rate of de-icing materials during the winter depending on the grade of the road; increasing rates on steep roads or at intersections while decreasing rates on less traveled or level roads. This new variable rate technology has challenged makers of broadcast spreaders to provide a spreader that can achieve optimum spread patterns while applying varying low and high rates of materials while the spreader is traveling at variable ground speeds (MPH) over the field, lawn or road. Variable ground speeds combined with variable application rates result in a variable amount of material (cubic feet per minute) passing across the spinner(s). As the rate of material changes, it is necessary to change the drop point onto the spinner(s) to achieve optimal spread patterns.
Furthermore, it is common to spread different density materials with the same spreader, which makes it necessary to change the drop point onto the spinner(s) to achieve optimal spread patterns when switching from high to low density material applications.
In conventional prior art spreaders, the drop area of the material from the conveyor(s) is fixed in relationship to the spinner(s). Minor adjustability of the drop area has been accommodated by adjusting the position of a material divider(s) such that the material is deflected by the divider(s) onto a different drop area on the spinner(s). However, such movement of the divider(s) relative to the spinner(s) does not provide uniform material flow through the divider(s) creating difficulty in achieving uniform spread patterns. Furthermore, the aperture of the divider(s) must be large enough to accommodate the highest rate of application lest it would hinder material flow onto the spinner(s). The divider aperture therefore creates a null zone where the divider setting or the divider movement has no consistent affect on the drop area of the material during a change from high to low rate applications. Also, the movement of the divider(s) is substantially limited due to the structure of the divider and/or conveyor and does not allow for the proper material placement on the spinner for achieving optimum spread patterns of both low and high rates of material. Therefore, the limitations of a conventional prior art spreader does not allow achieving optimal spread patterns when applying variable volume rates of material or different densities of material.
Accordingly, a primary objective of the present invention is the provision of an improved particulate material spreader that achieves proper placement of both low and high volumetric and density based rates of material.
Another objective of the present invention is the provision of a particulate material spreader having spinner(s) which are incrementally adjustable, fore and aft, relative to the conveyor(s) discharge end and material divider(s).
A further objective of the present invention is the provision of an improved spreader for agricultural, lawn care, and road maintenance use with uniform material flow from the conveyor(s) discharge end through the material divider(s) and onto the adjustable spinner(s) of the spreader.
Another objective of the present invention is the provision of an improved particulate material spreader wherein the position of the spinner(s) is quickly and easily adjustable.
A further objective of the present invention is the provision of spinner(s) for particulate material spreader which can be manually adjusted to accommodate varying low and high application rates of material onto an area, such as a field, lawn or road.
Another objective of the present invention is the provision of an improved particulate material spreader to automatically adjust the spinner(s) position, fore and aft in relationship to the conveyor discharge end and material divider, based on the rate being applied while the spreader is moving over the field, lawn, or road at either fixed or variable ground speeds (MPH).
These and other objectives will become apparent from the following description of the invention.
SUMMARY OF INVENTION
The adjustable spinner of the present invention is adapted for use with a spreader for broadcasting particulate material onto a field, lawn, road, or other area. The spinner includes a frame which is adapted to be adjustably mounted to the spreader beneath a conveyor discharge end and a material divider. Spinner disc(s) and blades are rotatably mounted on the spinner frame and adapted to receive material from the conveyor through the material divider and broadcast the material as the truck or trailer moves through the field, lawn, or along a road. The position of the spinner(s) relative to the conveyor discharge end and material divider is adjustable, either manually or automatically, with or without automatic position feedback, by any number of means such as mechanical, electrical, pneumatic, or hydraulic, so as to adjust the drop point of the material onto the spinner(s), and thereby accommodate varying application rates of the particulate material.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an overview of a truck mounted material storage box, divider, and spinner spreader.
FIG. 2A is a prior art cross section view of the discharge area, divider, and spinner with divider in a forward position.
FIG. 2B is a prior art cross section view of the discharge area, divider, and spinner with divider in a rearward position.
FIG. 3A is a cross section view of the discharge area, fixed position divider, and adjustable spinner(s) in a forward position.
FIG. 3B is a cross section view of the discharge area, fixed position divider, and adjustable spinner(s) in a rearward position.
FIG. 4 is a perspective view of a dual spinner configuration.
FIGS. 5A , 5 B and 5 C are perspective views of a dual spinner configuration with one spinner, spinner motor, and divider removed.
FIG. 6A is a top view of spinners in a rearward position.
FIG. 6B is a top view of spinners in a forward position.
FIG. 7A is a logic schematic of an automatic control for variable ground speed.
FIG. 7B is a logic schematic of an automatic control for variable rate applications driven by a positioning system such as GPS.
DETAILED DESCRIPTION
FIG. 1 is a somewhat diagrammatic perspective view of a truck for spreading particulate material generally designated 2 . The truck 2 includes a material storage bin 4 with sloping side walls and a belt conveyor 6 for transporting material to the discharge opening 8 . Mounted at the rear of the material storage bin 4 at the discharge end of the conveyor is a material divider 10 . Mounted below the material divider 10 is the spinner spreader apparatus generally designated 12 .
The spinner spreader 12 of FIG. 1 consists of spinners 14 mounted to motors 16 positioned to accept materials falling from the conveyor end 18 and through material divider 10 .
The above described structure is conventional and does not constitute a part of the present invention.
FIG. 2A is a somewhat diagrammatic longitudinal section view of conventional prior art showing a spinner 20 fixed in relative position to the conveyor end 18 and a moveable material divider 22 in a full forward position with a quantity of material falling through the divider aperture without influence from the divider front surface 24 or rear surface 26 . It is obvious that the divider would need to move significantly rearward before affecting where this quantity of material is dropped onto the fixed position spinner 20 . At the same time, a larger quantity of material flowing from conveyor end 18 may strike the rear surface 26 of the divider. There is no consistent relationship between the drop area 27 on the spinner, the material flow and divider setting.
FIG. 2B is a somewhat diagrammatic longitudinal section view of conventional prior art similar to FIG. 2A , but showing a moveable material divider 22 in a rearward position with material falling through the divider aperture with influence from the divider front surface 24 . It is obvious that the divider front surface 24 would affect the shape of the column of material as the divider 22 is moved fore and aft. The drop area 27 on the fixed spinner 20 changes accordingly with the shape of the material column.
FIG. 3A is a somewhat diagrammatic longitudinal section view of the present invention showing material falling from the conveyor end 18 onto the front surface 28 of a fixed divider 30 , off a fixed drop edge 32 , through the front part of the divider aperture, and at a drop point 27 on a moveable spinner 34 shown in a forward position. Divider 30 is not required for the present invention to operate as intended. With divider 30 removed, the conveyor end 18 will serve the same function as the fixed drop edge of a divider.
FIG. 3B is a somewhat diagrammatic longitudinal section view of the present invention showing material falling from the conveyor end 18 onto the front surface 28 of a fixed divider 30 , off a fixed drop edge 32 , through the front part of the divided aperture, and at a drop point 27 on a moveable spinner 34 shown in a rearward position. It is obvious that the material is falling in the same column shape as shown in FIG. 3A but landing at a drop point 27 further forward on the spinner. Because the material strikes the divider 30 consistently, the material arrives at the moveable spinner 34 consistently and will thus have a spread pattern consistent and repeatable with the location of moveable spinner 34 in relation to divider surface 28 and the fixed drop edge 32 .
The present invention of the improved spreader generally designated 36 is shown in the perspective view of FIG. 4 in a dual spinner configuration. Material from storage bin 4 is conveyed through discharge opening 8 by conveyor 6 until the material falls from conveyor end 18 onto the front surface of fixed divider 30 . The fixed divider 30 is mounted to the storage box 4 in a position fixed relative to the end of conveyor 18 . The material further falls through the divider aperture along the same front edge, or drop edge 32 , of divider 30 and onto the moveable spinners 34 . It is the fixed drop edge 32 of the divider 30 that results in a consistent drop point 27 of material onto the moveable spinners 34 . The spinners are rotated by motors 16 from below. The spinners rotate in opposite directions. The spinners and motors are moveable fore and aft relative to the fixed divider 30 .
FIGS. 5A and 5B are upper and lower perspective views of the present invention in a dual spinner configuration spreader generally designated 36 with one spinner 34 , spinner motor 16 , and the fixed divider 30 of FIG. 4 removed. The spinners and motors are mounted to a subframe 38 . In this configuration, the subframe 38 with mounted motors and spinners, is moveable fore and aft along longitudinal shaft 40 secured to main supporting frame 42 . Further, the subframe 38 rests on longitudinal members 44 of the main supporting frame 42 . The main supporting frame 42 is mounted to the storage bin 4 and is fixed in position relative to the conveyor end 18 and divider drop edge. In this configuration, fore and aft movement of the subframe 38 and the associated motors and spinners is accomplished through means of a screw jack 46 or, for example, hydraulic cylinder 47 as shown in FIG. 5C , placed between the main supporting frame 42 and subframe 38 . In manually operated form, the operator of the spreader can adjust the position of the spinners relative to the conveyor end and divider drop edge by extending or collapsing the screw jack 46 by means of a rotatable handle 48 . Location of the spinners relative to the drop edge is indicated by scale 50 and pointer 51 .
When using laterally spaced spinners having opposite rotation, the operator can adjust for higher or lower application rates by moving the spinners 34 forward or rearward with respect to the fixed drop edge 32 of the fixed divider 30 .
FIG. 6A is a top view of the spinners of the present invention depicting a low application rate with a small column of material, represented by hatched sections 52 , which has passed over the front surface of the divider, off the drop edge 32 and onto the spinners 34 . The spinners 34 are retracted forwardly such that the small column of material 54 has a drop point near the spinners centerline. Furthermore, as the rate of material is reduced, the material would be introduced later in respect to the spinner's rotation. For any spinner rotation, as the rate of material is reduced, the column of material 52 and the associated drop point, would move in the same direction as the spinner rotation.
FIG. 6B is a top view of the present invention showing a higher application rate, which has a larger column of material, represented by hatched sections 54 . The spinners 34 are moved rearwardly such that the added volume of material is introduced earlier in respect to the spinner's rotation. The center of the drop point moves in a direction opposite the spinner rotation. For any spinner rotation, as the rate of material is increased, the column of material 54 and the associated drop point, would move in the direction opposite the spinner rotation.
The spinners 34 can be adjusted to any position between full extension and full retracted positions to accommodate various application rates of materials. Spinner location is also adjustable to accommodate varying material densities. The accurate adjustability of the spinners allow for a more accurate deposit of material onto the spinners, and thus more accurate application of the material onto the field, lawn, or road.
In an automatically adjustable form, the screw jack 46 of FIGS. 5A and 5B is replaced with any number of actuating means, such as mechanical electrical actuators, pneumatic cylinders, or hydraulic cylinders, with a positive feed back to control spinner location from the operator's driving position or other remote location. The operator can immediately adjust the spinner position for accurate broadcast of material based on an application rate.
FIG. 7A is a logic flow chart of a general type of control for the remote adjustment just described. Spreader main system processor 60 controls conveyor motor 62 , spinner motor 64 , and spinner position actuator 66 by constantly monitoring conveyor speed sensor 68 , spinner rotation speed sensor 70 , spinner position actuator sensor 72 and vehicle ground speed sensor 74 to meet the rate requirements 76 manually input by the operator to meet predetermined material application rates. When a new rate requirement 76 is input, the main system processor 60 adjusts one or more of the conveyor motor speed 62 , spinner speed 64 , and spinner position actuator 66 until feedback from conveyor speed sensor 68 , spinner speed sensor 70 , and spinner position actuator sensor 66 meet programmed requirements for the new rate for any given vehicle speed from sensor 74 . Specifically, it is the ability to change the drop point onto the spinners that allow for optimum spread patterns.
In a further automatically adjustable form, the screw jack 46 is replaced with any number of actuating means, such as mechanical electrical actuators, pneumatic cylinders, or hydraulic cylinders, with a positive feed back to control spinner location and thereby adjusting automatically for variable rate technology application of the particulate material. In this case, the spinner location is changed as the spreader is moving about the field, lawn or along the roadway for accurate broadcast of material based on predetermined application rates and position knowledge gained from a location positioning system such as a common Global Positioning System (GPS).
FIG. 7B is a logic flow chart of a general type of control for variable rate technology. With variable rate technology, the spreader main system processor 60 controls conveyor motor 62 , spinner motor 64 , and spinner position actuator 66 by constantly monitoring conveyor speed sensor 68 , spinner rotation speed sensor 70 , spinner position actuator sensor 72 and vehicle ground speed sensor 74 , and a positioning system such as a common Global Positioning System 78 . The addition of the positioning system and a set of predetermined variable application rate needs for a field grid or roadway gives the spreader the information necessary to apply different rates of material at variable ground speeds. However, it is the ability to consistently change the effective material drop point on the spinners that allows a spreader to achieve the optimal spread patterns needed for the variable ground speeds and high to low application rates. Therefore, as the spreader is moving about the field, lawn or along the roadway, the main system processor 60 constantly monitors and adjusts the spinner position for best results with regard to application rates based on the positioning system's location information and vehicle ground speed. | An improved particulate material spreader includes an adjustable spinner apparatus which is incrementally adjustable forwardly and rearwardly to a plurality of operating positions relative to the discharge end of the material conveyor. The adjustment may be manual or automatic to adjust the drop point of the material onto the spinners, thereby accommodating varying application rates of the particulate material on a field, lawn, road, or other area. The spreader may be operatively connected to a microprocessor to receive data input and sensor feedback for variable rate technology. | 4 |
This application is a continuation of application Ser. No. 758,779 filed July 25, 1985, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to circuits for providing high frequency energizing signals to electrical devices such as luminescent lamps and is an improvement on my U.S. Pat. No. 4,066,930 dated Jan. 3, 1978, incorporated herein by reference.
A standard measure of the efficiency of energy utilization in luminiscent sources is a parameter called "efficacy" which is the ratio of luminous flux output to the total power input. For example, the efficacy of present day fluorescent tubes is about 55 to 65 lumens per watt as compared to a figure of about 40 lumens per watt for typical incandescent lamps. Solely from the standpoint of energy utilization efficiency, therefore it is desirable to use fluorescent lamps for many lighting needs.
However, as relatively efficient as they are when compared with other light sources, present day fluorescent lamps fall far short of the efficiencies theoretically possible. Fluorescent lamps require a high voltage to initiate current flow across the lamp terminals and require a high current to initiate and to maintain ignition. This is due to the fact that there is an infinitely high impedance existing in the tube prior to ignition. Ignition occurs when the gases inside the tube are ionized permitting current to flow between the electrodes at opposite ends of the tube. Once a gaseous discharge tube has ignited, it exhibits a negative resistance characteristic and some form of current control device, such as a ballast, is typically utilized to limit the current to the tube.
Typically a fluorescent lamp ballast includes circuitry adapted to direct a high voltage (which may be as high as 1600 volts) to the gas tube electrodes. This high voltage is necessary in order to force electron emission from the electrodes and to thereby initiate ionization of the gases in the tubes. One or both of the electrodes generally comprises a filament which has the capacity of more readily emitting electrons when heated and subjected to high voltage and current.
One disadvantage with present day mercury, sodium vapor, and fluorescent lamp circuits is the loss of energy in the operation of the ballasts and in the heating of the filament electrodes. Another disadvantage is that the lifetime of the lamps is controlled principally by the mechanical integrity of the filaments. Once the filaments break and cease to emit electrons, a lamp no longer functions even though the light producing components of the lamp such as the gases in the tube and the phosphors on the tube walls remain functional. The present day ballasts continue to feed voltage and current into the system even though there is no live tube to effectively utilize it. This causes lamp flickering and overheating and can become extremely hazardous.
It is generally acknowledged that the energization of fluorescent tubes with high frequency signals is more effective and efficient than the standard ballast circuits. For one reason or another such as improper frequency circuit malfunctions in critical areas, excess radio frequency interference, or electromagnetic interference, however, these systems have not been commercially feasible. Apparently, in prior art circuits too much energy is lost in the switching and amplification of transistors and in the operation of the power transformer.
Another disadvantage of present circuits is the fact that bulb life is greatly reduced and the ends of the tubes tend to become blackened due to current distortions in the tubes caused by the introduction into the tubes of signals carrying too many harmonics.
SUMMARY OF THE INVENTION
The present invention may be characterized generally as a energizing circuit for the ignition of fluorescent lamps and other gas discharge luminiscent devices. The energizing circuit of the invention comprises an AC or DC voltage source coupled to an oscillator circuit. The oscillator circuit is adapted to generate energizing signals at a fixed frequency which is predetermined by the size and characteristics of the device being energized. The frequency may be in the range between 60 Hz to 30 MHz. The waveform of the energizing signals approximates a sine wave and the oscillator circuit comprises at least one transistor.
An embodiment of the energizing circuit of the present invention includes a ferromagnetic pot core power transformer or ferromagnetic power E transformer which is operable over a wide range of frequencies. The cores are interchangeable with a ferromagnetic U core. The power E core, which is ferromagnetic, includes a primary winding coupled between the DC power supply positive terminals and the collector of a transistor through a biasing diode. The secondary winding is connected to the fluorescent tube. A tertiary winding is connected to a parallel R-C circuit, and optional heater windings are connected to the fluorescent tubes.
The present embodiment also contains triacs at the input section which function as safety devices which open when a fluorescent tube is pulled out of the circuit or is no longer functional.
The present embodiment contains Darlington transistors which serve to shape the current waves to the power transistor and in the "soft-on" section of the circuit.
It is a feature of the present invention that the operating lifetimes of gaseous discharge lamps are greatly extended by the elimination of the filament electrodes, although the present invention is adaptable to and can be used on tubes containing filament electrodes.
It is also a feature of the present invention that the triac safety section, the wave-shaping Darlington transistors and the "soft-on" section of the circuit are unique in their functions and useful to the circuitry in promoting the longevity of the circuit and of the gaseous discharge tube.
Other and further objects, aspects and features of the present invention will become more apparent from the following detailed description of the preferred embodiments when read in conjunction with the appended drawing figures, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein:
FIG. 1 is an electrical schematic diagram illustrating one embodiment of the electrical energizing circuit of the present invention, and
FIG. 2 is an electrical schematic diagram illustrating another embodiment of the electrical circuit of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the energizing circuit of the present invention is illustrated in FIG. 1. One side of the input voltage, from AC source 1, is connected to one side of safety fuse F1, the opposite side of safety fuse F1 is connected to one side of thermal switch B1, and the opposite side of thermal switch B1 is coupled to one side of choke coil L1 and capacitor C1. The opposite sides of capacitor C1 and choke coil L1 are connected to one side of capacitor C2, and the opposite side of C2 is coupled to trigger T1 of triac Q4. The opposite side of triac Q4(T2) is connected to one side of capacitor C3 and the opposite side of capacitor C3 is connected to the opposite side of the input voltage. The gate G of triac Q4 is coupled to one side of polarized capacitor C4 (positive) and one side of diode CR1 (negative). The positive side of diode CR1 is coupled to the end windings of transformer T2, and the start winding of isolation transformer T2 is coupled to one side of C4 (negative) and to one side of resistor R1. The opposite side of resistor R1 is connected to bridge rectifier CR2 (AC), and the opposite side of bridge rectifier CR2, (AC) is connected to capacitor C3. The opposite side of transformer T2 (primary start) is connected to the end winding N5 of transformer T1 and the opposite side of winding N5 is coupled to a of the fluorescent tube and to one side of capacitor C12.
The end winding of transformer T2 is connected to another lead (normally) to the fluorescent tube 30. The positive side of capacitor C12 is coupled to the start winding N2 of transformer T1 and the lower end of winding N2 is connected to the end winding N6 of transformer T1. Start winding N6 is connected to a lead (normally blue) of the fluorescent tube 30, and the end winding N6 is connected to a blue lead to the fluorescent tube.
The positive side of full wave bridge rectifier CR2 is commonly coupled to one side of parallel time constant circuit TC1 comprised of resistor R2, and capacitor C5, parallel time constant circuit TC2 comprised of resistor R4, and capacitor C8, to one side of biasing resistor R7 and to the upper end of primary winding N1 of transformer T1. Start winding N1 is also coupled to the positive end of biasing diode CR4, and the negative side of CR4 is coupled to the collector of transistor Q3. Resistor R7 reduces sensitivity and gain of transistor Q1, and if desired, a similar resistor could be included in the base circuit of transistor Q2 (to correspond to resistor R29 connected to the base of transistor Q22 of FIG. 2). Diode CR4 regulates the voltage to transistor Q3 and prevents overload. The positive side of CR4 is also coupled to one side of capacitor C11, and the opposite side of capacitor C11 is connected to the positive side of the DC input from bridge rectifier CR2. The base of transistor Q3, is connected to one side of biasing resistor R8 and the opposite side of resistor R8 is connected to the collectors of Darlington transistor pair Q1. The base of the Darlington transistor pair Q1 is connected to one side of biasing resistor R7 and the opposite side of resistor R7 is connected to the positive side of the DC input from bridge rectifier CR2. The emitters of the Darlington transistor Q1 are connected to one side of the manual dimmer potentiometer R6 and the opposite side of potentiometer R6 is connected to the parallel time constant circuit TC3 comprised of resistor R5 and capacitor C9. The opposite side of parallel time constant TC3 is connected to the end winding of tertiary N3 on transformer T1 and the start winding of N3 thereof is connected to one side of parallel time constant circuit TC2 comprised of parallel resistor R4 and capacitor C8. The opposite side of parallel time constant circuit TC2 is connected to the positive DC input of bridge rectifier CR2.
The emitter of transistor Q3 is connected to the negative side of capacitor C10, the negative side of capacitor C7, the positive side of voltage regulating zener diode VR1, the negative side of parallel time constant circuit TC1, and to the negative side of bridge rectifier CR2. The positive side of capacitor C10, is connected to the emitters of Darlington transistors Q2, and the collectors of Darlington transistors Q2 are connected to one side of the photocell PC1, one side of capacitor C6, and to one side of resistor R6, and to the parallel time constant R5, C9. The base of Darlington transistor Q2 is connected to the opposite side of photocell PC1. Capacitor C10 isolates the emitter of transistor Q2 so this transistor does not receive a brute force turn-on and also assists in "soft" turn-on of transistor Q3. Photocell PC1 is connected to the positive side of capacitor C6, the positive side of diode CR3, and the collectors of Darlington transistors Q2. The negative side of capacitors C6 is also coupled to one side of resistor R3, one side (positive) of zener diode VR1, and the negative of diode bridge CR2. The positive side of zener diode VR1 is coupled to the negative side of diode CR3 and the positive terminal of capacitor C7.
The leads of photocells PC1, PC21 (FIG. 2) and resistor R29 (FIG. 2) are covered with shielding to prevent unwanted interference, and interruption of steady function.
Heater windings N4 (FIG. 2), N5, N6 of T1 contain the output leads to the fluorescent tubes. Winding N2 of transformer T1 is the secondary winding, winding N1 of transformer T1 is the primary winding, and winding N3 is the tertiary winding, all of the power E core.
Capacitor C11, between the start and end winding of N1 is a snubber capacitor which prevents spikes from entering winding N1, and capacitor C11 also stabilizes the frequency of the circuit.
Capacitor C12 (FIG. 2) and winding N2 has a similar function for secondary winding N2 of transmitter T1.
The tertiary winding N3 is connected to the outputs of capacitor C10, resistor R5, and capacitor C9, resistor R4. Capacitor C9 and C10 act as voltage regulators keeping the voltage into the tubes at a constant level.
TABLE I PARTS LIST (FIG. 1)
L1 input choke approximately 165 millihenries grain oriented silicon steel
C1,2mfd 200 v
C2,1mfd 200 v
C3,0.5mfd 50 v
C4,0.5mfd 50 v
C5,1mfd 200 v
C6,100mdf 150 v electrolytic
C7,0.03mfd 200 v
C8,1000mfd 16 v electroytic
C9,0.047mfd 200 v
C10,0.047mfd 200 v
C11,0.047mfd 200 v
C12,0.02mfd 1000 v
C13,0.02mfd 1000 v
PC1 photocell
F1 fuse 3 amp
B1 Thermal switch (resetting 95 degrees celcius
CR1, CR2, CR4, CR6, CR7, 1N4002, 100 v, 1A
CR8, diac 100 v 1A or two 1N4002 100 v 1A
CR3, full wave bridge rectifier 400 v 1A
CR5, 1N4005, 600 v 1A
VR1, 1N4747 20 v 1 W
R1, 1 ohm 1 W
R2, R4, R5, 82000 ohm 0.5 W
R3, 4,700 ohm 0.5 W
R6, 500 ohm 1 W potentiometer
R7, 150,000 ohm 0.5 W
R8, 68 ohm 1 W
R9, 100,000 ohm 1 W
R10, R11, 10 ohm 0.5 W
Q1, Q2 Darlington or signal transistor
Q3, power transistor
Q4, Q5, triac
T1, ferromagnetic power E core or pot core
T2, T3, ferromagnetic torroidal cores
FIG. 2 illustrates a preferred embodiment of the present invention. Protective fuse F21 protects the circuit from overloads and current surges which exceed the fuse rating. In a short circuit condition fuse F21 will open, saving the components from damage and preventing fire. A thermal protective resetting switch B21 protects the circuit from overvoltage or current surges for prolonged periods. In a sustained overload condition which is still too minimal to cause fuse F21 to open, thermal resetting switch B21 will open when its temperature maximum (approximately 90 Degrees C.) is reached; thermal resetting switch B21 recloses allowing normal circuit operation when the surge or fault is removed. Input inductive choke L21 causes a lagging voltage of approximately 90 degrees relative to the current. Choke L21 increases the power factor of the circuit insuring maximum operation and also acts as a feedback filter for electromagnetic interference since the coil has a high AC resistance.
Filter capacitor C21 causes a lagging current relative to the voltage and approximately 90 degrees out of phase with it. Coupled with the lagging voltage there is an out-of-phase operation between voltage and current of approximately 180 degrees. Capacitor C21 also increases the power factor and its value is determined by the input frequency and its reactance to closely approximate the inductive reactance of L21 creating a parallel resonant circuit.
Filter and loading capacitor C22 also eliminates noise in the circuit and acts as a start up capacitor for the circuit. Capacitor C22 aids in eliminating electromagnetic interference from the triacs (Q24, Q25) and capacitor C22 also aids in eliminating noise from the full wave rectifier CR23, while providing a cleaner AC signal to rectifier CR23. Surge protective resistor R21 protects rectifier CR23 and prevents overloads, especially on the turn-on of the circuit.
Filter capacitors C23 and C24 are connected to the gate electrodes of triac Q24 and triac Q25 respectively. Capacitors C23 and C24 provide constant DC signals to the gate electrodes of triacs Q24, Q25 which keep the triacs switched on, rather than having them switch on and off which would shorten component life and waste energy. Diodes CR21 and CR22 provide positive DC voltage to the gate electrodes of triacs Q24 and Q25, respectively, to limit the voltage to a safe level. Safety resistors R30 and R31 insure a smooth steady level of voltage to the gates of Q24 and Q25. Diodes CR26 and CR27 keep the voltage through transformer windings T22 and T23, respectively, constant and at a low level and also insure low level voltages to capacitors C23 and C24.
The secondaries (n 21) of torroidal transformer T22 and T23 take the low voltage from the tube heater windings of the primaries (n 22) to provide the signal to diodes CR21 and CR22 to turn on the gates of triacs Q24 an Q25.
Signal transformers T22 and T23 receive signals from N25 and N26 of T21, respectively, and provide the signal for the gates of Q24 and Q25. Since T22 and T23 are isolation transformers, they prevent surges from reaching the gate electrodes of triacs Q24 and Q25.
Filter capacitor C25 aids in eliminating electromagnetic interference and assists in improving the power factor of the circuit and also provides a purer AC signal for full wave bridge CR23. Filter capacitor C26 reduces the ripple voltage from CR23 and provides a purer DC voltage. Bleeder resistor R22 insures the discharge of C26 during the off cycle.
Still referring to FIG. 2, an analysis of the features is as follows: In the AC input section the components labeled L21, C21, C22, C23, C24, Q24, Q25, CR21, CR22, T22, T23 have the following functional qualities. Capacitor C21 smoothes the voltage input to choke L21 and as a parallel resonant circuit has minimal ripple current conducted to it and these components (L21 and C21) have approximately equal impedance at the ripple frequency. Capacitor C22 allows the starter voltage in the circuit to remain constant at low levels and keeps the oscillator stage at approximately 1 to 2 watts should a tube fail or be pulled from the circuit.
Capacitor C23 aids in elimination of electromagnetic interference and smooths the pulse into transistors Q24 and Q25. Choke coil L21 causes a lagging voltage and capacitor C 21 causes a lagging current approximately 180 degrees out of phase which together give an increased power factor and reduce electromagnetic interference. Capacitor C23 is also a filter capacitor and is connected to the gate of transistor Q24 and is part of the positive DC network and it provides a constant positive DC signal to the gate of transistor Q24 which keeps that transistor switched on rather than having it constantly switching on and off which would waste energy and shorten component life.
As noted above diode CR21 provides a positive signal to the gate of triac Q24 and limits the voltage so that no overload occurs. The voltage is limited to approximately 2 volts at approximately 50 milliamps. The primary of transformer T22 is in series with the heater windings of a fluorescent lamp load L. Secondary winding N21 of this transformer boosts voltage received from approximately 1.5 volts to approximately 3 volts and provides the signal to diode CR21.
Another function of triac Q24 is that its gate will open when a tube is pulled or fails in the circuit thereby putting the circuit into an idle state with a very low voltage (open circuit) and negligible current thereby vastly reducing the shock hazard present in all other circuits.
Biasing resistor R27 is on the base of Darlington transistor pair Q21. Transistor Q21 is a signal transistor which shapes the wave to the base of transistor Q23. Transistor Q23 receives a signal from resistor R26 which is mainly sawtooth and reshapes into a square wave. Transistor Q21 also controls the current into the base of transistor Q23 with resistor R28. Wave shaping is accomplished by the rapid turn on and resistance offered to the sawtooth wave.
The "Soft-on" section circuit includes capacitor C27, resistor R23, voltage regulator VR21, diode CR24, capacitors C28 and C27 and is part of the biasing network for transistor Q23, and aids in controlling the voltage and current through resistor R25, capacitor C30, and prevents transistor Q23 from ramping. Capacitor C27 is also part of the wave shaping network. Resistor R23 is a bleeder resistor for capacitor C28 to insure discharge after turn-off. Capacitor C28 is part of the delayed "soft-on" network for the base of transistor Q23 has a relatively large capacitance value. Tertiary winding N23 YZ of transformer T21 provides a turn-on signal to capacitor C29 and resistor R24, and capacitor C30 and resistor R25. Capacitor C28 causes a delay while charging. Diode CR24 passes a positive voltage and zener diode VR21 controls the amount of voltage on capacitor C28 to approximately 20 volts. Diode CR24 passes the positive voltage to the base of Darlington transistor Q22, through the photocell PC21 and resistor R29, which constitute an automatic dimming network, through Darlington transistors Q22 and Q21, resistor R27 which shapes the wave and prevents unwanted noise from reaching transistor Q23. This network prevents hard turn-on of transistor Q23 and provides a soft turn on thus prolonging component life and tube life, and suppress radio frequency interference (RFI).
Capacitor C29 and resistor R24, and capacitor C30 and resistor R25, reduce the signal from tertiary winding N23, and capacitor C30 and resistor R25 provide a positive signal to diode CR24, while capacitor C30 and resistor R25, capacitor C29 and resistor R24 also act as a regulator for winding N23. The two parallel RC time constants also aid in rounding the sawtooth waves.
In the automatic dimming section, as light strikes photocell PC21, the resistance increases causing the base of transistor Q22 to open and allows the current to pass through capacitor C31, thus causing a drop in current on transistor Q23 which causes the unit to dim automatically since transistor Q23 is not being driven with a normally high voltage. Resistor R21 in conjunction with the photocell PC21 provides biasing for transistor Q22. Photocell PC21 may be utilized independently of manual dimmer potentiometer or in conjunction with it for great energy savings.
Still referring to FIG. 2, resistors R30 and R31 limit voltage and current to diodes CR21 and CR22 and to the gates of the triacs Q24 and Q25. Voltage from the primary of torroidal transformers T22, T23, is increased at the secondaries thereof, especially during a dead tube or pulled tube condition or when power is turned on and off rapidly. Resistors R30 and R31 aid in preventing the triacs Q24 and Q25 from overloading on their gates.
Diac CR28 limits current to the gates of the triacs Q24 and Q25 during a pulled tube or dead tube condition. Diac CR28 prevents the triacs from being overloaded with voltage. Diac CR28 also aids in suppressing spikes, electromagnetic radiation and radio frequency interference.
The leads of photocell PC21 and resistor R29 are covered with shielding to prevent unwanted interference and interruption of steady function.
Secondary winding N22 of transformer T21, primary winding N21 and tertiary N23 are all on the power E core of transformer T21.
Capacitor C32 is connected between the start and end winding of winding N21 and is a snubber capacitor which prevents pikes from entering the winding and capacitor C32 also stabilizes the frequency of the circuit.
Capacitor C33 performs a similar function for the secondary winding N22 of transformer T21.
The tertiary winding N23 is connected to the outputs of RC capacitor C30, resistor R25, RC capacitor C29, resistor R24 and capacitor C29 and C30 act as voltage regulators for keeping the voltage to the tubes at a constant level.
Referring to FIG. 2, the high frequency signal generated by the circuit is produced at a voltage level sufficient to excite the gases inside the fluorescent tubes to ionization. This leads to the release of ultraviolet and visible radiation. Taking a standard fluorescent tube as an example, both argon and mercury are present in the tube. The argon molecules are brought to their ionization potential by the high frequency voltage signal and begin to ionize. The movement of the argon ions coupled with the high frequency oscillations of the field then causes ionization of the more predominant mercury atoms. The mercury ions in turn give off the desired radiation as the electrons in their outer shells move from one energy level to another. A chain reaction of collissions among the mercury atoms, as the high frequency signals continue at a reduced voltage and current, has the effect of maintaining the overall ionization state.
The higher the frequency of the electrical field oscillations, the more excited the mercury atoms become, the more collisions there are among the atoms in the tube an the greater the degree of the emitted radiation. Another feature of the present invention results from high frequency signals being used for ionization making the tube filaments as presently known unnecessary. Instead, solid electrically conductive discs which last longer and emit more atoms may be used. Another unique feature of the present invention is that at the frequency range mentioned (60 Hz to 50 MHz), that the current through the lamps may be decreased to the point that very low levels of power may be used to maintain ignition of the lamps thereby saving energy and increasing lamp life.
The high frequency signal which is impressed into the tube at a sufficient voltage causes ionization of the argon at its fundamental ionization potential, and since argon has a higher ionization potential than mercury the ionized argon atoms will cause ionization of the mercury atoms.
The embodiments of the present invention can be utilized for tubes from 4 watts to 96 watts, and the circuits can be used for 1 or more tubes in series, parallel, or series parallel.
The high frequency energy saving ballast may replace the standard ballast on a one for one basis, or the high frequency energy saving ballast may be made to replace more than one standard ballast. The high frequency energy saving ballast may also be made as a central unit to handle banks of lights, or a series of them may be employed at a central location to ignite banks of lights.
The particular components of the present invention have the ability to be used over a wide range of frequencies with negligible losses.
The circuitry of the present invention will operate at a high power factor, a minimum of 0.91 and a maximum of 1.00.
The construction of the transformers of the present invention were carefully engineered to include particular materials which will be evident to those skilled in the art, for maximum performance. This includes L1 input choke, the ferromagnetic power E core of T1, and the ferromagnetic torroidal cores of T2, T3. Of course, the transformers are interchangable with other shapes having the same electrical characteristics and designed properly.
The gapping techniques used in the transformers to prevent saturation (L21, and T21), are also engineered to specific tolerances.
Skin effect and eddy current losses are negligible in the present invention, and electromagnetic interference as well as radio frequency interference are also negligible.
The dimming concept of the present invention is linear and the energy saving is proportional to the amount of dimming employed either manually with resistor R26, automatically with photocell PC21, or by utilizing both.
The present invention generates negligible heat thereby keeping losses at a minimum, prolonging component life, and increasing energy savings in an installation by reducing the air conditioning requirement.
Referring to FIG. 2, resistor R30, diode CR26, resistor R31 and diode CR27 on the secondaries of transformer T22 and T23 secondaries prevent surges from reaching the gates of triacs Q24, Q25, thereby increasing circuit reliability. These triacs are fail safe devices which have gates that will immediately open should a tube break, die, or be pulled from the circuit and reduce the open circuit voltage to a negligible level thereby removing shock and fire hazard when a tube foils or is removed from the circuit.
The R/C time constants of resistor R22 and capacitor C26, resistor R24 and capacitor C29, resistor R25 and capacitor C30 also aid in filtering out unwanted noise and they attenuate the upper and lower frequencies not desirable for proper circuit operation.
The AC input stage consisting of the AC input is unique in that it contains filtering through the choke L21 and capacitor C21 sections. This section also increases the power factor increasing the circuit efficiency. A filtering of electromagnetic and radio frequency interference is also accomplished through capacitors C22, C23, C24. Diac CR28 keeps the voltage from secondary N21 of transformer T22 and T23 at a low level preventing the gates of triacs Q24 and Q25 from overloading.
The DC and oscillator section comprises diodes CR23, CR25, RC resistor R22, and capacitor C26, RC resistor R24 and capacitor C29, RC resistor R25 and capacitor C30, manual potentiometer dimmer resistor R26 "soft-on" section capacitor C27 and resistor R23, zener voltage regulator VR21, diode CR24, capacitor C28, automatic dimming section photocell PC 21, capacitor resistor R29 and resistor transistor Q22, and capacitor C31, wave shaping section resistor R27 and transistor Q21; biasing resistor R28, power transistor Q23, capacitor C32, and primary winding N21 of output power transformer T21, secondary winding N22, snubber capacitor C33, heater windings N24, N25 and N26. The "soft-on" section is unique in that capacitor C28 causes a delay because of the loading time thereby eliminating high voltages from being applied to the base of transistor Q23, and eliminating a hard turn-on of transistor Q23. Diode CR24 and regulator VR21 function in keeping the operating voltages at a low level to insure the proper operation of capacitor C28.
The automatic dimming section is unique in that the dual function of transistor Q22, both as a signal transistor and as a wave shaping section, permits transistor Q23 to operate at lower voltages and saves significant amounts of energy over other systems. Resistor R29 prevents overloads from reaching the base of transistor Q22, and insures stable operation of photocell PC21.
The resistor R27 and transistor Q21 wave shaping section prevents waves such as sawtooth waves from reaching the base of transistor Q23 is functioning with an essentially pure square wave which optimizes its function and allows more energy to be saved, component life to be prolonged and eliminates noise generation. The preferred embodiments illustrated save significant amounts of energy in the range of 35% to 85% and are relatively reasonable to produce, as well as being commercially viable.
As various changes may be made in the form, construction and arrangement of the invention and without departing from the spirit and scope of the invention, and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not a limiting sense. | A circuit is disclosed for energizing electrical devices such as fluorescent lamps and other gas discharge luminescent devices. The circuit provides energizing signals for gaseous discharge tubes at a voltage sufficient to initiate ionization of the gases therein. The signals are characterized by frequencies in the range of from about 60 hertz to 30 megahertz. After ignition the circuit automatically reduces the voltages and currents of the devices to a level sufficient to maintain gas ionization, and save energy. The circuit also reduces shock hazard. A preferred wave shaping in the energizing circuit is disclosed which creates purer square and sine waves for reducing radio frequency interference and electromagnetic interference, and a "soft-on" circuit is disclosed which greatly reduces the voltages applied to the devices thereby increasing the life of the devices. An automatic and a manual dimming section are also disclosed which dim the light output for the devices. The dimming sections, which are independent of each other, save additional energy. | 8 |
RELATED APPLICATIONS
This application is related to U.S. Ser. No. 07/424,443 filed Oct. 20, 1989, now U.S. Pat. No. 5,056,036.
BACKGROUND OF THE INVENTION
The present invention relates to diaphragm metering pumps. Specifically, an apparatus for monitoring and controlling the extension of a diaphragm being actuated via a hydraulic fluid in a metering pump is described.
Metering pumps find diverse uses in many industrial processes. Diaphragm metering pumps operate from flexure of a flexible diaphragm which applies pressure to a pumped media, forcing the media through an outlet check valve. Reduction of the hydraulic pressure against the diaphragm returning to its preflexed state results in the diaphragm creating a pressure differential between the pumping chamber and pumping media inlet. A second valve permits additional pumping media to fill the pumping chamber.
The different applications for these metering pumps require diaphragms as diverse as stainless steel and Teflon. A major source of failure for metering pumps of this type results when the diaphragm ruptures, through excessive flexure and overextension. The overextension of a diaphragm results when the hydraulic force applied to the diaphragm either pushes or pulls it beyond material specific flexural limits.
Limitations against overextension of the diaphragms in either direction are provided by first and second dish plates in the hydraulic fluid chamber and pumping chamber. An overextension condition will occur as a result of a hydraulic imbalance as can be caused by leakage of hydraulic fluid past the piston. During retraction of the piston, which produces the hydraulic force for actuating the diaphragm, the diaphragm retracts against the rear dish plate before achieving an overextended state. Likewise, when the diaphragm is in the forward extended position during forward extension of the piston, a forwardly located dish plate retains the diaphragm from achieving an overextended state. Contact of the diaphragm with the dish plate can result in excessive stress levels and can contribute to pre-mature diaphragm failure and is therefore, undesirable.
The subject of monitoring diaphragm failure has been described in several prior art patents. In U.S. Pat. No. 4,781,535 to Mearns, a leak detector was provided which essentially detected the occurrence of a rupture in the diaphragm after the fact. Although this technique minimizes the amount of contamination which results from hydraulic fluid mixing with pumped media and otherwise signals corrective action at the earliest possible time, it does not control diaphragm deflection to be certain that the deflection is within safe limits to avoid the possibility of a rupture and to prolong the life of a diaphragm.
The sensing of diaphragm position has been considered in U.S. Pat. Nos. 4,619,589 and 4,828,464. In these devices, the position of the diaphragm is monitored in an effort to precisely control the amount of fluid being pumped. The problem of overextension of the diaphragm in both directions, however, has not been completely addressed by the prior art. Experience has shown that the rearward dish plate will cause extrusion of some diaphragm materials such as Teflon when the diaphragm is drawn against the porous dish plate when the piston is retracted. Further, cavitation has been experienced wherein an air interface occurs between the diaphragm and hydraulic fluid in some extreme circumstances, due to the dish plate inhibiting further rearward movement of the diaphragm. The cavitation effect reduces the metering accuracy of the pump and is otherwise undesirable.
Given the foregoing difficulties of maintaining metering pump reliability, the present invention has been provided.
SUMMARY OF THE INVENTION
It is an object of this invention to accurately control deflection of a metering pump diaphragm.
It is a more specific object of this invention to continuously monitor diaphragm position and control hydraulic pressure against the diaphragm based on the position.
In accordance with the invention, a diaphragm position indicator is incorporated in a metering pump for detecting when a diaphragm has reached an overextended position. The hydraulic pressurizing fluid of the metering pump is connected via a solenoid-operated valve to a reservoir of intermediate pressurizing fluid. A control circuit connected to the diaphragm position sensor determines when the diaphragm deflection exceeds a maximum safe displacement. At such time, the control circuit will energize the solenoid-operated valve, venting the pressurizing chamber to the reservoir of intermediate pressurizing fluid. The result of venting the pressurizing chamber immediately inhibits further extension of the diaphragm.
Overextension of the diaphragm can occur either during the pressurizing stroke, when the piston advances, or during a pressure reduction which occurs when the piston retracts and pumping media is forced into the pumping chamber. During retraction of the piston, further extension of the diaphragm is prevented by operating the solenoid operated valve, connecting the pressure chamber to the reservoir, permitting a reverse flow of pressurizing fluid from the reservoir to the pressure chamber. When the pressurizing stroke of the diaphragm metering pump begins, the hydraulic fluid will be inhibited from flowing back through the solenoid-operated valve to the reservoir. Pressurizing of the diaphragm will then continue such that the diaphragm moves forward, pressurizing the pumping chamber and displacing pumped media. The diaphragm position sensor will generate a signal to close the valve once the diaphragm has moved forward into a region of safe displacement.
The invention may be implemented to prevent diaphragm over extension during the pressurizing stroke. When the diaphragm position is detected to have reached a second maximum displacement, a second valve means is operated connecting the pressurizing chamber to the intermediate reservoir. This will effectively terminate further diaphragm expansion. As the pressure is reduced due to the operation of the valve means, the diaphragm returns to a safe displacement. The new diaphragm position is detected, closing the second solenoid valve means.
By controlling the effective diaphragm displacement, it is possible to avoid overflexing of the diaphragm, thereby prolonging the life of the diaphragm and the need for any replacement. Controlling the deflection of the diaphragm will result in a predictable life expectancy for the diaphragm, permitting its replacement to be made before catastrophic failure occurs.
DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic illustration of an embodiment of the invention for controlling diaphragm displacement.
FIG. 2A illustrates the piston position versus crank position for the metering pump of FIG. 1.
FIG. 2B illustrates the relationship of actual diaphragm position to the crank position.
FIG. 2C illustrates the sensor output signal in relationship to the crank position.
FIG. 2D illustrates the control signal applied to the solenoid-operated valve for limiting displacement of the diaphragm.
FIG. 3A is a cross-section of a metering diaphragm pump of the apparatus schematically shown in FIG. 1.
FIG. 3B illustrates detail A of FIG. 3A which provides an overpressure bypass to the hydraulic fluid chamber.
FIG. 4 is a schematic drawing of the control circuit for generating the solenoid valve operating signal
FIG. 5 illustrates another embodiment of the invention for controlling diaphragm deflection in two directions.
FIG. 6A illustrates the piston position vis a vis crosshead position for the diaphragm pump of FIG. 5.
FIG. 6B illustrates the sensed diaphragm position during the pumping operation.
FIG. 6C illustrates the diaphragm position sensor output with respect to a retraction threshold and extension threshold.
FIG. 6D illustrates the controller output to the solenoid valve 36.
FIG. 6E illustrates the output to the solenoid valve 37.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a schematic representation of a metering pump 7 connected to a pumped media reservoir 12. A check valve 10 on the inlet of the diaphragm pump 7 and check valve 9 on the outlet of the diaphragm pump 7 permit the pumped media to enter and leave the pumping chamber 13 under pressure from the diaphragm 11.
Opposite the pumping chamber 13 is a hydraulic fluid chamber 14 which pressurizes the diaphragm 11 during a pumping stroke and creates a partial vacuum within the pumping chamber 13 during an intake stroke. The flexure of the diaphragm 11 is sensed by a sensor 16 facing a magnet 15 fixed to the diaphragm 11. Thus, motion of the diaphragm 11 may be effectively monitored by the proximity sensor 16. The sensor 16 may be positioned by a positioning member 17 to maintain the sensor 16 at the preferred distance from the magnet 15.
Pressurizing of the hydraulic pressure chamber 14 is accomplished via a piston 26 operating within cylinder 20. A reciprocating crosshead 28 will position the piston 26 to pressurize the chamber 14 and in a reverse motion, spring 25 will return the piston to its starting position as the crosshead 28 is retracted. The entire assembly is driven by a crank 27.
A pressure relief check valve is shown in the hydraulic circuit connecting the piston cylinder 20 to the hydraulic pressurizing chamber 14. The check valve 21 serves as a pressure relief valve such that an excessive amount of pressure causing excessive deformation of the diaphragm 11 and damage to the drive mechanism 42 would be avoided. The intermediate media reservoir 34 receives the hydraulic fluid passed by the pressure relief valve 21.
There is a solenoid-operated valve 31 connected via a check valve 32 to the hydraulic pressurizing chamber 14. When the diaphragm 11 is detected as having moved rearwardly to a position where it will be overextended, controller 30 will supply an operating signal to the solenoid-operated valve 31. Valve 31 opens, permitting the intermediate media hydraulic fluid from reservoir 34 to enter the hydraulic pressurizing chamber 14. This will inhibit further movement of the diaphragm 11 toward the sensor 16.
Thus, the diaphragm 11 will remain in its sensed position until the piston 26 pressurizes the hydraulic pressure chamber 14, closing check valve 32.
FIGS. 2A, 2B, 2C and 2D illustrate the operation of the device of FIG. 1. As is shown, the crosshead displacement varies from a reference line of 0% to 100% forward, and then back to 0%, cyclically. Due to the lost motion coupling between the piston 26 and crosshead 28, the piston position advances when the crosshead moves from 50% of its stroke length to 100% stroke length--dependent on the current mechanical stroke adjustment setting.
The diaphragm position 2B can be shown in response to motion of the piston 26. The scale on the y-axis of FIG. 2B is shown in units of percentage of diaphragm displacement where the 100% value is indicative of the diaphragm attached magnet 15 in close proximity to the sensor 16. When the diaphragm is being retracted from a forward position rearwardly, where it would normally be stopped by a rearwardly located dish plate, the controller 30 will activate valve 31. This position is illustrated in FIG. 2C as a dotted line, and the resulting control signal is shown in FIG. 2D. The diaphragm position which will result in operation of solenoid valve 31 is experimentally determined and specified to the controller 30 such that the diaphragm 11 is not overflexed. This position is represented by the dotted line in FIG. 2C and is dependent on the material type and other considerations known to those skilled in the art.
With respect to FIGS. 1 and 2A-2D, the general operation of the preferred embodiment has been described. A practical embodiment of the foregoing system design is shown in FIGS. 3A and 3B. FIG. 3A is a section-view of a diaphragm metering pump employing the system of FIG. 1 for limiting diaphragm deflection. Detail "A", shown in FIG. 3B shows the hydraulic pressure relief valve 21, positioned to be in communication with piston cylinder 20. The embodiment of FIG. 3A provides for an intermediate media reservoir 40 which surrounds the pump piston 26. The motor drive 41 and gear structure 42 is used to drive the cam 28 to reciprocate the piston 26 via the cam follower 43, also known as a cross-head. A stroke adjustment 45 is provided which will limit the rearward travel of the piston 26 when pushed rearwardly by spring 25. These structural details regarding the driving of the mechanism for the piston 26 are conventional in metering pump design, and will not be further described.
The solenoid valve 31 is shown connected via the conduit 46 to the internal intermediate hydraulic fluid reservoir 40. Check valve 32 connects hydraulic inlet of solenoid valve 31 to the piston chamber 20.
The magnet 15 is mounted to the diaphragm 11 and is sensed by the sensor 16 supported at the outlet of the piston cylinder 20. Sensor 16 may be a Hall proximity transducer device which detects the magnetic field of magnet 15 and which provides a current proportional to the distance between the magnet 15 and the sensor 16. Electrical connections 47 from the sensor are connected to the controller 30. In the preferred embodiment, the controller 30 includes a pair of light indicators 59 and 48 to show the status of solenoid valve 31 as being either open or closed. Further, a threshold adjustment 49 permits the position threshold at which the solenoid valve 31 will be open to be manually adjusted. Thus, for various diaphragms, one may set the threshold at a greater or lesser value, depending on the limits of deflection sought to be imposed on the diaphragm 11. The adjustment of the threshold voltage can be facilitated by using a voltage metering device across resistor 51. Thus, as shown in FIGS. 3A and 3B, the foregoing preferred embodiment may be implemented in a conventional metering pump design.
The controller 30 is illustrated in greater detail in the schematic drawing of FIG. 4. Referring now to FIG. 4, the control circuit can be seen to include a first operation amplifier 50 connected via a series resistor 51 to receive a signal from the Hall effect transducer 16. An internal offset control 52 causes amplifier 50 to offset the output signal. A conventional internal gain control 53 is also shown for setting at the factory an appropriate gain setting for amplifier 50. Those skilled in the art will also recognize it possible to provide a volt meter connected to the output of amplifier 5 to monitor the diaphragm position.
Switch 54 is shown for connecting either the output of the amplifier, a 10 volt reference level, or a floating reference level to the input of comparator 56. Selection causes the valve to operate in the automatic, forced open or forced closed states. The threshold adjustment control 49 comprises a potentiometer connected in series with two limiting resistors. The output of comparator 56 will change when the Hall effect transducer produces a signal on the input of comparator 56 greater than the signal provided by the threshold adjustment potentiometer 49. The two states provided by comparator 56 represent either the valve open or valve closed condition, depending on the proximity of magnet to sensor 16.
Indicators 59 and 48 are conventional LED diodes, responsive to the signal produced by the comparator 56. Comparator 58 conditions the signal to the opto-isolators as required by the solenoid valve. Thus, it can be seen that the controller for the embodiment of FIG. 3A can be constructed of standard electronic components which will provide for an indication of the current operating condition of the solenoid valve, thus illustrating whether or not an overextension condition is being imposed on the diaphragm 11.
The foregoing description is illustrative of only one embodiment of several which may be implemented to avoid overextension of the diaphragm 11. The example illustrates diaphragm overextension in the context that diaphragm 11 and attached magnet 15 are in close proximity to sensor 16. This same system may be used to protect diaphragm 11 from overextension in the opposite direction--when diaphragm 11 is furthest away from sensor 16. This can be accomplished by simply reversing the input to comparator 56 shown in FIG. 4 and reversing the stop direction of check valve 32 shown in FIG. 3A. Such a configuration would prevent the overextension of the diaphragm into the pumped media chamber. Additionally, both protection mechanisms can be applied simultaneously.
FIG. 5 illustrates an embodiment in which the diaphragm 11 is protected from overextension during the pressurizing stroke. The sensor 16 is capable of providing an indication of when the diaphragm 11 exceeds an extension threshold. The controller 30, upon sensing the diaphragm position beyond the extension threshold, will issue a signal as shown in FIG. 6E to control solenoid valve 37. Valve 21, as in the previous embodiment, provides a failsafe relief valve in the event an excess amount of pressure occurs which is not relieved by valve 37.
In this embodiment, further pressurizing of chamber 14 ceases as the pressure is vented back to the intermediate reservoir when the extension threshold has been met. The appropriate operation then for the diaphragm is shown in FIG. 6B, wherein the diaphragm position is maintained within a retraction limit and extension limit to avoid overstressing of the diaphragm in two directions of flexure. During retraction, the embodiment of FIG. 5 works as the embodiment of FIG. 1, such that a signal is applied from controller 30 to the solenoid-operated valve 31, thus limiting the extension of the diaphragm during retraction of the piston.
Although not illustrated in FIG. 3A, the conventional dish plate structure, which normally inhibits rearward movement of the diaphragm 11 may continue to be used as a secondary backup means for checking overextension of the diaphragm 11 during the intake cycle of the diaphragm pump.
The foregoing embodiments are not limited to a particular type of diaphragm material 11 but may be used on diaphragms of all types with suitable changes in the threshold implemented, presenting the maximum safe displacement of diaphragm 11. Additionally, it is not limited to a particular means of adjusting the pump displacement. Those skilled in the art will recognize yet other embodiments as described by the claims which follow. | A diaphragm metering pump having control over diaphragm extension is described. A position sensor is incorporated in a diaphragm metering pump to indicate the relative position of the diaphragm during flexure. When excessive extension of the diaphragm is sensed by the position sensor, a control valve will provide hydraulic fluid from a reservoir for inhibiting further deflection of the diaphragm in the direction in which it was moving. Diaphragm life is extended as well as the accuracy of metering provided by the pump maintained. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority to U.S. provisional patent application 62/343,825, filed May 31, 2016, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure provides derivatives of amanitin conjugated to a targeting antibody to form an ADC (antibody drug conjugate).
BACKGROUND
[0003] The amatoxins are rigid bicyclic peptides having eight amino acid units. These compounds are isolated from a variety of mushroom species (e.g., Amanita phalloides (also known as green death cap mushroom), Galerina marginata, Lepiota brunneo - incamata ) or are prepared synthetically. Different mushroom species contain varying amounts of different Amatoxin family members. A member of this family, alpha-amanitin, is known to be an inhibitor of eukaryotic RNA polymerase II (EC2.7.7.6) and to a lesser degree, RNA polymerase III, thereby inhibiting transcription and protein biosynthesis. Wieland (1983) Int. J. Pept. Protein Res. 22(3):257-276. Alpha-amanitin binds non-covalently to RNA polymerase II and dissociates slowly, making enzyme recovery unlikely. Prolonged inhibition of transcription is thought to induce cellular apoptosis.
[0004] Exemplary amatoxins include
[0000]
[0005] The use of antibody-drug conjugates (ADCs) for the local delivery of cytotoxic or cytostatic agents, including drugs that kill or inhibit tumor cells, allows targeted delivery of the drug moiety to tumors, and intracellular accumulation therein. Syrigos and Epenetos (1999) Anticancer Res. 19:605-614; Niculescu-Duvaz and Springer (1997) Adv. Drug Delivery Rev. 26:151-172; U.S. Pat. No. 4,975,278; Baldwin et al. (1986) Lancet (Mar. 15, 1986):603-05; Thorpe (1985) “Antibody Carriers of Cytotoxic Agents in Cancer Therapy: A Review,” in Monoclonal Antibodies '84: Biological and Clinical Applications, A. Pinchera et al. (eds.), pp. 475-506. This type of delivery mechanism helps to minimize toxicity to normal cells that may occur from systemic administration of unconjugated drug agents. The toxins may cause their cytotoxic and cytostatic effects through a variety of mechanisms including tubulin binding, DNA binding, or topoisomerase inhibition. Both polyclonal antibodies and monoclonal antibodies have been reported as useful in these strategies. Rowland et al. (1986) Cancer Immunol. Immunother. 21:183-87. Toxins used in antibody-toxin conjugates include radioisotopes, bacterial toxins such as diphtheria toxin, plant toxins such as ricin, fungal toxins such as amatoxins (WO2010/115629, WO2012/041504 or WO2012/119787), and small molecule toxins such as geldanamycin (Mandler et al. (2000) J. Natl. Cancer Inst. 92(19):1573-1581; Mandler et al. (2000) Bioorg. Med. Chem. Lett. 10:1025-1028; Mandler et al. (2002) Bioconjugate Chem. 13:786-791), maytansinoids (EP 1391213; Liu et al. (1996) Proc. Natl. Acad. Sci. USA 93:8618-8623), calicheamicin (Lode et al. (1998) Cancer Res. 58:2928; Hinman et al. (1993) Cancer Res. 53:3336-3342), daunomycin, doxorubicin, methotrexate, and vindesine (Rowland et al. (1986), supra).
[0006] Several antibody-drug conjugates have shown promising results against cancer in clinical trials, including ZEVALIN® (ibritumomab tiuxetan, Biogen/Idec), an antibody-radioisotope conjugate composed of a murine IgG1 kappa monoclonal antibody (directed against the CD20 antigen found on the surface of normal and malignant B lymphocytes) connected with an 111In or 90Y radioisotope via a thiourea linker-chelator.
[0007] The use of antibody-drug conjugates (ADCs) for the local delivery of cytotoxic or cytostatic agents, including drugs that kill or inhibit tumor cells, allows targeted delivery of the drug moiety to tumors, and intracellular accumulation therein. This type of delivery mechanism helps to minimize toxicity to normal cells that may occur from systemic administration of unconjugated drug agents. The toxins may cause their cytotoxic and cytostatic effects through a variety of mechanisms including tubulin binding.
[0008] As such, there remains a need for potent RNA polymerase inhibitor antibody conjugates with desirable pharmaceutical properties.
SUMMARY
[0009] The present disclosure provides improved amatoxin derivatives used in an ADC (antibody drug conjugate) structure. More specifically, the present disclosure provides an antibody drug conjugate (ADC) having the structure of Formula I
[0000]
[0000] or a pharmaceutically acceptable salt thereof,
wherein:
[0010] Ab is a monoclonal antibody;
[0011] L 1 -L 2 is a linker selected from the group consisting of
[0000]
[0000] whereby the wavy line indicates the point of attachment to Ab;
[0012] L 2 -X is a linker having structure of
[0000]
[0000] wherein R 4 is hydrogen, C 1-6 alkyl, —(CH 2 CH 2 O) m —, or the combination thereof, and
[0013] m is an integer from 1-24;
[0000] wherein the wavy line indicates the point of attachment to D
[0014] D is a drug moiety active agent derived from amatoxin and selected from the group consisting of alpha-amanitin, beta-amanitin, gamma-amanitin, and epsilon-amanitin having the structure below:
[0000]
Name
R1
R3
alpha-amanitin
NH 2
OH
beta-amanitin
OH
OH
gamma-amanitin
NH 2
H
epsilon-amanitin
OH
H
[0015] n is an integer from 1-10;
[0016] L 2 is a linker selected from the group consisting of an amino acid, peptide consisting of up to 10 amino acids, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, PAB (p-aminobenzyl), Val-Cit-PAB, Val-Ala-PAB, Ala-Ala-Asn-PAB, —R 6 OC(O)NR 5 —, —R 8 —S—S—R 7 , and combinations thereof,
[0017] wherein R 5 is selected from the group consisting of hydrogen, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, and combinations thereof;
[0018] R 6 is selected from the group consisting of an amino acid, peptide consisting of up to 10 aminoacids, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, PAB, Val-Cit-PAB, Val-Ala-PAB, Ala-Ala-Asn-PAB and combinations thereof;
[0019] R 7 is C 2-6 alkylene, or —(CH 2 CH 2 O) m —;
[0020] R 8 is selected from the group consisting of an amino acid, peptide consisting of up to 10 aminoacids, C 1-6 alkyl, C 1-6 alkylene, substituted C 1-6 alkylene, —C(O)NH—, —C(O)—NH—CHR 9 —CR 10 R 11 —, —NHC(O)—CHR 9 —CR 10 R 11 —, —(CH 2 CH 2 O) m —, PAB, Val-Cit-PAB, Val-Ala-PAB, Ala-Ala-Asn-PAB, and combinations thereof;
[0021] wherein R 9 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 1-6 alkylene, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, —C(O)NH—(CH 2 ) p —SO 3 H, C(O)NH—(CH 2 ) p —CO 2 H, —NHC(O)—(CH 2 ) p —SO 3 H, —NHC(O)—(CH 2 ) p —CO 2 H and combinations thereof;
[0022] R 10 and R 11 are each independently selected from the group consisting of hydrogen, C 1-6 alkyl, and combinations thereof;
[0023] wherein —R 6 OC(O)NR 5 — is connected to L 1 through R 5 or R 6 ;
[0024] wherein —R 8 —S—S—R 7 — is connected to L 1 through R 8 ;
[0025] m is an integer from 1-24; and
[0026] p is an integer from 1-6.
[0027] In another aspect, L 2 in the compounds having the structure of Formula I is a linker selected from the group consisting of an amino acid, peptide consisting of up to 10 amino acids, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, PAB (p-aminobenzyl), -Val-Cit-PAB-, -Val-Ala-PAB-, -Ala-Ala-Asn-PAB-, —R 6 OC(O)NR 8 —, —R 8 —S—S—R 7 , and combinations thereof,
[0028] wherein R 5 is selected from the group consisting of hydrogen, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, and combinations thereof;
[0029] R 6 is selected from the group consisting of an amino acid, peptide consisting of up to 10 aminoacids, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, PAB, -Val-Cit-PAB-, -Val-Ala-PAB-, -Ala-Ala-Asn-PAB- and combinations thereof;
[0030] R 7 is C 2-6 alkylene, or —(CH 2 CH 2 O) m —;
[0031] R 8 is selected from the group consisting of an amino acid, peptide consisting of up to 10 aminoacids, C 1-6 alkyl, C 1-6 alkylene, substituted C 1-6 alkylene, —C(O)NH—, —C(O)—NH—CHR 9 —CR 10 R 11 —, —NHC(O)—CHR 9 —CR 10 R 11 —, —(CH 2 CH 2 O) m —, PAB, -Val-Cit-PAB-, -Val-Ala-PAB-, -Ala-Ala-Asn-PAB-, and combinations thereof;
[0032] wherein R 9 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 1-6 alkylene, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, —C(O)NH—(CH 2 ) p —SO 3 H, C(O)NH—(CH 2 ) p —CO 2 H, —NHC(O)—(CH 2 ) p —SO 3 H, —NHC(O)—(CH 2 ) p —CO 2 H and combinations thereof; R 10 and R 11 are each independently selected from the group consisting of hydrogen, C 1-6 alkyl, and combinations thereof;
[0033] wherein —R 6 OC(O)NR 5 — is connected to L 1 through R 5 or R 6 ;
[0034] wherein —R 8 —S—S—R 7 — is connected to L 1 through R 8 ;
[0035] m is an integer from 1-24; and
[0036] p is an integer from 1-6, wherein the remaining values are as described above for Formula I.
[0037] In yet another aspect, L 2 in the compounds having the structure of Formula I is a linker selected from the group consisting of an amino acid, peptide consisting of up to 10 amino acids, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NH(4-phenyl)CH 2 O—, -Val-Cit-NH(4-phenyl)CH 2 O—, -Val-Ala-NH(4-phenyl)CH 2 O—, -Ala-Ala-Asn-NH(4-phenyl)CH 2 O—, —R 6 OC(O)NR 8 —, —R 8 —S—S—R 7 —, and combinations thereof,
[0038] wherein R 5 is selected from the group consisting of hydrogen, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, and combinations thereof;
[0039] R 6 is selected from the group consisting of an amino acid, peptide consisting of up to 10 amino acids, C 1-6 alkyl, —(CH 2 ) p —, —(CH 2 CH 2 O) m —, —C(O)NH—, —NH(4-phenyl)CH 2 —, -Val-Cit-NH(4-phenyl)CH 2 —, -Val-Ala-NH(4-phenyl)CH 2 —, -Ala-Ala-Asn-NH(4-phenyl)CH 2 —, and combinations thereof;
[0040] R 7 is C 2-6 alkylene, or —(CH 2 CH 2 O) m —;
[0041] R 8 is selected from the group consisting of an amino acid, peptide consisting of up to 10 amino acids, C 1-6 alkyl, C 1-6 alkylene, substituted C 1-6 alkylene, —C(O)—NH—CHR 9 —CR 10 R 11 —, —NHC(O)—CHR 9 —CR 10 R 11 —, —(CH 2 CH 2 O) m —, -PAB-, -Val-Cit-NH(4-phenyl)CH 2 —, -Val-Ala-NH(4-phenyl)CH 2 —, -Ala-Ala-Asn-NH(4-phenyl)CH 2 —, and combinations thereof;
[0042] wherein R 9 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 1-6 alkylene, —(CH 2 CH 2 O) m —, —C(O)NH—, —NHC(O)—, —C(O)NH—(CH 2 ) p —SO 3 H, —C(O)NH—(CH 2 ) p —CO 2 H, —NHC(O)—(CH 2 ) p —SO 3 H, —NHC(O)—(CH 2 ) p —CO 2 H and combinations thereof;
[0043] R 10 and R 11 are each independently selected from the group consisting of hydrogen, C 1-6 alkyl, and combinations thereof;
[0044] wherein —R 6 OC(O)NR 5 — is connected to L 1 through R 6 ;
[0045] wherein —R 8 —S—S—R 7 — is connected to L 1 through R 8 ;
[0046] m is an integer from 1-24; and
[0047] p is an integer from 1-6, wherein the remaining values are as described above for Formula I.
[0048] Preferably, D has a structure of Formula II:
[0000]
[0000] whereby the wavy line indicates the point of attachment to X;
wherein R 1 is NH 2 or OR 2 , wherein R 2 is H, or C 1 -C 10 alkyl, and wherein R 3 is H or OH.
[0049] Preferably, the disclosed ADC is selected from the group consisting of:
[0000]
BRIEF DESCRIPTION OF THE FIGURES
[0050] FIG. 1 shows a comparison of in vitro cytotoxicity of ADC A (22) and ADC B on four cell lines, one cell line in each of the four panels of FIG. 1 .
[0051] FIG. 2 shows in vitro cytotoxity of ADC24 (see Table 2).
[0052] FIG. 3 shows in vitro cytotoxicity of ADC 22 (see Table 2) on various cell lines.
[0053] FIG. 4 shows in vitro cytotoxicity of ADC 26 on various cell lines.
[0054] FIG. 5 shows in vitro cytotoxicity of ADC 27 on various cell lines.
[0055] FIG. 6 shows in vitro cytotoxicity of ADC 25 on various cell lines.
[0056] FIG. 7 shows in vitro cytotoxicity of ADC 29 on various cell lines.
[0057] FIG. 8 shows efficacy of cMet/EGFR-22, cMet-22 and Nimo-22 in H292 xenograft: cMet/EGFR-22 and Nimo-22 significantly inhibited H292 tumor growth compared to PBS control group.
[0058] FIG. 9 shows a tumor size comparison for compound 29. cMet/EFFR-22 and Nimo-22 significantly reduced tumor size/Weight compared to PBS Control group. Nimo-22 had some complete tumor regression (4 out of 7 mice was tumor free).
[0059] FIG. 10 shows no significant cMet/EGFR-22, cMet-22, Nimo-22 treatment-related body weight loss was observed.
[0060] FIG. 11 shows cMet/EGFR-23, cMet-23 and Nimo-23 treated groups showed significantly reduced tumor volume compared to PBS Control group.
[0061] FIG. 12 shows cMet/EGFR-23, cMet-23 and Nimo-23 treated groups showed significantly reduced tumor weight compared to PBS Control group.
[0062] FIG. 13 shows that no body weight loss was observed in cMet-23, cMet/EGFR-23, and Nimo-23 treated group.
[0063] FIG. 14 shows that a single dose of cMet/EGFR-25 at 3 mg/kg or 1 mg/kg had no significant tumor growth inhibition in H1975 xenograft.
[0064] FIG. 15 shows that a single dose of cMet/EGFR-27 at 3 mg/kg or 1 mg/kg, or a single dose of cMet-27 had no significant tumor growth inhibition in HCC827 xenograft.
[0065] FIG. 16 shows that no significant body weight loss was observed with a single dose of cMet/EGFR-ADC27 at 3 mg/kg or 1 mg/kg, or a single dose of cMet-ADC27 at 0.3 mg/kg during the study.
DETAILED DESCRIPTION
[0066]
[0000]
TABLE 1
Examples of compounds synthesized (“Ab” stands for antibody).
Com-
pound
#
Structure
6
8
10
14
17
21
28
[0000]
TABLE 2
Examples of antibody drug conjugates of Formula I
Com-
pound
#
Structure
22
23
24
25
26
27
29
Definitions
[0067] As used herein, common organic abbreviations are defined as follows:
Ac Acetyl
[0068] aq. Aqueous
BOC or Boc tert-Butoxycarbonyl
Bu n-Butyl
° C. Temperature in degrees Centigrade
Cit Citrulline
[0069] DCM methylene chloride
DEPC Diethylcyanophosphonate
[0070] DIC diisopropylcarbodiimide
DIEA Diisopropylethylamine
DMA N,N-Dimethylacetamide
DMF N,N-Dimethylformamide
DMSO Dimethylsulfoxide
[0071] EDC 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide
Et Ethyl
[0072] EtOAc Ethyl acetate
Eq Equivalents
Fmoc 9-Fluorenylmethoxycarbonyl
g Gram(s)
[0073] h Hour (hours)
HATU 2-(1H-7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyl uronium
hexafluorophosphate
HOBT N-Hydroxybenzotriazole
HOSu N-Hydroxysuccinimide
[0074] HPLC High-performance liquid chromatography
LC/MS Liquid chromatography-mass spectrometry
Me Methyl
MeOH Methanol
MeCN Acetonitrile
mL Milliliter(s)
[0075] MS mass spectrometry
PAB p-aminobenzyl
RP-HPLC reverse phase HPLC
rt room temperature
t-Bu tert-Butyl
TEA Triethylamine
[0076] Tert, t tertiary
TFA Trifluoracetic acid
THF Tetrahydrofuran
[0077] TLC Thin-layer chromatography
μL Microliter(s)
[0078] Where used, a hyphen (-) designates the point to which a group is attached to the defined variable. A hyphen on the left side indicates connectivity to the left side structural component of formula (I) and hyphen on the right side indicates connectivity to the right side structural component of formula (I). For example, unless other specified when L 2 is defined as —(CH 2 CH 2 O) m —, it means that the attachment to L 1 is at the —CH 2 carbon and the attachment to X is at the oxygen atom.
General Synthesis Procedure—Formation of an Activated Ester (e.g. NHS) from an Acid
[0079] An acid was dissolved in DCM (methylene chloride) and DMF (N,N′dimethyl formamide) was added to aid dissolution if necessary. N-hydroxysuccinimide (1.5 eq) was added, followed by EDC.HCl (1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide) (1.5 eq). The reaction mixture was stirred at room temperature for 1 h until most of the acid was consumed. The progress of the reaction was monitored by RP-HPLC. The mixture was then diluted with DCM and washed successively with citric acid (aq. 10%) and brine. The organic layer was dried and concentrated to dryness. The crude product was optionally purified by RP-HPLC or silica gel column chromatography.
Example 1
Preparation of Compound 6
[0080]
[0081] To a solution of alpha-amainitin 1 (46 mg, 50 μmol) in anhydrous dimethylsulfoxide (DMSO) (1 mL) was added bis (4-nitrophenol) carbonate (17 mg, 55 μmol), followed by diisopropylethylamine (DIEA, 10 μL). The mixture was stirred at room temperature for 30 minutes. Compound 3 (12 mg) was added, followed by DIEA (10 μL). LC/MS indicated all the compound 2 was consumed after 1 h. All the solvents were removed under reduced the pressure and the residue was treated with trifluoroacetic acid (TFA) in dichloromethane (DCM) (20%, v/v, 2 mL). The reaction mixture was concentrated after 30 min and the residue was purified by reverse phase HPLC to give compound 4 as a white solid in TFA salt form after lyophilization (45 mg, 78%). MS: m/z 1033.4 (M+H+).
[0082] Compound 4 (45 mg) was dissolved in anhydrous dimethylformamide (DMF, 1 mL) and 9-Fluorenylmethyloxycarbonyl-valyl-citrullyl-(4-aminobenzyl)-(4-nitrophenyl)carbonate (Fmoc-Val-Cit-PAB-PNP, 38 mg) was added, followed by DIEA (20 μL). The mixture was stirred at room temperature for 2 h. LC/MS analysis indicated the completion of reaction. Piperidine (50 μL) was added and after 2 h, the reaction mixture was neutralized by addition of acetic acid (200 μL). The crude mixture was purified directly by reverse phase HPLC to give compound 5 as a white solid in TFA salt form after lyophilization (48 mg, 80%). MS: m/z 1438.7 (M+H+).
[0083] To a stirred solution of compound 5 (16 mg, 10 μmol) in DMF (1 mL) was added N-ε-Maleimidocaproyl oxysuccinimide ester (4 mg), followed by DIEA (4 μL). The mixture was stirred at room temperature for 2 h. The crude reaction mixture was injected to a Prep HPLC column for purification. Compound 6 was obtained a white solid after lyophilization. (12 mg). MS: m/z 1631.8 (M+H+).
Example 2
Preparation of Compound 8
[0084]
[0085] To a stirred solution of compound 5 (16 mg, 10 μmol) in DMF (1 mL) was added acid 7 (6 mg), followed by diisopropylcarbodiimide (5 μL). The mixture was stirred at room temperature for 2 h. The crude reaction mixture was injected to a Prep HPLC column for purification. Compound 8 was obtained a white solid after lyophilization. (8 mg). MS: m/z 1761.8 (M+H+).
Example 3
Preparation of Compound 10
[0086]
[0087] To a stirred solution of compound 2 (30 μmol) in DMSO (1 mL) was added amine 9 (40 mg), followed by DIEA (15 μL). The mixture was stirred at room temperature for 16 h. The crude reaction mixture was injected to a Prep HPLC column for purification. Compound 10 was obtained a white solid after lyophilization. (32 mg). MS: m/z 2046.2 (M+H+).
[0088] Compound 10 was converted to the corresponding activated ester following a general procedure prior to conjugating to an antibody.
Example 4
Preparation of Compound 14
[0089]
[0090] To a stirred solution of compound 2 (50 μmol) in DMSO (1 mL) was added amine 11 (65 mg) in DMF (1 mL), followed by DIEA (20 μL). The mixture was stirred at room temperature for 16 h. Piperidine (100 μL) was added. After 30 mins, the mixture was purified directly by reverse phase HPLC to give compound 12 in TFA salt form as a white solid (54 mg). MS: m/z 1862.1 (M+H+).
[0091] Compound 12 (20 mg) was dissolved in DMF (1 mL). Anhydride 13 (11 mg) was added, followed by DIEA (5 μL). The reaction mixture was stirred at room temperature for 5 minutes and purified by reverse phase HPLC to give compound 14 as a white solid after lyophilization (19 mg). MS: m/z 2203.9 (M+H+).
Example 5
Preparation of Compound 17
[0092]
[0093] To a stirred solution of compound 2 (50 μmol) in DMSO (1 mL) was added amine 15 (65 mg) in DMF (1 mL), followed by DIEA (20 μL). The mixture was stirred at room temperature for 16 h. Piperidine (100 μL) was added. After 30 mins, the mixture was purified directly by reverse phase HPLC to give compound 16 in TFA salt form as a white solid (49 mg). MS: m/z 1862.3 (M+H+).
[0094] Compound 16 (20 mg) was dissolved in DMF (1 mL). Anhydride 13 (11 mg) was added, followed by DIEA (5 μL). The reaction mixture was stirred at room temperature for 5 minutes and purified by reverse phase HPLC to give compound 17 as a white solid after lyophilization (20 mg). MS: m/z 2204.1 (M+H+).
Example 6
Preparation of Compound 21
[0095]
[0096] To a stirred solution of compound 2 (50 μmol) in DMSO (1 mL) was added amine 15 (25 mg) in DMF (1 mL), followed by DIEA (20 μL). The mixture was stirred at room temperature for 5 h. The solvents were removed under reduced pressure and the residue was dissolved in 20% TFA/DCM (2 mL). After 30 mins, the mixture was purified directly by reverse phase HPLC to give compound 19 as a white solid (31 mg). MS: m/z 1309.5 (M+NH 4 +).
[0097] To a stirred solution of compound 19 (25 mg, 20 μmol) in DMF (1 mL) was added acid 20 (16 mg), followed by diisopropylcarbodiimide (8 μL). The mixture was stirred at room temperature for 2 h. The crude reaction mixture was injected to a Prep HPLC column for purification. Compound 21 was obtained a white solid after lyophilization. (12 mg). MS: m/z 1791.4 (M+H+).
Example 7
Preparation of Compound 28
[0098]
[0099] To a stirred solution of compound 2 (50 μmol) in DMSO (1 mL) was added amine 30 (46 mg, 50 μmol) in DMF (1 mL), followed by DIEA (20 μL). The mixture was stirred at room temperature for 16 h. Piperidine (100 μL) was added. After 30 mins, the mixture was purified directly by reverse phase HPLC to give compound 31 in TFA salt form as a white solid (25 mg). MS: m/z 1640.5 (M+H+).
[0100] Compound 31 (20 mg, 11.4 μmol) was dissolved in DMF (1 mL). Anhydride 13 (8 mg) was added, followed by DIEA (5 μL). The reaction mixture was stirred at room temperature for 5 minutes and purified by reverse phase HPLC to give compound 28 as a white solid after lyophilization (16 mg). MS: m/z 1981.9 (M+H+).
Example 8
[0101] This example provides a comparative study, comparing two different amatinin conjugates shown as “A” and “B” below.
[0000]
Amanitin Antibody Conjugate Structure A (ADC 22)
[0102]
Amanitin Antibody Conjugate Structure B
[0103] A comparative study was carried out to evaluate the efficacy of amanitin antibody conjugate structure A wherein alpha-amaintin was attached to the linker via a cleavable carbamate bond (reported in this disclosure) and amanitin antibody conjugate structure B wherein alpha amanitin was attached through a non-cleavable ether bond (reported in WO2012/041504) in various in vitro cell killing assays ( FIG. 1 four panels for four different cell lines. ADC A completely outperformed ADC B in all 4 Her-2 positive cell lines tested.
Example 9
[0104] This example provides the results of EC50 assays (nM) of the designated drug conjugated antibodies measured in vitro in specified cells. The antibody used was an anti-HER2 IgG class of antibody. Seven breast cancer cell lines with various level of Her2 expression as indicated with plus or minus signs in the table below were plated in 96 well plate. The ADCs were serial diluted and added onto cells for treatment for 5 days. At the end of the study, cell proliferation was measured by Promega's CellTitreGlo. EC50 (in nM) was determined as the concentration of 50% cell growth inhibition. The selection criteria for a successful compound included high efficacy, such as killing cell lines with high expression of the target receptor, with EC50 less than 3 nM. Also, the successful candidate should have low toxicity and good therapeutic window, as determined by relatively low killing of the control cell line (MDA468) with low expression of the target receptor. Both ADCs 22 ( FIG. 3 ) and 24 ( FIG. 2 ) were selected as successful candidates with high efficacy and good therapeutic window.
Example 10
[0105] This example provides the results of EC50 assays (nM) of designated ADCs described herein measured in vitro in specified cells. The antibody used targets a receptor tyrosine kinase on cell surface. Eight cancer cell lines with various level of receptor expression, as indicated with plus or minus signs in the table below, were plated in 96 well plate. The ADCs were serial diluted and added onto cells for treatment for 5 days. At the end of the study, cell proliferation was measured by Promega's CellTitreGlo. EC50 (in nM) was shown below and determined as the concentration of 50% cell growth inhibition. The selection criteria for a successful compound includes high efficacy, such as killing cell lines with high expression of the target receptor, with EC50 less than 3 nM. Also, the successful candidate should have low toxicity and good therapeutic window, as determined by relatively low killing of the control cell lines (T-47D) with low expression of the target receptor. ADC 25 ( FIG. 6 ) shows good cell killing efficacy in cell lines H1993, HCC827, SNU-5, and H292, but did not show efficacy in Hs746T, EBC-1 and U 87. It showed good therapeutic window since it did not kill the negative control cell line T-47 D. ADC 26 ( FIG. 4 ) shows good cell killing activity in H1993 and SNu-5. However, it is not active in the other 6 cell lines. ADC 27 ( FIG. 5 ) shows excellent cell killing activity in H1993 (EC50=11 pM) and SNu-5 (EC50=75 pM). It also shows good efficacy in Hs746T (EC 50=0.4 nM). ADC 29 ( FIG. 7 ) shows good cell killing efficacy in cell lines Hs746T, but did not show efficacy in EBC-1, U87, HCC827, H1993 and T-47.
Example 11
[0106] This example provides the results for the efficacy of ADCs conjugated with small molecule 22, 23, 25, or 27 in a model of H292, HCC827, and H1975 Human Xenograft Tumor Growth in Nude Mice. HCC827, H292, H1975 cell lines were obtained from ATCC. The cells were cultured in RPMI 1640 1X (Corning 10-041-CV) medium with 10% FBS (Seradigm 1500-500) and penicillin streptomycin (Corning 30-002-CI) at 37° C. in a 5% carbon dioxide humidified environment. Cells were cultured for a period of 2 weeks and passaged 4 times before harvest. The cells were harvested with 0.25% trypsin (Corning 25-050-CI). Prior to injection, HCC827 cells were mixed in a 1:1 ratio of HBSS (Hank's balanced salt solution; Ward's 470180-784) and matrigel (Corning 354234) mixture, and 7 million cells per 0.2 ml were injected subcutaneously into the upper right flank of each mouse. H292 cells were resuspended in HBSS, and 5 million cells per 0.2 ml were injected subcutaneously into the upper right flank of each mouse. H1975 cells were resuspended in HBSS, and 3 million cells per 0.2 ml were injected subcutaneously into the upper right flank of each mouse.
[0107] Female Nu/Nu mice aged 5-7 weeks (Charles River) were used throughout these studies.
[0000] Upon receipt, mice were housed 5 mice per cage in a room with a controlled environment. Rodent chow and water was provided ad libitum. Mice were acclimated to laboratory conditions for 72 hours before the start of dosing. The animals' health status was monitored during the acclimation period. Each cage was identified by group number and study number, and mice were identified individually by ear tags.
[0108] The study design and dosing regimens are shown in Table 3.
[0000]
TABLE 3
Animals
Treatment
Tumor
per
volume/
Dose/
model
Groups
Group
route
Frequency
H292
1
7
PBS
200 μl/i.v.
0 mg/kg,
single dose
2
7
cMet/
200 μl/i.v.
3 mg/kg,
EGFR-22
single dose
3
7
cMet-22
200 μl/i.v.
3 mg/kg,
single dose
4
7
Nimo-22
200 μl/i.v.
3 mg/kg,
single dose
HCC827
1
7
PBS
200 μl/i.v.
0 mg/kg,
single dose
2
7
cMet/
200 μl/i.v.
3 mg/kg,
EGFR-23
single dose
3
7
cMet-23
200 μl/i.v.
3 mg/kg,
single dose
4
7
Nimo-23
200 μl/i.v.
3 mg/kg,
single dose
H1975
1
8
PBS
200 μl/i.v.
0 mg/kg,
single dose
2
8
cMet/
200 μl/i.v.
1 mg/kg,
EGFR-25
single dose
3
8
cMet/
200 μl/i.v.
3 mg/kg,
EGFR-25
single dose
HCC827
1
8
PBS
200 μl/i.v.
0 mg/kg,
single dose
2
8
cMet-27
200 μl/i.v.
0.3 mg/kg,
single dose
3
8
cMet/
200 μl/i.v.
1 mg/kg,
EGFR-27
single dose
4
8
cMet/
200 μl/i.v.
3 mg/kg,
EGFR-27
single dose
[0109] Tumor growth was monitored by measurement of tumor width and length using a digital caliper starting day 5-7 after inoculation, and followed twice per week until tumor volume reached ˜100-250 mm 3 . Tumor volume was calculated using the formula: Volume (mm 3 )=[Length (mm)×Width (mm) 2 ]/2. Once tumors were staged to the desired volume, animals were randomized, and mice with very large or small tumors were culled. Mice were divided into groups with animal numbers per group as indicated in study design. Mice were then treated intravenously (0.2 ml/animal) with either PBS or antibody conjugated with 22, 23, 25, or 27 as dose indicated in study design. Tumor growth was monitored, and each group of mice was sacrificed when the average tumor load for the control group exceeded 2000 mm 3 .
[0110] Tumor volume was measured twice weekly throughout the experimental period to determine TGI (tumor growth inhibition %). The body weight of each mouse was measured twice weekly by electric balance. Group average and standard deviation were calculated, and statistical analyses (one-way ANOVA with Dunnett's multiple comparison test; GraphPad Prism 6.0) was carried out. All treatment groups were compared with the PBS group. P<0.05 was considered statistically significant.
[0111] A single dose of cMet/EGFR-22 and Nimo-22 treatment at 3 mg/kg significantly inhibited H292 tumor growth when compared to PBS treated control group. While cMet-22 inhibited tumor growth in the first 10 days after treatment, tumor regained growth after 10 days ( FIGS. 8 and 9 ). In this study, a single dose of cMet/EGFR-22 and cMet-22 at 3 mg/kg showed skin rash at 3-6 days after treatment, and dry, flaky skin between day 6 to 14. Those skin issues recovered after day 14. There was no significant treatment-related body weight loss observed during the study. ( FIG. 10 ). Although there was body weight loss during the first week in cMet/EGFR-22 treated group, the weight loss was transient and less than 10% of total body weight. Also, the animals regained weight and was healthier overall compared to PBS treated control group
[0112] A single dose of cMet/EGFR-23, cMet-23, or Nimo-23 treatment at 3 mg/kg each significantly inhibited H292 tumor growth when compared to PBS treated control group ( FIGS. 11 and 12 ). No body weight loss was observed in cMet-23, cMet/EGFR-23, and Nimo-23 treated group (3 mg/kg) ( FIG. 13 ).
[0113] A single dose of cMet/EGFR-25 at 3 mg/kg or 1 mg/kg had no significant tumor growth inhibition in H1975 xenograft ( FIG. 14 ). A single dose of cMet/EGFR-27 at 3 mg/kg or 1 mg/kg, or a single dose of cMet-27 at 0.3 mg/kg had no significant tumor growth inhibition in HCC827 xenograft ( FIG. 15 ). No significant body weight loss was observed during the study ( FIG. 16 ). | There is disclosed derivatives of amanitin conjugated to a targeting antibody to form an ADC (antibody drug conjugate). | 0 |
This application is a continuation of PCT/JP99/02198, which was filed Apr. 26, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sweetener composition having excellent solubility, which includes N-{N-(3,3 -dimethylbutyl)-L-α-(aspartyl}-L-phenylalanine 1-methyl ester (Neotame, abbreviated hereinafter to “NM”) and Aspartame (abbreviated hereinafter to “APM”) as active ingredients.
2. Discussion of the Background
It is reported that the sweetness strength or sweetening potency of the synthetic high-potency sweetener, NM, is about 10,000 times that of sucrose in terms of weight ratio (Japanese Patent Kohyou Publication JP-A-8-503206). The properties of sweetness quality for NM are not reported in detail, but the present inventors have found that such a compound has an extremely weak early taste (i.e., wherein the sweetener, when put in the mouth, tastes sweet as early as sucrose), and is extremely strong in later taste (i.e., wherein the sweetener tastes sweet later than sucrose). Further, NM has a strong astringent taste. Accordingly, the balance of the quality of sweetness properties for NM is poor when compared to sucrose. Sucrose is generally regarded as the standard for evaluating the properties or characteristics of the quality of sweetness.
It is also reported that the sweetness strength of the amino acid type synthetic sweetener, APM, is about 200 times that of sucrose in weight ratio (See Japanese Patent Kokoku Publication JP-B-47-3 1031). APM has a sweetness quality characterized by a weak early taste and a strong later taste as compared with sucrose.
Various proposals have been made for the improvement in quality of the sweetness of NM and APM, particularly for the improvement in quality of the sweetness of the latter, thus achieving considerable effects. However, NM and APM have a further problem with dissolution characteristics; that is, NM and APM powders (crystalline raw powders) have poor dissolution characteristics in water (that is, they are not readily dissolved due to their easy formation of agglomerates, or their dissolution rate is low, etc.). Poor dissolution characteristics, which may result from the formation of agglomerates, or the like is significantly disadvantageous to industrial production, since the production yield of foods and drinks such as soft drinks that contain NM or APM to confer sweetness is undesirably reduced.
For improvement of the dissolution rate of APM, various proposals using pelletizing methods (granulations) have been made. However, these methods are not satisfactory in that they require further improvement of dissolution rate (See Japanese Patent Kokai Publication JP-A-4-346769 etc.) and require the simultaneous use of a relatively large amounts of excipients (See Japanese Patent Kokai Publications JP-A-49-126855, JP-A-50-19965, JP-A-57150361 etc.).
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is thus to improve the dissolution rate of NM and APM.
The present inventors have unexpectedly found that the dissolution rate of NM, and particularly that of a specific crystal of NM (which may be also called “C-type crystal”) is improved by APM in a certain range, and vice versa, and further that the dissolution rate of a mixture of both of them at a specific mixing range is higher than not only that of NM alone but also that of APM alone, and this phenomenon is particularly remarkable and significant when NM is in the form of C-type crystal.
Accordingly, one embodiment of the present invention provides a sweetener composition, which includes:
N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester; and
Aspartame, wherein a ratio of the Aspartame to a total amount of the Aspartame and the N-{N-(3,3 -dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester is in the range of 10 to 99.5% by weight.
Another embodiment of the present invention provides a drink composition, which includes:
a mixture of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester;
Aspartame; and
a potable liquid, wherein
a ratio of the Aspartame to a total amount of the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester and the Aspartame is in the range of 10 to 99.5% by weight.
Another embodiment of the present invention provides a method for preparing a sweetener composition, which includes:
drying an A-type crystal of N-{N-(3,3 -dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester to obtain a C-type crystal of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester.
Another embodiment of the present invention provides a method for producing a sweetener, which includes:
admixing N-{N-(3 ,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester with Aspartame, wherein a ratio of the Aspartame to a total amount of the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester and the Aspartame is in the range of 10 to 99.5% by weight.
Another embodiment of the present invention provides a method for improving the dissolution rate of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester, which includes, prior to dissolving the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester, admixing the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester with Aspartame, wherein a ratio of the Aspartame to a total amount of the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester and the Aspartame is in the range of 10 to 99.5% by weight.
BRIEF DESCRIPTION OF THE FIGURES
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 : A powder X-ray diffraction pattern of A-type crystals.
FIG. 2 : A powder X-ray diffraction pattern of C-type crystals.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the preferred embodiments of the invention.
Preferably, the NM is in the form of a powder or crystals in the mixture. Likewise, the APM is preferably in the form of a powder or crystals in the mixture. Preferably, the mixture itself is in the form of a powder or crystals. Most preferably, the powder and/or crystals is a dry, free-flowing powder or crystals.
The crystalline form of powdery NM that is one of the active ingredients in the novel sweetener composition of the present invention is not particularly limited. For example, it may be either the known crystals (which may be also called “A-type crystal(s)”) or the “C-type” crystal(s) described below. The C-type is significantly superior to the former and is thus most preferred.
In an additional remark, the crystal structure of known NM as disclosed in W095/30689, the entire contents of which are hereby incorporated by reference, is described as IR spectrum data therein. Further, the present inventors analyzed the structure of its single crystal, and as a result, they confirmed that this crystal is a monohydrate, and when measured by powder X-ray diffractometry, the crystal shows characteristic peaks in diffractive X-ray (X-ray diffraction pattern) at diffraction angles of at least 6.0°, 24.8°, 8.2°, and 16.5° (2θ, CuKα radiation (ray;line)). For the sake of convenience, the present inventors referred to this crystal as “A-type crystal”.
The present inventors have also found that the water content of dry A-type crystal is usually in the range of 3 to 6% by weight (including crystal water), but if this A-type crystal is further dried until its water content is reduced to less than 3%, a novel crystal of N-(3,3-dimethylbutyl)-APM with improved dissolution rate wherein the crystal water has been eliminated, is obtained, and this novel crystal was referred to as “C-type crystal”.
Thus, a preferred embodiment of the present invention provides a novel form of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester, which is referred to herein as the “C-type crystal”, methods of making, and methods of use.
When measured by powder X-ray diffractometry (using CuKαradiation), this C-type crystal shows characteristic peaks in the X-ray diffraction pattern at diffraction angles different from those of the A-type crystal, that is, at diffraction angles (20) of at least 7.1°, 19.8°, 17.3°, and 17.7°. Reference is made to Reference Examples 1 to 3 below.
APM that is the other active ingredient in the novel powdery sweetener composition of the present invention can be used in the form of e.g. the hydrated crystals, to which it is not particularly limited. Preferably, the APM is in the form of a dry, free-flowing powder.
The mixing ratio of NM and APM used in the novel sweetener composition of the present invention is in the range of 10 to 99.5% by weight in terms of the ratio of APM to 5 the total amount of both NM and APM. If the ratio of APM used therein is less than 10% by weight, the effect of APM on the promotion of NM dissolution is decreased, whereas with the ratio of more than 99.5% by weight, the effect of APM on the promotion of NM dissolution is hardly observed. More preferably, the mixing ratio ranges from 20 to 97%, more particularly preferably, the mixing ratio is 50 to 97%, more particularly preferably 55 to 10 95%, most preferably 60 to 90%, and most particularly preferably 75 to 85%. These ranges include all values and subranges therebetween, including 12%, 18%, 22%, 35%, 45%, 58% and 91%.
C-type crystals, when mixed with APM in the range of 10 to 99.5%, have significant promoting effect on dissolution rate and are thus superior to A type crystals, as can be seen from Tables 1 and 2 below. If C-type crystals are used as powdery NM, the ratio of APM to the total amount of NM and APM used therein is preferably in the range of 10 to 97% by weight, and more preferably 20 to 97%, more particularly preferably, the mixing ratio is 50 to 97%, more particularly preferably 55 to 95%, most preferably 60 to 90%, and most particularly preferably 75 to 85%. These ranges include all values and subranges therebetween, including 12%, 18%, 22%, 35%, 45%, 58% and 91%.
The dissolution rate of a mixture of NM C-type crystals and APM in the range of 10 to 90% by weight of APM thereto is higher than that of NM A-type crystals alone, and the dissolution rate of a mixture of NM C-type crystals and APM in the range of 50 to 97% by weight of APM thereto is higher than the dissolution rate of not only that of NM C-type crystals alone but also that of APM alone. Each of the above ranges includes all values and subranges therebetween, including 12%, 18%, 22%, 35%, 45%, 58% and 89%.
If NM and APM are separately and at the same time added to water (i.e., separate but simultaneous addition) without being previously mixed, preferably at the predetermined ratio, neither NM nor APM affect their mutual dissolution rate, and in this case, the dissolution rate as a whole is low but identical to the dissolution rate of one of them which has a lower dissolution rate when used alone. See, e.g., Experimental Example 3 below.
For the purpose of easy application or improvement in quality of sweetness, the novel sweetener composition of the present invention, similar to the case of conventional high-potency sweetener compositions, can incorporate diluents (thinners) and excipients such as sugar alcohols, oligosaccharide, food fibers (dietary fibers) and the like, or other synthetic high-potency sweeteners such as Alitame, saccharin, Acesulfame K etc. as necessary in an amount within such a range as not to spoil the NM and APM dissolution rate (solubilities) improved by the present invention. The diluents and excipients in this case include low-potency sweeteners such as sucrose, glucose or the like.
The sweetener composition according to the present invention is particularly suitable for use in food and drink compositions for human and animal consumption. Preferred examples include without limitations beverages, table-top sweeteners, sweetener packets, candies, ice cream, coffee, tea, cereal, liquid sweeteners, low-calorie sweeteners, gelatin desserts, bread, cookies, fruit flavored beverages, cake mixes, fruit juices, syrups, salad dressings, pet foods, carbonated and non-carbonated soft drinks, foodstuffs, and the like. The composition of the present invention is also suitable for other applications such as cough medicines, cough drops and tonics. The composition of the present invention may be suitably mixed with a diluent or solvent including aqueous-based, alcohol-based, mixed aqueous/alcohol-based, water, propylene glycol, a water/propylene glycol mixture, ethanol or a water/ethanol mixture. Preferably, the sweetener composition of the present invention may be used alone or will make up anywhere from 0.1% to greater than 99% by weight of the food or drink composition, more preferably 1-95%, more particularly preferably 2-90%, more especially preferably 5-85%, most preferably 10-75%, most particularly preferably 20-65%, and most especially preferably 30-55% by weight, based on the total weight of the food or drink composition. These ranges include all values and subranges therebetween, including 4%, 14%, 22%, 43%, 49%, 82% and 91%.
EXAMPLES
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified. The amounts are given as percentages by weight, except where otherwise mentioned.
Reference Example 1
Preparation of NM
The following were introduced successively under stirring to a reactor equipped with an agitating blade for ensuring very efficient transfer of gaseous hydrogen to a liquid layer. That is, 700 ml ion exchanged water, 4.21 ml of acetic acid, 20 g of 10% palladium carbon, 1,300 ml of methanol, 56 g of Aspartame and 25 ml of 3,3-dimethylbutylaldehyde were introduced.
The reactor was filled with a nitrogen gas stream, and then the reaction mixture was hydrogenated at a H 2 gas flow rate of 200 ml/min. at room temperature. The progress of this reaction was monitored by sampling the reaction mixture and analyzing the product in high performance liquid chromatography (HPLC). After the hydrogenation reaction for 6 hours, this reaction was terminated by filling the reactor with a nitrogen gas and filtering the reaction mixture through a fine pore filter (0.45 μm) to remove the catalyst.
As a result of the analysis of the resulting filtrate (1,494 g), the yield was 81%. Subsequently, this filtrate was concentrated to 281 g to remove the methanol, and crystals were precipitated under stirring at 10° C. overnight. Finally, 87 g white wet crystals of NM (yield: 77%) were obtained at a high purity (99% or more, HPLC)
Reference Example 2
Production of A-type crystals
A part of NM prepared in Reference Example 1 was used to prepare 100 g aqueous solution of NM at a concentration of 3% by weight (dissolved at 60° C.) . Then, the solution was cooled from 60° C. to 30° C. for 5 minutes under stirring. When the liquid temperature was reached to 30° C., crystallization of white crystals was initiated. After overnight aging under the liquid temperature kept at 30° C., the crystals were collected on a filter paper.
(a) The diffractive X-ray (X-ray diffraction pattern) of the wet crystals obtained above was measured by powder X-ray diffractometry (diffractometer) using CuKα ray(radiation). The obtained powder X-ray diffraction pattern is shown in FIG. 1 .
As is evident from the pattern of the figure, the wet crystals showed characteristic diffraction peaks at least 6.0°, 24.8°, 8.2°and 16.5°, and they were A-type crystals.
Further, (b) the wet crystals were placed in a vacuum dryer set at 50° C., and dried until their water content was reduced to 5% by weight. The dried crystals thus obtained were measured by powder X-ray diffractometer using CuKα Radiation (ray) , indicating that the crystals were A-type crystals as well.
Further, as a result of IR spectrum (KBr) measurement, its values agreed with those described in W095/30689, the entire contents of which being hereby incorporated by reference.
Reference Example 3
Production of C-type crystals
The dried A-type crystals with a water content of 5% by weight described above were continued to be dried in the vacuum dryer until their water content was reduced to 0.8% by weight.
The X-ray diffraction pattern of the dried crystals was measured by powder X-ray diffractometry (diffractometer) using CuKα ray. The thus obtained powder X-ray diffraction pattern is shown in FIG. 2 .
As is evident from the pattern of the figure, the dried crystals showed characteristic diffraction peaks at least at 7.1°, 19.8 17.3°, and 17.7°. As described above, the crystals are C-type crystals.
Experimental Example 1
(Dissolution rate of raw (original) powders each from NM C-type crystals and APM, and a mixture thereof) A predetermined amount of the sample was introduced into 900 ml water (20° C.) in a 1-L elution tester (the Japanese Pharmacopoeia, Paddle method, 100 rpm) and its dissolution time was measured (end point was visually confirmed).
Specifically, 1 g of sample taken from each mixture consisting of NM C-type crystal raw powder (average particle size of about 100 μm) and APM raw powder (average particle size of about 15 μm, IB-type bundled crystals) at the predetermined various ratios (APM content (% by weight)) shown in Table 1 below, was weighed, and then measured for its dissolution time. For comparison, 1.00 g, 0.90 g, 0.50 g, 0.10 g, 0.03 g, and 0.005 g samples were taken from said NM raw powder, and then their dissolution times were determined in the same manner as above. For the same purpose, 1.00 g, 0.97 g, 0.90 g, 0.50 g, and 0.10 g samples were taken from said APM raw powder, and then their dissolution times were determined in the same manner.
The dissolution time (min) (time needed for the dissolution) of each sample is shown in Table 1 below.
TABLE 1
Dissolution times of NM C-type crystals, APM raw
(original) powder, and mixture thereof
NM C-type crystals alone
(original powder)
Weight of NM
Dissolution
APM alone (original powder)
C-type crystals
time
Weight of APM
Dissolution time
1.00 g
62 min
0.10 g
10 min
0.90
60
0.50
20
0.50
55
0.90
27
0.10
40
0.97
29
0.03
30
1.00
30
0.005
4
—
—
Mixture (1 g)
Content of APM
Weight of
original powder
APM
Weight of NM
Dissolution time
10 weight %
0.10 g
0.90 g
25 min
50
0.50
0.50
15
90
0.90
0.10
8
97
0.97
0.03
18
99.5
0.995
0.005
25
As can be seen from this table, the dissolution rate (solubility) of the mixture thereof (the sweetener composition of the present invention) is always remarkably and significantly improved as compared with not only those of the NM C-type raw (original) crystals alone but also those of the APM alone.
The degrees of sweetness of NM and APM are respectively about 10,000 and about 200 times that of sucrose, as described above. From this viewpoint, the dissolution time of 1 g mixture should be compared with the dissolution time of an amount of NM necessary to achieve the same degree of sweetness, but even in such comparison, there is the promoting action of APM on the dissolution of NM, as follows. That is, the sweetness of 1 g mixture containing 50% APM raw (original) powder is equal to the sweetness of 0.51 g of NM alone, and the dissolution time of the former is 15 minutes, while the dissolution time of the latter is about 55 minutes, so there is a significant difference therebetween.
Experimental Example 2
(Dissolution rate of raw (original) powders each from NMA-type crystals and APM, and a mixture thereof)
The same experiment as that in Experimental Example 1 was conducted except that NM A-type crystal original powder (average particle size of 100 μm) was used in place of NM C-type crystal original powder.
The dissolution time (min) of each sample is shown in Table 2.
TABLE 2
Dissolution times of NM A-type crystals, APM original
powder, and mixture thereof.
NM A-type crystals alone
(original powder)
Weight of NM
Dissolution
APM alone (original powder)
A-type crystals
time
Weight of APM
Dissolution time
1.00 g
42 min
0.10 g
10 min
0.90
40
0.50
20
0.50
35
0.90
27
0.10
16
0.97
29
0.03
10
1.00
30
0.005
—
—
—
Mixture (1 g)
Content of APM
Weight of
original powder
APM
Weight of NM
Dissolution time
10 weight %
0.10 g
0.90 g
35 min
50
0.50
0.50
25
90
0.90
0.10
23
97
0.97
0.03
29
99.5
0.995
0.005
30
As can be seen from this table, the dissolution rate of the mixture (the sweetener composition of the present invention) is improved remarkably and significantly as compared with NM A-type crystals original powder alone.
It can also be seen that the dissolution rate of the mixture at a range of the certain mixing ratios (50 to 97% by weight of APM) is superior to that of APM powder alone (original powder).
In a similar comparison to that in Experimental Example 1, there is the promoting action of APM on the dissolution of NM, for example, as follows. That is, the sweetness of 1 g mixture containing 50% APM original powder is equal to the sweetness of 0.51 g of NM alone, and the dissolution time of the former is 25 minutes, while the dissolution time of the latter is about 35 minutes, so there is a significant difference therebetween.
Experimental Example 3
(Separate addition of NM original powder and APM original powder)
The same NM and APM as in Experimental Example 1 were used, and the dissolution time was determined in the same manner as that in Experimental Example 1.
That is, 0.5 g each of both of them was weighed (1.0 g in total) and introduced simultaneously without being previously mixed, into the elution tester (separate addition). The results are shown in Table 3 below. For reference, the dissolution time of 0.5 g NM original powder alone (Experimental Example 1) is also shown together in the table.
TABLE 3
Dissolution time of NM and APM when separately added
Separate addition (1 g in total)
NM C-type crystals alone
(0.5 g NM C-type crystals/0.5 g
(0.5 g)
APM original powder)
55 minutes
55 minutes
From this table, the improvement of NM dissolution rate (solubility) by APM is not observed when NM and APM are separately added without being previously mixed.
According to the present invention, Aspartame (APM) is mixed with Neotame (NM) whereby poor dissolution characteristics of NM can be significantly improved, and further, the dissolution rate of APM can also be improved depending on the mixing ratio.
According to the present invention, Aspartame (APM) is mixed with Neotame (NM) whereby the poor dissolution characteristics (solubility) of NM can be significantly improved, and simultaneously a sweetener excellent in quality of sweetness can be easily obtained. Accordingly, the present invention is advantageous particularly for use in drinks where a sweetener is dissolved in industrial production, but the present invention is not limited thereto and can be used as an improved sweetener composition in any uses.
Having now fully described this invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.
This application is based on International Application No. PCT/JP99/02198, filed Apr. 26, 1999, and Japanese Patent Application No. 10-125989, filed May 8, 1998, the entire contents of each of which being hereby incorporated by reference, the same as if set forth at length. | One embodiment of the present invention provides a sweetener composition, which includes N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester, and Aspartame, wherein a ratio of the Aspartame to a total amount of the Aspartame and the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester is in the range of 10 to 99.5% by weight, methods of making and of using. Another embodiment of the present invention provides a method for preparing a sweetener composition, which includes drying an A-type crystal of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester to obtain a C-type crystal of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester. Another embodiment of the present invention provides a method for producing a sweetener, which includes admixing N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester with Aspartame, wherein a ratio of the Aspartame to a total amount of the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester and the Aspartame is in the range of 10 to 99.5% by weight. Another embodiment of the present invention provides a method for improving the dissolution rate of N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester, which includes, prior to dissolving the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester, admixing the N-{N-(3,3-dimethylbutyl)-L-α-aspartyl }-L-phenylalanine 1-methyl ester with Aspartame, wherein a ratio of the Aspartame to a total amount of the N-{N-(3,3-dimethylbutyl)-Lα-aspartyl}-L-phenylalanine 1-methyl ester and the Aspartame is in the range of 10 to 99.5% by weight. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to torque limiting mechanisms, especially those used in geared rotary actuators (“GRAs”) for actuating aircraft control surfaces.
BACKGROUND OF THE INVENTION
[0002] GRAs are used, for example, in aircraft for actuating flaps, slats, and other aerodynamic control surfaces. GRAs typically incorporate a torque limiter for limiting transmission of torque between an input shaft and an output shaft of the GRA in the event of a malfunction. Conventional torque limiting devices include a disc brake pack having multiple brake discs utilizing frictional contact between adjacent discs for limitation of torque transmission. Such torque limiting devices have several inherent problems. Because the friction coefficient is very sensitive to lubrication, changes in the lubrication environment can cause the friction coefficient to drop below a critical value required to provide a positive torque limit. This can cause the torque limiter to exceed the maximum torque limit setting. If too little lubrication is present in the disc brake pack and moisture is present, the disc brake pack can freeze up, causing nuisance lock-ups. When adequate lubrication is provided to the disc brake pack, considerable viscous drag is present. The viscous drag is not a problem as long as it is accurately predicted and accounted for in the torque limiter setting and power control unit (“PCU”) sizing, however, such viscous drag causes inefficiency in the system and higher limit loads on components downstream of the torque limiter.
[0003] Known torque limiting mechanisms respond to input torque to the GRA rather than GRA output torque. Consequently, the lock-up torque limit setting must be significantly higher than the maximum operating torque of the GRA, and therefore the GRA is designed with a relatively large limit output torque. As a result, each GRA has a greater weight associated therewith, and structure downstream from the GRA is increased. Given that an aircraft may have many GRAs, for example thirty or more, a cumulative weight cost is imposed on the aircraft design.
[0004] There is a need for a torque limiter that solves the problems described above.
SUMMARY OF THE INVENTION
[0005] The present invention provides a torque limiter that limits transmission of torque between an input shaft rotatable about an input axis and an output shaft rotatable about an output axis, and does so in a manner that solves the problems discussed above. In an illustrative embodiment of the present invention, the torque limiter is incorporated in a GRA for actuating an aircraft control surface, e.g. a flap or a slat movable relative to a fixed wing. The torque limiter of the present invention is characterized by the fact that it is responsive to output torque associated with the output shaft instead of input torque associated with the input shaft.
[0006] A torque limiter of the present invention generally comprises a structural ground and a gear assembly for transmitting rotational motion of the input shaft to the output shaft. The gear assembly includes a reference gear coupled to the structural ground such that movement of the reference gear relative to the structural ground is dependent upon an output torque at the output shaft. The reference gear is stationary relative to the structural ground when the output torque is below an output torque limit, and the reference gear moves relative the structural ground when the output torque exceeds the output torque limit.
[0007] In accordance with a specific embodiment of the invention, the gear assembly may also include an input gear rotated relative to the structural ground in response to rotation of the input shaft, a driven gear associated with the output shaft such that the output shaft is rotated in response to rotation of the driven gear, and at least one transmitting gear engaging the input gear, the reference gear and the driven gear such that rotation of the input shaft causes rotation of the output shaft without causing movement of the reference gear relative to the structural ground unless the torque limit is exceeded. The reference gear moves relative to the structural ground when the torque limit is exceeded, for example the reference gear may rotate about its axis relative to the structural ground. The gear assembly may be configured as a planetary gear assembly in which the input gear is arranged as a sun gear on the input shaft, the reference gear is arranged as a ring gear about the input gear, and the at least one transmitting gear includes a plurality of planet gears arranged between the input gear and the reference gear. The input gear, reference gear, and driven gear may be arranged coaxially along a main axis, and the planet gears may extend axially in a direction parallel to the main axis of the assembly.
[0008] In a further aspect of the present invention, the torque limiter may comprises a lockout mechanism for preventing transmission of torque between the input shaft and the output shaft after the torque limit has been exceeded, wherein the lockout mechanism redirects torque from the input shaft to the structural ground after the torque limit has been exceeded. The lockout mechanism may comprise a pawl carrier arranged to rotate with the input shaft, and at least one pawl member pivotally coupled to the pawl carrier. The lockout mechanism may further comprise a lockout ring including at least one stop extending radially inward, wherein the lockout ring is arranged along the main axis and is axially displaceable from a non-lockout position wherein each stop is radially clear of each pawl member to a lockout position wherein each stop radially interferes with each pawl member. A spring may be arranged to urge the lockout ring toward the non-lockout position, and a plurality of ball bearings may be seated between the lockout ring and the reference gear. The ball bearings maintain the lockout ring in the non-lockout position when the lockout ring and the reference gear are in a predetermined angular orientation about the main axis relative to one another, and displace the lockout ring toward the lockout position when the reference gear rotates about the main axis relative to the lockout ring. When activated by rotation of the reference gear, the lockout mechanism may redirect input torque through the lockout ring to the structural ground.
BRIEF DESCRIPTION OF THE DRAWING VIEWS
[0009] The invention will be described in detail below with reference to the accompanying drawing figures, in which:
[0010] FIG. 1 is a perspective view of a GRA formed in accordance with an embodiment of the present invention;
[0011] FIG. 2 is a cross-sectioned perspective view showing the GRA of FIG. 1 ;
[0012] FIG. 3 is another cross-sectioned perspective view showing the GRA of FIG. 1 ;
[0013] FIG. 4 is a longitudinal cross-sectional view of the GRA shown in FIG. 1 ;
[0014] FIG. 5 is a transverse cross-sectional view of the GRA taken generally along the line A-A in FIG. 4 ;
[0015] FIG. 6 is a transverse cross-sectional view of the GRA taken generally along the line B-B in FIG. 4 ;
[0016] FIG. 7 is a transverse cross-sectional view of the GRA taken generally along the line C-C in FIG. 4 ;
[0017] FIG. 8 is a transverse cross-sectional view of the GRA taken generally along the line D-D in FIG. 4 ;
[0018] FIG. 9 is a perspective view showing a lockout mechanism of the GRA according to an embodiment of the present invention;
[0019] FIGS. 10A and 10B are enlarged cross-sectional views illustrating axial displacement of a lockout ring of the lockout mechanism from a non-lockout position to a lockout position when the torque limit is exceeded;
[0020] FIGS. 11A-11E are a series of transverse cross-sectional views illustrating operation of the lockout mechanism when the torque limit is exceeded;
[0021] FIGS. 12A-12E are a series of transverse cross-sectional views illustrating resetting of the lockout mechanism by counter-rotation of a pawl carrier of the lockout mechanism; and
[0022] FIG. 13 is a detailed cross-sectional view illustrating an asymmetrical ball pocket in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIGS. 1-7 depict a GRA 10 embodying the present invention. GRA 10 may be used in an aircraft control surface actuation system or in other applications involving torque transmission. GRA 10 is configured to transmit torque between an input shaft 12 rotatable about an input axis and an output shaft 14 rotatable about an output axis. In the current embodiment, the input axis and output axis coincide with one another along a main axis 11 .
[0024] GRA 10 comprises a structural ground in the form of an outer housing 16 that may include a housing shell 18 , a housing end plate 20 at an end of housing shell 18 , and a spacer ring 22 held in an axially fixed location adjacent housing end plate 20 . Spacer ring 22 may define a ring-shaped radial step surface 24 . Input shaft 12 may be rotatably supported at an input end of housing 16 by a rotary bearing 13 . Output shaft 14 may be rotatably supported at an end of input shaft 12 by another rotary bearing 15 .
[0025] GRA 10 also comprises a gear assembly for transmitting rotational motion of input shaft 12 to output shaft 14 . As shown in the illustrated embodiment, the gear assembly may include an input gear 26 , a reference gear 28 , a driven gear 30 , and at least one transmitting gear 32 . Input gear 26 may be fixedly mounted on input shaft 12 or integrally formed with the input shaft such that it rotates relative to housing 16 in response to rotation of the input shaft. Reference gear 28 is coupled to housing 16 such that the reference gear does not move relative to housing 16 unless a torque limit is exceeded. For example, reference gear 28 may be in the form of an internally-toothed ring gear held within housing 16 such that the reference gear will not rotate about main axis 11 relative to housing 16 unless the reference gear is subjected to torque about main axis 11 that exceeds the torque limit. Driven gear 30 is associated with output shaft 14 , for example by fixedly connecting the driven gear to output shaft 14 or integrally forming the driven gear with output shaft 14 , wherein output shaft 14 is rotated in response to rotation of driven gear 30 . As shown in the illustrated embodiment, driven gear 30 may be an internally-toothed ring gear.
[0026] The at least one transmitting gear 32 engages input gear 26 , reference gear 28 and driven gear 30 such that rotation of input shaft 12 causes rotation of output shaft 14 without causing movement of reference gear 28 relative to the structural ground provided by housing 16 unless the torque limit is exceeded. When the torque limit is exceeded, reference gear 28 moves relative to the structural ground (i.e. housing 16 ) by rotating about main axis 11 relative to housing 16 .
[0027] As shown in the figures, the gear assembly may be a planetary gear assembly in which input gear 26 is arranged as a sun gear on input shaft 12 , reference gear 28 is arranged as a ring gear about the input gear, and the at least one transmitting gear 32 includes a plurality of planet gears arranged between input gear 26 and the reference gear 28 . In the depicted embodiment, the plurality of planet gears (i.e. transmitting gears 32 ) extend axially in a direction parallel to main axis 11 . Input gear 26 and driven gear 30 may be arranged coaxially with one another along main axis 11 . Furthermore, reference gear 28 may be arranged coaxially with input gear 26 and driven gear 30 along main axis 11 . Transmitting gears 32 may be arranged about input gear 26 , and each transmitting gear may include a first toothed portion 32 A meshing with input gear 26 and reference gear 30 , a second toothed portion 32 B meshing only with reference gear 28 , and a third toothed portion 32 C meshing only with driven gear 30 .
[0028] As mentioned above, reference gear 28 moves relative to housing 16 when the torque limit is exceeded. Reference gear 28 may be coupled to housing 16 by frictional contact such that the torque limit corresponds to a torque necessary to overcome static friction associated with the frictional contact. The frictional contact may include frictional contact between a cylindrical exterior surface of reference gear 28 and a cylindrical interior surface of housing shell 18 . The frictional contact may also include an annular end surface 28 A of reference gear 28 and a radial step surface 24 of housing 16 . The frictional contact between end surface 28 A and radial step surface 24 may be spring-loaded, for example by an axially-loaded spring or spring pack 36 . Spring 36 may be a Belleville spring, for example.
[0029] Additional reference is now made to FIGS. 8 through 12E . GRA 10 may further comprise a lockout mechanism generally identified by reference numeral 40 , for preventing transmission of torque between input shaft 12 and output shaft 14 after the torque limit has been exceeded. Lockout mechanism 40 may operate by redirecting torque from input shaft 12 to the structural ground provided by housing 16 after the torque limit has been exceeded.
[0030] Lockout mechanism 40 may comprise a pawl carrier 42 arranged to rotate with input shaft 12 , and at least one pawl member 44 pivotally coupled to pawl carrier 42 . Lockout mechanism 40 may also comprise a lockout ring 46 including at least one stop 48 extending radially inward, wherein the lockout ring is arranged along main axis 11 . In the described embodiment, lockout ring 46 is axially displaceable from a non-lockout position (see FIG. 10A ) wherein each stop 48 of lockout ring 46 is radially clear of each pawl member 44 to a lockout position wherein each stop 48 of lockout ring 46 radially interferes with each pawl member 44 (see FIG. 10B ). Lockout ring 46 may be mounted in housing shell 18 by axial slide pins 49 received in corresponding external axial grooves in lockout ring 46 and internal axial grooves within housing shell 18 , whereby lockout ring 46 is free to move axially through a range, but is prevented from rotating about main axis 11 relative to housing 16 . Exactly two pawl members 44 , or a different number of pawl members 44 , may be provided. If more than one pawl member 44 is provided, the pawl members 44 may be arranged at regular angular intervals about main axis 11 . Exactly four stops 48 , or a different number of stops 48 , may be provided. If more than one stop 48 is provided, the stops 48 may be arranged at regular angular intervals about main axis 11 .
[0031] As best seen in FIGS. 8 , 9 , and 10 A, each pawl member 44 may be pivotally mounted on pawl carrier 42 by a pivot pin 50 , and releasably held in a neutral pivot position as shown in FIG. 8 by a radially-directed spring-loaded ball plunger 52 seated in pawl carrier 42 . When pawl member 44 is in its neutral position, ball plunger 52 engages a central recess 54 of the pawl member. Each pawl member 44 may also include lateral recesses 56 on opposite sides of central recess 54 for engagement by ball plunger 52 when pawl member 44 pivots about an axis defined by pivot pin 50 , as will be described later below. Each pawl member 44 may have a pair of catch members 58 extending in opposite lateral directions relative to pivot pin 50 , and an outer tab 60 in radial alignment with ball plunger 52 . In the illustrated embodiment, tab 60 is adjacent a radial clearance surface 62 in a direction of main axis 11 . As will be understood, radial clearance surfaces 62 of pawl members 44 are axially aligned with stops 48 of lockout ring 46 when lockout ring 46 is in its non-lockout axial position, such that pawl carrier 42 is free to rotate relative lockout ring 46 without any of the pawl members 44 engaging any of the stops 48 . Thus, pawl carrier 42 is free to rotate with input shaft 12 about main axis 11 under normal operating conditions.
[0032] Lockout mechanism 40 may also comprise spring 36 arranged to urge the lockout ring 46 toward the non-lockout position, and a plurality of ball bearings 64 seated between lockout ring 46 and reference gear 28 . Ball bearings 64 are seated so as to maintain lockout ring 46 in the non-lockout position when lockout ring 46 and reference gear 28 are in a predetermined angular orientation about main axis 11 relative to one another, and to displace lockout ring 46 toward the lockout position when the reference gear 28 rotates about main axis 11 relative to lockout ring 46 . For example, ball bearings 64 may be seated within a corresponding set of pockets 66 in lockout ring 46 and another corresponding set of pockets 68 in reference gear 28 , and the ball bearings 64 roll out of respective pockets 66 and 68 incident to rotation of reference gear 28 relative to lockout ring 46 .
[0033] Operation of GRA 10 and lockout mechanism 40 is now described. Under normal operating conditions, torque applied to input shaft 12 rotates the input shaft about main axis 11 , thereby rotating input gear 26 about main axis 11 . The rotation of input gear 26 causes counter-rotation of transmitting gears 32 . The transmitting gears 32 are meshed with reference gear 28 , which remains stationary under normal loading conditions, such that the transmitting gears 32 orbit about input gear 26 . The rotation of transmitting gears 32 causes output gear 30 to rotate, which in turn causes output shaft 14 to rotate for displacing a load, e.g. moving an aircraft control surface.
[0034] Under certain abnormal or unexpected operating conditions, such as the malfunction or jamming of a control surface panel, rotation of output shaft 14 is impeded while input torque continues to be applied, and a sudden increase in torque at the output shaft occurs. Consequently, transmitting gears 32 experience increased torque loading and thus transmit additional torque to reference gear 28 . When a designed torque limit is exceeded, static friction is overcome and reference gear 28 will move relative to housing 16 by rotating about main axis 11 in the illustrated embodiment. This slippage within GRA 10 helps to prevent structural damage to output shaft 14 and downstream components.
[0035] After the torque limit has been exceeded, lockout mechanism 40 is activated to prevent transmission of torque between input shaft 12 and output shaft 14 . As reference gear 28 rotates relative to housing 16 , it also rotates relative to lockout ring 46 , which is prevented from rotation with respect to housing 16 by slide pins 49 . This relative angular displacement causes ball bearings 64 to roll out of their respective pockets 66 in lockout ring 46 and pockets 68 in reference gear 28 , thereby displacing lockout ring 46 axially toward its lockout position against the bias of spring 36 .
[0036] Reference is now made to FIGS. 11A-11E , which illustrate what happens once lockout ring 46 is in its lockout position and input shaft 12 . In FIG. 11A , lockout ring 46 is still in its non-lockout position, whereas in FIG. 11B , lockout ring has been axially displaced to its lockout position. When lockout ring 46 is in its lockout position, stops 48 interfere radially with the circular travel path of tabs 60 on pawl members 44 . As pawl carrier 42 rotates, tab 60 of a pawl member 44 engages a stop 48 as shown in FIG. 11B . As depicted in FIG. 11C , this engagement causes pawl member 44 to pivot about an axis defined by pivot pin 50 , thereby compressing ball plunger 52 as the ball plunger moves out of central recess 54 in the pawl member. Rotation of pawl carrier 42 continues, accompanied by further pivoting of pawl member 44 , until ball plunger 52 resiliently decompresses and is received within a lateral recess 56 in pawl member 44 , as may be seen in FIG. 11D . At this stage, pawl member 44 is set in a lockout pivot position wherein one of its catch members 58 will radially interfere with stops 48 and the other catch member 58 will be braced against pivoting by engagement with pawl carrier 42 . As pawl carrier 42 continues to rotate about main axis 11 , the cocked pawl member 44 will engage the next stop 48 as shown in FIG. 11E . Consequently, transmission of torque between input shaft 12 and output shaft 14 is prevented. In the embodiment described herein, torque from input shaft 12 is redirected by lockout mechanism 40 to the structural ground provided by housing 16 .
[0037] FIGS. 12A-12E illustrate how lockout mechanism 40 may be reset by commanding counter-rotation of input shaft 12 to thereby counter-rotate pawl carrier 42 . Initially, it will be understood that ball bearings 64 have already realigned with pockets 66 and 68 , and the bias of spring 36 has returned lockout ring 46 to its non-lockout axial position. Pawl carrier 42 and pawl members 44 begin from the full lockout condition depicted in FIG. 12A (this is the same condition shown in FIG. 11E ). Pawl carrier 42 is counter-rotated until the trailing, radially outer catch member 58 engages the previous stop 48 as shown in FIG. 12B . As may be understood from FIG. 12C , this causes pawl member 42 to pivot about the axis of pivot pin 50 , thereby compressing ball plunger 52 as pawl carrier 42 continues its counter-rotation. Proceeding to FIG. 12D , it will be seen that further counter-rotation of pawl carrier 42 causes pawl member 44 to continue pivoting until ball plunger resiliently decompresses and is received in central recess 54 . Consequently, as shown in FIG. 12E , pawl member 44 is now reset with radial clearance relative to stops 48 of lockout ring 46 .
[0038] As best seen in FIG. 13 , the pockets 66 in lockout ring 46 and pockets 68 in reference gear 28 may have a first slope 70 associated with a first angular direction about main axis 11 , and a second slope 72 associated with a second angular direction about the main axis opposite the first angular direction, wherein the first slope differs from the second slope. In this way, the torque required to actuate lockout mechanism 40 may be made greater in one rotational direction, e.g. the rotational direction associated with flap or slat extension, than in the opposite rotational direction, e.g. the rotational direction associated with flap or slat retraction.
[0039] Because the torque limiting mechanism of GRA 10 responds to output torque instead of input torque, the lock-up torque limit can be set closer to the maximum operating torque, resulting in a lower limit torque at the output of each GRA. This can result in significant weight savings of not only the GRA itself, but more importantly the downstream structure that it protects.
[0040] The output torque sensing GRA described herein also solves the problems associated with the disc brake pack of the prior art. First, the invention eliminates the friction disc brake pack and replaces it with a pawl lockout mechanism. This change drastically reduces the viscous drag torque generated by brake plates and eliminates reliance on friction for positive torque limiting. With as many as thirty GRAs in an aircraft control surface system, this change also greatly reduces the power required by the PCU. Significant reduction in the weight of the entire drive system may be achieved. Second, the invention also has the potential to eliminate the requirement for a skew detection system on some aircraft control surface (e.g. flap and slat) actuation systems, resulting in dramatic improvements in cost, weight and system reliability.
[0041] Embodiments of the present invention are described in detail herein, however those skilled in the art will realize that modifications may be made. As one example, it is noted that alternative configurations are possible in which only one ramp surface is provided, either on armature 26 or on opposing plate 14 . Such modifications do not stray from the spirit and scope of the invention as defined by the appended claims.
PARTS LIST
[0042] 10 Geared rotary actuator (“GRA”)
[0043] 11 Main axis
[0044] 12 Input shaft
[0045] 13 Rotary bearing
[0046] 14 Output shaft
[0047] 15 Rotary bearing
[0048] 16 Housing (structural ground)
[0049] 18 Housing shell
[0050] 20 Housing end plate
[0051] 22 Spacer ring
[0052] 24 Radial step surface
[0053] 26 Input gear
[0054] 28 Reference gear
[0055] 30 Driven gear
[0056] 32 Transmitting gear
[0057] 36 Spring
[0058] 40 Lockout mechanism
[0059] 42 Pawl carrier
[0060] 44 Pawl member
[0061] 46 Lockout ring
[0062] 48 Stop on lockout ring
[0063] 49 Slide pin
[0064] 50 Pivot pin
[0065] 52 Ball plunger
[0066] 54 Central recess in pawl member
[0067] 56 Lateral recess in pawl member
[0068] 58 Catch member of pawl member
[0069] 60 Tab of pawl member
[0070] 62 Radial clearance surface of pawl member
[0071] 64 Ball bearing
[0072] 66 Ball pocket in lockout ring
[0073] 68 Ball pocket in reference gear
[0074] 70 First slope of ball pocket
[0075] 72 Second slope of ball pocket | A torque limiter limits transmission of torque between an input shaft an output shaft. The torque limiter may be incorporated in a geared rotary actuator for actuating an aircraft control surface. The torque limiter is responsive to output torque associated with the output shaft instead of input torque associated with the input shaft. The torque limiter includes a structural ground and a gear assembly for transmitting rotational motion of the input shaft to the output shaft. The gear assembly includes a reference gear coupled to the structural ground such that movement of the reference gear relative to the structural ground is dependent upon an output torque at the output shaft. The reference gear is stationary relative to the structural ground when the output torque is below an output torque limit, and the reference gear moves relative the structural ground when the output torque exceeds the output torque limit. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent application Ser. No. 14/037,170, filed Sep. 25, 2013, which is a divisional of U.S. patent application Ser. No. 13/168,089, filed Jun. 24, 2011 and issued on Oct. 1, 2013 as U.S. Pat. No. 8,544,239, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/398,461, filed on Jun. 25, 2010. The disclosures of all of the above-referenced prior applications, publications, and patents are considered part of the disclosure of this application, and are incorporated by reference herein in their entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The field of the invention relates to roofing materials, and more particularly to methods and systems for spacing panels on roofs.
[0004] 2. Description of the Related Art
[0005] Roofs cover the uppermost part of a space or building, protecting the space or building interior from rain, snow, wind, cold, heat, sunlight, and other weather effects. Many roofs are pitched or sloped to provide additional protection against the weather, allowing rain or snow to run off the angled sides of the roof. Roofs generally include a supporting structure and an outer skin, which can be an uppermost weatherproof layer. The supporting structure of a roof typically includes beams of a strong, rigid material such as timber, cast iron, or steel. The outer layer of a roof can comprise panels or boards constructed of timber, metal, plastic, vegetation such as bamboo stems, or other suitable materials.
[0006] In some cases, a pitched roof is desired to shield a space against elements such as rain or snow, while still admitting light into the space and allowing air to freely circulate through the roof and into the space. Thus, methods and systems to efficiently and reliably attach an outer skin to the supporting structure of a roof such that the roof shields against weather elements, admits light, and allows advantageous air circulation are desired and remain a significant challenge in the design of roofing systems.
SUMMARY OF CERTAIN EMBODIMENTS
[0007] The systems, methods, and devices of the invention each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of this invention, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this invention provide advantages over other roofing systems.
[0008] Methods and devices for spacing panels on a roof are provided. In one embodiment, a wedge-shaped device for spacing panels on a roof includes a bottom surface; a top surface inclined at an angle α relative to the bottom surface; and an integral support structure connecting the top surface and the bottom surface. The support structure includes a plurality of support ribs and a plurality of nail boxes.
[0009] Another embodiment provides a method of installing roof panels on roof support beams. The method includes fastening a plurality of wedge-shaped spacers to a top surface of one or more roof support beams; and fastening a bottom surface of one or more roof panels to the spacers.
[0010] In yet another embodiment, a roof panel spacer system for constructing a roof is provided. The system includes a plurality of support beams; a plurality of spacers fastened to at least some of said support beams; and a plurality of roof panels fastened to the plurality of spacers. Each spacer orients each roof panel substantially horizontal to the ground. Each spacer is positioned to create a space between adjacent roof panels allowing air and light to pass through the roof. Each spacer is also positioned to create an overlap between adjacent roof panels, inhibiting rain and other weather elements from passing through the roof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1A is a top perspective view of an embodiment of a roof panel spacer device.
[0012] FIG. 1B is a bottom perspective view of the device of FIG. 1A .
[0013] FIG. 1C is a bottom elevational view of the device of FIG. 1A .
[0014] FIGS. 2-7 illustrate the device of FIG. 1A in use on a roof.
[0015] FIG. 8 is a top elevational view of the device of FIG. 1A .
[0016] FIG. 9A is a side elevational view of the device of FIG. 1A .
[0017] FIG. 9B is a side elevational view of the device of FIG. 1A showing additional internal features.
[0018] FIG. 10A is a back elevational view of the device of FIG. 1A .
[0019] FIG. 10B is a back elevational view of the device of FIG. 1A showing additional internal features.
[0020] FIG. 11A is a bottom perspective view of another embodiment of a roof panel spacer device.
[0021] FIG. 11B is a bottom elevational view of the device of FIG. 11A .
[0022] FIG. 11C is a cross-sectional view of the device of FIG. 11A taken along line 11 C- 11 C of FIG. 11B .
[0023] FIG. 11D is a cross sectional view of the device of FIG. 11A taken along line 11 D- 11 D of FIG. 11B .
[0024] FIGS. 12-15 illustrate the device of FIG. 11A in use on a roof.
DETAILED DESCRIPTION
[0025] Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this description, and the knowledge of one skilled in the art. In addition, any feature or combination of features may be specifically excluded from any embodiment of the present invention. For purposes of summarizing the present invention, certain aspects, advantages, and novel features of the present invention are described herein. Of course, it is to be understood that not necessarily all such aspects, advantages, or features will be present in any particular embodiment of the present invention.
[0026] It is to be understood that embodiments presented herein are by way of example and not by way of limitation. The intent of the following detailed description, although discussing exemplary embodiments, is to be construed to cover all modifications, alternatives, and equivalents of the embodiments as may fall within the spirit and scope of the invention.
Roof Panel Spacer for Two-Sided Roof
[0027] FIG. 1A is a top perspective view of an embodiment of a roof panel spacer 100 according to the present invention. FIG. 1B is a bottom perspective view of the spacer 100 . FIG. 1C is a bottom elevational view of the spacer 100 . The spacer 100 generally has a width W measured along an x-axis of the spacer 100 , a length L measured along a y-axis of the spacer 100 , and a height H measured along a z-axis of the spacer 100 . The spacer 100 includes a top surface 102 ; a bottom surface 104 ; sides 106 , 108 ; a back 110 ; and a front 112 .
[0028] The height H of the spacer 100 can be measured at different locations along the spacer 100 . For example, the height of the spacer 100 at the back 110 can be H BACK , while the height of the spacer 100 at the front 112 can be H FRONT . Embodiments of the spacer 100 can be wedge-shaped. For example, the top surface 102 can be inclined at an angle α relative to the bottom surface 104 . Additionally, the bottom surface 104 can be inclined at an angle β relative to the back 110 . In some aspects, the top surface 102 is oriented at an angle of 90° or about 90° relative to the back 110 .
[0029] The spacer 100 can include an integral support structure connecting the top surface 102 and the bottom surface 104 . The support structure can include a plurality of support ribs. For example, the spacer 100 includes width ribs 130 , 132 extending along the width W of the spacer 100 between the sides 106 , 108 . The spacer 100 can also comprise a length rib 134 extending along the length L of the spacer 100 between the back 110 and the front 112 . Bottom surfaces of the ribs 130 , 132 , 134 can form all or a portion of the bottom surface 104 of the spacer 100 .
[0030] In some aspects, the support structure also includes a plurality of nail boxes. For example, the spacer 100 includes nail boxes 150 , 152 , 154 , 156 , which will be described in greater detail below with reference to FIGS. 8-10B . The nail boxes can be configured to accept nails or other fasteners. Some embodiments of the nail boxes 150 , 152 , 154 , 156 comprise a hollow tube extending from the top surface 102 and the bottom surface 104 . The nail boxes can be connected to the width ribs 130 , 132 via flanges 160 , 162 , 164 , 166 , respectively. The spacer 100 may also comprise a nail box 168 disposed in the length rib 134 . Other configurations are possible. For example, in some aspects, the spacer 100 may not comprise one or more of width ribs, length ribs, nail boxes, and/or flanges.
[0031] FIGS. 2-7 illustrate one embodiment of a spacer according to the present invention in use on a roof 268 . Referring now to FIG. 2 , a first spacer 200 according to one embodiment is positioned between a first support beam 270 and a roofing panel or board 275 . The support beam 270 includes a top surface 272 . The panel 275 comprises a top surface 276 and a bottom surface 278 . A second spacer 200 is also positioned between a second support beam 280 and the panel 275 . The support beams 270 , 280 can comprise portions of the support structure of a roofing system, and the panel 275 can comprise a portion of the outer skin of the roofing system.
[0032] A top surface 202 of the spacers 200 are adjacent to and contact the bottom surface 278 of the panel 275 , while a bottom surface 204 of the spacers 200 are adjacent to and contact the top surfaces 272 of the support beams 270 , 280 . Other configurations are possible. For example, in another embodiment, the top surface 202 of the spacers 200 may be adjacent to the support beams 270 , 280 and the bottom surface 204 of the spacers 200 may be adjacent to the panel 275 .
[0033] FIGS. 3 and 4 illustrate embodiments of the spacers 200 in use. The support beams 270 , 280 are inclined relative to a horizontal axis x of the roof 268 by an angle ABEAM. The panel 275 is inclined relative to the horizontal axis x of the roof 268 by an angle θ PANEL . As described above, the spacers 200 are positioned between the panel 275 and the support beams 270 , 280 . Additional spacers 200 (not illustrated in FIGS. 3 and 4 , but illustrated in FIG. 5 ) are positioned between a panel 282 and the support beams 270 , 280 . An “n” number of panels can be positioned on the support beams 270 , 280 using the spacers 200 . Additionally, the panels 275 , 282 can be positioned on “n” number of support beams using the spacers 200 in order to construct the roof 268 .
[0034] In some embodiments, the spacers 200 are positioned on the support beams 270 , 280 such that the panels 275 , 282 are horizontal or substantially horizontal to the ground and θ PANEL is 0° or about 0°. The spacers 200 may be positioned on the support beams 270 , 280 such that a vertical space 284 separates the panels 275 , 282 . In the embodiment illustrated in FIG. 3 , for example, each of the adjacent panels on the roof 268 are separated by the vertical space 284 . The spacers 200 can be positioned along the support beam 270 at the same or substantially the same distance intervals, such that the vertical spaces 284 separating adjacent panels are the same or substantially the same. It will be understood, however, that the vertical space 284 separating adjacent panels of the roof 268 need not be the same or substantially the same across the entire roof 268 . The vertical spaces 284 can advantageously allow for air to enter the space underneath the roof 268 and circulate within the space. Advantageously, the vertical spaces 284 can also allow light to enter the space underneath the roof 268 .
[0035] In some aspects, the top surface 276 of the panel 275 and the bottom surface 278 of the panel 282 overlap in a region 286 . This overlap between adjacent panels 275 , 282 can advantageously restrict rain and other weather elements from passing through the vertical space 284 and entering the space underneath the roof 268 . For example, embodiments of spacers described herein can shield the interior of a building or other space below a roof from light rain and/or rain without horizontal wind.
[0036] Persons of skill in the art will understand that the spacers 200 can be used with roofs 268 of varying slope or pitch. For example, the support beams 270 , 280 may be less sloped relative to the horizontal axis x of the roof 268 (corresponding to a smaller beam angle θ BEAM than that illustrated in FIGS. 2-7 ), in which case the angle α of the spacer 200 may be decreased. Similarly, the support beams 270 , 280 may be more sloped relative to the horizontal axis x of the roof 268 (corresponding to a greater beam angle θ BEAM than that illustrated in FIGS. 2-7 ). In such cases, the angle α of the spacer 200 can be increased accordingly. Of course, it will be understood that beam angle θ BEAM may not be equal to the angle α of the spacer 200 .
[0037] FIG. 5 illustrates a plurality of spacers 200 in use on adjacent panels 275 , 282 . For example, the panel 275 is spaced from the support beam 270 by a first spacer 200 , from the support beam 280 by a second spacer 200 , and from a support beam θ BEAM by a third spacer 200 . The panel 282 is spaced from the support beam 270 by a fourth spacer 200 , from the support beam 280 by a fifth spacer 200 , and from the support beam θ BEAM by a sixth spacer 200 . Each of the panels of the roof 268 can be spaced from the support beams in a similar manner.
[0038] FIG. 6 illustrates the vertical spaces 284 that can be provided between adjacent panels 275 , 282 according to some embodiments of the present invention. As described above with reference to FIGS. 3 and 4 , the vertical spaces 284 between adjacent panels of the roof 268 can allow air and light to enter through the roof 268 , while also preventing weather elements such as rain from entering the space below the roof 268 .
[0039] FIG. 7 illustrates a plurality of spacers 200 in use on the roof 268 . A spacer is provided at the interface between each panel and each supporting beam. As described above with reference to FIG. 3 , the top surface of a first panel and the bottom surface of a second, higher panel are horizontally overlapped such that rain and other weather elements falling in a vertical direction do not enter the vertical spaces 284 and penetrate the space below the roof 268 .
[0040] Embodiments of the spacers 200 can advantageously be used to construct two-sided roofing structures. For example, the roof 268 illustrated in FIGS. 2-9 comprises a first side 288 and a second side 290 . The spacers 200 are positioned between support beams and panels on the first side 288 , as well as between support beams and panels on the second side 290 .
[0041] FIG. 8 is a top elevational view of the spacer 100 . FIG. 9A is an elevational view of the side 106 of the spacer 100 , illustrating internal features in dashed lines. FIG. 9B is an elevational view of the side 106 showing additional internal features such as the width ribs 130 , 132 . FIG. 10A is an elevational view of the back 110 of the spacer 100 , illustrating internal features in dashed lines. FIG. 10B is an elevational view of the back 110 illustrating additional internal features, including ribs and nail box features.
[0042] As described above with reference to FIGS. 1A-1C , the spacer 100 can include nail boxes 150 , 152 , 154 , 156 , and 168 . In one embodiment, the nail box 150 comprises a recessed area 151 and the nail box 152 comprises a recessed area 153 . The recessed areas 151 , 153 can accommodate the head of a nail or other fastener disposed in nail boxes 150 , 152 , respectively. It will be understood that other nail boxes of the spacer 100 can comprise recessed areas, and that the spacer 100 need not comprise any recessed areas around the nail boxes.
[0043] Referring now to FIG. 9A , the bottom surface 104 of the spacer 100 may be inclined at an angle α relative to the top surface 102 . The angle α can be between about 10° and about 25°. In one embodiment, the angle α corresponds to the angle θ BEAM of the support beams of the roof relative to a horizontal axis x of the roof. Where a equals θ BEAM , the top surface 276 of the panels of the roof may lie substantially horizontally on the spacers, such that the angle θ PANEL of the panels relative to the horizontal axis x of the roof is 0° or about 0°.
[0044] Additionally, the bottom surface 104 can be inclined at an angle β relative to the back 110 . The angle β can be between about 80° and about 65°. In the embodiment illustrated in FIG. 9A , angle α is about 18° and the angle β is about 72°. Other configurations are possible. For example, for a roof comprising support beams disposed at an angle θ BEAM of 20°, the spacer 100 can be modified such that the angle α is 20° and the angle β is 70°.
[0045] FIGS. 10A and 10B show additional views of the spacer 100 . FIG. 10A illustrates nail boxes 150 , 152 , 154 , 156 , 168 , as well as recessed areas 151 , 153 in dashed lines. FIG. 10B illustrates rib 134 in dashed lines.
[0046] FIG. 1A illustrates advantageous dimensions of certain specific embodiments of the spacer 100 . For example, the top surface of the spacer 100 is about 6 inches by about 4 inches; and the back 110 is about 4 inches by about 2 inches. Persons of skill in the art will understand that other dimensions are possible, and embodiments of the spacer 100 are not limited to the number or configuration of nail boxes shown, or the dimensions of spacer 100 .
[0000] Roof Panel Spacer for Roof with Three or More Sides
[0047] FIG. 11A is a bottom perspective view of an embodiment of a roof panel spacer 1300 according to the present invention. FIG. 11B is a bottom elevational view of the spacer 1300 . FIG. 11C is a cross-sectional view taken along line 11 C- 11 C of FIG. 11B . FIG. 11D is a cross-sectional view taken along line 11 D- 11 D of FIG. 11B . Embodiments of the spacer 1300 can be used to construct roofing structures with three or more sides.
[0048] The spacer 1300 generally has a width W measured along an x-axis of the spacer 1300 , a length L measured along a y-axis of the spacer 1300 , and a height H measured along a z-axis of the spacer 1300 . The spacer 1300 includes a first top surface 1302 A; a second top surface 1302 B; a bottom surface 1304 ; and sides 1306 , 1308 , 1310 , 1311 , 1312 , and 1313 . In some aspects, the spacer 1300 includes a peaked top surface.
[0049] The height H of the spacer 1300 can be measured at different locations along the spacer 1300 . For example, the height of the spacer 1300 where the sides 1310 , 1311 meet can be H MAX , while the height of the spacer 1300 where the sides 1308 , 1311 meet can be H MID . Embodiments of the spacer 1300 can be wedge-shaped. For example, the top surface 1302 of the spacer 1300 may be inclined at an angle α relative to the bottom surface 1304 . The bottom surface 1304 can also be inclined by an angle β 1 relative to the intersection of the sides 1308 , 1311 . Additionally, the bottom surface 1304 can be inclined at an angle β 2 relative to the intersection of the sides 1310 , 1311 .
[0050] The spacer 1300 can include an integral support structure connecting the top surface 1302 and the bottom surface 1304 . The support structure can include a plurality of support ribs. For example, the spacer 1300 includes width ribs 1330 , 1332 extending along the width W of the spacer 1300 between the sides 1306 , 1308 . The spacer 100 can also comprise a length rib 1334 extending along the length L of the spacer 1300 between the sides 1310 , 1311 and the sides 1312 , 1313 . Bottom surfaces of the ribs 1330 , 1332 , 1334 can form a portion of the bottom surface 1304 of the spacer 1300 .
[0051] In some aspects, the support structure includes a plurality of nail boxes. For example, the spacer 1300 comprises nail boxes 1350 , 1352 , 1354 , 1355 , 1356 , and 1357 . Some embodiments of the nail boxes 1350 , 1352 , 1354 , 1355 , 1356 , and 1356 comprise a hollow tube extending from the top surface 1302 and the bottom surface 1304 . The nail boxes 1354 , 1355 can be connected to the width rib 1331 via flanges 1360 and 1362 . Other configurations are possible. For example, in some aspects, the spacer 1300 may not comprise width ribs, length ribs, nail boxes, and/or flanges.
[0052] In some aspects, the nail box 1354 comprises a recessed area 1351 and the nail box 1355 comprises a recessed area 1353 (not illustrated). The recessed areas 1351 , 1353 can accommodate the head of a nail or other fastener disposed in nail boxes 1354 , 1355 , respectively. It will be understood that other nail boxes of the spacer 1300 can comprise recessed areas, and that the spacer 1300 need not comprise any recessed areas around the nail boxes.
[0053] FIGS. 12-15 illustrate this embodiment of a spacer according to the present invention in use on a roof 1468 that has three or more sides. Referring now to FIG. 12 , a spacer 1400 according to one embodiment is positioned between a support beam 1470 and a first roofing panel or board 1475 . The roof 1468 also comprises a second spacer 1400 positioned between the support beam 1470 and a second panel 1482 . The support beam 1470 includes a top surface 1472 . The panels 1475 , 1482 each include a top surface 1476 and a bottom surface 1478 . The support beam 1470 can comprise a portion of the support structure of a roofing system, and the panels 1475 , 1482 can comprise a portion of the outer skin of the roofing system.
[0054] A top surface 1402 of the spacers 1400 are adjacent to and contact the bottom surfaces 1478 of the panels 1475 , 1482 , while a bottom surface 1404 of the spacers 1400 are adjacent to and contact the top surface 1472 of the support beam 1470 . Other configurations are possible.
[0055] In one embodiment of the present invention, the spacers 1400 are positioned on the support beam 1470 such that a vertical space 1484 separates the panels 1475 , 1482 . In some aspects, each of the adjacent panels on the roof 1468 are separated by a vertical space 1484 . As described above with reference to FIG. 3 , the vertical spaces 1484 can advantageously allow for air to enter the space underneath the roof 1468 and circulate within the space. Advantageously, the vertical spaces 1484 can also allow light to enter the space underneath the roof 1468 .
[0056] In some aspects, the top surface 1476 of the panel 1475 and the bottom surface 1478 of the panel 1482 overlap in a region 1486 . This overlap between adjacent panels 1475 , 1482 can advantageously restrict rain and other weather elements from passing through the spaces 1484 and entering the space underneath the roof 1468 .
[0057] FIGS. 13-15 illustrate a plurality of panels spaced from the support beam 1470 by the spacers 1400 . The panel 1475 and a panel 1492 are positioned on a first spacer 1400 (not illustrated), and the panel 1482 and a panel 1494 are positioned on a second spacer 1400 (not illustrated). A third spacer 1400 is also positioned on the support beam 1470 , ready to receive panels. As described above, the spacers 1400 allow the panels 1492 , 1494 to be advantageously separated by a vertical space 1484 .
Installation of Roofing Spacers
[0058] Embodiments of the roofing spacers described herein can be installed using fasteners such as nails. In one embodiment, a spacer according to the present invention is first positioned on a support beam. Nails are driven into one or more nail boxes of the spacer. The nails may be driven into nail boxes comprising recessed areas, for example. These nails may initially restrict movement of the spacer relative to the support beam until additional nails are driven into the spacer. Next, a panel is positioned over the spacer, and additional nails are driven through the panel into the spacer. In some aspects, the installer is aware of the general location of the nail boxes which remain empty, but is not able to see the precise location of the empty nail boxes through the panel. The installer can estimate the location of the empty nail boxes and aim the nails so that they enter the spacer at or near the empty nail boxes.
[0059] It will be understood by those of skill in the art that positioning nails precisely in the nail boxes is not required to install embodiments of spacers described herein. Nails and other fasteners can effectively secure the spacers to support beams, and panels to the spacers, if they are driven into the nail boxes, the ribs, and/or the flanges described herein. It will also be understood that a nail need not be driven into each nail box provided on the spacers in order to secure the spacer to a support beam, or to secure a panel to the spacer.
Materials for a Roofing Spacer
[0060] Embodiments of the spacers described herein can be made of any suitable material, including plastic or metal. In one embodiment, spacers according to the present invention are made of polypropylene copolymer. In some aspects, the comonomer of the polypropylene copolymer is ethylene. Polypropylene copolymer is characterized as having high impact resistance strength. Polypropylene copolymer also has slightly increased elongation at break, and is thus more pliable, compared to unmodified polypropylene homopolymer. Typical material properties of polypropylene copolymer are provided in Table 1 below.
[0000]
TABLE 1
Property
Yield Point
24
MPa
Elongation at Yield
10-12%
Tensile Break
33
MPa
Elongation at Break
650%
Tensile Modulus
1050
MPa
Flexural Modulus
1270
MPa
Flexural Strength
25-26
MPa
Tensile Impact
800
kJ/m2
[0061] Spacers described herein need not be made of polypropylene copolymer, and can be made of any suitable material, including but not limited to materials exhibiting material properties similar to that of polypropylene copolymer. Spacers made of polypropylene copolymer can advantageously accept fasteners without shattering or suffering other adverse structural effects which may result when a nail or other fastener is driven into the spacer.
[0062] Embodiments of the spacers described herein can be molded from one piece of injection-molded plastic, such that the spacer is monolithic. The spacers described herein can also be manufactured by connecting together separate components, such as the top surface, the bottom surface, the back, and the integral support structure, to form one spacer.
[0063] The above-described embodiments have been provided by way of example, and the present invention is not limited to these examples. Multiple variations and modifications to the disclosed embodiments will occur, to the extent not mutually exclusive, to those skilled in the art upon consideration of the foregoing description. Additionally, other combinations, omissions, substitutions and modifications will be apparent to the skilled artisan in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the disclosed embodiments. | Devices, methods, and systems are provided herein for spacing an outer skin of a roof from the supporting structure of the roof such that the roof shields against weather elements, admits light, and allows advantageous air circulation. In one embodiment, a wedge-shaped device for spacing panels on a roof includes a bottom surface, a top surface inclined at an angle relative to the bottom surface, and an integral support structure connecting the top surface and the bottom surface, the support structure including a plurality of ribs and a plurality of nail boxes. | 4 |
FIELD OF THE INVENTION
This invention relates generally to a process and apparatus for contamination-free processing of semiconductor parts. More specifically, this invention relates to a process and apparatus for contamination-free processing of semiconductor parts in an oven or a furnace. This invention also relates to a process and apparatus for contamination-free processing of semiconductor parts in a furnace, such as a belt type furnace that sequentially stops the belt at the vicinity of at least one heating or cooling unit to heat or cool the part.
BACKGROUND OF THE INVENTION
For many years the electronics or semi-conductor industry has been using various types of ovens and furnaces for high volume heating and/or cooling applications. In the oven and furnace industry many inventions have occurred. However, most of them have been directed to innovations in either cooling or heating of the parts that are being processed.
U.S. Pat. No. 4,554,437 (Wagner et al.) discloses a continuous speed belt type tunnel oven which allows a user to select different top and bottom temperatures within each of the plural cooking zones.
U.S. Pat. No. 4,693,211 (Ogami et al.) discloses a surface treatment apparatus, which is composed of a supporting die for holding a substrate thereon to heat and/or cool the substrate. A cover defines a treatment space over the entire surface of the substrate on the supporting die. Preferably, a heat-insulating housing could be outside the cover.
U.S. Pat. No. 4,886,954 (Yu et al.) discloses a hot wall diffusion furnace and a method for operating the furnace. Yu et al. disclose that the heating elements in the upper section of the furnace be connected to one circuit, and the heating elements of the lower section of the furnace be connected to a second circuit, and that each circuit be controlled in response to the temperature in that section, so that uniform temperature can be obtained in the processing chamber.
U.S. Pat. No. 4,903,754 (Hirscher) discloses a method and apparatus for the transmission heat to or from plate like object. The plate-like object, such as a Si wafer, is held on a back plate and inside a cover. This patent discloses both the heating and cooling of the plate-like object.
U.S. Pat. No. 4,950,870 (Mitsuhashi et al.) discloses a heat-treating apparatus having at least three heaters and the power to these heaters can be supplied from independent power sources so that the heating temperatures of the individual heaters can be freely adjusted. Additionally, the multiple heaters in the vertical furnace attain a uniform heat distribution throughout the heating zone.
U.S. Pat. No. 4,966,547 (Okuyama et al.) discloses a heat treatment method using a zoned tunnel furnace. The furnace has roller conveyer and each of the zones in the furnace walls are provided with electric resistance heating wires. The heaters in each zone are under programmed control, independent of the heaters in the other zones. Similarly, the roller conveyer in each zone can be driven independent of the roller conveyer in the other zones by programmable controllers.
U.S. Pat. No. 4,982,347 (Rackerby et al.) discloses process and apparatus for producing temperature profiles in workpiece as it passes through a belt furnace. Each of the heaters has their own separate thermostats, which enables the temperature of each heater to be separately set. Thus a workpiece can be subjected to a temperature profile which varies from heater to heater along the passageway.
U.S. Pat. No. 5,054,418 (Thompson et al.) discloses a device for holding wafers of semi-conducting materials during thermal processing or coating, where the device is a cage boat having removable slats.
The parts or products using conventional furnaces and ovens have changed over time. Some of the parts have been getting larger and others are getting smaller, and still other require more stringent processing controls. Therefore, it has become increasingly difficult to do the same type of processing on the parts, as done by the ovens and furnaces known in the art.
For some parts the thermal mass or thermal weight resists being heated quickly, and therefore they may have to be processed for a longer period. Another factor is that newer and different materials are being used to make these parts, and these newer materials require different heating regimes. These issues are further compounded by the fact that now closer temperature control and lower intra-part gradients are being required by the electronics industry.
The manufacturers of conventional ovens and furnaces have made quite a few upgrades to their system in response to the industrial needs. Some upgrades include providing better and more efficient gas flows. Others have provided improved zone separation. And, still others are providing better cooling in the cool down section. Most of these changes are required because the parts or products are less tolerant to thermal process irregularities and the resultant mechanical stresses, etc.
Another problem faced in the use of conventional ovens or furnaces is that when flux or similar contaminants are used in a conventional oven or furnace they get deposited on the walls of the furnace creating a contamination problem for the furnace as well as the parts that are being processed in the furnace. Flux and similar contaminants results from many processes, such as a soldering process, and therefore cannot be eliminated. Similarly, there are other solvents which evaporate from the surface of the part, as the part is being heated, and they enter the flow of the gases in the furnace, flowing from the hotter end or area to a colder area. This causes the vaporized solvents and similar other material to condense on cooler furnace areas or parts and this collects as contamination.
For an application, such as chip join, the operation is characterized by loading many parts on a belt, followed by continuous movement of the belt through the furnace's heating and/or cooling areas, and thus it is not very practical to stop and clean the furnace for a different part and/or a different process.
Therefore, during a typical high volume heating and/or cooling applications care must be taken to prevent the parts being processed from being contaminated with contaminants that are inside the furnace, and that the contamination be kept to the minimum.
For the above-mentioned reasons, parts cannot always be processed within specification using the conventional ovens or furnaces, and therefore there is a need for improvement in the furnace and oven industry.
The above-mentioned and other problems have been overcome by the novel apparatus and the process of this invention.
BRIEF SUMMARY OF THE INVENTION
In one aspect the invention comprises a process for processing a part in a contaminating environment wherein said part is protected from said contamination, comprising the steps of:
(a) placing said part on a part carrier in a first environment,
(b) placing a cover over said part carrier and enveloping said part so as to form a boat,
(c) removing said boat from said first environment,
(d) placing said boat in a second, more contaminating, environment and processing said part.
In another aspect the invention comprises an apparatus for processing at least one part comprising a covered boat enveloping said part and having a first environment while said apparatus having a second more contaminating environment, wherein said covered boat is placed inside said apparatus and further comprising at least one means for processing said part.
PURPOSES OF THE INVENTION
One purpose of this invention is to provide a process that is very economical.
Another purpose of the invention is to provide a process that is easily adaptable to the existing ovens and furnaces.
Still another purpose of this invention is to provide a system that transports the parts through a contaminating environment without contaminating the part.
Yet another purpose of this invention is to process the part such that the part is itself in a less contaminated environment than its surroundings.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention may be best understood by the description which follows, taken in conjunction with the accompanying drawings in which:
FIG. 1, is a perspective view of a preferred embodiment of the present invention.
FIG. 2, is a perspective view showing another embodiment of the present invention.
FIG. 3A, is a perspective view showing yet another embodiment of the present invention.
FIG. 3B, is a sectional view taken along section 3B--3B of FIG. 3A.
FIG. 4, is a cross-sectional view of still another embodiment of the present invention.
FIG. 5, is a cross-sectional view of still yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the invention is illustrated in FIG. 1, where a part or a substrate 10, to be processed is placed on a base 12, and is protected from the environment by a cover 14. The base 12, having an upper surface 18, is typically made from quartz, glass, metal, etc. Similarly, it is preferred that the cover 14, having peripheral base edge 28, be also made from quartz, glass, metal, to name a few.
In a typical application the substrate 10, is placed on the upper surface 18, of the base 12, for example, in a Class 10 clean room, and then the cover 14, is subsequently placed to protect the substrate 10, in the same Class 10 clean room. A Class 10 clean room, for example, is a room or area where there are less than 10 particles of not greater than 0.3 micron particle size per cubic foot of air. This way the contamination inside the cover is Class 10, and there is no reason to create a vacuum inside the cover 14, to keep the area inside the cover 14, and over and around the substrate 10, contamination free. The base 12, along with the cover 14, will be referred to as a parts carrier or boat 20.
For some applications it may be necessary to create a vacuum or extract certain contaminants out of under the cover 14, and keep the substrate 10, in a contamination free environment. This can be done as illustrated in FIG. 2, where a boat 40, having a cover 24, has at least one vent or plug 16, through which the contaminating gases and/or particles could be extracted. Of course this vent or plug 16, could be on the top of the cover 24, or could be a part of the base 12. The vent or plug 16, could also be used to prevent the creation of a pressure differential between inside and outside of the boat.
FIG. 2, also illustrates that the substrate 10, could also be placed on a substrate or part pedestal or support 22. The substrate pedestal 22, allows the part or substrate 10, to be processed without the need to have the substrate 10, itself be physically moved. For some applications the substrate 10, could be secured to the substrate pedestal 22, by means well known in the art, such as, screws, bolts, clamps, etc.
FIG. 3A, is a perspective view showing yet another embodiment of the present invention, while FIG. 3B is a sectional view taken along section 3B--3B of FIG. 3A. A boat or parts carrier 60, has a base 32, having a groove or a trench or channel 30, to accommodate the peripheral base edge 28, of the cover 14. The base edge 28, could have rectangular-type shape or circular-type shape or polygonal-type shape or a triangular-type shape, to name a few. Of course the trench or channel 30, in the base 32, should have a shape complementary to that of the base edge 28, to provide the maximum seal or contamination free environment to the part 10.
For some applications it may be necessary to put a seal or similar such media between the base edge 28, and the upper surface 18, of the base 12 or 32. Typical seals that are used in the industry are seals made from silicon or polymers, to name a few.
FIG. 4, illustrates a cross-sectional view of a boat or parts carrier 80, which is still another embodiment of the present invention. The boat 80, typically has a pan-shaped base 42, having side-walls 44. The part 10, to be processed could be placed on a support or pedestal 46, having a plurality of posts or stand-offs 48. Cover 54, having ledge 56, is then used to provide a cover for the part 10, and posts or stand-offs 45, typically, separate the cover 54, from the base 42. For some applications, the stand-offs 45 and/or 48, could be made from material that allows the movement of fluid through it. This movement of fluid, such as air, of course will prevent or reduce any pressure differential that might exist between the inside and outside of the boat 80.
FIG. 5, is a cross-sectional view of still yet another embodiment of the present invention showing a boat or parts carrier 100. The boat 100, has a pan-shaped base 62, having side-walls 64. The base 62 and the side-walls 64, could have one or more electrical implants, such as, resistance thermal heater 65, to provide local thermal heating to the part 10, which may be on a plurality of posts or stand-offs 48. A cover 74, having ledge 76, could also have at least one electrical implant or resistance thermal heater 75, to provide local thermal heating to the part 10. The boat 100, could also have one or more breathers or vents 66, to allow for the part to "breathe" or to prevent a pressure differential from occurring inside the boat 100. In some cases the boat 100, could of course itself be placed inside an oven for further processing of the part 10.
The boat 20, 40, 60 or 80, along with the substrate 10, is typically placed in an oven or furnace or a cooling environment and the processing of the part 10, continues.
As will be appreciated that now, for example, the boat 20, can be placed in an oven or a furnace (not shown) that has, for example, a Class 100 or Class 1000 or more environment but the part 10, being in the boat 20, will not be exposed to the outside contamination, and will only see the cleaner, for example, Class 10, environment.
The boat or parts carrier 20, 40, 60 or 80, could also be placed on a sequential belt type furnace, as disclosed in U.S. patent application Ser. No. 07/920,948, entitled "Sequential Step Belt Furnace With Individual Concentric Heating Elements", assigned to the assignee of the instant Patent Application and the disclosure of which is incorporated herein by reference, and the part 10, could be processed without being contaminated by carrier gasses that might exist in a belt type furnace.
Similarly, the boat or parts carrier 20, 40, 60, 80 or 100, could also be placed on a sequential belt type furnace, as disclosed in U.S. Pat. Application Ser. No. 218,105, filed on Mar. 25, 1994, now U.S. Pat. No. 5,421,723, entitled "Sequential Step Belt Furnace With Individual Concentric Cooling Elements" assigned to the assignee of the instant Patent Application and the disclosure of which is incorporated herein by reference, and the part 10, could be processed without being contaminated by the contaminants that might exist in the furnace.
The part 10, could be an I. C. (Integrated Circuit) chip or a semiconductor substrate or a semiconductor module, or similar such product.
It has been found that the parts 10, described in this invention, could be large parts, such as ceramic substrates which are typically about 100 mm by 100 mm to about 20 mm by 20 mm or smaller parts, such as semiconductor chips which are typically about 10 mm by 10 mm.
The heating or "cooling" is typically provided to the boat 20, 40, 60, 80 or 100, and in-turn to the part 10, by one or more of the upper, lower or side heating or cooling units in a furnace.
If a sequential belt type furnace is used then the boat 20, 40, 60 or 80, is typically accelerated, and then decelerates, and the part 10, is placed typically in the center of the heating or cooling zone. Of course, using a computer or a controller one could program or control or monitor the transit or soak times or the belt speeds, etc.
Using the inventive boat 20, 40, 60, 80 or 100, the contaminating gases or particles or evaporated flux that may exist in an oven or a furnace, never gets an opportunity to condense on the surface of the part.
As one can see that the process and apparatus of this invention provides a substantial improvement over the state of the art.
This inventive furnace can be used for a variety of processes, for example, pin brazing process, chip join process, C4 (Controlled Collapse Chip Connection) bonding, to name a few. (C4 and Controlled Collapse Chip Connection are Trademarks of IBM Corporation, Armonk, N.Y., USA.)
The thermally conductive closed boat or container of this invention provides isolation of the product and shields it from contamination that is generated, such as from the surrounding environment, processing machinery, etc.
The invention also provides a mean to uniformly heat the part while shielding it from the contaminants.
It has also been discovered that the boat or parts carrier having a limited number of holes or openings or vents or material that allow for limited amount of fluid flow does not have any major adverse affect on the part being processed. As a matter of fact the amount of contaminants in a fully sealed boat was not any lower than a similar boat with limited vents that allowed for limited fluid flow.
EXAMPLES
The following examples are intended to further illustrate the invention and are not intended to limit the scope of the invention in any manner.
EXAMPLE 1
A large sized semiconductor substrate A, was placed inside a contamination control box and then covered. The covered container was then placed inside a Blue M oven and the substrate A was baked at approximately 400° C. After the processing of substrate A, a surface particle count was made and it was found that the surface of substrate A, had 1,228 particles. A similar substrate B, was also processed in the same Blue M oven under the same processing conditions, but on an open boat, and upon inspection a total of 2,312 particles were counted on the surface of substrate B. This is an increase of 1,084 particles after the baking step.
EXAMPLE 2
A medium sized semiconductor substrate C, was placed inside a contamination control box and then covered. The covered container was then placed inside a Blue M oven and the substrate C, was baked at approximately 400° Centigrade. After the processing of substrate C, a surface particle count was made and it was found that the surface of substrate C, had 221 particles. A similar substrate D, was also processed in the same Blue M oven under the same processing conditions, but on an open boat, and upon inspection a total of 333 particles were counted on the surface of substrate D. This is an increase of 112 particles after the baking step. The surface of both parts C and D, had a coating of a layer of polyimide.
EXAMPLE 3
A small sized semiconductor substrate E, was placed inside a contamination control box and then covered. The covered container was then placed inside a Blue M oven and the substrate E, was baked at approximately 400° Centigrade. After the processing of substrate E, a surface particle count was made and it was found that the surface of substrate E, had 190 particles. A similar substrate F, was also processed in the same Blue M oven under the same processing conditions, but on an open boat, and upon inspection a total of 257 particles were counted on the surface of substrate F. This is an increase of 67 particles after the baking step. The surface of both parts E and F, had a coating of a layer of approximately 200 angstroms of chromium.
While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention. | This invention relates generally to a process and apparatus for contamination-free processing of semiconductor parts. More specifically, this invention relates to a process and apparatus for contamination-free processing of semiconductor parts in an oven or a furnace. This invention also relates to a process and apparatus for contamination-free processing of semiconductor parts in a furnace, such as a belt type furnace that sequentially stops the belt at the vicinity of at least one heating or cooling unit to heat or cool the part. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cam follower device which is incorporated in a valve driving mechanism in an engine used to run, for example, an automobile, to reduce the friction occurring in the valve driving mechanism, thereby achieving a reduction in output loss during the running of the engine. More particularly, the present invention pertains to a cam follower device for a valve driving mechanism in an engine, which is designed to achieve improvements in the performance of the engine, particularly an increase in engine speed.
2. Description of the Prior Art
Among various types of engine which are used to run, for example, automobiles, reciprocating engines are all provided with a pair of suction and exhaust valves which are opened and closed synchronously with the rotation of a crankshaft, except for two-cycle engines.
There are various types of valve driving mechanisms for driving the suction and exhaust valves. For example, in an SOHC type valve driving mechanism, which is shown in FIG. 12, a suction valve 4 and an exhaust valve 5 are driven to reciprocate through respective rocker arms 3 by a single cam shaft 2 that rotates at a speed which is half the speed of a crankshaft 1 (in the case of a four-cycle engine). Cams 6 which are rigidly secured to the cam shaft 2 that rotates synchronously with the crankshaft 1, rotate in slide contact with the respective end portions of the rocker arms 3, thereby reciprocatively driving the suction valve 4 and the exhaust valve 5.
Incidentally, it has recently been proposed to provide cam follower devices, which rotate in response to the rotation of the cams 6, in between the cams 6 and the mating rocker arms 3, respectively, to reduce the friction occurring between the peripheral surfaces of the cams 6 and the contact portions of the rocker arms 3 during the running of the engine, thereby achieving a reduction in output loss, and thus improving the engine's efficiency, as disclosed, for example, in Japanese Utility Model Public Disclosure (KOKAI) No. 64-34406 (1989).
More specifically, a cam follower device which is incorporated in an engine for this purpose, is arranged as shown in FIGS. 13 and 14. A pair of spaced support wall portions 7 are provided at the end portion of a rocker arm 3 that faces a cam 6, and two end portions of a shaft 8 are fitted into respective through-holes 11 which are formed in the support wall portions 7, thereby securing the shaft 8 between the pair of support wall portions 7. An outer ring 10, which is in the form of a short cylinder, is provided around the shaft 8 through needle bearings 9. The outer peripheral surfaces of the outer ring 10 and the cam 6 are brought into contact with each other so that the outer ring 10 rotates about the shaft 8 in response to the rotation of the cam 6.
By providing such a rotatable outer ring 10 to change the friction occurring between the cam 6 and a member mated therewith from sliding friction to rolling friction, the output loss during the running of the engine is lowered and fuel consumption decreases, so that the engine efficiency is improved.
There has been another prior art wherein part of the above-described cam follower device is formed from a ceramic material with a view to reducing the overall weight of the cam follower device and improving the high-speed follow-up performance, and thus being suitable in line with the recent tendency for the rotational speed of engines to be increased, as disclosed in Japanese Patent Public Disclosure (KOKAI) No. 63-113108 (1988) and Japanese Utility Model Public Disclosure (KOKAI) Nos. 60-159805 (1985), 62-203911 (1987) and 63-42805 (1988).
Among the conventional cam follower devices of this type, the one disclosed in Japanese Patent Public Disclosure (KOKAI) No. 61-113108 is arranged as shown in FIGS. 15 and 16.
More specifically, a bush 12 which is made of a ceramic material is rotatably fitted around the shaft 8 that is provided between the support wall portions 7 formed at the end of the rocker arm 3, and an outer ring 13 which is similarly made of a ceramic material is fitted around the bush 12 in such a manner that the outer ring 13 is rotatable relative to the bush 12.
In the case of the cam follower device disclosed in Japanese Patent Public Disclosure (KOKAI) No. 63-113108, the ceramic bush 12 is provided between the inner peripheral surface of the ceramic outer ring 13 and the outer peripheral surface of the shaft 8, which is made of steel, thereby lowering the relative sliding velocity between the outer peripheral surface of the steel shaft 8 and the inner peripheral surface of the ceramic bush 12 (in contrast to the arrangement where the outer ring 13 is fitted directly onto the shaft 8), and thus reducing output loss and preventing wear of the outer peripheral surface of the steel shaft 8.
However, a conventional cam follower device for a valve driving mechanism in an engine, such as that disclosed in the above-described Japanese Patent Public Disclosure (KOKAI) No. 63-113108, does not always perform satisfactorily.
More specifically, although the relative velocity between the inner peripheral surface of the bush 12 and the outer peripheral surface of the shaft 8 is lower than in the case where the outer ring 13 is fitted directly onto the shaft 8, it is still impossible to avoid the occurrence of friction therebetween, and no satisfactory reduction in output loss can be achieved. In addition, it is necessary in order to prevent wear of the shaft 8 made of steel, which is softer than a ceramic material, to supply sufficient lubricating oil to a very small clearance that is present between the two peripheral surfaces. The necessary lubrication mechanism accordingly becomes complicated.
On the other hand, Japanese Patent Public Disclosure No. 01-142206 (1989) discloses a cam follower device for an engine, which comprises an outer ring at least the outer surface of which is formed from a ceramic material, a shaft for the outer ring, and a plurality of needle bearings which are interposed between the outer ring and the shaft. By interposing needle bearings between the outer ring and the shaft therefor, it is possible to reduce output loss during the running of the engine and retain an adequate amount of lubricating oil in the area between each pair of adjacent needle bearings. Accordingly, it is possible to effectively lubricate the area between the inner peripheral surface of the outer ring and the outer peripheral surface of the shaft, where the needle bearings are provided.
Although not mentioned in the above-described Japanese Patent Public Disclosure (KOKAI) No. 01-142206, there are many restrictions in practice on the selection of a part of the cam follower device which is to be replaced with a ceramic material. In addition, if a part of the cam follower device is replaced with a ceramic material, very difficult problems arise in combination with other parts which are made of steel.
For example, if one or all of the parts, i.e., the shaft 15, the outer ring 14 and the needle bearings 16, in the structure shown in FIGS. 17 and 18, are made of a ceramic material, it is possible to reduce the inertial mass of the cam follower device correspondingly to the number of parts made of a ceramic material and the mass of these parts and hence cope with the increase in engine speed. However, when the parts 15, 14 and 16 are merely formed from a ceramic material, the following problems arise:
First, when the shaft 15 is made of a ceramic material, if the support wall portions 7 made of either aluminum, which is relatively soft, or a steel, which is plastically deformable, are subjected to staking to secure the shaft 15, the support wall portions 7 cannot bite into the ceramic shaft 15 because it is not plastically deformable. Thus, the support wall portions 7 cannot be effectively staked, and it is therefore difficult to firmly secure the shaft 15 to the support wall portions 7. Accordingly, it has been considered to form the shaft 15 from a steel material so that the end portions of the shaft 15 are plastically deformable, with a view to firmly securing the shaft 15. In this case, the mass increases a little, but the increase in the mass can be minimized, for example, by forming the shaft 15 in a hollow structure. When the needle bearings 16 are made of a ceramic material, the production of the needle bearings 16 becomes difficult, so that the production cost of the cam follower device becomes significantly higher. Since the needle bearings 16 are thin and even the total volume thereof is not large, even if the constitutent material of the needle bearings 16 is changed from a steel material to a ceramic material, the reduction in the weight that is brought about by the change of constituent materials is not large, so that no significant improvement in the high-speed follow-up performance of the cam follower device can be expected. It is therefore preferable to form the needle bearings 16 from a steel material. Under the above-described circumstances, it is concluded that a practically effective way is to form only the outer ring 14 from a ceramic material.
However, the following problems newly arise due to the difference in thermal expansion between the outer ring 14 made of a ceramic material, which has a relatively small coefficient of thermal expansion, and the shaft 15 and the needle bearings 16, which are made of a steel material having a relatively large coefficient of thermal expansion:
When the engine is at rest, the cam follower device is at an ordinary temperature (e.g., 20° C.), whereas, when the engine is in an operative state, the temperature of the cam follower device rises to about 120° C. The thermal expansion of the shaft 15 and the needle bearings 16 that is caused by the rise in the temperature is greater than that of the outer ring 14 made of a ceramic material.
Accordingly, when the temperature of the cam follower device rises as the engine is run, the size of the clearance that is present where the steel needle bearings 16 are disposed, that is, the dimension h that is determined by subtracting the sum of the outer diameter D of the shaft 15 and double the outer diameter d of a needle bearing 16 from the inner diameter R of the outer ring 14, i.e., h=R-(D+2d), decreases. If the clearance h becomes excessively small on such an occasion, the needle bearings 16 may seize. In an extreme case, the ceramic outer ring 14 may be cracked by being forcibly extended outwardly.
If the clearance h at ordinary temperature is set at an excessively large value with a view to preventing the seizure of the needle bearings 16 and possible cracking of the outer ring 14, the level of noise generated from the cam follower device becomes excessively high during the initial running stage of the automotive engine when the temperature of the cam follower device is still low and, in an extreme case even when the temperature of the engine has risen.
SUMMARY OF THE INVENTION
In view of the above-described problems of the prior art, it is an object of the present invention to provide a cam follower device for a valve driving mechanism in an engine, which is designed so as to reduce friction, enable effective and easy lubrication, permit easy and reliable securing of the shaft, lower the noise level, eliminate the fear of seizure or cracking, and improve the high-speed follow-up performance.
The cam follower device of the present invention is incorporated in a valve driving mechanism of an engine to contact the outer peripheral surface of a cam secured to a cam shaft that rotates synchronously with a crankshaft of the engine, thereby transmitting the motion of the cam to a valve that opens and closes a suction port or an exhaust port in the engine.
The cam follower device of the present invention comprises: a pair of spaced support wall portions which are formed on a member that is provided in opposing relation to the cam to receive the motion of the cam; through-holes which are formed in the support wall portions at respective positions that are aligned with each other; a steel shaft which has been hardened at an intermediate portion thereof, two end portions of the shaft, which are not hardened, being fitted into the through-holes and then staked toward the inner peripheral surfaces of the through-holes where the end portions are disposed, thereby being secured between the pair of support wall portions; and a ceramic outer ring which is rotatably supported through a plurality of hardened steel needle bearings around the intermediate portion of the shaft that is located in between the pair of support wall portions, the outer ring being in contact at the outer peripheral surface with the outer peripheral surface of the cam.
In addition, the clearance gap which is present where the steel needle bearings are disposed at an ordinary temperature is set within the range of from (5 μm+9.5×10 -4 Di) to (18 μm+9.5×10 -4 Di), where Di is the inner diameter of the outer ring.
In the cam follower device of the present invention that is arranged as described above, the power transmitting function per se that is performed between the cam and the cam follower is the same as in the case of the conventional cam follower device that is disclosed, for example, in the above-described Japanese Utility Model Public Disclosure (KOKAI) No. 64-34406 (1989). That is, when the engine is running, the outer ring rotates around the shaft, and while doing so, it transmits the motion of the cam to the member that is provided in opposing relation to the cam. Since this transmission is performed on the basis of the rolling of the needle bearings that are provided between the outer ring and the shaft, the output loss due to friction is small, so that the engine efficiency improves.
The outer ring rotates around the shaft in response to the rolling of the plurality of needles. Lubrication of these needle bearings can be readily and surely effected by means of a lubricating oil that is retained in the area between each pair of adjacent needle bearings.
In the cam follower device according to the present invention, only the outer ring is formed from a ceramic material and the shaft is formed from a steel material which has been hardened only at the intermediate portion. Accordingly, the steel shaft can be reliably secured by staking the two end portions, which are not hardened, so that these end portions bite into the support wall portions while deforming the latter. In addition, since the outer ring, which has a relatively large volume, is formed from a ceramic material, the inertial mass of the cam follower device decreases. As a result, the high-speed follow-up performance of the cam follower device improves, and it becomes easy to cope with an increase in engine speed. In addition, the force with which the outer ring presses the needle bearings when performing high-speed reciprocating motion decreases, so that the lifetime of the needle bearings is lengthened.
Since the clearance gap which is present where the steel needle bearings are disposed at ordinary temperature is set within the range of from (5 μm+9.5×10 -4 Di) to (18 μm+9.5×10 -4 Di), where Di is the inner diameter of the outer ring, it is possible to maintain a low level of noise over the whole engine operation, i.e., from the time when the engine has been just started to the time when the temperature of the engine has risen generated by the cam follower device, while preventing any seizure of the needle bearings and cracking of the outer ring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show one embodiment of the cam follower device according to the present invention, in which FIG. 1 is equivalent to a sectional view taken along the A--A of FIG. 14, and FIG. 2 is a sectional view taken along the line B--B of FIG. 1;
FIG. 3 is a graph showing the relationship between the size of the clearance that is present where the steel needle bearings are disposed at ordinary temperature and the level of noise generated by the cam follower device in one example in which the inner diameter of the outer ring is 18 mm;
FIGS. 4 to 7 are side views showing four examples of the staked configuration of the shaft end portion;
FIGS. 8 to 11 show another example of the staking of the shaft end portion, in which FIG. 8 is an end view of a jig that is used for the staking process, FIG. 9 is a sectional view taken along the line C--C of FIG. 8, FIG. 10 is a side view showing the staked configuration of the shaft end portion, and FIG. 11 is a sectional view taken along the line D--D of FIG. 10;
FIG. 12 is a perspective view showing one example of an engine which incorporates the cam follower device of the present invention;
FIG. 13 is a side view of a cam follower device which is assembled to a rocker arm;
FIG. 14 is a sectional view taken along the line E--E of FIG. 13;
FIGS. 15 and 16, which are similar to FIGS. 1 and 2, show one example of conventional cam follower devices; and
FIGS. 17 and 18, which are similar to FIGS. 1 and 2, show another example of conventional cam follower devices.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention will be described below in more detail with reference to the accompanying drawings.
As shown in FIGS. 12 and 13, cams 6 are secured to a cam shaft 2 which rotates synchronously with the crankshaft of an engine, and a rocker arm 3 is provided in opposing relation to each of the cams 6 to receive the motion of the cam 6, the rocker arm 3 being made of aluminum or steel. Referring to FIGS. 1 and 2, a pair of spaced support wall portions 17 are provided at an end portion of the rocker arm 3. The central portions of the support wall portions 17 are provided with circular through-holes 18 at respective positions which are aligned with each other.
The through-holes 18 are fitted with two end portions of a shaft 19 which is formed from a bearing steel in the shape of a hollow tube, and the two end portions of the shaft 19 are staked toward the inner peripheral surfaces of the through-holes 18 where these end portions are disposed, thereby plastically deforming the inner peripheral surfaces of the through-holes 18, and thus securing the shaft 19 extending between the pair of support wall portions 17.
It should be noted that the intermediate portion of the shaft 19 that is located between the pair of support wall portions 17 has been hardened by a conventional hardening method, for example, induction hardening, cementation, etc., so that the surface hardness of the hardened portion is in the range of from Hv 640 to Hv 840, with a view to preventing the outer peripheral surface of the intermediate portion of the shaft 19, which is in contact with needle bearings 20 (described later), from becoming worn or damaged. The two end portions of the shaft 19 are not hardened so that the hardness thereof is in the range of from Hv 200 to Hv 336, thereby enabling these end portions to be staked when the shaft 19 is secured to the support wall portions 17.
The two end portions of the shaft 19 are staked in such a manner that the staked portions are non-concentrical with respect to the through-holes 18 (see the above-described Japanese Utility Model Public Disclosure (KOKAI) No. 64-34406), as shown in FIGS. 4 to 7, or each end portion of the shaft 19 is staked as shown in FIGS. 10 and 11 by pressing a jig 22, shown in FIGS. 8 and 9, against the end face of the shaft 19, thus preventing the shaft 19 from rotating within the through-holes 18 formed in the support wall portions 17.
A ceramic outer ring 21 is rotatably supported through a plurality of steel needle bearings 20 around the intermediate portion of the shaft 19 which extends between the pair of support wall portions 17 and which is secured at two end portions thereof by these support wall portions 17, as described above. The outer ring 21 is formed from a ceramic material, for example, silicon nitride (Si 3 N 4 ), which has a hardness of not less than Hv 1000 and a specific gravity of not more than 4. The needle bearings 20 are formed from a bearing steel having a surface hardness of about Hv 900.
The size of a clearance which is present where the steel needle bearings 20 are disposed at ordinary temperature is set within the range of from (5 μm+9.5×10 -4 Di) to (18 μm+9.5×10 -4 Di), where Di is the inner diameter of the outer ring 21.
The reason for setting the clearance within the above-described range is as follows.
An experiment carried out by the present inventor confirms that, when the inner diameter Di of the outer ring 21 is 18.0 mm, the relationship between the above-described clearance h at ordinary temperature and the noise that is generated by the cam follower device is such as that shown in FIG. 3; as will be clear from the graph, the level of noise generated during the rotation of the outer ring 21 rises when the clearance h exceeds 35 μm. In some of the samples having a clearance of 17 μm or less, indicated by the mark Δ in the figure, the needle bearings 20 (see FIGS. 1 and 2) seized during the rotation of the outer ring 14. In some of the samples having a clearance of 10 μm or less, indicated by the mark x, the ceramic outer ring 21 (see FIGS. 1 and 2) cracked as the temperature of the cam follower device rose.
In actual use of the cam follower device in an engine, the seizure of the needle bearings 20 and the cracking of the outer ring 14 must be prevented and it is therefore necessary to leave a surplus of about 5 μm when setting a lower-limit value for the clearance h, with the machining accuracy being taken into consideration. It will therefore be understood from the experimental results shown in FIG. 3 that the suitable range of the clearance h at ordinary temperature is from 22 μm to 35 μm.
The experimental results shown in FIG. 3 are what were obtained in regard to the outer ring 21 having an inner diameter Di of 18 mm. To enable the range (from 22 μm to 35 μm) of the proper clearance h at ordinary temperature to apply to cam follower outer rings having an inner diameter Di of from 10 mm to 18 mm, which are used for ordinary automotive engines, an expression of from [5+(α 1 -α 2 )·Δt·Di] to [18+(α 1 -α 2 )·Δt·Di] is deduced from the above-described experimental results with the following factors being taken into consideration: the difference between the coefficient of linear thermal expansion α 1 of a bearing steel used to form the shaft 19 and the needle bearings 20 and the coefficient of linear thermal expansion α 2 of a ceramic material used to form the outer ring 21, and the rise Δt in temperature of the cam follower device during the running of the engine. On the basis of this expression, the above-described range of the clearance h that is present where the steel needle bearings 20 are disposed at ordinary temperature, i.e., from (5 μm+9.5×10 -4 Di) to (18 μm+9.5×10 -4 Di), is determined.
In the cam follower device of the present invention that is arranged as described above, the power transmitting function per se that is performed between the cam and the cam follower is the same as in the case of the conventional cam follower device described above.
More specifically, the rotatable outer ring 21 is provided around the shaft 19 that is secured to the distal end portion of the rocker arm 3 to change the friction occurring between the rocker arm 3 and the cam 6 (see FIGS. 12 and 13), which rotates synchronously with the crankshaft 2 of the engine, from the sliding friction to the rolling friction, thereby enabling a reduction in output loss and an improvement in the engine efficiency.
If, in the foregoing arrangement, the outer peripheral surface of the outer ring 21 is subjected to crowning (i.e., if each edge portion of the outer peripheral surface of the outer ring 21 is formed into a curved surface where the diameter gradually decreases toward the edge), the contact between the outer peripheral surfaces of the cam 6 and the outer ring 21 is made uniform, so that the wear of the cam 6, which is made of steel, can be reduced furthermore.
In the cam follower device of the present invention, wherein the engine efficiency is improved by a reduction in the power loss, since the outer ring 21 is formed from a ceramic material, which has a relatively small specific gravity (i.e., the specific gravity of a typical bearing steel is about 7.83, whereas the specific gravity of the above-described silicon nitride ceramic material is 4.0 or less), the inertial mass of the cam follower device decreases. In consequence, the high-speed follow-up performance of the cam follower device is improved, and it becomes easy to cope with an increase in engine speed. In addition, since the load on the needle bearings 20 decreases in accordance with the acceleration that acts on the outer ring 21, the lifetime of the needle bearings 20 can be lengthened.
Since the steel shaft 15 is secured to the steel or aluminum support wall portions 17, the two end portions of the shaft 15 and the support wall portions 17 are engaged deeply with each other. Thus, the shaft 15 can be firmly secured so that it will not rotate.
In addition, since the clearance h that is present where the steel needle bearings 20 are disposed at ordinary temperature is set within a proper range, it is possible to prevent seizure of the needle bearings 20 and cracking of the outer ring 21 irrespective of the rise in temperature during the running of the engine. Moreover, the noise that is generated by the cam follower device can be maintained at a low level at all times independently of a temperature change which occurs when the engine is started or stopped.
Although in the foregoing embodiment the cam follower device is provided at the end portion of the rocker arm 3, in the case of a DOHC engine it may be provided at the proximal end portion of the associated valve or at the intermediate portion of the rocker arm 3, as disclosed in the above-described Japanese Utility Model Public Disclosure (KOKAI) No. 64-34406.
When the cam follower device is attached to an aluminum rocker arm, an annular plate member may be provided in between each end of the needle bearings 20 and the inner side surface of each of the pair of support wall portions 17 that are provided on a part of the aluminum rocker arm, to prevent wear of the inner side surfaces of the aluminum support wall portions 17, which would otherwise be caused by direct contact with the needle bearings 20, which are made of a bearing steel.
Such an annular plate member may be attached to the inner side surface of each of the support wall portions 17, or supported at the inner peripheral edge thereof on the outer peripheral surface of the shaft 19. It is also possible to merely fit an annular plate member on a part of the shaft 19 in between each end of the needle bearings 20 and the inner side surface of the corresponding support wall portion 17.
However, such consideration is not always necessary in the case of a steel rocker arm (since a steel rocker arm can be formed to be thinner than an aluminum rocker arm and does not always lead to an increase in the inertial mass, it may be used even in a high-speed engine).
As has been described above, it is possible according to the cam follower device of the present invention to perform effective lubrication, surely secure the shaft, achieve a reduction in the load on the needle bearings, lower the noise level and improve the high-speed follow-up performance. Thus, a cam follower device which has satisfactory durability and reliability and is capable of satisfactorily coping with an increase in engine speed is obtained at relatively low cost. | A cam follower device which is incorporated in a valve driving mechanism for an engine to contact the outer peripheral surface of a cam secured to a cam shaft that rotates synchronously with a crankshaft of the engine, thereby transmitting the motion of the cam to a valve that opens and closes a suction port or an exhaust port in the enigne. A ring-shaped member which contacts the cam is formed from a ceramic material, and this ceramic ring-shaped member is rotatably supported around a steel shaft. The clearance between the inner peripheral surface of the ceramic ring-shaped member and the steel shaft is set within a specific range, thereby preventing the occurrence of problems, for example, noise, arising due to a difference in thermal expansion coefficient between the two members and thus improving the high-speed follow-up performance of the cam follower device. | 5 |
BACKGROUND OF THE INVENTION
This invention relates generally to a method and apparatus for extinguishing fires and, more particularly, to a method and apparatus for extinguishing fires in storage vessels filled with flammable liquids.
Extinguishing fires in flammable liquid filled vessels is difficult because of the typically very volatile nature of the stored liquids. The techniques generally employed to extinguish such fires, often called tank fires, entail the discharge of an extinguishing agent onto the surface of the burning liquid. Usually, the fire extinguishing agent is released from a portable, manually operated extinguisher. Particularly for fires in large capacity storage tanks, the manual application of a fire extinguishing agent exhibits inconsistent effectiveness and presents the possibility of injury to fire fighting personnel. Those problems are somewhat alleviated with fixed extinguishing systems having electrical controls that are actuated either automatically in response to fire detection or manually by remotely positioned operators. However, fixed systems also exhibit certain disadvantages including the requirement for release of copious quantities of extinguishing agent to insure the presence thereof over the entire exposed surface of the flammable liquid. Even then, the deposition of extinguishing agent over the entire exposed surface of the flammable liquid is rendered difficult by the heavy turbulence inherently associated with fire. This difficulty is accentuated in tank installations having physical obstructions that inhibit the discharge of extinguishing agent onto all surface portions of the flammable liquid. Another problem is that the extinguishing agent, when discharged under pressure, can actually spread a fire by splashing burning fuel out of an open vessel.
Another technique previously suggested for extinguishing tank fires involved the release of CO 2 beneath the surface of the flammable liquid. According to the teachings of that technique, the released CO 2 would rise through the flammable liquid and extinguish a fire burning on its surface. A fire extinguishing method of that type is disclosed, for example, in U.S. Pat. No. 145,134. The subsurface release of CO 2 is impractical for large tank fires, however, because of the inherent condition that a majority of the released agent is absorbed by the flammable liquid. Therefore, most of the released CO 2 fails to reach the surface of the burning liquid and thereby function as an extinguishing agent. For those reasons excessive quantities of CO 2 must be used which is both inefficient and increases the possibility of fire spread due to splashing fuel.
The object of this invention, therefore, is to provide an improved method for extinguishing fires burning above and fueled by a flammable liquid stored in a storage vessel.
SUMMARY OF THE INVENTION
The present invention encompasses a method of extinguishing a fire burning above and fueled by a flammable liquid stored in a storage vessel and including the steps of providing a supply of a halogenated fire extinguishing agent, detecting the presence of combustion products above the surface of the flammable liquid, and discharging the extinguishing agent into the storage vessel and below the surface of the flammable liquid. The stored liquid absorbs very little of the halogenated agent, the majority of which rises to the surface of the liquid and chemically breaks the chain reaction of combustion to terminate the fire. Furthermore, the agent enters the fire at the fringe of the combustion wave where the burning velocity approaches zero, thereby minimizing the agent concentration required.
According to one feature of the invention, the extinguishing agent is stored as a liquified gas that is vaporized after fire detection so as to rise through the flammable liquid in a vapor phase. Vaporization of the liquified agent facilitates its ascension to the surface of the stored liquid.
According to yet another feature of the invention, the discharge network is a sparging network having discharge pipes with downwardly opening discharge openings and distributed through a horizontal cross-section of the storage vessel. The sparging network facilitates a prompt and uniform release of the extinguishing agent.
According to another feature of the invention, the extinguishing agent is bromotrifluoro methane also known by the generic name Halon-1301. Because Halon-1301 exhibits a liquid to vapor phase change at a very low temperature of -72° F., the advantageous vaporization of the agent is assured even in extremely cold environments.
The invention further encompasses a fire extinguishing system including a storage vessel retaining a flammable liquid, a container retaining a halogenated extinguishing agent, an agent discharge network disposed in the storage vessel below the surface of the flammable liquid, and a distribution network for distributing the extinguishing agent from the container to the discharge network for discharge thereby into the flammable liquid. Also included is a release mechanism for inducing the distribution of the extinguishing agent from the container to the discharge network, a detector for detecting combustion products above the surface of the flammable liquid, and a control means for activating the release mechanism in response to detection of combustion products by the detector. This system automatically provides the desired extinguishing method.
According to another feature, the halogenated extinguishing agent is a liquified gas that experiences a liquid to vapor phase change below 32° F., and the release mechanism comprises a valve opened in response to detection of combustion products by the detector. This feature facilitates vaporization of the agent for ascension through the stored liquid to the surface thereof.
DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention will become more apparent upon a perusal of the drawings wherein:
FIG. 1 is a schematic representation of a fire extinguishing system according to the invention;
FIG. 2 is a schematic cross-sectional view taken along lines 2--2 of FIG. 1;
FIG. 3 is a schematic cross-sectional view taken along lines 3--3 of FIG. 2 and depicting the presence of a fire;
FIG. 4 is a schematic diagram illustrating the fuel fraction gradient in the fire of FIG. 3; and
FIG. 5 is a schematic view illustrating a modified distribution network for the system shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Illustrated in the drawing is a fire extinguishing system 11 according to the present invention. A storage vessel 12 is partially filled with a flammable liquid 13 such as oil. Mounted within the storage vessel 12 and below an exposed surface 14 of the flammable liquid 13 is an extinguishing agent sparging network 15. As shown in FIG. 2, the sparging network 15 includes a plurality of pipes 20 having downwardly opening discharge openings 17. The pipes 20 are arranged in a pattern corresponding to a horizontal cross section through the tank 12. A combustion products detector such as a continuous line type fire detector 16 extends around the entire inner surface of the vessel 12 above the exposed surface 14 of the liquid 13.
Located outside the vessel 12 is a hermetically sealed storage container 21. Retained by the container 21 is a liquified, halogenated extinguishing agent 22. Preferably the extinguishing agent 22 is bromotrifluoro methane (halon 1301) marketed, for example, by DuPont as Freon 13B1. Liquification of the extinguishing agent 22 within the container 21 is maintained by a pressurized inert gas 23 such as dry nitrogen. A release valve 24 is mounted on the top surface of the container 21 and communicates with a dip tube 25 that extends axially through the container 21 and opens into the lower portion thereof. Connected between the sparging network 15 and the valve 24 and providing fluid communication therebetween is a fluid distribution pipe 26.
A remote control interface 31 controls the operation of the extinguishing system 11. The control interface 31 receives an input from the fire detector circuit 16 on an input line 32 and an input from a manually operated actuator 33 on an input line 34. An output line 35 of the control interface 31 is operatively connected to the release valve 24 on the storage container 21. Another output line 36 of the control interface 31 is operatively connected to both an audible alarm 37 and a visual alarm 38.
OPERATION
In response to the detection of combustion products above the surface 14 of the flammable liquid 13, the detector 16 produces an output signal that is applied over the line 32 to the control interface 31. Resultant fire indicating output signals are provided by the control interface 31 on output lines 35 and 36. The output signal on line 36 actuates both the audible alarm 37 and the visual alarm 38 to indicate the presence of the fire detected by the detector 16. Simultaneously, the output signal on line 35 opens the valve 24 allowing the pressurized gas 23 in the container 21 to forcibly discharge the extinguishing agent 22 through the dip tube 25. After release from the pressurized container 21, the extinguishing agent 22 passes through the distribution pipe 26 and is discharged by the sparging network 15 into the body of flammable liquid 13 within the storage vessel 12. The released agent rises through the flammable liquid 13 and penetrates the surface 14.
In order to support combustion, the liquid fuel 13 must undergo a liquid to vapor phase change. As shown in FIGS. 3 and 4, the fuel vapor forms above the liquid surface 14 a fuel rich volume R, a flame zone, and a fuel lean volume L. Thus, after penetrating the liquid surface 14, the released agent passes through the fuel rich volume R and enters the flame zone at the upper flammable limit UL. The agent enters, therefore, the reaction at the fringe of the combustion wave where the burning velocity approaches zero. Such fuel limit mixtures require the minimum concentrations of agent to break the chain reaction of combustion and extinguish flame.
Preferably, the halogenated agent 22 is a type that experiences a liquid to vapor phase change at a temperature below 32° F. A particularly desirable such agent is bromotrifluoro methane known as halon 1301. Halon 1301 experiences a liquid to vapor phase change at -72° F. and thereby insures that the agent will vaporize under even extremely cold environmental conditions and remain in the vapor state after discharge into the liquid 13. That factor is important in that a vaporized, halogenated agent will rise rapidly through the liquid 13 and the fuel rich volume R to reach the fire zone thereabove.
Another embodiment of the invention is illustrated in FIG. 5. In this embodiment a vessel 51 of cylindrical shape retains a liquid fuel 52. Entering the vessel 51 from a fire extinguishing system as shown in FIG. 1 is a distribution pipe 53 that is connected to a sparging network 54. In this case the sparging network consists of a circular discharge pipe 55 that conforms to a horizontal cross-section of the vessel 51 so as to provide uniform distribution of agent through downwardly oriented openings.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example only, combustion products detectors other than a heat detector 16 can be used. It is to be understood, therefore, that the invention can be practiced otherwise than as specifically described. | A method of extinguishing a fire burning above and fueled by a flammable liquid stored in a storage vessel and including the steps of providing a supply of a halogenated fire extinguishing agent, detecting the presence of combustion products above the surface of the flammable liquid, and discharging the extinguishing agent into the storage vessel and below the surface of the flammable liquid. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of processes for converting oxygenate by-products from the Fischer-Tropsch synthesis to useful hydrocarbon products, particularly, middle distillate.
2. Description of the Prior Art
The conversion of oxygenated organic compounds to hydrocarbons has been the subject of numerous prior-art disclosures. U.S. Pat. No. 3,928,483 discloses a process for the production of aromatic rich gasoline boiling range hydrocarbons from lower alcohols such as methanol, ethanol, propanol and corresponding ethers. In this patent, the process is carried out in two or more stages wherein the alcohol or ether is contacted with a condensation catalyst to produce aliphatic dehydration products and water. The dehydration product is thereafter converted to gasoline boiling hydrocarbon by contact with a special crystalline aluminosilicate zeolite providing a silica-to-alumina ratio greater than 12, a constraint index within the range of 1 to 12 and a dried crystal density of not less than about 1.6 grams per cubic centimeter. A ZSM-5 crystalline zeolite is representative of the special class of zeolite providing the above defining characteristics. U.S. Pat. No. 3,907,915 is directed to the conversion of aliphatic carbonyl containing compounds with the special zeolite above defined. U.S. Pat. No. 3,998,898 is directed to converting a mixture of a difficult to convert aliphatic organic compound in combination with easily converted aliphatic alcohols, esters, acetals and analogs thereof over the special crystalline zeolite above defined to produce highly aromatic gasoline hydrocarbons and light aliphatic hydrocarbons.
SUMMARY OF THE INVENTION
The present invention is directed to an improved method and combination of processing steps for converting a wide spectrum of water soluble oxygenated products such as those obtained from a Fischer-Tropsch operation to middle distillate hydrocarbon products. The term "middle distillate" as used herein shall be understood to refer to hydrocarbon fractions whose boiling points at a pressure of one atmosphere lie in the mid-range, generally considered to be from about 300° F. to as high as about 800° F., and includes such products as jet fuel, diesel fuel, furnace fuel, industrial fuel and kerosene.
The improved process of this invention generally involves collecting and passing the mixed water soluble oxygenates of a Fischer-Tropsch syngas conversion operation comprising alcohols, ethers, aldehydes, ketones, acids and water after separation of acids and some water in contact with a dehydration catalyst under conditions to achieve at least 25% dehydration conversion of the feed and thereafter processing all or a part of the product of dehydration over a special crystalline aluminosilicate defined below to produce a complex mixture of products comprising a minor amount of gases and high octane C 5 + gasoline and a major amount of middle distillate boiling range hydrocarbons. In this combination operation, the dehydration of the charged oxygenates is important and effected under conditions to achieve an elevated conversion level normally falling short of complete conversion dehydration of the oxygenates. Thereafter a water phase containing unconverted oxygenates is separated from a water insoluble phase comprising dehydrated oxygenates. This water insoluble phase comprises a mixture of gaseous products, for the most part light olefins, and may also contain a relatively minor amount of liquid C 6 + organic materials made up largely of dehydration products of aldehydes and ketones. The water phase containing unreacted oxygenates is recycled to the primary distillation zone upstream of the dehydration zone. The substantially water-free dehydrated oxygenates, preferably from which the C 6 + dehydration products have been previously removed, are thereafter converted by a special zeolite catalyst herein described in a separate zeolite catalytic conversion zone.
The combination process of the invention achieves significant advantages at least with respect to the zeolite catalyst life by substantially reducing the amount of water and unconverted oxygenates contacting the zeolite catalyst. The special zeolite catalytic conversion of the water-feee dehydrated oxygenates is more efficient, since quenching of the zeolite catalyst conversion operation is virtually eliminated.
The processing combination of the invention is particularly concerned with processing C 2 + oxygenates of a Fischer-Tropsch syngas conversion operation and dehydration products thereof. The significant advantages of the processing combination reside in operating the middle distillate forming stage independently of the initial dehydration state, and any unconverted (dehydrated) oxygenates can be separated and recycled to the distillation operation upstream of the dehydration zone and/or to the zeolite catalytic conversion zone. Where maximum conversion of dehydrated oxygenates to middle distillate is desired, any gasoline present in the effluent from the zeolite catalytic conversion zone can be separated therefrom and recycled to this zone together with fresh dehydrated oxygenates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The crystalline aluminosilicate component used is a special crystalline zeolite such as ZSM-5 zeolite which is characterized by a pore dimension greater than about 5 Angstroms, i.e., it is capable of sorbing paraffins, it has a silica-to-alumina ratio of at least 12 and a constraint index within the range of 1 to 12. Zeolite A, for example, with a silica-to-alumina ratio of 2.0, is not useful in this invention, and it has no pore dimension greater than about 5 Angstroms.
The crystalline aluminosilicates herein referred to, also known as zeolites, constitute an unusual class of natural and synthetic minerals. They are characterized by having a rigid crystalline framework structure composed of an assembly of silicon and aluminum atoms, each surrounded by a tetrahedron of shared oxygen atoms, and a precisely defined pore structure. Exchangeable cations are present in the pores.
The zeolites utilized herein exhibit some unusual properties. They are very active even with silica-to-alumina ratios exceeding 30. This activity is surprising, since catalytic activity of zeolites is generally attributed to framework aluminum atoms and cations associated with these aluminum atoms. These zeolites retain their crystallinity for long periods in spite of the presence of steam even at high temperatures which induce irreversible collapse of the crystal framework of other zeolites, e.g., of the X and A type. Furthermore, carbonaceous deposits, when formed, may be removed by burning at higher than usual temperatures to restore activity. In many environments the zeolite of this class exhibit very low coke forming capability, conducive to very long times on stream between burning regenerations.
An important characteristic of the crystal structure of this class of zeolites is that it provides constrained access to, and egress from, the intracrystalline free space by virtue of having a pore dimension greater than about 5 Angstroms and pore windows of about a size such as would be provided by 10-membered rings of oxygen atoms. It is to be understood, of course, that these rings are those formed by the regular disposition of the tetrahedra making up the anionic framework of the crystalline aluminosilicate, the oxygen atoms themselves being bonded to the silicon or aluminum atoms at the centers of the tetrahedra. Briefly, the preferred zeolites useful in this invention have a silica-to-alumina ratio of at least about 12 and a structure providing constrained access to the crystalline free space.
The silica-to-alumina ratio referred to may be determined by conventional analysis. This ratio is meant to represent, as closely as possible, the ratio in the rigid anionic framework of the zeolite crystal and to exclude aluminum in the binder or in cationic or other form within the channels. Although zeolites with a silica-to-alumina ratio of at least 12 are useful, it is preferred to use zeolites having higher ratios of at least about 30. Such zeolites, after activation, acquire an intracrystalline sorption capacity for normal hexane which is greater than that for water, i.e., they exhibit "hydrophobic" properties. It is believed that this hydrophobic character is advantageous in the present invention.
The zeolites useful as catalysts in this invention freely sorb normal hexane and have a pore dimension greater than about 5 Angstroms. In addition, their structure must provide constrained access to some larger molecules. It is sometimes possible to judge from a known crystal structure whether such constrained access exists. For example, if the only pore windows in a crystal are formed by 8-membered rings of oxygen atoms, then access by molecules of larger cross-section than normal hexane is substantially excluded and the zeolite is not of the desired type. Zeolites with windows of 10-membered rings are preferred, although excessive puckering or pore blockage may render these zeolites substantially ineffective. Zeolites with windows of 12-membered rings do not generally appear to offer sufficient constraint to produce the advantageous conversions desired in the instant invention, although structures can be conceived, due to pore blockage or other cause, that may be operative.
Rather than attempt to judge from crystal structure whether or not a zeolite possesses the necessary constrained access, a simple determination of the "constraint index" may be made by continuously passing a mixture of equal weight of normal hexane and 3-methylpentane over a small sample, approximately 1 gram or less, of zeolite at atmospheric pressure according to the following procedure. A sample of the zeolite, in the form of pellets or extrudate, is crushed to a particle size about that of coarse sand and mounted in a glass tube. Prior to testing, the zeolite is treated with a stream of air at 1000° F. for at least 15 minutes. The zeolite is then flushed with helium and the temperature adjusted between 550° F. and 950° F. to give an overall conversion between 10% and 60%. The mixture of hydrocarbons is passed at 1 liquid hourly space velocity (i.e., 1 volume of liquid hydrocarbon per volume of catalyst per hour) over the zeolite with a helium dilution to give a helium to total hydrocarbon mole ratio of 4:1. After 20 minutes on stream, a sample of the effluent is taken and analyzed, most conveniently by gas chromatography, to determine the fraction remaining unchanged for each of the two hydrocarbons.
The "constraint index" is calculated as follows: ##EQU1##
The constraint index approximates the ratio of the cracking rate constants for the two hydrocarbons. Catalysts suitable for the present invention are those which employ a zeolite having a constraint index from 1.0 to 12.0. Constraint Index (C.I.) values for some typical zeolites, including some not within the scope of this invention, are:
______________________________________CAS C.I.______________________________________Erionite 38ZSM-5 8.3ZSM-11 8.7ZSM-35 6.0TMA Offretite 3.7ZSM-38 2.0ZSM-12 2Beta 0.6ZSM-4 0.5Acid Mordenite 0.5REY 0.4Amorphous Silica-alumina 0.6______________________________________
The above-described Constraint Index is an important, and even critical, definition of those zeolites which are useful to catalyze the instant process. The very nature of this parameter and the recited technique by which it is determined, however, admit of the possibility that a given zeolite can be tested under somewhat different conditions and thereby have different constraint indexes. Constraint Index seems to vary somewhat with severity of operation (conversion). Therefore, it will be appreciated that it may be possible to so select test conditions to establish multiple constraint indexes for a particular given zeolite which may be both inside and outside the above defined range of 1 to 12.
Thus, it should be understood that the parameter and property "Constraint Index" as such value is used herein is an inclusive rather than an exclusive value. That is, a zeolite when tested by any combination of conditions within the testing definition set forth hereinabove to have a constraint index of 1 to 12 is intended to be included in the instant catalyst definition regardless that the same identical zeolite tested under other defined conditions may give a constraint index value outside of 1 to 12.
The class of zeolites defined herein is exemplified by ZSM-5, ZSM-11, ZSM-12, ZSM-21, and other similar materials. U.S. Pat. No. 3,702,886 describing and claiming ZSM-5 is incorporated herein by reference.
ZSM-11 is more particularly described in U.S. Pat. No. 3,709,979, the entire contents of which are incorporated herein by reference.
ZSM-12 is more particularly described in U.S. Pat. No. 3,832,449, the entire contents of which are incorporated herein by reference.
Abandoned U.S. patent application Ser. No. 358,192, filed May 7, 1973, the entire contents of which are incorporated herein by reference, describes a zeolite composition designated as ZSM-21, and a method of making such, which is useful in this invention. There is evidence which suggests that this composition may be composed of at least two different zeolites, designated ZSM-35 and ZSM-38, one or both of which are the effective material insofar as the catalysis of this invention is concerned. Either or all of these zeolites is considered to be within the scope of this invention. ZSM-35 is described in U.S. Pat. No. 4,016,265 and ZSM-38 is described in U.S. Pat. No. 4,046,859.
The specific zeolites described, when prepared in the presence of organic cations, are substantially catalytically inactive, possibly because the intracrystalline free space is occupied by organic cations from the forming solution. They may be activated by heating in an inert atmosphere at 1000° F. for 1 hour, for example, followed by base exchange with ammonium salts, followed by calcination at 1000° F. in air. The presence of organic cations in the forming solution may not be absolutely essential to the formation of this special type zeolite; however, the presence of these cations does appear to favor the formation of this special type of zeolite. More generally, it is desirable to activate this type zeolite by base exchange with ammonium salts, followed by calcination in air at about 1000° F. for from about 15 minutes to about 24 hours.
Natural zeolites may sometimes be converted to this type zeolite by various activation procedures and other treatments such as base exchange, steaming, alumina extraction and calcination, alone or in combinations. Natural minerals which may be so treated include ferrierite, brewsterite, stilbite, dachiardite, epistilbite, heulandite and clinoptilolite. The preferred crystalline aluminosilicates are ZSM-5, ZSM-11, ZSM-12 and ZSM-21, with ZSM-5 in the acid form, i.e., H-ZSM-5, being particularly preferred.
In a preferred aspect of this invention, the initial zeolites useful as catalysts herein are selected as those having a crystal framework density, in the dry hydrogen form, of not substantially below about 1.6 grams per cubic centimeter. It has been found that zeolites which satisfy all three of these requirements are most desired. Therefore, the preferred catalysts of this invention are those comprising zeolites having a constraint index as defined above of about 1 to 12, a silica-to-alumina ratio of at least about 12 and a dried crystal density of not substantially less than about 1.6 grams per cubic centimeter. The dry density for known structures may be calculated from the number of silicon plus aluminum atoms per 1000 cubic Angstroms, as given e.g. on page 19 of the article on "Zeolite Structure" by W. M. Meier. This paper, the entire contents of which are incorporated herein by reference, is included in "Proceedings of the Conference on Molecular Sieves, London, April 1967", published by the Society of Chemical Industry, London, 1968. When the crystal structure is unknown, the crystal framework density may be determined by classical pycnometer techniques. For example, it may be determined by immersing the dry hydrogen form of the zeolite in an organic solvent which is not sorbed by the crystal. It is possible that the unusual sustained activity and stability of this class of zeolites are associated with its high crystal anionic framework density of not less than about 1.6 grams per cubic centimeter. This high density of course must be associated with a relatively small amount of free space within the crystal, which might be expected to result in more stable structures. This free space, however, seems to be important as the locus of the catalytic activity.
Crystal framework densities of some typical zeolites, including some which are not within the purview of this invention, are:
______________________________________ Void FrameworkZeolite Volume Density______________________________________Ferrierite 0.28 cc/cc 1.76 g/ccMordenite .28 1.7ZSM-5, -11 .29 1.79Dachiardite .32 1.72L .32 1.61Clinoptilolite .34 1.71Laumontite .34 1.77ZSM-4 (Omega) .38 1.65Heulandite .39 1.69P .41 1.57Offretite .40 1.55Levynite .40 1.54Erionite .35 1.51Gmelinite .44 1.46Chabazite .47 1.45A .5 1.3Y .48 1.27______________________________________
Table 1 below identifies a typical oxygenated product stream of a Fischer-Tropsch syngas conversion operation.
TABLE 1______________________________________Oxygenated Product of Fischer-Tropsch SynthesisComponents wt. %______________________________________Water 15.0Acetaldehyde 2.4Methanol 5.1Ethanol 44.3Acetone + C.sub.3 Aldehyde 12.2Isopropanol 3.8Propanol 6.2Methyl Ethyl Ketone + C.sub.4 Aldehyde 4.0Butanol .52-Methyl-1-propanol .5C.sub.5 Ketones 1.01-Butanol 2.9C.sub.5 Alcohols 1.5C.sub.6 + Oxygenates .4 99.8______________________________________
Table 2 below identifies the boiling points of the major oxygenated components of the charge materials and their dehydration products. It will be noted from Table 2 that at the indicated "Proposed Cut Point" the unconverted portion of the charge will separate with the water phase and the dehydration product may be separated as vaporous material from a separation zone maintained under the identified temperature and pressure conditions. This vapor/liquid separation operation is maintained independent of the initial reactor dehydrating operating conditions.
TABLE 2______________________________________ Boiling Point at 100 PSIA______________________________________Ethylene -79.9° F.Propylene 42.3Dimethyl Ether 70.0Butene 133.Acetaldehyde 168.Pentene 212. Proposed Cut PointPropionaldehyde 246.Methanol 252.Acetone 258.Ethanol 276.Isopropanol 281.Hexene 284.n-Propanol 318.Methyl Ethyl Ketone 322.Water 328.______________________________________
The drawing is a schematic showing of the processing arrangement of this invention comprising a primary distillation zone, a dehydration zone, a dehydrated product separation zone, a zeolite catalytic conversion zone and a product separation zone.
Referring now to the drawing by way of example, a stream of oxygenated products and water separated from the product of a Fischer-Tropsch syngas conversion operation is charged to the process of this invention by conduit 2 to a distillation column or zone 3 maintained at a temperature and a pressure selected to achieve separation of water and acids from the remaining oxygenates. In distillation zone 3, a separation is made in the presence of relatively large amounts of water, a water phase and acids withdrawn from the bottom of the zone by conduit 4, with the remaining oxygenates and water being recovered from the top thereof by conduit 5. The oxygenates and water in conduit 5 are heated in heat exchanger 6 to an elevated temperature within the range of about 600° to 1100° F. and preferably about 900° F. before being passed in contact with a dehydrating catalyst in dehydration zone 7. A portion of the material in conduit 5 may be passed to vent as shown when required. In dehydration zone 7, the oxygenates and retained water are passed in contact with a dehydration catalyst suitable for the purpose. Any of the many dehydration catalysts known in the art can be used herein with gamma alumina being preferred. Dehydration zone 7 is maintained under temperature conditions which will achieve a high conversion of the oxygenates to a dehydrated product suitable for passing upon recovery in contact with the middle distillate forming special zeolite catalyst. Table 3 below identifies conditions which may be employed to achieve a desired conversion to dehydrated oxygenates preferably to within the range of 25 to 100%.
TABLE 3______________________________________Endothermic Heats of Dehydration at 700° F.Alcohol → Olefin + WaterAlcohol - H Kcal/Mole - H cal/gm______________________________________Ethanol 11.20 243n-Propanol 8.93 149i-Propanol 12.15 203n-Butanol.sup.1 5.37 72n-Pentanol.sup.2 4.19 48n-Hexanol.sup.3 4.31 42______________________________________Estimated Adiabatic Temperature DropFor 900° F. InletCharge MoleComposition %______________________________________Ethanol 84.3n-Propanol 8.3i-Propanol 3.0n-Butanol 3.4n-Pentanol 1.0______________________________________Conversion .sup.T Adiabatic% °F.______________________________________100 42050 57525 745______________________________________ .sup.1 Olefin product taken as t2-butene .sup.2 Olefin product taken as 2M--2butene .sup.3 Olefin product taken as 2M--2pentene
The product of the dehydration operation and comprising dehydrated oxygenates, water and unconverted oxygenates (not dehydrated) is passed by conduit 8 to a separation zone 9 maintained at a selected temperature and pressure designed to achieve a separation of dehydration product commensurate with a separation shown, for example, by Table 2 above. Thus, a separation is made in zone 9 under selected temperature and pressure conditions which will achieve the recovery of water and unconverted oxygenates withdrawn by conduit 10 for recycle to distillation zone 3. In a preferred embodiment, the water insoluble C 6 + dehydration products are withdrawn from zone 9 through conduit 11 where, if desired, they may be conveyed to a gasoline conversion unit. The presence of these C 6 + dehydration products in the feed to the zeolite catalytic conversion zone where the middle distillate is to be used as diesel fuel is undesirable since these products tend to undergo conversion in this zone to aromatic compounds which result in a lower cetane number for the diesel fuel. Separation of water from unconverted oxygenates before recycle is not essential. Light olefins and other dehydration products such as herein identified are recovered from separation zone 9 by conduit 12 for passage to heater 13 wherein the temperature of the light olefin stream is raised before contacting the special zeolite catalyst herein identified in zone 14. In zone 14, the temperature is maintained within the range of from about 300° F. to about 800° F., preferably from about 350° F. to about 600° F., a pressure within the range of from about 100 psig to about 2,000 psig, preferably from about 500 psig to about 1,000 psig, and an LHSV (Liquid Hourly Space Velocity) of from about 0.2 to about 10 and preferably from about 0.5 to about 2. In this special zeolite catalyst contacting operation, the light olefins and other products of dehydration are converted to middle distillate and, smaller quantities of C 5 + gasoline.
The product of the zeolite catalyst conversion step is passed by conduit 15 from zone 14 to a separator zone 16 wherein a separation is made to recover overhead vapor made up mostly of C 4 and lower boiling material which is withdrawn through conduit 17 for recycle and/or through conduit 19 for further conversion, e.g., in an alkylation zone, a polymerization zone or a combination thereof, or for use as a fuel to satisfy part or all of the thermal requirements of the process. When used for recycle, it is contemplated passing all of the C 4 and lighter material through conduit 18 to a compression zone 20 to raise the pressure therein sufficient for recycle by conduit 21 and admixture with the dehydrated feed in conduit 12 charged to heater 13 and/or for recycle by conduit 22 and admixture with the oxygenated products stream in conduit 5 charged to heater 6. The liquid stream recovered from separation zone 16 through line 23 is conveyed to distillation zone 24 with the middle distillate product (330 + ° F.) being recovered through conduit 25 and the C 5 + gasoline being recovered through conduit 26 for recycle through line 27 and admixture with the dehydrated feed in conduit 12 and/or through conduit 28 for use as such.
The following examples are further illustrative of the invention.
EXAMPLES 1-2
These examples illustrate the dehydration operation of the present invention as applied to feed streams similar to that of the Fischer-Tropsch oxygenated product whose composition is given in Table 1.
______________________________________ Example 1 Example 2______________________________________DehydrationConditions°F. 704 852PSIG 200 290LHSV 3.3 2.1% Conversion 18 91Selectivity toHydrocarbons (wt %)Liquid* 0 26Gas 100 74ApproximateComposition ofGas (Wt %)Ethylene 8 21Propylene 52 32Butylene 18 18Pentene 9 9C.sub.1-5 paraffins 2 6Unidentified 11 14______________________________________ *In the preferred practice of the present invention, the liquid phase, if present, is separated from the gaseous phase prior to introducing the latter into the zeolite catalytic conversion zone.
EXAMPLES 3-4
These examples illustrate the conversion of dehydrated oxygenates to middle distillate and a relatively minor amount of C 5 -330° F. gasoline. The feed in both examples (passing through conduit 12) possessed the following composition:
______________________________________Component Weight %______________________________________Ethane/Ethylene 0.1Propylene 27.8Propane 9.6Isobutane 22.5Butylenes 32.8n-Butane 6.2iso-+n-Pentane .5Pentenes .5 100.0______________________________________
The zeolite catalytic conversion zone was operated at about 600 psig and an LHSV of about 0.65 based on the olefin in the feed. The results were as follows:
______________________________________ Example 3 Example 4______________________________________Days on stream °F. 1 15reaction zone inlet 440 480Weight % product basedon olefin in feedC.sub.1-4 * Paraffins 1.4 1.4Unreacted C.sub.3-4 olefins* 11.7 13.2C.sub.5 - 330° F. gasoline** 9.7 10.5330° F..sup.+ middle distillate 77.2 74.9 100.0 100.0______________________________________ *Recyle to provide heat sink temperature control within the reaction zone **Recycled to maximum conversion of feed to middle distillate. The recycled gasoline was essentially 100% olefins.
Having thus generally described the method and processing combination of this invention and provided specific examples in support thereof, it is to be understood that no undue restrictions are to be imposed by reason thereof except as defined by the following claims. | Water soluble oxygenates of Fischer-Tropsch synthesis separated from water and acids are sequentially converted by a dehydration catalyst and a special zeolite catalyst to provide a product containing a major proportion of middle distillate. | 8 |
BACKGROUND OF THE INVENTION
Devices for drying or dehumidifying air in a vehicle passenger compartment are known. For example, German patent publication DE-A 20 50 898 discloses a device for drying air utilizing a flexible band, namely a fabric band impregnated with lithium chloride. A drive rotates the band so that air to be dehumidified continually flows through a regenerated band section. The regeneration takes place by guiding the band past a heating device. One problem with this type of drying device is that the salt solutions used therewith can corrode metals. Also, the salt can crystallize, which can lead to possible instability. Accordingly, either the desorption temperature or the salt concentration has to be controlled or continuously monitored. A heating device required for the desorption (drying) process also has to be extremely powerful to ensure adequate regeneration of the rapidly rotating band. Another drawback is that complete air drying is not possible with this type of device.
German patent publication DE-A 23 47 335 describes a ventilation device for an armored vehicle equipped with a dehumidifying device consisting of two dehumidifiers. Each dehumidifier is associated with a housing containing regeneratable moisture absorbing means. The two dehumidifiers are connected to air guiding pipes, one end receiving fresh air to be dehumidified and the other end exhausting hot regenerated air. A heating installation heats the regenerating air. Changeover devices in the air guiding pipes on both sides of the dehumidifying device connect the operating dehumidifier and have the moisture absorbing means in the ventilation flow, while the other dehumidifier loaded with moisture is simultaneously dried by air taken in from the heated ambient air. The known arrangement exclusively takes in fresh air from the ambient (outside), which air is dehumidified, filtered, and then exhausted from the interior of the armored vehicle into the ambient air. The regenerating air is always completely taken in from outside, thus necessitating enormous heating power at low outside temperatures to regenerate of the respective dehumidifier. For motor vehicles lacking capacity to generate an enormous amount of heat, this type of device cannot be used on energy efficiency grounds since the heat energy contained in the interior is released unused to the outside air and great heating power has to be available to heat the regeneration air.
In this respect, German patent application P 44 08 796.9 describes an air drying device for vehicle interiors, which device uses two parallel air flow paths formed in a housing. A reactor having an adsorbent is located in each of the air flow paths. With the aid of air-flow control elements for adjusting the air flows through the reactors, which are acted upon by an adsorption or desorption air flow during operation in the opposite sense and during the respective exchange.
There is a need for an energy efficient air drying device particularly in a motor vehicle. The present invention fulls this need.
SUMMARY OF THE INVENTION
The present invention is drawn to a device adapted for drying or dehumidifying air, particularly in a passenger compartment of a motor vehicle. According to one embodiment of the present invention, the air drying device has an air guiding housing defining at least two air flow paths. The guiding housing has an inlet for receiving inlet air to be dehumidified and an outlet for discharging dehumidified air, which outlet can be adapted to communicate with the passenger compartment using air ducts for example. Two reactors, each having an adsorbent for adsorbing moisture from air, are each positioned in one of the two air flow paths. A heat exchanger, which has an air passageway for exhausting air to the ambient, is provided upstream of the reactors to heat the inlet air (desorption) passing therethrough. Air-flow control elements direct air to flow through both the reactors. According to the present invention, the flow control elements are positionable between adsorption operation or mode where the control elements direct the inlet air (adsorption) through each of the reactors and guide the inlet air (adsorption) passing through the reactor to dehumidify the inlet air (adsorption) and guide the dehumidified air to the outlet; and desorption operation or mode where the control elements guide the inlet air (desorption) passing through the reactor to dry the reactor and exhaust the inlet air (desorption) passing through the reactor through the passageway in the heat exchanger. One of the reactors dehumidifies the inlet air, while the other of the reactors is dried by the inlet air. The operation of these reactors can be selectively reversed.
In this respect, no two reactors are dried or dehumidify the inlet air at the same time. Thus, according to the present invention the flow control elements alternately direct the inlet air through each of reactors (first and second) between a first position and a second position. In the first position, the flow control elements guide the inlet air to pass through one of the reactors (the first reactor) to dehumidify the inlet air and guide the dehumidified air to the outlet, and guide the inlet air to pass through the other reactor (the second reactor) to dry the second reactor and exhaust air passing therethrough to the passageway in the heat exchanger. In the second position, the flow control elements guide the inlet air to pass through the second reactor to dehumidify the inlet air and guide the dehumidified air to the outlet, and guide the inlet air to pass through the first reactor to dry the first reactor and exhaust air passing therethrough to the passageway in the heat exchanger.
According to the invention, the heat exchanger is adapted to heat the inlet air passing through the heat exchanger by transferring heat from exhaust air passing through the heat exchanger passageway.
Preferably, the two air flow paths are parallel and defined by two secondary air chambers. The air guiding housing further includes a common main air chamber separating the two secondary air chambers. The two reactors define the common main air chamber. Each of the secondary air chambers is defined between one of the reactors and a wall of the air guiding housing. The air-flow control elements are positioned in the main air chamber and each of the secondary air chambers, and are selectively and alternately movable between the first position and the second position.
According to one embodiment of the present invention, the heat exchanger comprises a plurality of aligned parallel plates joined together by bonding corrugated ribs to the plates. The air-flow control elements comprise air-flow control flaps adapted to be pivoted by a common actuating device so that all of the flaps are pivoted simultaneously. The heat exchanger is preferably positioned transversely with respect to a longitudinal direction of the main air chamber and upstream thereof.
According to one embodiment of the present invention, the air guiding housing further includes an inlet chamber, the inlet leading to the inlet chamber. At least one air duct is formed in the inlet chamber for passage of the inlet air to be dehumidified, with the heat exchanger positioned in the inlet chamber so that part of the inlet air passing from the inlet chamber passes through the heat exchanger and travels into the main air chamber and through one of the reactors to be dried. Preferably, the air guiding housing has two air ducts upstream of the inlet chamber and the heat exchanger is positioned centrally between the two air ducts. Further, the air guiding housing includes an outlet chamber downstream of the two air flow paths or secondary air chambers, the outlet being at the outlet chamber.
Preferably, a replaceable air filter, such as an activated carbon filter, is positioned in the outlet chamber upstream of the air outlet. Instead of the air filter or in addition thereto, at least one replaceable particulate air filter can also be placed in the air guiding housing, upstream of the reactors. Preferably, the particulate air filter filters the entire volume of the air flow entering the air guiding housing through the inlet.
According to an embodiment of the present invention, a flat housing projection extends along one side of the air guiding housing. The flat housing projection and the air guiding housing form an exhaust air duct for exhausting air passing through the reactor to be dried through the heat exchanger. An intermediate wall separates the exhaust air duct from the main air chamber and the secondary air chambers. Openings are provided in the intermediate wall, which openings are manipulated with the air-flow control elements to alternately block one of the openings to bypass air to the outlet and guide one of the openings to permit air to exhaust therethrough.
Preferably, a heating device is positioned upstream of the reactors. The heating device can be a PTC heating installation or one that uses heat by passing an engine coolant. The heating device is preferably positioned between the heat exchanger and the main air chamber. In this respect, a temperature sensor for detecting the temperature of the inlet air passed through the reactor being dried and a control circuit can be provided for controlling the heating power of the heating device.
The inlet can communicate with the passenger compartment or the ambient or both using a fan with an air duct or ducts.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become more apparent from the following description, appended claims, and accompanying exemplary embodiments.
FIG. 1 shows a diagrammatic illustration of an air-circulating duct of a ventilation system with an air dehumidifier according to the present invention, particularly for a motor vehicle.
FIG. 2 shows a perspective view of an embodiment of the present invention.
FIG. 3 shows a cross-section taken along line 3--3 of FIG. 2.
FIG. 4 shows a cross-section taken along line 4--4 of FIG. 3.
FIG. 5 shows a cross-section taken along line 5--5 of FIG. 4.
FIG. 6 shows another embodiment similar to FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a diagram of a ventilation system for a vehicle interior 1, including a fan 3 and an air drying or dehumidifying device 4 provided in an air guiding duct 2. The fan 3 can take in inlet air from the vehicle interior or passenger compartment 1 or fresh air from the ambient or both. The output side the fan 3 is connected to an inlet chamber 6 formed in a housing 5 via an inlet (not numbered). The air drying device 4 also includes a heat exchanger 7, which is designed as an air/air heat exchanger, as well as reactor means 8 containing an adsorbent, such as silica gel, zeolite or the like, for example. The heat exchanger thus has an exhaust air passageway for leading exhaust air through the ambient. Provided on the outgoing flow side of the reactor means 8 is an activated carbon filter 10 arranged in an outlet chamber 9 for filtering the dehumidified air fed to the vehicle interior via an outlet (not numbered). An air duct 11, through which the inlet air (exhaust) that has desorbed moisture from the reactor means 8 is guided from the reactor means 8 to the heat exchanger 7, is located on the housing 5. The air drying device 4 may, of course, also be combined with a heating or air-conditioning system of a motor vehicle.
In the air drying device 4, as shown in FIGS. 2 and 3, for drying air fed to the vehicle interior 1, the reactor means 8 comprises two reactors 12, 13, each having an adsorbent, arranged in the housing 5 and aligned in parallel to one another. A common main air chamber 16 is formed between the reactors 12, 13. A secondary air chamber 17 or 18 is formed between the housing 5 and each of the reactors 12, 13. Each of the two secondary air chambers 17, 18 extends parallel to the longitudinal direction of the reactors 12, 13. Each reactor 12, 13 forms an air-permeable adsorbent wall between the secondary air chambers 17, 18 and the main air chamber 16. The main air chamber 16 and the secondary air chambers 17, 18 are open at their ends facing the inlet chamber 6, the heat exchanger 7 being provided upstream of the inlet of the main air chamber 16.
The heat exchanger 7 is preferably designed as a counterflow heat exchanger and comprises a plurality of parallel plates, between which corrugated ribs are arranged and connected to the plates by bonding, the space therebetween forming the exhaust air passageway for the exhaust air (desorption air) to be released to the ambient. Since the main air chamber 16 is positioned in the center of the housing 5, the heat exchanger 7 is also located in the center, with the air duct 14, 15 leading to the secondary air chambers 17, 18 formed on each side of the heat exchanger.
In each secondary air chamber 17, 18 and the main air chamber 16, an air-flow control element 20, 21, 22, such as a flap, extends diagonally in the respective chamber 16, 17, 18 and can be pivoted around a pivot axis in the center of the flap. This allows the air-flow control elements to be switched over between the two end positions (first and second) determined by the diagonals of the air chambers, 16, 17, 18. All of the air-flow control elements 20, 21, 22 are actuated simultaneously, preferably by a common drive 31. The air-flow control flap 20 in the main air chamber 16 divides the latter, in each of the two possible positions, into a front or upstream region and a rear or downstream region. Adjoining the rear region of the main air chamber 16 is the outlet chamber 9 where the activated carbon filter 10 extends transversely with respect to the air flow direction over the entire width of the outlet chamber.
As can be seen in FIG. 2, the air duct 11 is arranged in a housing projection 19, i.e., the air duct 11 is formed by an intermediate floor or wall 23 and the housing projection extending from that end of the reactors on the outlet chamber side as far as that end of the heat exchanger 7, which is on the inlet chamber side. In the region of the secondary air chambers 17, 18, openings 24, 25 are provided in the intermediate wall 23, which openings are located at the ends of the secondary air chambers 17, 18 remote from the inlet chamber 6. Thus, the secondary air chambers 17, 18 can be connected to the air duct 11. The openings 24, 25 are closeable depending on the position of the air-flow control elements 21, 22, one of the openings always being blocked from communicating with the inlet air (adsorption) therethrough with the air duct 11 and the other opening communicating with the inlet air (desorption) with the air duct 11.
The inlet air entering the inlet chamber 6 of the housing 5 is divided into an adsorption air (to be dehumidified) flow 26a, 26b and a desorption air (for drying the reactor) flow 27. The desorption air flow 27 flows first through the heat exchanger 7 and enters the main air chamber 16. According to FIG. 3, owing to the position of the air-flow control elements 20, 21 and 22, the adsorption air flow 26a is guided through the reactor 12 and dehumidified there and then exits from the reactor 12 into the rear or downstream region of the main air chamber 16. After flowing through the activated carbon filter 10, the dehumidified and purified air is fed to the vehicle interior 1.
The desorption air flow 27 enters the front region of the main air chamber 16 from the heat exchanger 7 and, owing to the position of the air-flow control element 20, is guided through the reactor 13 where desorption air carries away (dries) the moisture stored in the adsorbent material. The desorption air flow 27 leaving the reactor 13 passes through the opening 25 located in the intermediate wall 23 of the secondary air chamber 18 into the air duct 11 through which an exhausting air flow 28 is fed to the heat exchanger 7, which provides a passageway for guiding the desorption air flow therethrough. In the heat exchanger 7, the exhaust air flow 28, which is loaded with moisture, releases its heat to heat the inlet air (desorption air flow) 27 flowing from the inlet chamber 6 through the heat exchanger 7 into the main air chamber 16. This raises the temperature level of the desorption air flow 27. The exhausting air flow 28 is released to the ambient air through an outlet nozzle 29.
If the air-flow control elements 20, 21, 22 are brought into the second possible position, as is illustrated in FIG. 3 by broken lines, owing to the position of the air-flow control elements 20, 21, 22, the reactor 13 serves for dehumidifying the adsorption air flow 26b passing from the secondary air chamber 18 into the rear or downstream region of the main air chamber 16 and from there feeds to the vehicle interior 1 the dehumidified and air purified (by the activated carbon filter 10). At the same time, the desorption air flow 27 passes through the reactor 12 into the secondary air chamber 17 and passes through the opening 24 in the intermediate wall 23 into the air duct 11 from which it is fed to the heat exchanger 7.
FIG. 4 shows a section along line 4--4 of FIG. 3. For parts that are identical, the same reference numerals correspond to those of the previously described figures. It is clear from this illustration that the desorption air flow 27 is fed from the inlet chamber through the heat exchanger 7 to the reactor 12 and passes on the outgoing flow side of the reactor through the opening 25 in the intermediate wall 23 into the air duct 11. In this arrangement, the air duct 11 is of flat design and is bounded by the housing projection 19 and the intermediate wall 23 and it extends from the front end of the heat exchanger 7 as far as the remotely located end of the secondary air chamber 18. The outgoing or exhausting air flow 28, which is guided in the air duct 11, enters on the upper side through an opening 30 in the intermediate wall 23 into the heat exchanger 7 and is guided through the outlet nozzle 29 on that end of the heat exchanger 7, which is on the outgoing flow side to the outside of the vehicle and hence into the ambient air.
FIG. 5 shows a section along the line 5--5 of FIG. 4. This illustration clarifies the arrangement of the openings 24, 25 in the end-side region of the secondary air chambers 17, 18 as well as the interaction with the air-flow control flaps 21, 22. A common drive for actuating the air-flow control flaps 20 to 22 is diagrammatically illustrated by the reference numeral 31. Additionally to the previously described design, the arrangement according to FIG. 5 has a further heating device 32 arranged downstream of the heat exchanger 7 and located directly upstream of the main air chamber 16. The heating device may, for example, be a positive temperature coefficient (PTC) heating installation or a heating unit through which coolant from an engine of the motor vehicle flows. By means of a heating device of this type, the temperature of the desorption air flow 27 can be raised further to obtain a better desorption action in the reactor connected downstream. So that the heating power can be adjusted depending on the particular demands, a temperature sensor for detecting the desorption air flow temperature and a control circuit can be provided.
FIG. 6 shows an embodiment similar to FIG. 5. The identical or similar components have the same reference numerals as the previously described figures. In FIG. 6, a particulate air filter 33 is arranged in the inlet chamber 6 formed in the housing 5. The entire volume of the entering air flow is guided through the particulate air filter 33 and is thus free from all solid constituents above a certain size, regardless whether the inlet air is the adsorption air flow 26a, 26b or the desorption air flow 27. As a result of the filtering out of solid constituents in the particulate air filter 33, the reactors 12, 13 are loaded with particles to a very small degree, freeing the reactor material for adsorption. The particulate air filter 33 is expediently designed as an easily exchangeable insert in the inlet chamber 6.
According to the present invention, the essential advantages are that the heat energy, which is required for drying the reactor (desorption operation), is substantially gained from the exhausting air flow. In a preferred development, the heat exchanger is designed as a counterflow heat exchanger and comprises a plurality of aligned parallel plates with corrugated ribs bonded to the plates. A particularly compact arrangement is achieved using a common main air chamber and two separate secondary air chambers formed in the air guiding housing, with each of the reactors arranged between the main air chamber and one of the secondary air chambers. Air-flow control elements are provided in the main air chamber and the secondary air chambers, by which control elements the reactors can be changed over alternately from adsorption operation (dehumidification of air) to desorption operation (reactor drying), and vice versa. In this arrangement, it is advantageous for the air-flow control elements in the main air chamber and the secondary air chambers to be driven by a common actuating device. The flaps in each case merely take up two end positions corresponding to the respective operating mode of the reactors. The reactor in adsorption operation is connected to an outlet chamber in the air guiding housing, from which chamber the air flow is guided to the vehicle interior. The reactor in desorption operation is connected to an air duct to which the exhausting air is fed to the heat exchanger.
The heat exchanger is preferably arranged transversely with respect to the longitudinal direction of the main air chamber, more preferably directly upstream of the latter, so that air can flow into the main air chamber without changing direction. An inlet chamber is expediently formed in the air guiding housing, from which inlet chamber at least one air duct for the adsorption air flow emerges. In addition, the inlet chamber is adjoined by the heat exchanger through which the desorption air flow exits from the inlet chamber. Since the main air chamber is located between the two secondary air chambers, it is advantageous for the heat exchanger to be arranged centrally between two air ducts leading to the secondary air chambers.
The air duct guiding the desorption air flow on the outgoing flow side of the reactor to the heat exchanger is preferably designed such that it extends along one side of the air guiding housing and is formed by a flat housing projection. An intermediate floor serves as the wall dividing the air duct from the main air chamber and the secondary air chambers, the intermediate floor having a closeable opening in that region of each secondary air chamber on the outgoing flow side, through which opening the desorption air flow can enter the air duct from the secondary air chamber.
Since the temperature of the desorption air flow is possibly inadequate for sufficient rapid desorption, it may be advantageous for a heating device, which may, for example, be a PTC heating installation or a heating unit through which liquid flows, to be arranged in the desorption air flow upstream of the reactor. The liquid used is preferably a water/glycol mixture, in particular in the case of use of the waste heat produced in a drive assembly, such as an engine. In this arrangement, it is particularly expedient to arrange the heating device between the heat exchanger and the main air chamber. So that the heating device is operated in a demand-optimized manner, it is advantageous for a temperature sensor, which detects the desorption air flow temperature, and a control circuit to be provided by means of which the heating power of the heating device can be controlled.
As the adsorption air flow is dehumidified in one of the reactors, some of the pollutants adhering to the moisture is bound to the adsorbent material of the reactor. For optimum use of the adsorption material in the reactors it is advantageous to not load the reactors with dirt particles since they would adversely effect the adsorption capability as the consequence of the deposits covering the surface of the adsorbent. It is therefore advantageous to provide a particulate air filter in the upstream of the reactors in the air guiding housing. To further isolate pollutants from air, it is advantageous to arrange an air filter, preferably an activated carbon filter, in both the inlet and outlet chambers. The particulate air filter is preferably designed such that the filter acts upon the entire air flow. Since a filter of this type is usually not capable of regeneration, the particulate air filter is designed such that it can easily be exchanged, for example, in the form of a filter cassette.
Given the disclosure of the present invention, one versed in the art would appreciate the fact that there may be other embodiments and modifications within the scope and spirit of the present invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention accordingly is to be defined as set forth in the appended claims. | An air dehumidifier or drier, particularly for a motor vehicle, has an air guiding housing defining three parallel air flow paths, which are defined by a common main air chamber separating two laterally spaced apart secondary air chambers. A reactor containing an adsorbent is positioned between the secondary air chambers, the common main air chamber being defined between the reactors. Air-flow control elements are positioned in each of the main and secondary air chambers. The control elements are pivotal between two operating positions. In each position, one of the reactors is in adsorption operation (dehumidify air) while the other reactor is in desorption operation (reactor being dried or recharged). The desorption air directed to the reactor being dried is heated by a heat exchanger, which has an air passageway for exhausting the air used for drying the reactor. Thus, the desorption air directed to the reactor being dried is preheated using the energy from the exhausting air. | 1 |
FIELD OF INVENTION
[0001] This invention concerns the interpolation of new images within a sequence of images.
BACKGROUND OF THE INVENTION
[0002] It is frequently necessary to interpolate a new image at some position within a sequence of images that does not align with an existing image in the sequence. A very common example is temporal interpolation. Temporal interpolation is performed whenever a representation of a video frame is required corresponding to a time instant that is not present in the input sequence. Examples of applications of temporal interpolation include: conversion of a video sequence to a new frame or field rate without changing the speed of any motion present in the scene, slow-motion effects where additional frames are created for playout at the original frame rate, or any combination of those processes that does not amount to simply playing out the input frames one by one at a different rate.
[0003] Another application of interpolation within a image sequence is where the sequence comprises a sequence of views of a common scene from different positions, and an interpolated image is created that represents the view of the scene from a position between two of the existing viewpoints. In this specification temporal interpolation will be described, however the skilled person will appreciate that the invention is equally applicable to ordered image sequences in general.
[0004] In this specification the term ‘position’ will be used to describe the position of an image in an ordered sequence of images. This may be a position in time or a position in whatever dimension defines the relationship between the images of the sequence; for example it could be a sequence of viewpoints along a path, which may or may not have associated time values. To avoid confusion, the term ‘spatial position’ will be used to indicate position within an image.
[0005] Examples of known techniques for temporal interpolation will now be described. FIG. 1 shows one-dimensional sections through frames in a sampled video sequence with time running horizontally in the diagram. Frames 101 and 102 are input frames, and frame 103 represents an output frame interpolated at a time instant 60% of the input frame period after the first input frame. In the remainder of this document, the desired output frame time is specified relative to the times of the two adjacent input frames as “display phase” on a scale from 0 to 1. Typically a regular sequence of output images is required, and, as is well known in the art, the display phase of each interpolated output image will differ from the display phase of the preceding interpolated output image by a phase increment that depends on the difference between the temporal sampling rates of the input and output image sequences.
[0006] In this example, the display phase is 0.6. In “non-motion-compensated” interpolation, a particular sample (pixel) ( 104 ) of the output frame may be derived from corresponding samples ( 105 ) and ( 106 ) in the input frames. Suitably, linear interpolation would be used, in which the value of output sample ( 104 ) would be equal to the sum of 40% of input sample ( 105 ) and 60% of input sample ( 106 ).
[0007] Linear interpolation as shown in FIG. 1 gives acceptable results unless there is significant movement of detailed objects in the scene; in this case the output frames become blurred, or a double image becomes apparent, as the result of the relatively-displaced contributions from the two input frames.
[0008] Motion compensated interpolation, illustrated in FIG. 2 , is a well known way of overcoming those problems. Referring to FIG. 2 , pixel ( 205 ) in input frame 201 has associated with it a forward motion vector ( 207 ). Similarly, pixel ( 206 ) in input frame 202 has associated with it a backward motion vector ( 208 ). Both input pixels are ‘projected’ onto the interpolated output frame 203 in the direction of their respective motion vectors, and contribute through a weighted sum or other method to the value of pixel ( 204 ) in the output frame.
[0009] In the projection of pixels from their respective spatial positions in input frames to their motion compensated spatial positions in output frames, the magnitudes of the respective motion vectors are scaled in proportion to the phase difference between the output frame and the respective contributing input frame. Thus input pixel ( 205 ) is shifted by 0.6 of the motion vector ( 207 ); and, input pixel ( 206 ) is shifted by 0.4 of the motion vector ( 208 ). Various methods exist to solve the problems that arise when particular output pixel locations either have no motion vectors pointing to them, or have vectors pointing to them from more than one location in an input frame. For example, International Patent Application No. WO 2004/025958 “Improved Video Motion Processing” describes a method of assigning weights to contributing pixels.
[0010] Occasionally, a frame ‘built’ by motion compensation may suffer from impairments. These can arise, for example: where the speed or complexity of the motion in the scene is too high for the motion estimator; where there is a significant incidence of transparent content in the scene; where there are significant changes in illumination between one frame and the next; or, where the input frames are corrupted by noise. Such impairments may sometimes be more annoying than the blur or double images produced by linear interpolation. For this reason, motion compensated interpolation systems may employ “fallback processing” in which a linearly interpolated value may be switched or mixed into the output in response to a confidence measure.
[0011] FIG. 3 illustrates a motion compensated temporal interpolator employing fallback processing. An input video signal ( 301 ) is applied to a motion compensated interpolation process ( 302 ) to produce a motion compensated output ( 303 ). The time of the output frame is determined by the display phase signal ( 311 ). A confidence measurement process ( 304 ) uses the input signal ( 301 ) and information ( 305 ) from the motion compensation process ( 302 ) to generate a switching signal ( 306 ). A linear interpolation process ( 307 ) is also carried out on the input signal ( 301 ) in accordance with the display phase ( 311 ) to produce linearly interpolated fallback frames ( 308 ). A mixing unit ( 309 ) mixes between the motion compensated interpolated frames ( 303 ) and the fallback frames ( 308 ) according to the switching signal ( 306 ) to produce a final output ( 310 ). The confidence measurement may be: pixel based, in which case the switching signal has high bandwidth; region based, in which case the switching or mixing signal has a lower bandwidth; or, frame based, in which a uniform decision about the degree of fallback processing is made across the whole frame.
[0012] Fallback processing using linear interpolation can be satisfactory but has several potential drawbacks. If, on the one hand, the control signal has too high a bandwidth, the artefacts introduced by the switching process can sometimes be more disturbing than the original artefacts. If, on the other hand, the control signal has low bandwidth, significant areas of the picture may be processed using the linear fallback mode when they would have benefited from motion compensated processing. Furthermore, linearly interpolated pictures, while sometimes acceptable in real-time display, show obvious impairments if individual frames of the output are viewed in isolation.
[0013] An alternative method of fallback processing is taught in International Patent Application WO 2011/073693. This method is applicable where the change in frame rate desired in the converter is small, for example when converting from 24 Hz film to 25 Hz video. The fallback processing, switched in when confidence in the motion estimation is low, consists of playing out input frames synchronized to the output frame rate, a process which can be maintained without dropping or repeating frames, for a limited time depending on the capacity of a frame-store buffer in the system. This method can be very effective, producing an unimpaired fallback signal, but is limited to close-frame-rate conversion and to short-lived dips in the level of confidence.
SUMMARY OF THE INVENTION
[0014] The invention consists in a method and apparatus for interpolating an ordered sequence of input images to obtain a new image at a required position in the sequence that does not align with an input image wherein interpolation-related impairments are reduced by interpolating at least part of the said new image at a position that is offset from the required position.
[0015] Suitably, the interpolated images are presented to an observer in a regular sequence and at least part of an interpolated output image is interpolated at a position that is offset from its presented position.
[0016] In certain embodiments the said interpolation is temporal interpolation.
[0017] Advantageously, the direction of the said offset is towards the input image that is nearest to the said required position of the interpolated output image.
[0018] In a preferred embodiment the said offset is reduced in dependence on the proximity of the said nearest input image to the said required position of the interpolated output image.
[0019] Advantageously, the magnitude of the offset depends on a measure of interpolation confidence generated using information from a temporal interpolation or motion estimation process.
[0020] The offset may be constant across each interpolated output image. Or, the offset may vary smoothly over each interpolated output image in dependence on spatial position within the output image.
[0021] Accordingly, the inventor has recognized that there is a hitherto unexplored aspect to fallback processing, namely the trade-off between motion compensation impairments and motion judder, that overcomes or ameliorates deficiencies of the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Examples of the invention will now be described with reference to the drawings in which:
[0023] FIG. 1 is a diagram illustrating non-motion-compensated temporal interpolation between two input video frames according to prior art;
[0024] FIG. 2 is a diagram illustrating motion compensated temporal interpolation between two input video frames according to prior art;
[0025] FIG. 3 is a block diagram of fallback processing according to prior art;
[0026] FIG. 4 is a block diagram of fallback processing according to the invention;
[0027] FIG. 5 is a diagram illustrating the relationship between display phase and built phase according to a first embodiment of the invention;
[0028] FIG. 6 is a family of graphs showing the relationship between display phase and built phase according to the invention;
[0029] FIG. 7 is a diagram illustrating the relationship between display phase and built phase according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] Referring again to FIG. 2 , it will be noticed that the two motion vectors ( 207 ) and ( 208 ) are similar in magnitude (the difference possibly being due to acceleration, if preceding or subsequent frames were involved in the motion estimation process). However, as explained in the introduction, the magnitudes of the scaled motion vectors used in the projection process differ as a function of the difference in the time intervals between frames 201 and 203 , and between frames 203 and 202 . The magnitude of the scaled vector used for projection from frame 201 will be greater than that used for projection from frame 202 . Consequently, the effects of any errors in the estimation of motion vector ( 207 ) will generally be worse than those arising from motion vector ( 208 ). In motion compensated interpolation, this tendency is taken into account by applying a higher weighting to pixel ( 206 ) than to pixel ( 205 ) in the interpolation mix. The combination of the difference in weighting and the difference in reliability of the two contributions to the output pixel has the outcome that the overall quality of the interpolation improves as the interpolated frame instant approaches one of the input frames.
[0031] In fallback processing according to the invention, we build an output frame closer in time to one of the input frames than the time at which it is displayed. In doing so, we improve the quality of the interpolated frame, at the expense of a spatial displacement between the expected and the actual position of moving objects at certain times, which manifests itself visually as motion judder. This is often an acceptable compromise, because motion judder is most objectionable when the observer can most easily track a moving object, but we are usually introducing it at times when motion is most difficult to track.
[0032] A first exemplary embodiment of the invention will now be described. Referring to FIG. 4 , input video ( 401 ) is applied to a motion compensated interpolation process ( 402 ) to produce temporally interpolated output video ( 404 ) under the control of a display phase signal ( 403 ). Information ( 405 ) obtained from the motion compensated interpolation process ( 402 ) is used in a confidence measurement process ( 406 ) to produce a confidence level ( 407 ) for each output frame. The confidence level is used in a phase modification process ( 408 ) to modify the desired display phase ( 409 ) to produce a “built phase” ( 403 ) which is the phase value used by the motion compensated interpolation process ( 402 ).
[0033] FIG. 5 illustrates an exemplary relationship between the display phase and the built phase for a particular confidence level. The display phase or the “required” phase is of course determined simply by the relative frame rates of the input frame sequence and the output frame sequence. It will typically cycle repeatedly through a range of phase values, the number of phase values in the range before the cycle repeats being of course determined by the relationship between the input and output frame rates. With respect to the input frames 501 and 502 , the display phase for the output frame 503 in FIG. 5 has a value of 0.6. However, the built phase has, in this example, a value of 0.75, so that the output frame is built at the position ( 504 ) that is closer to the input frame 502 . The output frame in this case, for a display phase of 0.6, will be identical to that which would be built by a prior art motion compensated interpolator at a display phase of 0.75. A feature of the invention is that the built phase is closer to the nearest input frame than the display phase. This means that if the display phase is greater than 0.5, the built phase will be greater than the display phase, whereas if the display phrase is less than 0.5, the built phase will be less than the display phase.
[0034] FIG. 6 further illustrates the relationship between display phase and built phase, in the form of a family of graphs. Graph ( 601 ) shows the relationship when the confidence level is very high. No modification is made to the display phase, so the built phase is equal to the display phase. Graph ( 602 ) is an example of the relationship when the confidence level has a moderate value, and graph ( 603 ) is an example of the relationship when the confidence level is low. In general, as the confidence level decreases, the built frames become closer to input frames. The particular case of a display phase of 0.5 can be dealt with either by setting the built phase to 0.5, or by making an arbitrary decision to categorise the display phase as just less than, or just greater than, 0.5.
[0035] Exemplary methods of measuring the confidence and of calculating the built phase will now be described in detail. The confidence measurement depends on the methods of motion estimation and motion compensation being used. One way of assessing the confidence of a vector for a pixel is to find the ‘displaced frame difference’ (DFD) for the vector and pixel by subtracting the value of the pixel from the value of a pixel in another frame that is ‘pointed to’ by the vector. The DFD corresponds to a vector error and a small difference corresponds to high confidence.
[0036] When the well known block-matching method is used to derive motion vectors, the match error associated with a vector is similarly related to its confidence.
[0037] UK Patent Applications 1206067.9 and 1206065.3 describe methods of motion estimation which work by selecting motion vectors so as to minimise motion vector ‘assignment errors’ derived from DFDs, and include methods of finding assignment errors for forward and backward vectors. The minimized assignment error for each pixel gives a very local measure of motion estimation confidence for that pixel.
[0038] In the following example we calculate, using data from a motion estimation process, a confidence measure that is valid for the whole frame and the whole interval between two input frames.
[0039] For the purposes of this example, we take, as 8-bit unsigned numbers:
h f , the set of forward assignment errors associated with the forward vectors assigned to the pixels of the previous frame; and, h b , the set of backward assignment errors associated with the backward vectors assigned to the pixels of the next frame;
and we calculate an error value for the current frame:
[0000]
H
=
max
9
blocks
〈
h
f
+
h
b
〉
[
1
]
[0000] where the angled brackets indicate averaging, and the average is taken of each of 9 rectangular regions that tile the picture in a 3×3 arrangement. This value of H is therefore a worst-case average error taken over the nine regions. The skilled person will recognise that other suitable formulae for calculating a representative error value for the picture could be used without departing from the scope of the invention.
[0042] A confidence value α is then calculated as follows:
[0000]
α
=
max
{
0
,
min
{
1
,
H
max
-
H
H
max
-
H
min
}
}
[
2
]
[0000] where
H max and H min are constants with the following typical values: H max =6.5 for high definition television (HD) pictures, or 13 for standard definition television (SD) pictures; and, H min =2.5 for HD pictures, or 5 for SD pictures.
[0048] This formula gives a linear relationship between error H and confidence α, scaled and clipped so that the confidence is 1 when H≦H min and 0 when H≧H max . The skilled person will recognise that the relationship between error and confidence can be determined by any monotonically decreasing function without departing from the scope of the invention. Furthermore, the confidence may be calculated using information other than, or in addition to, motion vector assignment errors. For example, UK Patent Application GB 2 448 336 describes the measurement of confidence using the peak heights arising from a phase correlation process.
[0049] Given the confidence α and a display phase φ, the phase modification process then calculates a built phase φ′ by the following formula:
[0000]
φ
′
=
{
αφ
φ
≤
1
2
1
-
α
(
1
-
φ
)
φ
>
1
2
[
3
]
[0050] This formula gives a piecewise linear relationship between display phase and built phase, that depends on the confidence α. Two examples are shown in FIG. 6 , at ( 602 ) and ( 603 ). In each case the relationship comprises two linear segments, both having a slope α, which is less than unity. When the display phase φ is less than or equal to ½, the display phase φ is attenuated by a constant α; and, when the display phase φ is greater than ½, a constant positive offset is applied to the attenuated display phase so that when the display phase is unity, the built phase is also unity.
[0051] The skilled person will recognise that other functions could be used without departing from the scope of the invention. Furthermore, a direct calculation of built phase could be made within the motion compensated interpolation process without the explicit intermediate calculation of a confidence value.
[0052] A second embodiment of the invention will now be described. A potential shortcoming of the first embodiment is the use of a single phase value for the whole frame. Motion judder will thereby be introduced not only to the parts of the picture where the motion is complex and therefore difficult to track, and where judder is therefore not very perceptible, but also to other parts where judder may be more objectionable. A possible solution to this problem is to allow the built phase to vary smoothly with spatial position, as a function of a spatially varying confidence value. As mentioned previously, a DFD for a pixel is a confidence value at the spatial position of the pixel, and the modification of the built phase could be increased for pixels having high DFDs. However, it is important that such variation should not be too abrupt from one part of the picture to another; otherwise shapes of moving objects may appear distorted. Nevertheless, a mild variation, for example between the edges and the centre of the picture, might be beneficial. Or, a spatial low-pass filter could be applied to DFDs, or other motion estimation error measures for the pixels to obtain a spatially smoothly varying confidence value.
[0053] An example of possible variation, illustrated in one spatial dimension, is given in FIG. 7 . The display phase is illustrated as a straight broken line ( 703 ) and has a phase of 0.6 with respect to the two input frames ( 701 ) and ( 702 ). The built phase is illustrated as a curved broken line ( 704 ). An image edge position ( 705 ), an image centre position ( 706 ) and an image opposite-edge position ( 707 ) are shown on the position axis of the Figure. The built phase ( 704 ) is greater at the image centre position ( 706 ) than at the two image edge positions ( 705 ) and ( 707 ). Of course, if the display phase were less than 0.5, the built phase at the image centre would be less than that at the image edges. Although FIG. 7 illustrates a one-dimensional modification of the built phase, the modification could be applied in two dimensions, by applying a smooth weighting function having no effect at the image centre and applying a smaller change to the built phase close to any image edge.
[0054] A third embodiment of the invention will now be described. In this embodiment, the benefits of building pictures at times closer to the input frames than the desired display times are considered to outweigh permanently the drawbacks of introducing judder. The system is therefore run in full “fallback mode” all the time, which can be achieved in either of the first two embodiments by setting the confidence to a minimum value so that the output pictures are always built at phase values close to zero or unity.
[0055] A fourth embodiment of the invention will now be described. In this embodiment, we exploit the possibility that building pictures closer to input pictures may also be beneficial even if there is no motion compensation. This can be achieved by removing motion compensation from any of the above embodiments so that output pictures are built by simple interpolation using weighted sums of input pixel values from input images that have not been shifted by motion vectors.
[0056] As the skilled person will appreciate the invention can be implemented in many ways, including: a real time process with streaming input and output image data; a process that interpolates stored image data at an arbitrary rate; and/or in the form of instructions for a programmable data processing device.
[0057] The spatial sampling structure of the images is not relevant to the invention, for example, in interlaced television, successive images have different vertical sample structures. | Apparatus for interpolating images generates motion vectors having a vector confidence value and has a motion compensated interpolation to use the motion vectors to interpolate a new image from two input images at a position determined by a phase control signal. The vector confidence values are used to generate an interpolation confidence measure. The phase control signal is then modified to offset the position at which the new image is interpolated toward the position of the closer of the two input images, if said interpolation confidence measure reduces. | 7 |
BACKGROUND OF THE INVENTION
The invention relates to tool couplers for excavation, demolition and construction equipment.
Some types of construction equipment, such as backhoes and excavators, have a movable dipperstick (also referred to as an arm) to which a variety of tools, such as, for example, buckets and grapples, can be attached. A hydraulic linkage allows the equipment operator to pivot the tool from the free end of the dipperstick. To simplify the process of changing tool attachments, a universal coupler can be fixed to the dipperstick linkage. A selected tool can then be removably attached to the coupler, a process that typically involves manually positioning at least one latch pin between the coupler and the tool.
There is a trend in the industry to use an actuated coupler on the end of the dipper stick for connecting and disconnecting a tool from the linkage. A great advantage of these systems is that the operator can actuate the coupler to connect or disconnect a tool without the assistance of another worker and without having to leave the cab of the vehicle.
One type of actuated coupler first engages a crossbar formed in the tool with hooks depending from the coupler, and then engages a latch pin (or a block or a wedge) with a mating receptacle formed in a collar on the tool. A double-action hydraulic cylinder in line with the latch pin is positioned so that the cylinder extends to push the latch pin into the receptacle. In disengaging the tool from the coupler, the operator retracts the rod into the cylinder body, pulling the pin out of the receptacle.
SUMMARY OF THE INVENTION
The invention provides a coupling assembly for coupling a tool to a dipperstick, or arm, on an apparatus which has a hydraulic system for moving the tool. The coupling assembly includes a coupler body having a frame that defines a central cavity, and also having link structure for pivotally coupling to the dipperstick. An actuator assembly positioned within the central cavity includes a latch pin movable between an extended position and a retracted position. In the extended position, an end of the latch pin projects rearward from an opening in a rear end of the frame for engaging an aperture or receptacle defined by the tool. In the retracted position, the end of the latch pin is disengaged from the tool receptacle and positioned substantially within the frame. The actuator assembly also includes a hydraulic latch cylinder that has a movable part, and a fixed part. The movable part is coupled to the latch pin by a latch pin coupling assembly, which is structured and arranged such that, when the movable part is extended from the fixed part, the latch pin moves to the retracted position.
According to another aspect of the invention, the latch pin coupling assembly includes a bias member structured and arranged to apply a bias force that urges the latch pin toward the extended position. When a threshold level of hydraulic pressure is applied to the latch cylinder, the movable part of the cylinder overcomes the bias force and extends to move the latch pin to the retracted position and out of engagement with the tool.
Another feature of the invention is that the latch cylinder can be a single-action cylinder.
According to another feature of the invention, the latch cylinder can be positioned on an axis different from an axis defined by the latch pin, such as along side the latch pin. This feature provides a compact arrangement. The system is easily adaptable to any type of quick coupler type system due to the compactness and placement of the actuating cylinder.
According to another feature of the invention, the hydraulic pressure to the latch cylinder can be controlled by an electrically actuated valve assembly that hydraulically couples the dipperstick hydraulics to the latch cylinder. The valve assembly can include one or more solenoid valves that only allow hydraulic pressure to enter and remain in the latch cylinder when they are energized.
According to another feature of the invention, the valve assembly can be structured and arranged such that the dipperstick hydraulics must be approximately fully pressurized while extended to pressurize the latch cylinder.
According to another feature of the invention, the coupling assembly can also include a pin indicator that readily shows whether the latch pin retracted. The indicator is located such that it can be viewed easily from the operator position.
According to another feature of the invention, a drop in hydraulic pressure in the latch cylinder below the threshold level allows the bias spring to push the coupling pin towards the extended position. As unexpected hydraulic pressure loss can be caused by a failure in the hydraulic system or by a failure in the valve assembly. The spring apply, hydraulic release system is safe in that it assures that an attached tool will not accidentally uncouple from the coupling assembly if there is a loss in hydraulic pressure in the latch cylinder.
The invention also provides a method of removing a tool from the coupler assembly having features as described above. An operator can remove a tool by the steps of applying hydraulic pressure to a latch cylinder that has a part fixed relative to the coupler body and a movable part rigidly coupled to the latch pin, extending the movable part from the fixed part, thereby urging the latch pin to the retracted position, engaging a cross member of the excavation tool with a hook structure depending and extending forward from the coupler body, rotating the coupler body toward the tool, aligning the latch pin with a mating receptacle formed in the excavation tool, reducing hydraulic pressure to the latch cylinder, and applying a bias force to the latch pin, urging the latch pin to the engaged position, thereby engaging the latch pin in the receptacle and securing the excavation tool to the coupler body.
According to another aspect of the invention, the method further includes the step of removing the tool from the coupler, including rotating the coupler body and the tool to a full forward position, again applying hydraulic pressure to the latch cylinder, again extending the movable part from the fixed part, thereby urging the latch pin to the retracted position and disengaging the latch pin from the receptacle, and disengaging the hook structure from the cross member of the excavation tool.
The latch cylinder extends using the more powerful head end to extract the latch pin, whereas coupling systems using an in-line dual-action cylinder and latch pin arrangement use the less powerful rod end for this purpose. This feature of the invention is important when extracting a frozen pin, which can require substantially more force than inserting a free moving pin.
Since the hydraulic system uses a single-action latch cylinder, it only requires one hydraulic line between the valve assembly and the latch cylinder. This is simple and inexpensive compared with coupling systems that use a dual-action cylinder, and that require two hydraulic connections.
The rod of the latch cylinder is normally in the retracted position during the tool working period. Because the latch cylinder is retracted, the rod of the latch cylinder is not subject to damage from rocks and sharp objects. Normally, the only time the rod is extended, and thereby exposed to the elements and contaminants, is when a tool is being attached or detached from the coupling assembly.
A feature of the invention is that if there is a loss of either electrical or hydraulic power, the latch pin will extend or “insert” automatically. If electrical power inadvertently gets to the solenoid valves, the tool has to be fully rolled forward and inward in order for the pressure to build up in the latch cylinder to retract latch pin. In this position, the coupler hooks are fully engaged and the likelihood of the tool falling off is minimized. One cannot simply throw the switch and have the tool fall to the ground.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of dipperstick with an attached coupling assembly, and a conventional bucket that can be attached to the coupling assembly.
FIG. 2 is a side view of a hydraulic coupling assembly shown coupling a conventional bucket to a dipperstick.
FIG. 3 is a top plan view of a coupling assembly, partially showing a bucket, with the latch pin in an unlatched, retracted position. FIG. 3A is a similar view, partially broken away, showing the latch pin in a latched, extended position.
FIG. 4 is a section view through line 4 — 4 of FIG. 3 . FIG. 4A is a similar section view through line 4 A— 4 A of FIG. 3 A.
FIG. 5 is a partial section view through line 5 — 5 of FIG. 3 . FIG. 5A is a similar partial section view through line 5 A— 5 A of FIG. 3 A.
FIG. 6 is a schematic diagram of a hydraulic system and an electrical system according to the invention. FIGS. 6A, 6 B and 6 C illustrate other embodiments of a valve assembly.
In the following detailed description of the invention, similar structures that are illustrated in different figures will be referred to with the same reference numerals.
It will also be noted that the figures are generally not drawn to scale.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIGS. 1 and 2, a hydraulic coupler assembly 10 according to the invention is attached to a conventional dipperstick or arm 12 . Only a free end of dipperstick 12 is illustrated in FIGS. 1 and 2. The other end of dipperstick 12 is pivotally coupled, typically via an intermediate articulation (not shown), to a base (not shown) that includes a hydraulic power system, and hydraulic and electric operator controls located in a cab. Coupler assembly 10 can be used for coupling the dipperstick 12 to any of a variety of tools, such as, for example, a conventional bucket 14 .
Dipperstick 12 linkage includes a bucket guide link 16 pivotally attached to the dipperstick 12 , a bucket cylinder 18 for actuating the coupling assembly 10 and the bucket 14 , and a bucket link 20 . Extending bucket cylinder 18 rotates coupling assembly 10 , and any tool attached to coupling assembly 10 , inwardly in a forward direction.
Referring now also to FIGS. 3-5, coupling assembly 10 includes a frame 24 forming a central space 22 . Frame 24 includes side walls 26 , a bottom plate 28 , a coupler spreader plate 30 and a rear face plate 32 . Depending from side walls 26 are a pair of forward extending hooks 34 that are adapted to fit through an opening or recess 36 formed in a back sheet 38 of bucket 14 (see FIG. 1 ). The hooks 34 can then engage a cross tube 40 to support a forward end of bucket 14 .
Coupling assembly 10 has a pair of dipper pivot fixtures 42 , located near a forward end of side walls 26 for coupling to dipperstick 12 . A pair of link pivot fixtures 44 for coupling to bucket link 20 are located closer to the rear end of the frame 26 . A pair of link pivot fixtures 46 are also provided at an alternate location.
Bucket 14 is adapted to be coupled to dipperstick 12 with coupling assembly 10 . As noted above, a recess 36 is formed in back sheet 38 of bucket for receiving hooks 34 . Once cross tube 40 is engaged by hooks 34 , the bucket can be lifted off the ground by raising the dipperstick 12 . This connection provides a first point of connection between coupling assembly 10 and bucket 14 . To enable the bucket 14 to rotate by operation of the bucket hydraulic cylinder 18 , a receptacle 50 formed in a latch collar 51 fixed to a plate 52 on the rear end of bucket 14 engages one end of a movable latch pin 48 .
Latch pin 48 slides within the bore of a bushing 60 welded to rear face plate 32 within frame 24 . On the other side of plate 32 there is an approximately semicircular-shaped coupler crescent 61 that fits over the top of latch collar 51 when bucket 14 is attached to coupling assembly 10 .
The latch pin 48 is part of an actuator assembly 54 that also includes a coil spring 56 , or other type of compression spring, for pushing the latch pin 48 through bushing 60 into engagement with the receptacle 50 , and a single-action latch pin hydraulic cylinder 58 that acts opposite the spring 56 to disengage the latch pin 48 from the receptacle 50 . Spring 56 is positioned approximately in line with latch pin 48 , and latch cylinder 58 is positioned on a parallel axis along side latch pin 48 and spring 56 . This arrangement allows the cylinder 58 to “push” the pin 48 out to retract. The spring 56 urges the pin 48 toward an engaged position with receptacle 50 when hydraulic pressure in the latch cylinder 58 is insufficient to overcome the spring force of spring 56 . The latch pin 48 is normally in the engaged position because latch cylinder 58 is normally not pressurized.
Coil spring 56 is kept in position by a latch spring assembly that forms part of actuator assembly 54 . One end of coil spring 56 bears against a pin block 62 that is welded to latch pin 48 . Pin block 62 includes an annular groove to receive coil spring 56 . The other end of coil spring 56 , towards the front of coupler 10 , bears against a winged end plate 64 and thereby holds the winged end plate 64 within the “V” formed by coupler spreader plate 30 . A spring guide rod 66 is positioned within the coils of spring 56 . Spring guide rod 66 extends transversely through a hole formed in end plate 64 and is welded thereto. A forward end of spring guide rod 66 includes a notch 68 that is positioned against an angled top edge 69 of coupler spreader plate 30 and held in place by the spring force from spring 56 . The other end of spring guide rod 66 acts as a stop for latch pin 48 in the retracted position (see FIG. 4 ).
The body 70 of latch cylinder 58 is fixed to pin block 62 . In the embodiment illustrated in FIGS. 3-5, body 70 has screw threads formed on its outer surface and screws into mating threads formed in a through hole in pin block 62 , and is held in place by a set screw 71 . The cylinder's extensible rod, or piston 72 , extends through the hole in pin block 62 . When hydraulic pressure coupled into cylinder 58 through hydraulic fitting 73 is increased, cylinder 58 extends and the free end of piston 72 bears against push plate 72 , which is welded to bushing 60 .
Extension of cylinder 58 with sufficient force to overcome spring's 56 spring force thereby urges latch pin 48 to a retracted position since latch pin 48 is welded to pin block 62 and pin block 62 is fixed to cylinder body 70 . Release of pressure in cylinder 58 allows spring 56 to extend, urging pin block 62 , and thereby latch pin 48 , toward a latched position wherein the latch pin 48 projects beyond rear face plate 32 .
Pin block 62 includes a cylindrical opening 76 that receives spring guide rod 66 when latch pin 48 is retracted by actuation of cylinder 58 (see FIG. 3 ). As mentioned above, spring guide rod 66 stops latch pin 48 from retracting beyond a predetermined point. When latch pin 48 is fully retracted, the end of spring guide rod 66 is inside the cylindrical opening 76 in pin block 62 and projects beyond the corresponding end of spring 56 . In this position, a transverse assembly hole 78 formed in the end of spring guide rod 66 is aligned with a U-shaped slot 80 formed in pin block 66 . An assembly pin (not shown) can be placed in assembly hole 78 . When pressure in cylinder 58 is released, latch pin 48 can be manually moved to the latched position, thereby releasing spring guide rod 66 from cylindrical opening 76 in pin block 62 . Assembly pin in hole 78 keeps spring 56 compressed on spring guide rod 66 . With pin block 62 out of the way, the assembled latch spring assembly, comprised of spring guide rod 66 , spring 56 , and winged end plate 64 , can be removed as a unit from coupler 10 . The latch spring assembly can be installed in coupler 10 by a reverse procedure.
Coupler 10 is structured to allow an operator in the control cab of the construction equipment to visibly assess whether the latch pin 48 is in the latched or retracted position, even when a tool is attached to coupler 10 . Back sheet 38 of bucket 14 extends forward only to the attachment point of hooks 34 , which leaves the forward portion of bucket 14 open between back sheet 38 and cross tube 40 . Bottom plate 28 of frame 24 forms a U-shaped indicator slot 82 positioned between hooks 34 . Indicator slot 82 is positioned such that pin block 62 is visible through the opening in bucket 14 and through indicator slot 82 when latch pin 48 is in the retracted position. When latch pin 48 is in the latched position, the operator's line of sight to pin block 62 is blocked by back sheet 38 . Pin block 62 can be made more noticeable by painting it a bright color.
Referring now also to FIG. 6, a hydraulic circuit 86 for operating latch cylinder 58 taps into the hydraulics of the excavator. A hydraulic pump 88 and a reservoir 90 are coupled to bucket cylinder 18 via a lever-operated, three-position, two-pole valve 92 . Pump 88 , reservoir 90 and valve 92 are located in the base 93 of the excavator. Hydraulic hoses 94 , 96 connect between valve 92 and the rod end 98 and cylinder end 100 of bucket cylinder, respectively. Hydraulic hose 96 has a T-connection leading to one port of a valve assembly 102 . The T-connection can be conveniently made at the hydraulic fitting for the cylinder side 100 of bucket cylinder 18 . The other port of valve assembly 102 connects via hydraulic hose 104 to fitting 73 in latch cylinder 58 . Valve assembly 102 can be strapped, bolted or otherwise attached to a fixed part of bucket cylinder 18 or to an upper portion of dipperstick 12 .
Valve assembly 102 includes two solenoid actuated valves 108 , 110 , each with a power connection controlled by a locking electrical toggle switch 111 located in the cab of the excavator. In an unlatch switch position the solenoids are energized and in a latch switch position the solenoids are shut off. When the solenoids are not energized (see FIG. 6 ), springs 112 , 114 urge valves 108 , 110 , respectively to a position wherein a check valve portion 116 of valve 108 and a through portion 118 of valve 110 are connected in series between lines 96 and 104 . When valves 108 , 110 are energized (not shown), a through portion 120 of valve 108 and a check valve 122 portion of valve 110 are placed in the circuit.
Check valve 116 blocks a hydraulic flow from bucket cylinder 18 to latch cylinder 58 , but is set to permit flow in the other direction when there is an over-pressure condition in the latch cylinder 58 relative to the cylinder side 100 of bucket cylinder 18 . Check valve 122 , on the other hand, blocks any back flow from latch cylinder 58 to bucket cylinder 18 , and is set to permit the latch cylinder 58 to be pressurized when the cylinder side 100 of bucket cylinder 18 is fully pressurized. With the cylinder side 100 fully pressurized, bucket cylinder 18 will be fully extended and the coupling assembly 10 will be rotated fully forward.
Referring now to FIG. 6A, another embodiment of a valve assembly 102 includes valve 108 in series with check valve 124 between lines 96 and 104 . Check valve 24 prevents back flow from line 104 to 96 . A drain line 126 normally connects between line 104 and reservoir 90 via through portion 128 of solenoid valve 130 . When valves 108 and 130 are energized, drain line 126 is blocked by check valve portion 132 of valve 130 , and through portion 120 is positioned in series connection with check valve 124 between lines 96 and 104 . Check valve 124 , similar to check valve portion 122 , is set to permit pressurization of line 104 and latch cylinder 58 when full hydraulic pressure is applied to extend bucket cylinder 18 .
Referring to FIG. 6B, in a third embodiment, valve assembly 102 ″ is configured with solenoid valves 108 and 110 , similar to the arrangement of valve assembly 102 . In addition, a drain line 134 connects between valves 108 and 110 . Flow through drain line 134 to reservoir 90 is limited by an orifice 136 flow limiter.
Referring now to FIG. 6C, a fourth embodiment of a valve assembly 102 ′″ includes solenoid valves 136 and 110 . In the normal, non-energized configuration shown in the drawing, cylinder 58 drains to reservoir 90 via through portion 118 of valve 110 and lower through portion 140 of valve 138 . When valves 110 , 138 are energized, pressure line 96 is coupled to cylinder 58 via upper through portion 142 of valve 138 and check valve portion 122 of valve 110 .
Valve assemblies 102 ′, 102 ″ and 102 ′″ can be safer than valve assembly 102 , especially in high back pressure systems, because of the drain connections to reservoir 90 , however, the drain connections require an additional hydraulic hose.
Referring again to FIG. 6, indicator lights 148 and an audible indicator 144 , such as a beeper sound device, located in the cab alert the operator that the switch 111 is in the energized, unlatch position. A warning lamp 146 mounted on the dipperstick 12 lights or flashes to help to alert surrounding personnel that the switch 111 is in the unlatch mode and that the latch pin 48 could be retracted. Of course, audible indicator 144 can be configured to be audible outside the operator cab.
A single operator in the cab of the excavation equipment can detach a tool, such as bucket 14 , to the coupling assembly 10 and attach a new tool to the coupling assembly without any assistance, as described in detail below. Some particulars of the following recitation of steps for coupling and removing a tool are made with reference to the embodiment of valve assembly 102 illustrated in FIG. 6 . It will be understood that the embodiments of valve assemblies 102 ′, 102 ″, and 102 ′″ illustrated in FIGS. 6A, 6 B, and 6 C, respectively, will function in much the same manner, and the operator will make essentially the same sequence of steps to attach or detach a tool.
To decouple a tool from coupling assembly 10 , the latch pin 48 must be moved to the retracted position. The operator first throws switch 111 in the cab to the unlatch position. The indicator lamps 148 and warning lamps 146 then light up, and the audible indicator 144 sounds. The solenoids becomes energized, which moves solenoid valves 108 , 110 in valve assembly 102 to their unlatch position. Check valve 116 is moved out of hydraulic circuit 89 and check valve 122 is moved into hydraulic circuit 89 . This, by itself, is insufficient to retract latch pin 48 . Check valve 122 is set to prevent passage of hydraulic fluid and thus prevent latch cylinder 58 from being pressurized until the pressure on the cylinder side 100 of bucket cylinder 18 is greater than a predetermined value.
In the illustrated embodiments, check valve 122 is set such that the coupling assembly 10 and attached tool 14 must be rotated fully forward and approximately full pressure must be applied in line 96 to bucket cylinder 18 to open check valve 122 . This assures that accidentally throwing switch 111 will not, by itself, be sufficient to retract latch pin 48 .
Once the pressure in latch cylinder 58 is great enough to overcome the spring force of spring 56 , latch cylinder 58 extends and thereby retracts latch pin 48 . The operator can confirm that the latch pin 48 is retracted if he sees the pin block 62 in the retracted position. While the switch 111 is still in the “unlatch” position, the latch pin 48 will be held back retracted.
Alternatively, to bring the latch pin 48 to the retracted position, the operator can first rotate coupling assembly 10 forward, fully pressurize bucket cylinder 18 , and then throw switch 111 to the unlatch position.
At this point, solenoid valves 108 , 110 are still energized and in the unlatch position, and check valve 122 retains pressure in latch cylinder 58 . The operator can then use free hands to maneuver the vehicle to disengage the hooks 34 from cross member 40 to uncouple the tool.
If the equipment is to remain idle for a period of time, the operator throws toggle switch 111 to the latch position, de-energizing the solenoid valves in valve assembly 102 , and lowers hydraulic pressure in line 96 . This allows pressure to drop in latch cylinder 58 such that spring 56 urges latch pin 48 to the engaged, or latched position, thereby bringing the piston 72 of cylinder 58 to a protected position retracted into cylinder body 70 .
To attach a new tool, with the latch pin 48 still in the retracted position and the valves in the valve assembly 102 still energized, the operator adjusts pressure in the bucket cylinder 18 and maneuvers the coupling assembly 10 to insert hooks 34 into the recess 36 of the new tool and engage cross tube 40 . The operator then lifts the tool off the ground, and rolls coupling assembly 10 forward by extending bucket cylinder 18 . Coupler crescent 61 engages an upper side of latch collar 51 , thus bringing latch pin 48 into alignment with receptacle 50 on bucket 14 . The operator knows that the coupler crescent 61 has engaged latch collar 51 when he sees the bucket 14 visibly begins to roll forward. Less than full pressurization of the bucket cylinder 18 is typically required to bring the coupling assembly to this position.
The operator then throws switch 111 to the latch position. This de-energizes solenoid valves 108 , 110 and moves check valve 122 out of hydraulic circuit 86 and check valve 116 into hydraulic circuit 86 . Check valve 116 is set to open at a low differential pressure, such that hydraulic pressure will be released from the latch cylinder 58 when the back pressure in bucket cylinder 18 is much less than full pressure but great enough to rotate coupling assembly forward so that the coupling crescent engages the tool latch collar 50 .
When the hydraulic pressure in latch cylinder 58 is released, spring 56 moves latch pin 48 into the engaged position with receptacle 50 . The position of pin block 62 gives the operator a visible signal that the pin 48 is latched and the tool secured. Check valve 116 thereafter prevents the latch pin assembly from being inadvertently pressurized.
Other embodiments of the invention are within the scope of the following claims. | The invention provides a coupling assembly for coupling a tool to a dipperstick, or arm, on an apparatus which has a hydraulic system for moving the tool. The coupling assembly includes a coupler body having a frame that defines a central cavity, and also having link structure for pivotally coupling to the dipperstick. An actuator assembly positioned within the central cavity includes a latch pin that can slide between an engaged position and a retracted position. In the engaged position, an end of the latch pin projects out from a rear end of the frame for engaging a receptacle defined by the tool. In the retracted position, the end of the latch pin does not project out from the frame. A bias structure normally urges the latch pin toward the engaged position with a bias force. A hydraulic latch cylinder has a fixed part and a movable part rigidly coupled to the latch pin such that, when the movable part is extended from the fixed part, the latch pin is urged to the retracted position. | 4 |
This is a division application of Ser. No. 560,357, filed Jul. 31, 1990 now U.S. Pat. No. 5,118, .
FIELD OF THE INVENTION
The present invention relates to the fading or decolorization of dyes or coloring agents on garments. More particularly, the invention is concerned with the decolorization and/or fading of dyed garments containing cellulosic materials through the use of ozone without any substantial deterioration of the garment. The invention is particularly useful in preparing fashion garments such as faded denim blue jeans, and the like, without the use of harsh chemical bleaches on the abrasive effects of stones, pumice, sand or the like.
BACKGROUND OF THE INVENTION
Denim blue jeans which have been faded, "stone-washed", ice washed, or sand blasted to produce a particular appearance are very popular. However, to produce the desired effect it has been necessary to utilize processes which cause substantial deterioration or degradation of the fabric. Bleaching solutions containing chlorine or actual pelleting of the garment with sand or stones to produce a fashion effect causes damage to the fabric which affects its wear life.
Ozone has been used in the bleaching of cellulosic materials. U.S. Pat. No. 4,283,251 to Singh discloses the bleaching of cellulosic pulp with gaseous ozone in an acidic pH followed by an alkaline treatment.
U.S. Pat. Nos. 4,214,330 and 4,300,367 to Thorsen, which are herewith incorporated by reference, describe a method and an apparatus for treatment of undyed fabrics with a ozone-steam mixture. The process is used to shrinkproof the fabric with a minimum amount of deterioration of the fabric fibers. The ozone treatment reacts with the undyed fibers and provides whiter fibers. The treatment is stated to increase subsequent dyeability and dye fastness of the garment.
W. J. Thorsen et al in their paper entitled, "Vapor-Phase Ozone Treatment of Wool Garments", Textile Research Journal, Textile Research Institute, 1979, p. 190-197, describe the treatment of wool fabrics and garments with ozone and steam to provide shrink resistance to the fabric or garment. The process is based on the reaction of the ozone with the wool fibers.
It should be understood that the term "dye" as used herein is meant to include any of the materials which are used to provide a color to a fabric such as conventional dyes, pigments, or the like.
It should be understood that the term "ozone and steam" as used herein denotes a preferable method of the invention and is meant to include ozone alone or ozone diluted with inert gases.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a process for selectively decolorizing a garment containing cellulosic material which in its simplest form comprises the steps of 1) providing the garment containing a dye which is reactive to ozone, 2) wetting said garment, and then, 3) contacting the wetted garment with ozone or a mixture of ozone and steam so as to cause a reaction of the ozone with the dye. The garment may comprise cotton, linen, or other bast fibers or rayon alone or in combination with other materials including natural and synthetic fibers.
Preferably, the dyed garment is decolorized or faded without bleaching the fabric and causing degradation of the fabric.
The ozone primarily reacts with the dye of the garment when the garment is wet. Therefore, the garment is wetted or treated in a wet state. The water content of the wetted garment is preferably about 20 to 40% by weight or higher depending upon the degree of treatment and the effect desired. The process may either be batchwise or continuous and is performed in a chamber in which the ozone is generally present in an amount of about 10 to 100 mg. per liter. The ozone and the steam are injected into the chamber so as to provide a temperature in the chamber of about 40° to 100° C., preferably 50° to 65° C. In the absence of steam, heating elements in the chamber can be used to maintain the temperature. Any excess ozone emitted may be recycled back into the chamber or used to treat any effluent of the process.
In accordance with a preferred embodiment of the invention, one or more ozone reactive dyed wet garments which have been treated with an ozone blocking agent or dyes of different ozone reactivity or sensitivity are placed in an enclosed chamber. A spectrophotometer in association with a computer continuously senses the garment and the reaction of ozone with the dye by means of the color change of the dyed garments. Steam is emitted into the chamber until the temperature is between about 40° and 100° C. When the desired temperature is reached, ozone is emitted into the chamber so as to mix with the steam and react with the dye of the garments. The concentration of the ozone in the chamber is maintained between 10 to 100 mg per liter by monitoring with an ozone photometer. When the garments reach a predetermined color, that is, the dye undergone a decolorizing has reaction with the ozone whereby the desired color is obtained, the reaction is terminated prior to any substantial reaction of the ozone with the fabric of the garment.
It is a general object of the invention to fade or decolorize dyed garments.
It is a further object of the invention to decolorize dyed garments with ozone without bleaching the fabric.
It is yet still further object of the invention to selectively and/or evenly decolorize or fade dyed garments to produce fashion garments.
It is another object of the invention to provide garments with different degrees of color by use of dyes or varying ozone sensitivity and/or to provide different levels of colorization throughout the garment.
It is yet another object of the invention to provide a process for decolorizing dyed garments while sensing the degree of color loss so as to avoid fabric degradation.
Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of one form of an ozone treatment apparatus of the invention, and,
FIG. 2 is a schematic view of the process of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the invention selected for illustration in the drawings and are not intended to define or limit the scope of the invention.
In accordance with a simple form of the invention there is provided an enclosed apparatus 10 having an internal chamber 13. The apparatus 10 is provided with an ozone inlet 15 which is associated with an ozone generator (not shown) and a steam delivery means 14 with orifices 14a. Preferably, the apparatus has a sloping roof 20 so that condensation from the steam will form on the walls and be carried to the drain 16 without dripping on the garments 12 in the chamber 13.
A wetted garment 12 is carried into the chamber 13 by means of hook or rack means 11a suspended from a conveyor 11. The chamber may be initially purged with an inert gas from inlet 15a prior to admission of the ozone through inlet 15. The garment 12 would generally be wet before it is treated with ozone since it is usually treated with the ozone after laundering but before drying. However, if the garment has not been prelaundered, then it is necessary to prewet the garment before beginning with the ozone treatment.
Where the garment is to be selectively faded, it may be treated with an ozone blocking agent prior to or subsequent to wetting. If the blocking agent is a hydrophobic material such as a hydrocarbon grease or wax, there is no noticeable loss of blocking agent when wetted. However, an inorganic blocking agent, such as a clay can be added after wetting.
Once in the chamber 13, the garment 12 is subjected to steam which is emitted from a steam pipe 14 with openings 14a. Ozone is passed into the chamber 13 through inlet 15. The chamber may first be purged with an inert gas or ozone, if desired, depending on the type or degree of decolorization desired. The amount of ozone present in the chamber 13 is monitored by an ozone photometer 19, such as Dasibi Model 1003 HC ozone photometer. The temperature within the chamber 13 is monitored by thermocouples 18, 18'. During the decolorization process, a spectrophotometer such as a Bausch and Lomb Colorscan Spectrophotometer, constantly senses the color of the garment 13. The sensing is preferably coordinated with a computer means 22 which records the color change and inactivates the process when the desired amount of color has disappeared from the dyed garment 12. The process may be inactivated by stopping the flow of ozone and removing the ozone through exit 17, or by removing the garment from the ozone atmosphere as in a continuous process.
A drain 16 is provided at the bottom of the chamber 13 to collect and remove the steam condensate.
The dimensions of the chamber 13 are not critical except that the middle section of the chamber 13 should be sufficiently sealed or elevated so as to confine the main concentration of the ozone and steam to the area where the garment 12 is hanging. The chamber 13 may be fabricated by any airtight material which is unreactive with ozone such as stainless steel, aluminum, teflon, polyolefin, and the like.
The central introduction of the ozone allows the reactive ozone, which may be admixed with other gases such as argon, nitrogen, etc., to react with the dye as the garment 12 and chamber 13 are being heated by the hot steam. Fans (not shown) may be provided to circulate the steam and ozone throughout the chamber 13.
The proportion of steam mixed with the ozone is adjusted so as to attain the desired gas temperature. Thus, by increasing the proportion of steam coming from a steam generator (not shown) through the steam pipe 14, the temperature within the chamber is increased. Otherwise, heating elements (not shown) within the chamber can be used. The temperature within the chamber is generally about 40° C. to 100° C., preferably, about 50° to 65° C.
The apparatus used in performing the process of the invention can comprise an open-ended chamber or a closed-end chamber. In a continuous process an open-ended chamber is preferred which comprises a plurality of chambers. The temperature of the ozone treatment chamber is preferably controlled by the temperature of the steam which is admixed with the ozone. Thermocouples 18, 18' may be used to measure the chamber temperature.
A spectrophotometer is preferably used to sense and determine the degree of color loss on the garment desired. The spectrophotometer is helpful in preventing fabric degradation by detecting the amount of dye available for reaction with the ozone. Advantageously, the spectrophotometer is linked with a computer for reading color values and controlling this process.
The type of dye used on the garment is not critical. It is only important that the dye is ozone reactive where intended. Cellulose substantive dyes, such as vat dyes, which are common in the garment industry, are preferably used. Exemplary of the dyes which are substantive to cellulose that can be used include Acid Light Scarlet GL, an acid leveling dye, Sevron Brilliant Red 2B, indigo vat dye, a cationic dye, Sulfonine Brilliant Red B, an anionic dye, Brilliant Milling Red B, C.I. Disperse Blue, pyrazolone azomethine dye, hydroxy azo dyes, or the like. Where the dye is a xanthene dye, treatment also gives rise to chemiluminescence in the process. Other suitable dyes that can be used are identified in the paper of Charles D. Sweeney entitled, "Identifying a Dye can be Simple or it Can Involve Hours of Laboratory Analysis", Textile Chemist and Colorist, Vol. 12, No. 1, Jan. 1980, pp 26/11.
The garments may be treated with one or more dyes. Utilizing dyes of differing degrees of ozone reactivities provides the garment with zones of different appearances or effects. For example, faded, stone washed, ice-washed, sand blasted or mottled effects may be obtained. The same effect can be achieved by utilizing ozone blocking agents. The ozone blocking agents may comprise organic materials such as hydrocarbon oils, greases or waxes or inorganic materials such as clay. Masking tape, or other coverings may be used. A further alternative method to achieve a special effect is to partially or selectively wet the garment since the ozone-dye reaction effectively takes place where the garment is wet. The ozone generally does not react with the fabric where it is not wet.
The blocking agent can also be any chemical agent which itself is reactive with ozone but prevents or blocks a dye or portion of a dye on the fabric from becoming decolorized.
It is understood that the reaction period and amount of ozone utilized is dependent upon different factors. That is, the time and amount of ozone depends upon the effect desired, the type of dye utilized, the temperature, degree of wetness, etc. Longer treatment at lower concentrations of ozone can result in the same effect as a short treatment with a large excess of ozone on the same dyes. Therefore, the sensing of the conditions in the reaction chamber is essential to optimize the present process.
The ozone within the chamber is preferably measured periodically and kept at a minimal and within the range of about 10 to 100 mg per liter. The ozone can be generated by on ozone generator of the type available from Griffin Technics, Inc., Model GTC-2B which produces ozone from dry air or oxygen using electrical circuit breakers or Corona discharge. The ozone may be used alone or diluted with inert gases.
As shown schematically in FIG. 2, a garment to be faded, such as denim blue jeans, is generally first laundered to remove any sizing or fashion process coatings or materials which may interfere with the process of the invention. For example starch can act as an ozone blocking agent. The washing operation could include desizing using enzymes, as is common in the industry followed by laundering to cleanse the garment. The garment is then hydroextracted or padded dry so as to remove excess water. The water content of the garment should be about 20-40% by weight. If the garment is not wet, then it can be wetted by water spraying or the like.
The garment is treated with a blocking agent which is determined on the effect desired. For example, if a sand blasted or stone washed effect is desired, the wet garment can be sprayed with clay or some other inorganic powder to act as an ozone blocker. However, if a mottled look is desired, the garment may be treated with a suitable hydrocarbon oil, grease or wax which shields parts of the garment from the effects of ozone in a selected manner. The garment can be printed, the color can be applied by painting or using a mordant.
In lieu of the ozone blocking, special effects can also be achieved by selectively treating the garment with dyes having different degrees of ozone reactivity. The different dyes can be added earlier in the process so that the use of ozone blocking agents becomes optional. The non-reactive or lesser ozone reactive dyes may be applied by spraying, brushing, dipping, or the like. The non-reactive dyes include the pigment colors.
The wet garment is then conveyed into a closed ozone treatment chamber where its decolorization process is constantly sensed by a spectrophotometer, which is associated with an indicator such as a computer. The computer may be further associated with the controls for the ozone and the purge gas so as to stop the reaction as soon as the desired color or degree of dye reaction has been obtained.
The garment if treated with an ozone blocking agent may require the garment to be post washed to remove the blocking agent prior to other processing or treatment such as drying and pressing.
The present process has been found to eliminate the yellowing which occurs as a result of ice-washing blue denims.
The following example is illustrative of the invention, but is not to be construed as to limiting the scope thereof in any manner. The percentages herein disclosed relate to percent by weight.
EXAMPLE 1
A pair of cotton denim blue jeans vat dyed with a blue indigo dye (CI Vat Blue 1) was washed with a standard laundry detergent at 120° F. in a conventional washer which included a spin extractor. The garment after extraction had a moisture content of about 35% by weight. The garment was sprayed with clay to achieve a stone washed effect.
The garment was then hung in a closed chamber of the type seen in FIG. 1 of the drawing. The chamber was purged with nitrogen and steam heat was emitted into the chamber. When the chamber reached a temperature of about 52° C., ozone was emitted into the chamber until an ozone concentration of about 40 mg/l was obtained. After a residence time of 30 minutes, the ozone emission was stopped and the chamber was purged free of ozone.
Alternatively, the residence time may be determined by the use of a test fabric and programming a computer in association with a spectrophotometer to indicate when the desired color is achieved. Such sensing is preferred in a continuous process.
The garment was washed again in a commercial washer with a standard laundry detergent to remove the clay. The resulting garment had a stone washed effect and when examined with a scanning electron microscope did not reveal any signs of fiber degradation.
EXAMPLE 2
Grab Break tests were determined using ASTM Test Method D-1682 five breaks both warp and filling were made for each sample and averaged. Abrasion tests were determined according to ASTM Method D-3885 (stoll flex). Five samples both warp and filling were run and averaged. The fabrics were standard Levi style 501 garments.
Results
The overall results were given in Table 1. A standard ice wash procedure was used as the control.
A. Comparison of Ozone Treated Garments to Chlorine Treated Garments
The results for chlorine (Sodium Hypochloride) treatments are shown in Table 1. The treatment was done at normal (C1) medium (C2) and high (C3) chlorine contents in order to obtain increasing levels of color removal ranging from a medium blue to white. These treatments were matched to various ozone treatment times needed to achieve the same level of color removal. For example, C1 matched the ozone treatment for 1 hour while C2 matched the ozone treatment for 1.5 hours. No ozone treatment matched the C3 (totally white) jeans which is included for completeness. From the results it is observed that the ozone treated fabrics do not loose as much warp strength as the chlorine bleached garments. It is the warp yarns which contain the indigo dye. Filling yarns in denim are undyed hence the yarns were not protected from the full effects of the ozone. The test demonstrated that ozone treatments retain more of the abrasion resistance of the garments in both the warp and filling directions compared to chlorine bleach treatments.
B. Ozone Treatments
Fabrics were treated with ozone for 0.5 to 2.0 hours. The test results are given in Table 1. The fabric color became lighter with increasing time of ozone treatment. The color (dye) level in the garments was monitored by a Bausch and Lomb Color Scan Spectrophotometer.
C. Ozone Treatment of an Ice Washed Garment
An ice washed garment (control) was treated for 15 minutes in an ozone atmosphere (sample 03 1/4 hr.). Some loss in strength resulted, however, considerable abrasion resistance was restored as shown in Table 1. Also, the blue shade of the unbleached portion of the ice washed fabric could be further reduced in color to give a shading affect that cannot be achieved by the original ice washing technique. Further, ice washing produces a yellow color (staining) in the white (bleached) regions of the garment which reduces the garment attractiveness. This yellow colore (dye) is due to breakdown fragments (compounds) of the indigo dye which remain in the fabric to discolor the white background. The ozone treatment was effective in decolorizing these yellow compounds and gave a superior "white" background to the garments. That is, the ozone treatment corrected a major defect of ice wash treatments.
TABLE 1______________________________________Comparison of Strength (Grab Break and Abrasion)for Various Fabric Treatments Test Results Grab Break (lbs.) Abrasion (Cycles)Treatment Warp Fill Warp Fill______________________________________Part CIce Washed (control) 174 150 5473 3979Part BOzone (03) 0.25 Hrs. 139 120 9014 57840.50 Hrs. 224 120 9527 59551.0 Hrs. 245 105 20428 116651.5 Hrs. 195 141 8906 48942.0 Hrs. 174 110 5588 4278Part AChlorine(C1) Medium Blue 225 134 14080 7524(C2) Light Blue 179 101 5823 4350(C3) White 143 81 3266 2920______________________________________
Although the invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. | A process for selectively decolorizing a garment containing cellulosic material which comprises the steps of providing said garment with a dye or coloring agent reactive to ozone, wetting said garment and then contacting said wetted garment with ozone or a mixture of steam and ozone whereby the ozone is reacted with the dye or coloring agent. | 3 |
FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for cutting underwater structures.
The cutting of submerged structures, with the purpose of removal and/or substitution of same, is presently effected by adopting different methods and by utilising apparatus of different nature.
BACKGROUND OF THE INVENTION
There are known devices for the cutting of submerged structures which operate with fixed blades, such as the one described for example in the document U.S. Pat. No. 3,056,267, or provided with several rotary blades co-ordinated in their action as in the document U.S. Pat. No. 4,180,047. Both apparatus however present the disadvantage of operating only on the emerging and free end of the submerged structure.
In the document EP-B-0 540 834, owned by the same applicant, there is described a method and a device for cutting underwater structures which make use of a diamond cable as cutting means; the device permits the cutting of the underwater structure at any level comprised between the bottom end and the surface.
Presently, the new provisions which are in force practically everywhere, and which are extremely more severe as for what concerns the environmental impact, require that the cutting of the submerged structures cannot be effected by leaving the residual stump of the structure emerging from the (sea) bottom, but instead by effecting the cut below the level of the bottom itself. Under these conditions, by utilising the presently available means, it results necessary to remove a relevant quantity of sea bottom around the base of the structure to be cut. This further operation, besides being costly, is frequently damaging as for what concerns the environment, which on the contrary this type of “underground” cutting would tend to safeguard.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide for a method for cutting the underwater structures which permits the cutting below the level of the bottom and with a minimum expenditure of means and of energies, and with an impact with respect to the marine environment which is as limited as possible, obtained with a minimum removal of material from the bottom.
A further object of the present invention Is to provide an apparatus adapted for carrying out the thus conceived cutting method.
One object of the present invention is therefore a method for the cutting of underwater structures below the level of the sea bottom on which they are installed, comprising the following phases:
determination of the ideal plane of cutting, having considered the characteristic features of the structure i.e. its morphology and its positioning on the bottom, the shape and consistency of the bottom itself, and the depth below the level of the bottom at which the cut must be effected; positioning and anchoring of the cutting means in proximity of the cutting area; obtainment of at least one perforation or boring in proximity of the structure through the bottom at least up to the predetermined level for the cutting of the structure, along a direction parallel to the cutting direction and preferably lying on the cutting plane; and introduction of the cutting means inside said perforation or boring and cutting of the structure.
According to a preferred embodiment of the method according to the invention, there are obtained preferably two perforations or borings having parallel axes, and arranged in such a manner that the structure to be cut is placed between the said perforations or borings.
The positioning and the anchoring of the cutting means is effected both on the bottom in proximity of the structure to be cut, and onto the structure itself.
A further object of the invention is an apparatus for carrying out the method according to the invention, comprising means for perforation or boring, means for cutting which comprise a cutting frame and a movable cutting unit, means for positioning said perforation means and said cutting means, and anchoring means. Advantageously said perforation means and said cutting frame are associated, and the means for the positioning and anchoring of the perforation means and of the cutting means are the same.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and characteristic features of the present invention will appear evident from the following detailed description of some preferred embodiments of same, made as non-limiting example with reference to the annexed sheets of drawings, in which:
FIG. 1 is a perspective view of a first embodiment of the apparatus for carrying out the method according to the invention, during its positioning in proximity of a submerged structure to be cut;
FIGS. 2 to 4 show in succession the operative steps of the method according to the present invention;
FIG. 5 is a side elevation view with parts in section of a second embodiment of the apparatus according to the invention;
FIG. 6 is a transverse section view along line VI—VI of FIG. 5 ;
FIG. 7 shows the positioning in proximity of the structure to be cut of a third embodiment of the apparatus according to the invention;
FIG. 8 shows the operation of the apparatus shown in FIG. 7 ;
FIG. 9 is a section view along line IX—IX of FIG. 8 ;
FIG. 10 shows the operation of a further embodiment of the apparatus according to the present invention; and
FIG. 11 is a perspective view of the means for supporting the apparatus according to the invention shown in FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown the apparatus intended to perform the method according to the present invention. Reference numeral 1 designates the supporting base of the apparatus, having a substantially rectangular shape, which is provided in proximity of each of its corners on the upper face with four lugs 101 to which there are secured the lifting rods or cables 11 which connect the base 1 to the haulage cable 10 . The base 1 is further provided with means for anchoring to the bottom 20 in proximity of the structure 30 to be cut. The anchoring means comprise claws 201 which are swingable with respect to the ears 301 projecting out of the base 1 and connected to pairs of hydraulic jacks 401 , provided with opposed stems 411 .
To the base 1 , there is connected the plate 2 , to the lugs 112 of which there are hinged, at one of their ends, the two guides 302 , by means of the flaps 322 projecting out of same. In proximity of the other end the guides 302 are instead connected through the flaps 312 to the articulated arm 202 , 212 , hinged on its turn to the lugs 222 of the plate 2 . The two ends of the branches 202 , 212 of the articulated arm which are connected between each other, are connected to the stem 122 of the jack 102 which by its other end is swingably connected to the lug 112 . The two guides 302 are united between each other by means of the traverse bar 402 .
Onto the guides 302 there are arranged two tubular members 3 which are longitudinally slidable thanks to the slides 403 integral to said members 3 , mounted in overhanging manner in the same slides 403 . At the end of said tubular members 3 directed towards the end of the guides 302 directly hinged to the plate 2 there are arranged the means for boring the bottom, comprising the boring or cutting heads 303 while at the opposite end of said tubular members 3 there are arranged two ducts 203 for discharging the material removed during the boring of the bottom. On each one of the tubular members 3 there is obtained, facing the other tubular member, a longitudinal slot 103 ; between the two slots, of which only one is visible in the Figure, there is arranged the cutting tool, comprising the diamond cable 4 , movable within the said tubular members 3 by means of devices which will be after illustrated and described.
In FIG. 2 the apparatus according to the invention has been placed on the bottom 20 next to the structure to be cut 30 , and the claws 201 , under the action of the jacks 401 , have been driven into the bottom itself, thus anchoring the base 1 and setting the apparatus ready for subsequent operations.
In FIG. 3 the jacks 102 have been actuated so as to lift the articulated arms 202 , 212 which act on the guides 302 . Consequently the said guides 302 and also the tubular members 3 arranged onto same, have been suitably inclined with respect to the plane of the bottom; the said inclination is selected according to the ideal cutting plane which has been established for the cutting of the structure 30 , and which depends substantially from the characteristic features of the structure itself, such as position, section and material, from the characteristic features of the bottom and from the depth at which the cut must be effected below the level of the bottom itself. As soon as the desired inclination has been reached, the tubular members are displaced by means of the slides 403 along the guides 302 , and the boring heads 303 penetrate into the bottom 20 thus forming two perforations 21 . Said perforations are obtained parallely to the ideal cutting direction of the cutting tool 4 , and in such a manner that the structure is comprised between the said perforations. The material removed by the boring heads 303 , is suitably conveyed along the tubular members 3 and discharged onto the bottom thanks to the discharge ducts 203 .
In FIG. 4 the perforation phase of the bottom has been completed, and the boring heads have reached and passed beyond the level at which the cut must be effected. At this point, the cutting means are actuated and the cutting tool 4 , that is the diamond cable, is caused to interfere firstly with the portion of bottom comprised between the two perforations 21 and after with the structure 30 , thus originating the cut 31 . The cutting means can thereafter be retracted up to the position shown in FIG. 3 and the boring heads are extracted out of the respective perforations 21 , by causing the slides 403 to slide in opposite direction on the guides 302 ; the portion of the submerged structure 30 which is located above the cut 31 , can be conveniently grasped and removed.
From what above said it appears evident that the method according to the present invention obviates several inconveniences which were encountered up to the present date at the moment in which there should be effected the cutting of submerged structures below the level of the bottom on which said structures are positioned. In fact, instead of the ample excavations around the structure which are necessary up to the present date in order to reach the desired depth, the cutting means are guided inside perforations which remove a minimum portion of the bottom, thus remarkably limiting the environmental impact of the operation, and increasing remarkably the simplicity and rapidity of the action.
In FIG. 5 there is shown a second embodiment of the apparatus according to the invention; identical reference numerals designate identical parts. In this case the base 1 is mounted on sliding shoes 5 , provided with propellers 105 transversely oriented with respect to said sliding shoes and with propellers 205 axially oriented. The propellers 105 , 205 are mounted on respective supports 115 , 215 .
As it can be noted from the Figure, the boring head 303 at the end of the tubular member 3 is keyed onto the shaft 323 of a speed reducer 313 ; its side wall which has a substantially conical development, according to this embodiment is formed by the blades 343 which are angularly equispaced. In the portion of the tubular member immediately downstream of said speed reducer 313 , the wall 503 subdivides the interior of said member 3 into the duct 523 for the discharge of the material removed by the boring head 303 and into the portion 513 inside which there are arranged the cutting means, which communicates with the exterior through the slot 103 in which there slides the cutting tool 4 . At the opposite end of the tubular member 3 , on the discharge duct 523 there is positioned an aspirator 213 , which discharges the debris into the discharge duct 203 .
The tubular member 3 is mounted overhanging on the slide 403 which moves along the guide 302 thanks to the speed reducer 423 integral with said slide and which carries on its shaft 423 a pinion 433 which co-operates with the rack 332 arranged on the side wall of the guide 302 .
FIG. 6 is a section view along line VI—VI of FIG. 5 ; at the interior of the tubular member there are arranged the cutting means comprising the cable 4 preferably of the diamond type, which is arranged on the pulley 104 , keyed onto the shaft 114 which is inserted in the carriage 204 . One end of the shaft 114 is provided with a bevel pinion 124 which engages the bevel pinion 414 of the speed reducer 404 arranged on the carriage 204 . The carriage 204 is provided with two sliding shoes 214 which co-operate with the guides 304 connected with the wall 503 which divides the tubular member 3 into the portion 513 and into the duct 523 ; to the said wall 503 there is also applied the pipe 333 which carries the feeding fluid to the speed reducer 313 of the boring head 302 (see FIG. 5 ). On the carriage 204 there is overhangingly connected the speed reducer 504 on the shaft 524 of which there is keyed a pinion 514 which engages the rack 533 arranged on the wall 503 . The speed reducers 404 and 504 are fed through the pipes 424 and 534 carried by the supporting member 603 movable along the guide 613 formed on the inner wall of the tubular member 3 .
The operation of the apparatus adapted to carry out the method according to the invention will appear evident from the following. The positioning of the apparatus on the bottom 30 can be controlled from the surface, as shown in FIG. 1 , by means of the haulage cable 10 , or the apparatus can be positioned with respect to the structure to be cut by using means placed directly on the apparatus itself, as in the case of the propellers 105 , 205 shown in the embodiment of FIG. 5 . In both cases, after the positioning and the anchorage of the apparatus, the guides 302 are oriented with respect to the structure to be cut thanks to the jacks 102 which act onto the articulated arms 202 , 212 so as to position them on the ideal plane of cutting of the said structure.
Subsequently the speed reducers 413 are actuated to permit the forward movement of the slides 403 which carry the tubular members 3 , at the ends of which there are mounted the boring heads 303 which are driven in rotation by the speed reducers 313 . As the boring heads penetrate into the bottom 30 , the produced debris are conveyed into the ducts 523 provided at the interior of the tubular members 3 and under the action of the aspirators 213 are expelled through the discharge ducts 203 .
When the boring heads have reached the suitable depth with respect to the structure to be cut, the perforation is interrupted, and there is actuated the speed reducer 504 which is mounted on the carriage 204 which carries the diamond cable 4 , together with the speed reducer which drives the pulley 104 on which there is arranged the cable 4 itself. The cutting means move forward along the tubular members 3 , until they meet first the bottom 20 and then the structure 30 , into which there is made the cut 31 . At this point also the cutting means can be stopped and subsequently retracted by abandoning, if the case, the cable; afterwards the tubular members 3 will be retracted and there will be recovered the structure 30 thus cut.
In FIG. 7 there is shown another embodiment of the apparatus according to the present invention; identical reference numerals designate identical parts. In the illustrated case the already described plate 2 is connected to the support 7 which forms together with the movable plane 407 and the levers 107 and 207 , which are hinged to both, an articulated parallelogram. To the lever 207 there is connected in a swingable manner the stem of the jack 307 which by its other end is hinged to the plane 407 . The said plane 407 is hinged by one end to the lug 408 of the anchoring frame 8 , while at the other end it is coupled to the stem 318 of the jack 308 connected to the said anchoring frame 8 . The anchoring frame 8 is provided with two anchoring clamps 108 , intended to seize the structure 30 . The apparatus is connected to the haulage cable 40 by means of the lifting rods or cables 41 which are connected to the slots 508 and 507 .
In FIG. 8 the apparatus according to the embodiment of FIG. 7 is shown at the end of the cutting phase of the structure, with the tubular members inside the perforations 21 and the cutting tool 4 which has traversed the structure 30 itself. As it can be appreciated, in this case the anchoring of the apparatus is performed directly on the structure 30 itself, and the positioning of the boring means and of the cutting means is obtained thanks to the three, different possibilities of adjustment consented by the articulated parallelogram of the support 7 , by the jack 308 of the movable plane 407 and by the articulated arm 202 , 212 which, in co-operation with the jack 102 , operates on the other hand in a manner analogous to what previously described with reference to the other embodiments of the apparatus according to the present invention.
In FIG. 9 there is shown, in section along line IX—IX of FIG. 8 , a clamping jaw 108 . Onto the two fixed arms 108 there are mounted, swingable on the pins 138 , a pair of rocking levers 118 , each of which is provided at one end with a blocking element 128 , which is also swingable with respect to the lever 118 , and at its other end hinged to the stem 158 of the jack 148 , on its turn swingably connected to the anchoring frame 8 . Between the two jacks 148 connected to the arms there is arranged a jack 208 on the stem of which there is positioned a blocking element 228 which consents the seizing of the structure 30 and the centring with respect to same.
The advantages deriving from this embodiment are evident; in the first place it is not affected during its operation by any influence connected to the features of the bottom and to its regularity, since the only part which comes Into contact with the bottom is only the one which penetrates the bottom itself, that is the tubular members 3 , the boring heads 303 and the cutting tool 4 . In the second place the structure 30 , after the cutting, remains connected to the support of the apparatus, that is to its anchoring means represented by the clamping jaws 108 , and it can be therefore better controlled during its removal.
In FIG. 10 there is shown another embodiment of the apparatus according to the present invention; the plate 2 is mounted onto a base 409 connected to the upright of a stand frame 9 which comprises a diagonal beam 209 and a traverse beam 309 ; at the end of the diagonal beam 209 connected to the traverse beam 309 as well as at the end of the upright 109 connected to the traverse beam there is provided a foot 219 . All the feet 219 are provided with perforation means 509 and with expansion inserts 609 . The perforating means 509 generate the bores 22 inside which the foot 219 and the end of the upright are inserted, and the expansion inserts 609 perform the locking in place. As it can be seen in FIG. 11 , the stand frame 9 comprises two uprights 109 , two diagonal beams 209 and two traverse beams 309 , facing each other and connected by the transverse bars 119 and 319 .
The support of the apparatus of the invention, conceived in this manner, considerably reduces the space required for the positioning of the apparatus in proximity of the structure to be cut, and therefore can be useful in those cases in which the bottom in its proximity presents irregularities, or a flat bottom portion of limited extension. Moreover the anchoring system appears to be particularly quick and efficacious, capable of adapting itself to extremely difficult ambient situations.
The method according to the present invention and the apparatus for carrying out said method consent therefore to reach remarkable results from the point of view of the rapidity of operation, of the effectiveness and of the environmental impact which is extremely limited. | A method for the cutting of underwater structures below the level of the sea bottom on which they are installed, comprises determining an ideal plane of cutting, having considered the characteristic features of the structure i.e. its morphology and its positioning on the bottom, the shape and consistency of the bottom itself, and the depth below the level of the bottom at which the cut must be effected; positioning and anchoring of a cutter in proximity of the cutting area; obtainment of at least one perforation or boring in proximity of the structure through the bottom at least up to the predetermined level for the cutting of the structure, along a direction parallel to the cutting direction and preferably lying on the cutting plane; and introduction of the cutter inside the perforation or boring and cutting of the structure. An apparatus for carrying out the method is also provided. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention concerns a method and associated apparatus for playing casino games. More particularly, the invention is directed to an apparatus for assisting a craps player, the apparatus incorporating a method which increases the odds of obtaining a winning payout.
[0003] 2. Description of the Prior Art
[0004] Gaming accessories and devices for assisting casino players are well known in the art of gaming devices. Most of these devices are characterized by the provision of a number system or algorithm, e.g., card counting for blackjack, the calculations for which are printed and contained in various forms within a handheld apparatus. Manipulation of the apparatus produces a series of numbers upon which a bettor may rely in order to increase his odds.
[0005] U.S. Pat. No. 6,131,906 issued to Green discloses a blackjack strategy calculator which utilizes well known card counting algorithms. The device uses a microprocessor to generate suggested play, with the suggestions made viewable on an associated display. The display may be visual or tactile and the entire device is small enough to be held discreetly or hidden by the bettor.
[0006] U.S. Pat. No. 4,266,770 issued to Yeager discloses yet another blackjack strategy calculator. The device relies solely on mechanical movements, which allow the suggested strategy to be made available to the user discreetly using a tactile output.
[0007] U.S. Pat. No. 5,762,334 issued to Kosi discloses a reminder system for craps players. The system records the number of rolls of the dice and reminds the bettor to bet only when predetermined criteria are met. The present invention differs from the prior art devices and methods in that it contemplates a device which provides a recommended strategy which does not rely upon statistics or percentages. Instead, the present invention provides a device which allows a craps player to enter the game at any time, and provides a betting strategy which ensures no losses are incurred regardless of the outcome of the series of rolls.
[0008] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
[0009] Briefly, the invention comprises an apparatus which computes a betting strategy for a craps game, where the bets are placed at amounts which are based solely on the total amount the craps player wagers. The device comes in both a mechanical form and an electronic form. The mechanical form is configured to appear as a notepad in all respects and simply allows a player to select the total wager amount and provides instructions on which bets to place at selected areas of the craps table, and the suggested amounts. The electronic form is a microprocessor driven handheld device having a keypad to allow the bettor to manually enter the total amount to be wagered, and provides betting instructions based on the outcome of the roll of the dice. A display driven by the microprocessor will have a plurality of fields corresponding to the areas of the craps table. In response to the entry of a valid total wager amount, numeric values are assigned to the various fields thereby informing the bettor of the suggested betting strategy.
[0010] Accordingly, it is a principal object of the invention to provide a new and improved gaming device which overcomes the disadvantages of the prior art in a simple but effective manner.
[0011] It is a major object of this invention to provide an improved gaming device which calculates a winning strategy for a craps player given a selected total wager amount.
[0012] It is another object to provide an improved gaming device which can provide a winning craps betting strategy as an output on a microprocessor driven display given a predetermined valid input.
[0013] It is another object to provide an improved gaming device which can provide a winning craps betting strategy on a selected page of a notepad, the notepad having an overlay to isolate a selected entry.
[0014] Finally, it is a general goal of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
[0015] These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
[0016] The present invention meets or exceeds all the above objects and goals. Upon further study of the specification and appended claims, further objects and advantages of this invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0018] [0018]FIG. 1 is a plan view illustrating the layout of a typical craps table.
[0019] [0019]FIG. 2 a is a perspective view of a mechanical apparatus formed in accordance with the concept of the present invention.
[0020] [0020]FIG. 2 b is plan view detailing the arrangement of a component of the apparatus of FIG. 2 a.
[0021] [0021]FIG. 3 is a plan view illustrating the keypad and display of an electronic apparatus formed in accordance with concept of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring now to FIG. 1 a craps table layout is shown. There are a plurality of areas delineated on the craps table 20 where bettors can place bets. Bets are placed using chips which are purchased at predetermined incremental values, the placement of the chips on one of the delineated areas indicating that the bettor desires to bet the corresponding dollar amount. The delineated areas allow bettors to place bets which, depending upon the outcome of each roll (known as the roll sum) of a pair of dice (not shown), either win, lose, or remain on the table 20 pending subsequent rolls. A winning bet will win an amount corresponding to the payout odds in light of the value of the chips placed in the selected area, a losing bet results in the loss of an amount corresponding to the value of the chips placed in the selected area. A bettor may place bets on several of the areas at once in order to increase his odds of winning for a given roll. However, odds of winning when placing bets on some areas of the table are far worse than on other areas of the table. For example, the odds on the proposition bets such as the horn bet are so heavily in favor of the casino (also known as the house) that almost all experts recommend against making any of the proposition bets.
[0023] The present invention provides a method and an apparatus which allows a user to systematically place bets on both the high risk and low risk areas with a substantially increased chance of winning. In accordance with the method, bets placed on the pass line 24 or the come area 26 (when appropriate) are balanced against bets placed on the horn 28 . For the initial bet placed on the pass line, a corresponding bet is placed on the horn area 28 in amounts calculated to ensure at least some winnings, with no possibility of a loss. For example, if the initial pass line bet is 5 dollars, the corresponding bet placed on the horn would be 1,1,1,1 on the roll sums of 2, 3, 11, and 12 respectively, as illustrated in FIGS. 2 and 3. If a point is rolled, i.e. a number other than 2, 3, 7, 11, or 12, the horn bet is lost, but the pass line bet remains on the board. If a 7 is rolled, the pass line bet is won, and the player nets one dollar. If a 2 or 12 is rolled the player loses the pass line bet, but wins the horn bet at a 30 to 1 payout and thus nets 30 minus 8(pass line bet plus losing horn bets), or 22 dollars. Similarly, if the player rolls a 3 roll sum, which has a 15 to 1 payout, the player loses the 5 dollar pass line bet but wins 15 dollars on the horn for a net winning of 7 dollars. If the player rolls an 11 roll sum the player wins the pass line bet and the horn bet (also 15 to 1 payout) for a total gross winnings of 15 plus 5 or 20 dollars. It should be noted, however, that the bets placed on the horn area 28 are single roll bets, that is, after every roll the bets are either taken by the house, or winnings are paid out in accordance with the predetermined payout ratio.
[0024] As can be easily discerned from the above discussion, in order to implement the method of the invention, the craps player must understand and keep track of several bets. Furthermore, bets must be placed relatively quickly, on the correct areas of the board and in the correct amounts. The present invention includes apparatuses which ensure that, once the craps player has familiarized himself with the rules of the game and the nuances of the method, he/she can implement the method efficiently.
[0025] Both the electronic and manual form of the inventive apparatus utilize the following terminology to describe the various bets which are placed.
1. Present horn bet(PH) amount placed on the horn for the upcoming roll. 2. Cumulative horn bet(CH) amount lost on all horn bets for a particular roll series. 3. Horn bet payout(HP) amount won on the horn bet 4. Present come/pass bet(PC/PP) amount placed on the come/pass for the upcoming roll 5. Roll series all of the rolls occurring between a seven or an eleven roll sum. 6. Board total(BT) total of all bets currently on the board, not including the current come/pass bet or the horn bets. 7. Seven out a roll sum of seven which clears all bets on the board.
[0026] The basic principle of the method is that every current bet on the horn area 28 and the come or pass lines 24 , 26 , must be sufficient to cover for the cumulative horn bet as well as the board total, with at least a small net. Thus, for every roll, the amount placed on the come bet (the present come/pass bet) must be greater than the cumulative horn bet, plus the present horn bet, plus the board total. Likewise, for every roll, the horn bet payout (based on the current horn bet) must be greater than the cumulative horn bet, plus the board total. Thus we have:
[0027] If the present come/pass bet PC/PH is won with a roll of seven, BT, CH, and PH are all lost, but since PC is greater than BT, CH, and PH combined, the player will enjoy a net gain. If the PC/PH is won with an 11, the player wins in accordance with the above, plus wins the horn bet. If the player rolls a craps, i.e., a 2, 3, or 12, the player will win the horn payout, which is greater than the board total, the cumulative horn bets, and the present pass line/come bet. If the player rolls a point, the player neither wins or loses, unless the point is a previously rolled point, in which case the player wins the amount bet on that point, which amount is then deducted from the BT. If the point rolled is not a previously rolled point, the PC/PP is added to the BT, so that the player can determine the bet amounts for the next roll. When a seven is rolled, the player may conveniently cease making bets, as the BT and PH will go to zero, and the payout from the PC/PP will generate a small net. At this point, the player will have no bets at risk. It is readily apparent, therefore, to one of ordinary skill in the art that various sequences of betting combinations are possible given the above mentioned constraints. Regardless of the exact number combination employed, the player must keep a running total of the above mentioned variables and then calculate bet amounts based on the totals, which is difficult, if not impossible, for the typical craps player.
[0028] Referring specifically now to FIGS. 2 and 3, apparatuses for implementing the method are shown. As previously stated, the average craps player cannot perform the necessary calculations and place the appropriate bets in a timely enough manner, as there is only a limited amount of time to place bets between rolls. For casino gambling, craps players are not allowed to have any kind of mechanical or electrical device when gambling, but may have notes and figures. For internet gambling, the craps player can use whatever device he desires, as there is no visual supervision.
[0029] [0029]FIGS. 2 a and 2 b show a modified note pad 40 which includes several sheets 42 , having rows and columns of numbers imprinted thereon. The numbers preferably appear to be handwritten, and serve to allow the player to determine the appropriate bets once the board total, cumulative horn, and present pass/come bets are known. The note pad 40 should have a number of replaceable blank sheets 46 upon which the player can calculate the board total, cumulative horn, and present pass/come bets. The blank sheets 46 are on op of the sheets having predetermined list of numbers thereon 42 so that the pad appears, at a glance, to have no numbers imprinted thereon. The blank sheets 46 are custom designed to be removably replaced so that replacements must be special ordered, to enhance customer loyalty. For example, the sheets 46 may be ruled and have an adhesive across the top. Alternatively, the sheets 46 may have pre-arranged punch holes formed Herein, using non-standard spacing. Each page 48 containing a list of numbers is tabbed, the tab 50 indicating the range of numbers on that page. The tabs 50 are at the bottom of the page. Indica indicating the bet to be placed, e.g., horn, pass line, etc. are on the sliding member 52 which may also have a range of numbers imprinted on extending tab member 54 .
TABLE I BT + CH PH PC Initial Bet: $5 1 1 1 1 n/a $9 1 1 2 2 20 $35 4 4 8 8 65 $124 23 23 46 46 510
[0030] Referring now to Table I, an exemplary list of number sequences or roll formulas meeting the above mentioned criteria is shown. The player starts with the initial bet of 5 dollars on the pass line, and 1 each on the horn areas. If the player seven outs, he wins 1 dollar. If the player rolls any point, he will have lost 4 on the horn bet, and will have 5 on the board. Thus, in order for the next roll to net a profit, the roll will have to win more than 9 dollars, which covers the amount on the board (BT, 5 dollars) and the cumulative horn bet (CH, 4 dollars). The present horn bet PH (6 dollars) must also be covered by the present come bet for the next roll. Thus, the present come bet PC can be 20 dollars, as shown in line 2 of the list in Table I. The PH column of line 2 of Table I shows 2,2, 1,1, 20; corresponding to the bet amounts placed on the 2, 12, 11, and 3, areas of the horn (PH) plus the come bet (PC). It can be seen that the bets for the roll sums of 11 and 3 are exactly twice as high as the bets for the roll sums 12 and 2. These amounts reflect the fact that the payout odds are exactly double for the roll sums of 12 and 2, the objective being to ensure that exactly the same amount is won regardless of which of the horn bet roll sums is rolled. With these amounts, a horn bet win will result in a win of 30 dollars gross, less 3 dollars for the other horn bets, and 20 dollars for the present come bet (unless the horn is won with a roll sum of 11, in which case the 20 dollars placed on the come bet is won in addition to the 30 dollars won on the horn). Table T1 illustrates additional series of numbers or formulas which are consistent with the above mentioned constraints. It can be readily appreciated that the numbers can be varied, so long as the horn bet and the pass/come line bets are balanced as discussed above. In accordance with a preferred embodiment of the invention, a list of numbers having at least 200 entries is precalculated and printed onto the sheets 48 of the notepad, the numbers being made to look handwritten. With this scenario, the player does not have to calculate the actual bets to be made once the cumulative horn bet and board total is known. Since all casinos allow handwritten notes, the player will not look as if he/she is cheating when looking at the list to determine the appropriate bets. The player can keep track of the CH and BT on the blank sheets, the only calculations necessary being the incrementation of CH and BT, the number sequences having all other calculations presented for quick and easy access.
[0031] An electronic variation 100 of the inventive device, implementing the above discussed methodology is shown in FIG. 3. The device includes a housing 110 , having a keypad 112 and associated display 114 . The display 114 may be comprised of a plurality of LEDs, mounted behind a window 116 . The various bets are indicated by indicia 118 associated with the various areas located on the craps table 20 as discussed above. The keypad 112 includes a cursor which allows the bettor to enter numbers into each field. Microprocessor means (not shown) contained within the device 100 processes numbers entered via keypad 112 in accordance with the methodology of the invention. Alternatively, the keypad 112 may be simplified, and the device 100 pre-programmed to give the player sequences of betting combinations depending upon the total at risk (BT+CH), a desired profit margin for a given at risk total, or other criteria, continuing the progression until a seven is rolled, and restarting the progression when the bettor seven outs, or upon the occurrence of some other predetermined event. For example, the device operation may be further simplified by simply allowing the player to enter a starting pass line bet, and presenting the balancing horn bet on the display 114 . Thus, if the player enters a starting pass line bet of $5, the display will read as in line 1 of Table I. The player can continue to press a switch labeled, e.g., next ( 122 ), until she seven outs, whereupon she can press zero 124 , and start over. Each time the player presses the next roll button, the display will be incremented as in Table I, which is based on an initial bet of $5, with a relatively small average profit. The player can increase the average profit by pressing the increase profit switch 126 , whereupon she will be prompted on display 114 to enter a desired average profit for the next few rolls, with perhaps the average profit for the previous few rolls or roll sessions being displayed for quick reference.
[0032] Alternatively, the device 100 may be programmed to allow the player to enter any BT+CH, and generate a roll formula as shown in Table I. Again, the player may decide what the average profit will be for a few rolls at a time. Also, the device 100 may be programmed to calculate a maximum or minimum horn bet for a given board total.
[0033] Finally, in lieu of the device 100 , software for use on a PC may be used to emulate the device display and keyboard, creating the appropriate screen overlays as would be apparent to one of skill in the art in view of the above discussion.
[0034] In use, a player can start at a nominal initial betting amount such as 5 dollars. The player then places chips on the table in the amounts discussed above. If the player does not win the pass/come line bet, he may then total the chips on the board, add in the number of chips lost, and come up with a new total to be balanced which in this case would be 9 dollars. The player may use the replaceable blank sheets 46 to make the necessary calculations. Once the new total to be balanced is determined, the player then looks at the list, using tabs if necessary to get quickly to the correct page, and places bets accordingly. It should be noted that the numbers in table T1 allow a bettor to proceed sequentially, without making calculations, until a 7 or 11 roll sum is reached.
[0035] From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
[0036] It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims: | An apparatus and associated method which computes a betting strategy for a craps game based solely on the total amount the craps player wagers. The device comes in both a mechanical form and an electronic form. The mechanical form is configured to appear as a notepad in all respects and allows a player to select the total wager amount and provides instructions on which bets to place at selected areas of the craps table, and the suggested amounts. The electronic form is a microprocessor driven handheld device having a keypad to allow the bettor to manually enter the total amount to be wagered. A display driven by the microprocessor will have a plurality of fields corresponding to the areas of the craps table. In response to the entry of a valid total wager amount, numeric values are assigned to the various fields thereby informing the bettor of the suggested betting strategy | 0 |
The U.S. Government has rights in this invention pursuant to Contract NO. W-7405-ENG-48 between the U.S. Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.
BACKGROUND OF THE INVENTION
The present invention relates to a process for preparation of a seed layer for selective metal deposition on a substrate. More particularly, it relates to a process utilizing a laser for preparation of a seed layer for selective metal deposition.
Lasers and other directed energy sources such as ion and electron beams have been used to deposit and etch materials on surfaces. They have also been used to cause thin layers of materials to mix, alloy or react for various purposes. For example, U.S. Pat. No. 4,574,095 discloses the use of an excimer laser to deposit palladium onto a surface from a liquid precursor for the purpose of speeding a subsequent electroless plating process. Similarly, U.S. Pat. No. 4,701,347 teaches a method of laser depositing material from a metallorganic vapor which catalyses the subsequent deposition of metal on the laser-treated surface.
U.S. Pat. No. 4,555,301 discloses the use of a laser to cause the melting of a layer of nickel (Ni) on crystalline silicon (Si) to form substantially monocrystalline nickel silicide (NiSi2). Still another example, as disclosed in U.S. Pat. No. 4,495,255, is the use of a laser to cause alloying of gold (Au) with nickel (Ni) to form a good electrical connector. In addition, a pulsed laser is described in U.S. Pat. No. 4,877,644 which can be used to ablate a polymer masking layer off an underlying metal seed layer to permit deposition on that exposed metal.
The present invention relates to creation of plated metal interconnects from the surface of an integrated circuit (IC) chip, down the side of the chip, to contacts on the underlying silicon circuit board. Conductors are to be formed on the vertical sides of the chip, as well as on horizontal surfaces. Liquid precursors of a seed layer such as are used in U.S. Pat. No. 4,574,095 are unsatisfactory since they do not adequately cover the vertical surfaces on top edges. Liquid polymer precursors used in U.S. Pat. No. 4,877,644 are unsatisfactory of the same reason. Direct laser deposition of the entire conductor from the vapor phase has the disadvantage that deposition is too slow to be practical.
U.S. Pat. Nos. 4,555,301 and 4,495,255 describe alloying two or more materials, however, the laser step was not followed by a further deposition step.
U.S. Pat. No. 4,348,263 to Draper et al, discloses laser irradiation of a surface followed by electroplating, but the laser step does not form the alloy nor does it activate an otherwise inert surface for electroplating. The initial surface is active and the laser is only used to improve the surface morphology.
It would be desirable in the art to provide a process for activating a surface layer in a predetermined pattern suchh that metal could be selectively deposited thereon, and electronic circuits or interconnects formed. This invention is concerned with such a process.
SUMMARY OF THE INVENTION
It is an object of this invention to provide for preparation of a seed layer on a substrate, upon which a selective metal may be deposited.
It is a further object of this invention to provide a laser based process for preparation of an activated seed layer upon which a selective metal may be deposited.
It is a further object of this invention to provide an improved process for selective metal deposition on a substrate.
The foregoing and other objects of the invention will be apparent from the description and drawings to follow.
The invention encompasses the use of a laser or other directed source of energy to heat the surface area exposed to the energy source and convert it from an inactive state to an active one for the purposes of subsequent selective deposition of metal on the surface. In particular, a surface composed of an inert top layer and a metallic lower layer are caused to mix or alloy by the energy source, preferably a laser, to form a single layer which will allow a good electrical conductor to be electroplated onto it.
The invention, therefore, is a process for preparation of a seed layer upon which a metal can be selectively deposited which comprises:
a. formation of an initial surface comprised of at least two layers of material of which the uppermost is insert,
b. exposing surface to a source of heat in pre-determined places where surface activation is desired wherein said heat is applied at an energy level sufficient to form an alloy or mixture of and to activate said initial surface, and
c. depositing metal on activated portions of said surface.
IN THE DRAWINGS
FIG. 1 is a highly magnified perspective view of a typical semiconductor prepared in accordance with the process of this invention.
FIG. 2 is a cross-sectional view of a portion of a semiconductor before and after being subjected to the process of the invention.
FIG. 3 is a graph showing the operative range of a laser power as a function of thickness of the silicon layer.
FIG. 4 is a graph showing the operative range of laser power as a function of thickness of the gold layer.
DETAILED DESCRIPTION OF THE INVENTION
In carrying out the process of the invention (FIG. 2), a substrate 10 is first selected upon which it is desired to selectively deposit metal. Normally this will be a circuit board 12 or computer chip 14 or both. The substrate 10 is then covered with an adhesion layer 16, preferably a mixture of titanium (30%) and tungsten (70%). The titanium-tungsten (Ti-W) layer serves to promote adhesion between the metal and the silicon dioxide below it. Due to the refractory nature of this adhesion metal, it is preferred to pure titanium or chromium which are also commonly used for this purpose. In particular, it is found that this adhesion layer does not alloy or mix with the other materials during the process and therefore retains its integrity as an adhesion layer. After the adhesion layer 16 is applied a second metal layer 18 preferably gold (Au), is applied to the surface of the adhesion layer 16. The metal layer(s) should be thick enough to allow sufficient current to flow to all parts of the sample where electroplating occurs without significant drop in the voltage. Preferably, 4" diameter silicon wafers are used and 2000A of gold suffices. Much greater thicknesses only make the ultimate removal of the unplated structure more time consuming.
A further amorphous silicon insulator layer 20 is then applied to the surface of the second metal layer 18. At this stage (FIG. 2(a)), the coated substrate in inactive. That is, metal cannot be electroplated on top of the top surface silicon insulator layer 20 because it will not electrically conduct. Ideally, this top layer is applied as thin as posssible, consistent with its function of preventing plating on unirradiated areas.
Thereafter the inactive component 20, is irradiated with a laser 22 having a beam 24 being emitted therefrom (FIG. 2(b)). The direction of laser motion is indicated in FIG. 2(b) by an arrow. The preferred laser 22 for this purpose is a argon ion laser which is operated so that the beam 24 heats and melts the topmost inert layer 20, and underlying second metal layer 18, sufficient to cause intermixing of the components of the two layers to form an alloy or mixture 26 and thereby activate that portion of the layers 18 and 20 underlying the laser beam 24. The activation enables a subsequent plating metal 28, preferably copper (Cu), to be applied to the alloy 26 (FIG. 2(c)). It will bond to that area which has been activated by the laser.
In this manner, thick low resistance metallic lines and other structures can be plated to the coated substrate. It will have the circuit configuration of the activated alloy component 26 of the device.
A typical integrated circuit component 30 which can be produced in accordance with the method of the invention is shown schematically in FIG. 1. The circuit 30 comprises a substrate 30 upon which is positioned an integrated circuit chip 34 containing electronic circuits, not shown. A plurality of metallic interconnects 36 and 38 connect the integrated circuit chip 34 with other chips or buss lines, not shown. This component can be used in computers and other electronic devices.
While the preferred source of heat for activation of the surface layer is an argon ion laser, other sources can also be used such as pulsed eximer lasers and conventional flash lamps. If a flash lamp or excimer laser is to be used, it is necessary to place a mask over the surface layer whcih will allow exposure only in those areas of the surface layer in which activation is desired.
This invention will be more fully understood by reference to the specific examples which follow, which are intended to be illustrative of the invention, but not limiting thereof.
EXAMPLE 1
A series of 4" diameter silicon wafers were initially coated with silicon dioxide to simulate typical substrates prior to application of the seed layer structure. They were then coated with an adhesion coat, various thickness metal gold coats, and various thickness insulating amorphous-silicon coats.
After the insulating coat was applied, the wafers were subjected to an argon ion laser beam of power sufficient to cause the topmost insulating coat to mix with or be dissolved in the metal subcoat, thereby activating the seed layer. Thereafter the wafer was electroplated with copper. The copper plated only onto the activated material in the pattern created by the laser, thus forming an electronic circuit on the surface of the wafer.
The amorphous silicon renders the surface inactive to electroplating by virtue of the fact that it is an electrical insulator. The amorphous silicon is also a good absorber of the laser light. Thus, when exposed to the laser, the surface heats. When the surface becomes sufficiently hot, the layers mix. In this case, it is probable that the surface melts, but heating may also causing mixing by solid state diffusion. In other materials the heating may cause chemical reaction. When the laser exposure ceases, the surface cools rapidly, and tiny, dispersed silicon islands form in the solidifying gold matrix. The surface is now electrically conducting and can be electroplated easily, while areas not exposed to the laser continue to be insulating and will not plate. During the heating and cooling process the adhesion layer, being refractory, is substantially unaffected and retains its functionality. It is a further property of this layer that the molten gold-silicon wets it. Without this property, the molten metal tends to form beads and bands, leaving parts of the irradiated surface bare and inactive.
The preferred embodiment purposely does not use thicknesses of Au and silicon (Si) which approach eutectic composition (20 atomic % Si). Relatively large silicon fractions serve to provide superior light absorption, to increase protection against plating in unirradiated areas (e.g., because of pinholes), to prevent dewetting, and to increase the process margin (the range of laser fluence which can be used).
The attached graphs, FIGS. 3 and 4, summarize a series of tests which show laser powers which can be used with various material thicknesses. In FIG. 3 the thickness of the gold metal layer is always 2000 A and the Ti-W adhesion layer is approximately 400 A thick. The substrate consists of 6.5 μm of silicon dioxide on a 4" diameter silicon wafer of nominal thickness 525 μm. In FIG. 4 the silicon insulator layer thickness is always 4000 A and the Ti-W adhesion layer thickness is 400 A. The substrate consists of 6.5 μm of silicon dioxide on a 4" diameter silicon wafer of nominal thickness 525 μm. One of the very desirable properties of this structure is the extremely wide range (more than a factor of two) of lasers powers which can be used with various material thicknesses. Such wide margins make the process practical.
In the case of both silicon and titanium (see example 2 below) used as an insulating coat, a thin native oxide forms on the surface when the structure is exposed to air. This does not interfere with the laser processing, but it is sometimes advantageous to remove this oxide prior to electroplating using a hydrogen fluoride etchant containing vapor or liquid. The laser processing can be conducted in air, as well as in inert gas ambient. The HF treatment also removed the oxide so-formed, permitting successful electroplating of the laser-treated surface.
EXAMPLE 2
A series of silicon wafers were coated with an adhesion layer of Ti-W, followed by a layer of 2000 A of copper, then a 400 A layer of titanium. The titanium is itself a conductor, but it forms a strong oxide which prevents electroplating on areas which have not been exposed to the laser. In effect, then, the seed layer consists of four layers: Ti-W adhesion, copper metal, titanium metal and titanium dioxide insulator. The laser processing causes the titanium to dissolve in the copper, and the oxide layer is no longer present to prevent plating. The disadvantage with titanium structures is that the titanium is very reflective, so that much more laser power is required to initiate the process compared to silicon structures.
The foregoing description of preferred embodiments of the 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 teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications, as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended thereto. | Disclosed is a process for selective metal deposition comprising of the steps of:
a. formation of an initial surface on a substrate, said initial surface being comprised of at least two layers of which the uppermost is inert,
b. exposing the surface to a source of heat in pre-determined places wherein surface activation is desired, and
c. deposition of metal on activated portions of said surface. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional continuation patent application of Ser. No. 10/428,994, filed on May 5, 2003.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to laundry facilities. Specifically, a single device for both washing and drying clothes is disclosed using a common heat source for both washing and drying.
[0003] Commercial and home laundry facilities have typically required the use of separate appliances for washing and drying clothes, thereby dictating space requirements for the laundry facility. The machines are autonomous in that washing operations occur separate from drying operations, with independent washing and drying cycles and distinct operating controls of there own. A human operator must remove the clothes from the washer and load them in the dryer.
[0004] Commercial laundry facilities use larger capacity washing machines to wash clothes, linen and bedding. These facilities, including hospitals, nursing homes, hotels, etc., have a high volume of bedding, towels, and other common materials to wash and dry. Following the washing operation, an attendant must be available to transfer the washed materials to a separate large capacity dryer, and any delays in transferring the material results in a lower facility throughput.
[0005] The demands on commercial facilities for clean materials means that laundry facility throughput needs to be efficient and operating at a maximum level. The fact that washers and dryers are autonomous means that an attendant must promptly remove washed materials and load them in the dryer for maximum throughput efficiency, requiring the attention of at least one attendant who might otherwise be available for other tasks.
[0006] The high volume demands of these institutions typically means that a separate supply of hot water must be maintained on demand to meet the sanitary requirements for washing clothes which also impacts on space requirements.
[0007] The autonomous washing machine produces a load of centrifugally wrung materials which are transferred to a dryer at different times and at varying levels of moisture, depending on operator availability. In establishing an appropriate drying cycle, the beginning moisture level content of the wash load dictates, at least in part, the drying temperature and time for drying. In order to be certain that the drying temperature is at a safe level, so as not to scorch the dried materials, a lower, less than ideal temperature is set for the drying cycle. Accordingly, the drying cycle is longer and laundry throughput is lower than might otherwise be necessary due to each washed load having a different moisture content.
[0008] The present invention solves many of the foregoing problems which result from the use of separate autonomous washer and dryer appliances in a laundry facility.
SUMMARY OF THE INVENTION
[0009] The present invention provides for a single appliance and method for washing and drying clothes, particularly useful in a commercial laundry setting. In accordance with the invention, a combination washer/dryer is provided which has a common heat source for heating wash water and providing drying air during a drying cycle for the machine.
[0010] A sealed containment drum includes a rotating perforated clothes basket for rotating the load to be washed and dried. A water supply plenum extends around the rotating clothes basket and is in heat transfer relationship with a burner unit. The water plenum includes an outlet for discharging wash water through a controllable valve, as well as an inlet for receiving washing water. A drying air chamber extends from an opening in the top of the water plenum for delivering drying air from the heat source to the clothes basket, which passes through the perforated clothes basket to an exhaust chamber which discharges the moisture laden air.
[0011] In accordance with a preferred embodiment of the invention, the clothes basket is operated during a spin cycle to centrifugally remove a major quantity of water in the washed materials. In order to avoid caking, or compression of the wash load during a spin cycle, the spin cycle is alternately operated at a plurality of speeds, separated by pauses, to permit the clothing to separate from the wall of the perforated clothes drum.
[0012] In accordance with the preferred embodiment, a lint filter is supported in the exhaust chamber. The lint filter is cleaned by a jet of water directed to the lint screen, preferably prior to beginning a washing cycle, so that lint is forced from the filter surface down to the drain in the containment drum assembly to the waste water drain connection.
DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is a perspective view of a washer/dryer in accordance with a preferred embodiment of the invention.
[0014] FIG. 2 is a perspective drawing of the washer/dryer containment drum and burner for heating wash water and providing drying air.
[0015] FIG. 3 is a perspective view of containment drum.
[0016] FIG. 4 is a partial section view of the washing agent container and containment drum.
[0017] FIG. 5 is a top view of the washing agent container.
[0018] FIG. 6 is a side sectional view of washing agent container.
[0019] FIG. 7 is a sectional view of the containment drum and burner for heating wash water and supplying drying air.
[0020] FIG. 8 illustrates the washer/dryer cycle as a function of the clothes basket RPM.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring now to FIG. 1 , a perspective view of a washer/dryer in accordance with a preferred embodiment of the invention is shown. A housing 10 encloses a containment drum 11 which is open through the housing 10 and sealed by a door 14 . The containment drum 11 includes a rotating perforated basket 40 inside of a water plenum used for both washing and drying functions of fabrics which are loaded through the door 14 . Exhaust fan 15 provides a negative pressure to draw the moist drying air from containment drum 11 , and expelling the drying air through the exhaust 13 during the drying cycle.
[0022] A washing agent container 16 receives washing detergent, bleach, and other washing agents through door 17 , and as in a conventional washer, hose 18 carries the contents of the washing agent container 16 to the containment drum 11 . The plurality of waterjets 20 are cyclically operated by controller 12 to wash the contents of each compartment of the washing agent container 16 through the outlet hose 18 . Jet 21 periodically flushes the washing agent container 16 .
[0023] Controller 12 provides commands to a motor drive for rotating the basket within containment drum 11 in both washing and drying cycles to produce the washing/drying cycle of FIG. 8 . Additionally, the controller 12 commands an on-board heater to generate heat at the appropriate times during the washing and drying cycles. Temperature sensors within the exhaust 13 and containment drum 11 provide feedback to the controller 12 so that temperatures are maintained at predetermined levels which can sanitize the washing load, and which establish optimum drying temperatures while avoiding excessive temperatures which can damage clothing.
[0024] FIG. 2 is a perspective view of the washer/dryer with the housing 10 removed. The containment drum 11 is supported in a frame 29 . Frame 29 is supported via spring 26 to a base 25 . Vibrational forces produced by the rotating basket 40 within containment drum 11 are dampened by shock absorber 27 . Additionally, a front face plate 30 of the containment drum supports the sealed door 14 .
[0025] The burner assembly 22 is supported on a burner support 23 fixed to the base 25 . The burner assembly 22 includes burner tubes 21 which supply heat to the containment drum 11 during the washing and drying cycles.
[0026] FIG. 3 is a rear perspective view of the containment drum 11 . The shaft 33 for supporting and driving the rotating basket is coupled to a motor (not shown) operated under control of controller 12 . The containment drum 11 has a drain 34 which is coupled via a flexible coupling 35 to a motor operated valve 36 . The motor operated valve 36 is also under control of the controller 12 for discharging wash water at the end of a wash cycle, rinse cycle and spin dry cycle. Also shown is flushing port 38 connected to a water supply valve (not shown) which operates under control of controller 12 for periodically providing a jet of water for ejecting the lint washed from the lint screen through the S shaped trap formed by drain 34 , flexible coupling 35 and valve 36 .
[0027] The exhaust fan 15 is shown with the exhaust outlet 13 removed. A drip channel 42 collects water during the spin cycle of the washer/dryer and returns the water back to the water plenum containing the rotating clothes basket.
[0028] FIGS. 4-6 are sectional views illustrating the washing agent dispenser compartment 16 with respect to the containment drum 11 and rotating basket 40 . A water inlet 24 supplies water through a solenoid valve under control of the controller 12 to the dispenser compartment 16 which drains due to gravity to the containment drum 11 through outlet 18 . The various washing agents are placed in each of the removable compartments 41 a , 41 b , 41 c , 41 d , and 41 e . Rotation of the door 17 to pivot along the lower edge allows access to the washing agent compartments 41 a , 41 b , 41 c , 41 d , and 41 e . Each individual washing agent compartment is arranged below the jets 20 a , 20 b , 20 c , 20 d , and 20 e . The controller 12 controls a plurality of solenoid valves connected to the various jets 20 to rinse the compartments 41 a - 41 e at the appropriate time where washing agents are dispensed through outlet 18 into the containment drum 11 .
[0029] The operation of the combination washer/dryer is now described with respect to FIGS. 7 and 8 . Referring now to FIG. 7 , a sectional view of the washer/dryer is shown. The containment drum 11 includes the rotating perforated basket 40 holding the wash load. During the washing cycle, the water level is established within a water plenum 46 in the containment drum as shown. The water plenum 46 is joined at an opening 49 at the top of the water plenum with the hot air supply plenum 47 . An opening in the bottom of the water supply plenum 46 is joined with an exhaust plenum 48 . During washing, the illustrated water level is confined in the water plenum 46 and the lower portion of the exhaust plenum 48 .
[0030] Burner assembly 22 is in heat transfer relationship with water plenum 46 within the containment drum 11 . The burner 22 is operated cyclically under control of the controller 21 to heat water within the water plenum 46 and lower portion of exhaust plenum 48 to a predetermined programmed temperature level, including a sanitizing level as set forth by various regulatory bodies. A temperature sensor 43 provides temperature feedback information to controller 12 so that the correct temperature is established for the washing solution.
[0031] The rotating basket 40 reciprocates as is common in most side loading washing machines for a period of time to efficiently clean the load. Once the wash time has timed out in controller 12 , the water is drained from the water plenum 46 through the drain 34 , and the washer/dryer enters the first spin drying mode.
[0032] As will be clearer with respect to FIG. 8 , the rinse cycle re-establishes the water to a predetermined programmed level. Once the wash load is rinsed, the water is again drained, and the washer/dryer enters the final spin drying mode under the control of the controller 12 . The basket 40 is rotated at a multiplicity of speeds, coming to rest between each level of rotational velocity so as to prevent the wash load from adhering to the circumference of the clothes basket 40 .
[0033] The centrifugally wrung wash load has approximately 50% of the moisture removed from the wash load. During the centrifugal drying of the wash load, moisture spun from the clothes basket 40 may collect in channel 42 where it is returned by gravity to the water plenum 46 and to the drain 34 .
[0034] The drying cycle utilizes heat from burner 22 under control of the controller 12 to dry the moisture laden wash load. The hot air supply plenum 47 is formed between the outside wall 28 of the containment drum 11 and a wall 44 of the water plenum 46 . Hot air from the burner 22 rises through the hot air supply plenum 47 and enters the perforated clothes basket 40 at the top of the hot air supply plenum 47 through an opening 49 in the top of water supply plenum 46 . The hot moisture laden drying air is then withdrawn through the bottom of the clothes basket 40 through exhaust plenum 48 . The exhaust plenum 48 extends vertically from lower opening in water plenum 46 substantially diametrically opposite the end of the hot air supply plenum 47 . Fan 15 applies a negative pressure to the opposite end of the exhaust plenum 48 drawing moisture laden air from the perforated clothes basket 40 through the exhaust plenum 48 . The temperature of the drying air is monitored by sensor 45 which is connected to the controller 12 and is disposed at the top of the hot air supply plenum. The drying air temperature is regulated by controller 12 which cycles burner 22 in response to the measured air temperature so as not to exceed a predetermined programmed limit which will damage the wash load 7 . Since the initial conditions for drying including the moisture content of the load are fairly constant between loads, controller 12 may enter a drying routine with a drying temperature profile at its maximum drying efficiency and below a level which will damage the wash load.
[0035] A feature of the embodiment in accordance with FIG. 7 includes a lint trap having a filter 51 supported on a tray 50 which can be removed via handle 52 from the exhaust plenum for periodic inspection. Additionally, prior to starting the wash cycle, a water jet 59 may be operated by controller 12 to direct water on the filter forcing lint from the underside of filter 51 . The lint collects in a water pool at the bottom of water compartment 46 . Drain valve 36 is opened by controller 12 and a solenoid operates water valve connected to nozzle 38 is opened forcing the lint load and water to be ejected through drain 36 .
[0036] The washer/dryer in accordance with FIG. 7 maybe advantageously operated to provide for a wash/drying cycle under control of controller 12 as shown in FIG. 8 where the wash/dry cycle for the washer/dryer is illustrated with respect to the clothes basket 40 RPM.
[0037] The temperature for drying may be optimized for the finished wash load. Since the moisture content is at a known predetermined level, the drying temperature can be safely raised to a higher level than was previously utilized without incurring unacceptable risks of a fire or damage to a wash load.
[0038] The sequence of washing and drying begins by activating jet 59 for 5-10 seconds thereby forcing any lint collected on the lint filter 51 into the water plenum 46 and into the drain 34 . The drain valve 36 is opened by controller 12 , and the ejection nozzle 38 supplies a high velocity stream of water for 5-8 seconds flushing any collected residue through the drain 34 .
[0039] Following the cleansing of the lint filter 51 and operation of the drain valve, the containment compartment water plenum 46 is filled with wash water to the level shown in FIG. 7 by controller 12 to a predetermined programmed level. The controller 12 then enters a heating mode and enables burner assembly 22 to heat the water in water compartment 46 until the desired temperature is reached.
[0040] A wash cycle is entered and the basket is alternately rotated in each direction for a period of time selected by the user through controller 12 . Following the wash cycle, the drain valve 36 is opened and water drains from the water compartment 46 . The machine may then enter a spin cycle to centrifugally force water from the clothes into the drain 34 .
[0041] A rinse cycle commences for a period of time set in controller 12 . The water plenum 46 is refilled and the water is heated to an appropriately selected temperature set by controller 12 . The clothes basket 40 is then rotated in alternate directions for the duration of the rinse cycle. Following the rinse cycle, the drain valve 36 is reopened to drain the rinse water.
[0042] The spin cycle centrifugally removes 50% of the moisture in the load by initially rotating the clothes basket 40 at about 450 RPM. In order to prevent caking of the laundry load along the surface of the rotating basket 40 , a first pause is entered in the spin cycle for 5-10 seconds, wherein, in the preferred embodiment, the clothes basket 40 stops rotating. At this time, the clothes will drop from the exterior surface of the clothes basket 40 due to the force of gravity. The clothes basket is then operated at a second RPM, at least as high as the initial RPM of 450 RPM, but preferably at a higher RPM of about 750 RPM, to continue centrifugally drying the clothes. The spin cycle is again paused, to permit the clothing to drop from the surface of the clothes basket 40 preventing caking of the clothes to the surface of clothes basket and clumping together in a compact mass. Following a second pause of 5-10 seconds, the clothes basket is rotated through multiple steps to a final spin RPM. The final spin interval, being longer than the first two spin intervals, lasts approximately 4-5 minutes.
[0043] The foregoing sequence produces a load of an approximate known moisture content. The beginning of the final heated drying cycle therefore represents moisture conditions which are predetermined and constant from load-to-load. Accordingly, from the known starting point of moisture content, it is possible to select a final optimum drying temperature profile to minimize the time for drying, while maintaining a safe temperature margin for the wash load.
[0044] The heated drying cycle begins by actuating valve 36 by closing the drain. The drying cycle may be of the reversing type, wherein the clothes basket 40 is rotated in alternate directions for a predetermined period of time. Following a drying cycle of 30-60 minutes, a cool down cycle is begun wherein the temperature profile of the load is decreased for 3-5 minutes to reduce the possibilities of spontaneous combustion of line lints.
[0045] The completion of the drying cycle is signaled by the controller 12 to the facilities operator. From the beginning to end, operator intervention was unnecessary, and personnel involved in the laundry facility are permitted to engage in other tasks. Since the complete washing/drying cycle is automated, maximum throughput efficiency for the facility may be obtained.
[0046] The foregoing description of the invention illustrates and describes the present invention. Additionally, the disclosure shows and describes only the preferred embodiments of the invention in the context of a combination washer/dryer having common heat source, but, as mentioned above, it is to be understood that the invention is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the invention. Accordingly, the description is not intended to limit the invention to the form or application disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments. | The combination washer/dryer and method for operating a combination washer/dryer. The washer/dryer has a containment drum which receives wash water, and includes a perforated clothes drum which rotates within the containment drum. A heat plenum is provided in heat transfer relationship with the containment drum, and a source of heat coupled to the heat plenum supplies heat for water in the containment drum. During a drying cycle, hot air from the heat source supplied from the fire box to the containment drum for heating wash water during a washing cycle, and for supplying hot air during a drying cycle. A drying air plenum is connected to receive drying air from the source of heat, delivering the drying air to the top of the containment drum, where it enters the rotating basket. An exhaust plenum discharges hot air laden with moisture from the containment drum through a lint filter. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation of International Application Serial No. PCT/DE92/00303, filed Apr. 13, 1992.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a burner for fluid fuels, particularly oil, natural gas and/or coal gas, of the kind used for gas turbines.
In view of the worldwide efforts to lower the emissions of pollutants from furnace systems, in particular gas turbines, burner configurations have been developed in recent years that have especially low emissions of nitrogen oxides (NOX). Often, emphasis is placed on the capability of such burners to function with not merely a single fuel, but rather with the most varied possible fuels, such as oil, natural gas and/or coal gas, selectively or even in combination, in order to increase the reliability of a fuel supply and flexibility in operation. Such burners are described in European Patent No. 0 276 696 B1, for example.
One problem in constructing burners for all possible, different operating conditions and fuels is that the volumes of the various fuels required for operation in a given case are completely different, which makes it difficult to use the same delivery system and the same injection openings for all fuels. It is therefore known in the prior art to use different delivery systems for liquid and gaseous substances. However, another problem arises then if selective gaseous fuels with completely different specific gross calorific values, such as natural gas and coal gas, are to be used. The completely different volumetric situations when those two fuels are used, and the different chemical processes in their combustion, require modification or expansion of the known systems.
In a published paper entitled "The Development of Integrated Coal-Gasification Combined-Cycle (ICG-GUD) Power Plants" by John S. Joyce, read on Apr. 26, 1990 in Arnheim (a written version was distributed), FIG. 4 describes a burner that is selectively suitable for combusting natural gas or gas with a low specific gross calorific value. In that configuration, however, there is a diffusion burner for both fuels, which in the case of operation with natural gas leads to higher NOX emissions than would be the case with a premixing burner.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a burner configuration, particularly for gas turbines, for the low-pollutant combustion of coal gas and other fuels, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type, which is suitable for combusting both burnable gas with a low gross calorific value and a diffusion flame and burnable gas with a high gross calorific value, and/or for combusting oil in a premixing mode. The operational reliability of the known configurations should be preserved, and the additional expense for equipment should be low. The systems should not mutually have any negative impact on the quality of combustion, and in particular undesired flame development at turbulence points in the system upstream of the actual combustion zone should be avoided.
With the foregoing and other objects in view there is provided, in accordance with the invention, a burner configuration, comprising approximately concentrically disposed annular conduits for delivering various operating media; an approximately conically tapering outer annular-conduit air delivery system; a plurality of outlet nozzles for admixing a gaseous medium or a liquid medium in finely distributed form with an air flow flowing in the annular-conduit air delivery system; and a further annular conduit on an inflow side discharging into the annular-conduit air delivery system above the outlet nozzles.
The invention is based on the recognition that in the combustion of burnable low-BTU gas, none of the special provisions for lowering the pollutant emissions are necessary, since very high flame temperatures do not occur when such gases are combusted, and therefore NOX formation remains virtually insignificant. It is therefore sufficient to create a further simple delivery system, but care must be taken to assure that this system will neither negatively impact the other systems, nor reduce the operational reliability of the other systems. It is therefore important for the further annular conduit to discharge on the inflow side above the outlet nozzles for the other fuels. In this way, an ignitable mixture cannot reach the further annular conduit if the burner is supplied with fuel of a different type through the outlet nozzles.
In accordance with another feature of the invention, the further annular conduit conforms to the other annular conduits for delivering the operating media, so that the further annular conduit discharges on the inside into the annular-conduit air delivery system.
In accordance with a further feature of the invention, the supplemental delivery system for a further fuel may in particular be combined with an annular-conduit air delivery system, which has a system of swirl vanes on the downstream side, below or inside which outlet nozzles for a liquid medium are disposed. Alternatively or additionally, a combination with a plurality of outlet nozzles for a gaseous medium is possible. It is especially advantageous to provide the outlet nozzles for a gaseous medium in the swirl vane system itself.
Therefore, in accordance with an added feature of the invention, the swirl vanes are constructed as hollow vanes and are connected to a delivery system for a gaseous medium. A plurality of outlet nozzles at the swirl vanes, which are preferably oriented approximately perpendicularly to the locally prevailing flow direction at any given time, enables uniform admixture of a gaseous medium with the air flow. In addition, nozzles of various diameters, enabling the range of the emerging streams to be correspondingly varied, may also be used.
In accordance with an additional feature of the invention, the primary application for utilizing the further annular conduit is the delivery of a burnable gas with a low specific gross calorific value (low-BTU gas), in particular coal gas.
In accordance with yet another feature of the invention, the annular-conduit air delivery system and the further annular conduit in principle form a diffusion burner for combusting low-BTU gas with air.
Although a certain premixing does occur over the relatively long distance to the actual combustion zone, nevertheless it is not of the extent known with premixing burners. In particular, from directly downstream of the mouth of the further annular conduit to the region of the swirl vane system, undesired ignition of any mixture of air and burnable gas that may possibly have arisen need not be expected.
In accordance with yet a further feature of the invention, the outlet nozzles and the further annular conduit have means for preventing recirculation of at least one of the gaseous and liquid media into the further annular conduit.
In accordance with yet an added feature of the invention, the further annular conduit discharges directly above the swirl vane system, for preventing ignition in the vicinity of the swirl vane system.
In accordance with yet an additional feature of the invention, the gaseous medium is natural gas or water vapor and the liquid medium is oil or water. The main operating modes of a burner according to the invention can be found in a table given in FIG. 2. In principle, combinations of the primary operating modes shown therein are also possible.
In accordance with a concomitant feature of the invention, there are provided approximately concentrically disposed inner delivery conduits for delivering air and at least one of gaseous fuel and liquid fuel to produce a pilot flame stabilizing a flame of the entire burner configuration.
It should be noted that in order to stabilize the combustion flame in the burner configurations according to the invention, a pilot burner system, which maintains a central stable flame, as is known in various forms in the prior art, will generally be required. Any known pilot burner system is suitable for this purpose, but naturally it is especially preferred that the pilot burner be operable with the same fuel as the main burner. This is also shown in the table.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a burner configuration, particularly for gas turbines, for the low-pollutant combustion of coal gas and other fuels, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, diagrammatic, longitudinal axial-sectional view of a virtually rotationally symmetrical configuration of a preferred exemplary embodiment of the invention; and
FIG. 2 is a table showing primary options for operating modes of a burner configuration according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen a diagrammatic, longitudinal axial section through a burner configuration of the invention, with European Patent Nos. 0 276 696 B1 and 0 193 838 B1 being expressly incorporated by reference, to the extent that not absolutely crucial details of the configuration are involved. It should be noted that the configuration of the prior art in European Patent No. 0 276 696 B1 is altered by an advantageous modification and expansion by means of an annular conduit 16 and by shifting outlet nozzles for natural gas to a swirl vane system.
The burner configuration, which can be used in the combustion chamber of a gas turbine system for instance, optionally in combination with a plurality of identical configurations, includes an inner part, which is a pilot burner system, and an outer part that is concentric with it, which is a main burner system. Both systems are suitable for operation with gaseous and/or liquid fuels in an arbitrary combination. The pilot burner system includes a central oil delivery 1 (for a medium G) and an internal gas delivery conduit 2 (for a medium F) disposed concentrically around it. The internal gas delivery conduit 2 is in turn surrounded by a concentrically disposed inner air delivery conduit 3 (for a medium E). In or at this conduit 3, there may be a suitable ignition system, for which many possible embodiments are known and which need not be described in detail herein. The central oil delivery 1 has an oil nozzle 5 at its end, and the inner air delivery conduit 3 has a system of swirl vanes 6 in its end region. The pilot burner system 1, 2, 3, 5, 6 may be operated in a manner that is known per se.
The main burner system includes an outer annular-conduit air delivery system 4 that is disposed concentrically to the pilot burner system and extends obliquely toward it. This annular-conduit air delivery system 4 is likewise provided with a swirl vane system 7. The swirl vane system 7 includes hollow vanes with outlet nozzles 11 in a flow cross section of the annular-conduit air delivery system 4 (for a medium A). These nozzles are fed from a delivery line 8 and an annular conduit 9 through openings 10 for a medium B. In addition, the burner has a delivery line 12 for a medium C that discharges into an annular conduit 13, which has outlet nozzles 14 for the medium C in the region of or below the swirl vane system 7. A spray stream 15 of the medium C is also shown diagrammatically in the drawing. According to the invention, the burner additionally has the annular or further coal gas delivery conduit 16 (for a medium D). This conduit 16 discharges just above the swirl vane system 7 having the outlet nozzles 11, into the outer annular-conduit air delivery system 4, specifically on the inside thereof, so that in principle the two together form a diffusion burner. In this respect, it is important that in operation with the medium B, for instance natural gas, it is not possible to recirculate this medium at edges or into the coal gas delivery conduit 16, which could impair the operational reliability. Moreover, the coal gas delivery conduit 16 should not impede the flow below its entry, in order to preserve unchanged the good combustion properties for the media B and C. If the coal gas delivery conduit 16 were to discharge below the outlet nozzles 11 for the medium B or the outlet nozzles 14 for the medium C, the result would be a widening of the cross section at this point and a hindrance to the peripheral flow, both of which would be undesirable. The configuration of the coal gas delivery conduit 16 and of the hollow vanes in the form of the swirl vane system 7 according to the invention, requires only slight modifications of the burner system of the prior art and can therefore be structurally achieved at little effort or expense.
The table in FIG. 2 shows the options available for the selection of media and thus for various operating modes of the burner configuration. It may be operated with natural gas, coal gas or some other low-BTU gas, as well as with oil, in order to achieve advantageous properties in each case for pollutant emissions. If a further reduction of pollutant emissions is desirable in one of the operating modes, then an inert substance, particularly water or steam, or optionally additional substances if desired, can optionally be delivered through the systems that are not required for fuel delivery in this operating mode. The switchover of the various delivery systems to the variously desired media may be achieved by simple multiposition fixtures, which are known in the prior art. The expense for equipment remains low even though the most environmentally favorable possible mode of combustion is achieved for each fuel. In particular, NOX emissions are minimized in all operating modes. | A burner configuration includes approximately concentrically disposed annular conduits for delivering various operating media. A plurality of outlet nozzles admix a gaseous medium or a liquid medium in finely distributed form with an air flow flowing in an approximately conically tapering outer annular-conduit air delivery system. A further annular conduit on an inflow side discharges into the annular-conduit air delivery system above the outlet nozzles. | 5 |
FIELD OF THE INVENTION
[0001] This invention relates to the field of hydrocarbon extraction and more particularly to the extraction of heavy oil from underground formations. Particularly, this invention relates to a multi-step heavy oil extraction technique to be used, for example, after primary extraction is no longer effective. Most particularly this invention relates to a solvent based multi-step enhanced extraction process for heavy oil.
BACKGROUND OF THE INVENTION
[0002] Heavy oil is a loosely defined term, but heavy oil is generally understood to comprehend somewhat degraded and viscous oils that may include some bitumen. Heavy oils typically have poor mobility at reservoir conditions so are hard to produce and have very poor recovery factors. Heavy oil is generally more viscous than light or conventional oil, but not as viscous as bitumen such as may be found in the oil sands. Heavy oil is generally understood to include a range of API gravity of between about 10 and 22 with a viscosity of between about 100 and 10,000 centipoise. For the purposes of this specification the term heavy oil shall mean oil which falls within the foregoing definition.
[0003] Heavy oil exists, in situ, in large quantities, but is difficult to recover. A recent (2003) estimate of the resource by the US Geological Survey, using an estimated recovery factor of 19% puts the theoretically recoverable heavy oil in North America alone at 35.3 billion barrels. This USGS estimate implies that the total domestic North American heavy oil resource is about 200 billion barrels and that more than 80% of this domestic heavy oil is unrecoverable using the best currently available extraction process technology. The USGS report also implies that the worldwide heavy oil resource is 3.3 trillion bbls and that 87% of this resource is unrecoverable or “stranded” with current technology. The commercial opportunity for a better extraction technology is therefore substantial. More specifically, an advance in extraction technology which raises the recovery rate of heavy oil from the current 13% level to only 25%, would contribute an additional 400 billion bbls of recoverable oil worldwide.
[0004] The bitumen containing oil sands of Canada have received a much attention due to their immense store of hydrocarbon. However, it would only take a tiny change in the average recovery factor for worldwide heavy oil from 13% to 18% of oil in place to provide an equivalent amount of oil to that which is considered recoverable from the Canadian oil sands. With concerns about peak oil and a limited scope for new reservoir discovery, the ability to recover stranded heavy oil is becoming increasingly important. Furthermore, being able to recover additional oil using energy efficient extraction technology is also very desirable. Solvent has long been recognized to have the theoretical potential to mobilize and recover the stranded heavy oil. Solvent would potentially not require the application of high temperatures and consequent liabilities of high energy consumption and greenhouse gas emissions which plague steam driven bitumen extraction processes for example.
[0005] It is currently understood by those skilled in the art, based on best available computer simulation models, that solvent diffuses quickly and deeply into in situ heavy oil. This is evident in the published results from computer simulations (Tadahiro et al, May 2005 JCPT pg 41, FIG. 18) that shows propane solvent penetrating 8 meters (25 feet) beyond the edge of a vapour chamber into a 5200 cp heavy oil. Similarly Das (2005 SPE paper 97924 FIG. 12) comments that it is realistic to expect propane solvent will penetrate 5 meters beyond the edge of the chamber in an Athabasca reservoir.
[0006] However, lab studies by the inventor (Nenniger CIPC paper 2008-139, FIGS. 1 and 2) have shown that the solvent extraction mechanism for heavy oil and oil sands is quite different than as predicted by the computer simulations. In particular, rather than easily diffusing deep into an oil bearing zone, the solvent is observed to form a well defined interface with undiluted oil at what might be called a concentration shock front. The concentration shock front arises because the solvent has a very difficult time diffusing or penetrating into the high viscosity oil like heavy oil or bitumen. In a sandpack experiment, the inventor observed asphaltene deposition within a pore length of the raw bitumen, which means that the concentration gradient is extraordinarily steep over a very small length scale.
[0007] The physical length scale of the dissolution process of solvent into heavy oil observed is that of individual pores, which are about 100 microns long in 5 Darcy sand. It seems reasonable to assume that two miscible hydrocarbon fluids such as oil and solvent should mix quickly and fairly easily as shown in the simulations of Tadahiro and Das. Consequently, the experimental observation of a concentration shock was surprising and unexpected. More specifically, the observation of a concentration shock front indicates that conventional wisdom regarding rapid dilution of heavy oil and bitumen via solvent diffusion is incorrect.
[0008] Many attempts have been made in the prior art to develop solvent based extraction processes. For example, U.S. Pat. No. 5,720,350 teaches a method for recovering oil left behind in a conventional oil reservoir after the original conventional oil has been recovered. This process uses gravity drainage from a formation in which an oil miscible solvent having a density slightly greater than a gas contained in a gas cap is injected above the liquid level in the formation. Following solvent injection the production of oil is commenced from a lower portion of the formation. The idea seems to be that the solvent sweeps the remaining oil to the production well. However, conventional recoveries are generally very good meaning that 30 to 60% or more of the oil in place can be recovered, consequently very large and potentially uneconomic volumes of solvent may be required to recover any significant portion of the remaining oil.
[0009] U.S. Pat. No. 5,273,111 teaches a laterally and vertically staggered horizontal well hydrocarbon recovery method, in which a continuous process is used combining gravity drainage and gas drive or sweep (ie pressure drive) to produce the oil from a specific configuration of vertical and horizontal wells. The configuration of the wells is said to be optimized to reduce coning and solvent breakthrough between the wells, but the use of a gas drive or sweep will result in preferential recovery through the higher permeability portions of the reservoir. Thus, even if the coning and solvent breakthough is reduced, it will still be significant, meaning that the drive process will likely bypass much of the stranded oil.
[0010] U.S. Pat. No. 5,065,821 teaches a process for gas flooding a virgin reservoir with horizontal and vertical wells which involves injecting a gas through a first vertical well concurrently with performing a cyclical injection, soak and production of gas through a horizontal well, to eventually establish connection to the vertical well, after which time the vertical well becomes the production well and the horizontal well becomes the injection well. Again this process teaches the continuous solvent gas injection (i.e. a pressure drive) through the reservoir once connection is established between the wells. During the initial steps, into a virgin reservoir it will be very difficult to get the solvent to diffuse into and dilute the oil making this process slow and impractical.
[0011] Canadian patent application 2494391 to Nexen discloses a further solvent based extraction technique which uses a continuous solvent injection or extraction of the type that may be characterized as a solvent sweep or drive with a pattern of horizontal and vertical wells. Again, however, any attempt to push out the oil with a solvent drive process is anticipated to lead to rapid coning, short circuiting, by-passing and only marginal recovery.
[0012] Notwithstanding these and many other prior attempts to perfect a solvent based extraction process for heavy oil, the results remain unsatisfactory. There is a clear need for a different and better understanding of how to effectively use solvent to improve heavy oil recovery, in a way that reduces bypassing of stranded heavy oil. What is desired is a solvent extraction process which comprehends this understanding of how slowly the solvent penetrates into the in situ heavy oil and addresses this problem directly.
SUMMARY OF THE INVENTION
[0013] The initial penetration of solvent into oil is now understood to be extremely slow. On the other hand, as soon as a small amount of solvent perhaps only one or two percent, has diffused into the oil held within in a particular pore, in a pay zone, the subsequent dilution of the partly diluted oil is very rapid. This results in a distinct solvent/diluted oil to heavy oil interface that advances slowly across the pay zone of a reservoir, on a pore by pore basis. The present invention teaches a method and process which comprehends this slow solvent front propagation and consequently has an objective of allowing effective and predictable mobilization and recovery of large volumes of stranded in situ heavy oil.
[0014] The present invention recognizes how difficult it is to achieve uniform dispersal of the solvent within the pay zone of the heavy oil reservoir and provides certain process steps to encourage solvent dilution and homogeneity. The presence of the shallow penetration and steep concentration gradient at the shock front means that the rate of solvent dilution into the stranded oil on a reservoir wide basis is limited by two key variables, namely the amount of stranded oil interfacial area available to the solvent and the amount of time the solvent is exposed to the interfacial area of the stranded oil. The degree of solvent dilution into the heavy oil determines the change in viscosity of the solvent oil blend, which in turn is directly related to the mobility of the heavy oil blend in the reservoir and the ability to recover the same through gravity drainage from a production well.
[0015] According to the present invention a process which maximizes the opportunity for dilution of the heavy oil with solvent will maximize the opportunities for recovery of the stranded heavy oil.
[0016] The present invention therefore consists of a procedure having several steps, including, increasing the interfacial area by removing solvent blockers from the voids created in the reservoir by the primary extraction process. Clearing out the voids allows more solvent to be placed in the reservoir permitting more solvent to contact more stranded oil thereby enabling the extraction process to proceed at much higher rates than would be possible in a virgin reservoir or even a partially extracted reservoir having voids filled with solvent blocking reservoir fluids and gases. Furthermore this invention comprehends providing enough exposure time for the solvent and oil in a ripening step to permit the solvent to slowly but adequately penetrate into oil filled pores and achieve a reasonable degree of homogeneity or dissolution at a micro scale level, throughout the reservoir. According to an aspect of the present invention the degree of in situ ripening is measurable to permit a determination of when to proceed to the next step of the extraction process, which is the actual production of the oil from the reservoir, through gravity drainage.
[0017] Therefore according to the present invention there is provided, in one aspect, a multi-step in situ extraction process for heavy oil reservoirs, said process using a solvent and comprising the steps of:
a. Removing liquids and gases from areas in contact with said heavy oils to increase an interfacial area of unextracted heavy oil contactable by said solvent; b. Injecting said solvent in vapour form into said areas to raise the reservoir pressure until sufficient solvent is present in a liquid form to contact said increased interfacial area of said heavy oil; c. Shutting in said reservoir for a sufficient period of time to permit said solvent to diffuse into said unextracted oil across said interfacial area in a ripening step to create a reduced viscosity blend of solvent and oil; d. Measuring one or more reservoir characteristics to confirm the extent of solvent dilution that has occurred of the unextracted oil in the reservoir, and e. Commencing gravity drainage based production from said reservoir upon said blend having a viscosity low enough to permit said blend to drain through said reservoir to a production well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Reference will now be made, by way of example only, to preferred embodiments of the present invention by referring to the following figures, in which:
[0024] FIG. 1 shows a representation of target heavy oil reservoir with a horizontal well positioned near the bottom of the pay zone and a vertical injection well.
[0025] FIG. 2 is a graph of permeability in milli-darcies against total permeability for a typical heavy oil reservoir;
[0026] FIG. 3 is a graph of reservoir pressure vs. time for a sample reservoir according to the present invention;
[0027] FIG. 4 shows a viscosity vs temperature graph for various solvent to oil ratios of solvent diluted heavy oil;
[0028] FIG. 5 shows a plot of the vapour pressure of a specific solvent, ethane, as a function of volume fraction of ethane dissolved in a heavy oil, according to the present invention;
[0029] FIG. 6 shows the time in days for the solvent to travel a specified distance through a heavy oil reservoir by dilution of the heavy oil according to the present invention;
[0030] FIG. 7 shows a calculated oil production rate for an 800 m long horizontal well with 10 m of pay as a function of the degree of dilution of the solvent in oil for an average 1 Darcy permeability reservoir according to the present invention;
[0031] FIG. 8 shows a calculated oil production rate for a 800 m long horizontal well with 10 m of pay as a function of the degree of dilution of the solvent in oil for an average 7 Darcy permeability reservoir according to the present invention;
[0032] FIG. 9 shows the calculated solvent cost per cubic meter of oil recovered for the 7 Darcy heavy oil reservoir of FIG. 7 , as a function of the volume fraction of solvent in the oil (in this case ethane or C2) assuming the solvent is eventually recovered during the blowdown according to the present invention.
[0033] FIG. 10 shows the reservoir pressure versus time according to the present invention in the case where the solvent which is coproduced with the oil is not subsequently re-injected back into the reservoir; and
[0034] FIG. 11 shows the calculated injection and production volumes as a function of time for the extraction process of the present invention when applied to a reservoir having an active aquifer or other type of pressure support, so that the reservoir pressure is effectively constrained to a constant value.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] This present invention is most applicable to heavy oil reservoirs which have undergone a primary extraction and also which demonstrate good confinement. According to the present invention the primary extraction has resulted in an oil extracted region in the reservoir having either gas or water filled voids. A preferred reservoir has had a primary extraction which has recovered between about 5% and 25% of the original oil in place with a most preferred amount being between 8% and 15%. Most preferably a suitable target reservoir will have a significant pay thickness without extensive horizontal barriers so that when the viscosity of the in situ heavy oil is sufficiently reduced, gravity drainage can occur. While a primary extracted reservoir is preferred the present invention is also suitable for virgin reservoirs of the type having naturally occurring drainable voids having a volume of between about 5% and 25% of the original oil in place. An example of such a reservoir is one with a 20-40% water saturation and 60-80% oil saturation, but well confined reservoir in a porous formation.
[0036] FIG. 1 shows a schematic of a target oil reservoir with a vertical well 20 and a horizontal production well 22 . The horizontal well 22 is generally placed near the bottom of pay zone 24 , and is a production well through which fluids draining through the reservoir by gravity drainage, can be removed. The typical pay zone 24 has layers of different permeability shown as 28 , 30 , 32 , 34 , 36 , 38 , and 40 . Most preferably the pay zone 24 is confined by an impermeable overburden layer 25 and an impermeable under burden layer 26 , but as will be appreciated by those skilled in the art of reservoir engineering, the present invention also comprehends that man made means for confinement can also be used. Preferably the pay zone 24 has been produced using conventional primary extraction techniques, such as CHOPS (cold heavy oil production with sand), to the full extent possible which has left significant void volumes in what may be called an oil extracted zone. Although the pay zone layers 28 to 40 may be fairly uniform there are typically some permeability variations due to, for example, the original depositional process. There is also typically some natural variation in the oil quality and viscosity with position in the reservoir.
[0037] As a consequence of the primary oil recovery from the reservoir, the highest permeability zones in the pay zone 24 , in this case layers 30 and 38 will have been preferentially depleted of heavy oil, while the slightly less permeable zones 28 , 32 , 34 , 36 and 40 will have been mostly bypassed thus having higher proportions of “stranded oil”. If the reservoir was on primary depletion with no pressure support, the depleted regions will likely also have some gas saturation as the naturally occurring in situ dissolved gas comes out of solution and fills the pores as the oil is removed. Significant water or brine is also likely to be present in the voids of the extracted oil regions of the pay zone, especially where waterflooding has been applied. Solvent is being injected as shown by arrow 44 in vertical well 20 and a mixed solvent and oil blend 46 is being removed, for example by a pump 48 .
[0038] FIG. 2 shows with plot line 49 that an oil reservoir with a certain “average” permeability will typically encompass a large variety of different pore sizes and consequently will likely have a broad distribution of permeability that vary greatly from one pore to the next as well as from one layer to the next. This means that any gas or liquid drive based extraction process (where gas or liquid pressure is used to try to push the oil out of the formation) is vulnerable to preferentially movement of the sweep fluid, such as solvent, through the largest and highest permeability pores first thereby bypassing significant amounts of oil contained in smaller and lower permeability pores. This bypassed oil, which is not mobile at commercial recovery rates at reservoir conditions, is the stranded oil. This bypassing is particularly problematic for solvent type processes because the solvent will have a tendency to dissolve oil along the most permeable path and make the short circuiting or coning problem worse. There are a number of ways to physically measure and assess the heterogeneity of the natural permeability of the pay zone including logging tools and porosimetry measurements. In summary, FIG. 2 shows that a significant portion of the oil will be stranded in lower permeability pores within the pay zone.
[0039] FIG. 3 shows the sequence of steps for an extraction process according to a preferred embodiment of the present invention as a series of changes to the reservoir pressure over time. FIG. 3 shows the steps of voidage creation 50 , solvent charging 52 , ripening 54 , oil production 56 with simultaneous solvent recycle back into the formation and solvent blowdown 58 . Each of these preferred steps is discussed in more detail below. FIG. 3 illustrates a schematic plot of the process of the present invention being applied to a reservoir where the solvent is ethane and the initial reservoir temperature is 20 C and rises to about 24 C (see FIG. 4 ) with assumed values for the reservoir porosity and the viscosity of the stranded heavy oil.
[0040] The first step 50 of voidage creation occurs as a pretreatment or conditioning step. Mobile fluids and gases, which for ease of understanding are referred to as solvent blockers, are pumped or produced from the reservoir. Most preferably these solvent blockers can be extracted through existing wells that are left over from the primary extraction step, but in some cases it may be preferable to install a horizontal well towards the bottom of the formation and use that for removal of the solvent blockers. The most potent solvent blockers are believed to be water, brine and methane, all of which are likely present after the primary extraction process is no longer effective. Creation of additional voidage in the pay zone 24 can be further encouraged by introducing into the reservoir a relatively low pressure solvent vapour to remove as much solution gas and methane as possible. The preferred solvent is ethane, although propane may also be suitable in certain reservoir conditions. The choice of solvent will depend on certain factors including both the effectiveness of the solvent at the pressure of the reservoir (which is often a function of the depth of the reservoir) and the cost at that time of the solvent on the open market. It is preferred to use ethane for reservoirs located below 1000 feet, and propane in reservoirs that are more shallow than that. The voidage creation of the present invention comprehends a series of displacement steps in an organized pattern to maximize recovery of water and methane gas from the pay zone 24 of the formation. As such the present invention will take advantage of whatever existing well configuration might be left over from primary extraction.
[0041] Solvent purity is also an important aspect of the present invention. In any environment with mixed solvents, the more readily dissolving species will preferentially enter into solution with the oil, leaving the less readily dissolving species at the oil interface. Over a period of time therefore, the less soluble species becomes concentrated at the oil interface, and blocks the passage of the more readily dissolving solvent species into the oil, frustrating the process of dilution of the oil. Therefore, an aspect of the present invention is to replace relatively insoluble species, such as methane, that might be naturally present in the formation, with high concentrations of reasonably pure solvent such as ethane, or propane to prevent the less readily dissolving species from slowing down or preventing dilution. As well, water, between the oil and the solvent will act as a barrier to the solvent, and so is also preferably removed according to the present invention, from the void volumes, to the extent possible. In summary, a solvent blocker may be either a gas or a liquid at reservoir conditions, and are advantageous to be removed.
[0042] The present invention comprehends that the voidage creation step can be done with or without pressure maintenance, depending on the reservoir conditions. In some cases it will be necessary to use pressure maintenance to minimize inflow from an active aquifer during the voidage creation and subsequent solvent charging step. In other cases, the reservoir may be sufficiently isolated and stable enough to not require any such pressure maintenance. However the present invention comprehends both types of voidage creation, depending upon which is most suitable for the specific reservoir conditions.
[0043] The next step 52 in the present invention is solvent charging. This involves continuing to introduce solvent, as a vapour, into the reservoir to carefully raise the pressure in the formation until it is above the bubble point pressure of the solvent vapour. By introducing the solvent as a vapour the present invention attempts to extend the reach of the solvent into the furthest voids, and then by increasing the pressure above the bubble point, to fill all of the voidage volume created in the first step with liquid solvent. It is preferable to inject most of the solvent as a vapour to permit the solvent to easily penetrate the voids throughout the pay zone 24 without forming liquid or other barriers to further solvent penetration. The present invention comprehends that at the final stages of the injection the injection pressure will be high enough that most of the solvent is in a dense liquid like phase. This is required to provide sufficient volume of solvent to adequately dilute and thereby mobilize enough of the stranded oil. For this overcharging step, injection pressure has to be monitored carefully to avoid the risk of a possible loss of confinement of the reservoir with a consequential loss of solvent.
[0044] There are several strategies for solvent injection or charging according to the present invention, depending upon the reservoir. Most preferably the solvent charging will occur in a way that permits the solvent to penetrate the voids created in the first step of the process. In some cases this is best accomplished by means of an existing vertical well that accesses a high permeability zone in the reservoir. It might also be preferable to use packers or the like in a vertical well to ensure that the solvent is being placed in an appropriate void zone in the reservoir. As well, if there is significant removal of blocking fluids from a sump by means of a horizontal well, then solvent may also be injected through the horizontal well. What is desired according to the present invention is to place the solvent, as close as possible, to the voids created during the first step of the present invention, to try to fill those voids to fullest possible extent. Exactly how to do this will vary with the specific reservoir geology and characteristics but could be through one or more vertical wells and horizontal wells simultaneously.
[0045] The next step of recovery according to the present invention is a time delay or ripening step 54 in which sufficient time is provided for the solvent to slowly diffuse into the oil in the smaller less accessible pores, to dilute the oil contained therein and to reduce its viscosity such that the fully diluted or homogenized combination will be mobile within the formation. This homogenization process is also important to permit the oil to seep into the solvent filled pores, even as the solvent is seeping into the oil filled pores. Such a homogenization of the solvent in the oil will according to the present invention help deter the solvent from bypassing the oil during the production phase. In an adequately confined reservoir, the ripening step will be characterized by a reservoir pressure that decays with time as the relatively pure solvent becomes diluted with oil and its vapour pressure is reduced. This drop in reservoir pressure is in accordance with Henry's law. Pockets of pure solvent will tend to maintain a high pore pressure, representative of the vapour pressure of pure solvent. The shape of the pressure decline curve and an assessment of whether the pressure has reached an expected asymptote provide, according to the present invention, a useful diagnostic of the degree of homogeneity of the solvent within oil across the reservoir. In particular, a lack of pressure decay from an initial charged solvent pressure is indicative of poor solvent penetration.
[0046] The present invention comprehends different ripening times for different reservoirs. One of the variables is the diffusion distance, which in some cases can be estimated when the reservoir permeability and heterogeneity is known. The present invention further comprehends being able to predict an optimum amount of time for the ripening step based on the reservoir heterogeneity and physical data about the oil. For example, the oil dilution rate will vary and a light oil with a high initial void fraction may achieve homogeneity within a short time, such as a day, but a high viscosity bitumen, with a low voidage (and solvent) distribution may require a long time, perhaps even decades.
[0047] It can now be understood why achieving a reasonable degree of uniform penetration or absorption of the solvent in oil is desired according to the present invention. Where two fluids exist in the reservoir, one having a significantly lower viscosity than the other, the more mobile species will be preferentially produced. By achieving a reasonable degree of heterogeneity, there becomes substantially only one fluid present, namely oil diluted with solvent, increasing the chances that the oil will be fully mobilized which can greatly reduce solvent bypass and coning. Each reservoir will, according to the specifics of the reservoir, will likely have a unique maximum total recovery, due to natural anomalies and the like. However, the present invention comprehends allowing the ripening step to progress to the maximum extent possible, given the conditions, such as void volume, to realize as much production as possible of the oil in place from the pay zone. The present invention also comprehends that while production can start from one area of the pay zone, slow solvent dilution of the oil can still be occurring in another area, and so it may not, in all cases, be necessary to wait until dilution has been maximized throughout the reservoir, to begin the recovery step, in cases where production in one part does affect ongoing solvent dilution in another part.
[0048] However, if the ripening step is terminated too quickly, then one would expect to see fluid production which is mostly solvent containing only a small proportion of oil. This outcome is typical of many prior art reservoir drive processes, where the low viscosity of the drive fluid (i.e. solvent, or steam or water or gas) bypasses most of the target oil. Consequently, high concentrations of solvent in the produced fluid can provide a useful diagnostic criteria to assess whether the ripening time has been sufficient, at least in the near production well bore area.
[0049] The next step of the present invention is a production step 56 . Assuming, for example, a sufficient solvent volume was injected to achieve a certain volume fraction of solvent in the oil, then, the production fluids will be carefully monitored to determine if the solvent fraction exceeds this target fraction. If the liquid solvent volume fraction in the produced solvent/oil blend is larger than expected, then the solvent has not been successful at diluting all of the stranded oil that should be accessible to it and is likely bypassing significant amounts of oil. If the liquid solvent production rate is too high relative to the oil rate then the oil production rate can be restricted or the reservoir can be shut in again to allow the ripening step 54 further time to proceed towards more complete dilution.
[0050] As noted above the oil production step will also co-produce solvent dissolved in the oil. According to the present invention, this solvent may be recycled back into the formation or the solvent may be sold or shipped to a subsequent recovery project or even flared or burnt as fuel gas.
[0051] The pressure, during production could also be augmented according to the present invention by solvent recycle or additional solvent injection if it was desirable to keep the solvent concentration in the oil high enough to reduce the oil viscosity to a particular target value. This offers the possibility of increasing the solvent to oil ratio with time which might be helpful to maintain high oil production rates without excessive coning as the reservoir becomes depleted in oil. However, additional solvent injection also increases the risk of solvent de-asphalting and potential for formation damage. It may be desirable to inject a non-solvent fluid such as methane, nitrogen or the like for pressure maintenance towards the end of the production step, when adequate solvent is in the oil and solvent blocking across the interfacial area is no longer a concern.
[0052] The final step in the extraction procedure is the solvent blowdown and recovery 58 . If there are pressure constraints such as an active aquifer it may be desirable to sweep the solvent out using another gas like methane, carbon dioxide or nitrogen.
[0053] FIG. 4 shows a viscosity graph for a typical heavy oil as a function of solvent dilution and temperature. This graph allows the viscosity reduction from the application of a particular quantity of solvent to a particular heavy oil to be estimated. The graph also shows that the viscosity of pure solvent may be 100,000 times lower than that of the native oil so the ripening step 54 giving the solvent enough time to dilute the oil is very important to avoid the solvent bypassing the oil. According to the present invention similar graphs can be constructed for other oil solvent combinations. The beginning of the arrows 60 and 62 represents the viscosity of the pure unheated solvent and heavy oil reservoir fluid and the arrowheads show that the homogeneous oil solvent blend will have a viscosity just over one hundred centipoise. The graph shows a small temperature rise for this example due to the latent heat of condensation. However, it is clear in this particular case that the temperature rise does not provide a meaningful viscosity reduction. The graph of FIG. 4 also permits the predicted viscosity to be assessed for the homogeneous solvent-oil blend at different solvent volume fractions. For example increasing the solvent volume to 20% would allow the blend viscosity to be dropped by a further factor of 10 to a value of about 13 cP.
[0054] FIG. 5 shows a curve 64 of the expected vapour pressure of a preferred solvent species ethane as a function of the volume fraction of ethane dissolved in the heavy oil. The saturation pressure for pure ethane at 24 C is about 4100 kPa (absolute), so this is the level of injection pressure that is the minimum required to fill the voidage volume with liquid equivalent ethane. The total pressure will be somewhat higher depending on the residual amount of methane remaining in voidage at the end of the first step of voidage creation. However, with a 10% volume fraction of ethane in the oil the ethane vapour pressure is only about 1600 kPa (absolute). This means that if the ripening step achieves a homogeneous blend of oil and solvent, the partial pressure of ethane will drop from 4100 kPa (absolute) to about 1600 kPa (absolute). Thus according to the present invention the reservoir pressure will asymptote at a value that is about 2500 kPa below the injection pressure. As will be understood by those skilled in the art, this assumes that the reservoir is confined and that there is no pressure maintenance via an aquifer or gas cap.
[0055] Interestingly, if someone assumed that the solvent penetrates deeply as shown in the computer based models of Das and Okazawa, they could only interpret a pressure decline as a loss of solvent to a thief zone and consequently would limit further solvent injection would begin to recover the solvent as fast as possible. This appears to be the teaching behind U.S. Pat. No. 2,494,391 which uses very high pressure gradients to inject and remove solvent from the formation as fast as possible.
[0056] FIG. 6 shows the approximate time required for the ripening step 54 as a function of the distance the solvent front must travel into the pay zone 24 for target reservoirs having in situ hydrocarbons ranging from bitumen to conventional oil, with the plots 70 for bitumen, 72 for heavy oil and 74 for conventional oil shown. This FIG. 6 also shows the benefit of the initial voidage creation step 50 which increases the amount of solvent that can be safely injected into the target reservoir in step 52 , so that the distance the solvent must diffuse is reduced and the length of time required for the ripening step 54 is also reduced. One might expect for example that doubling the amount of solvent from 10% to 20% might disperse the solvent more effectively in the target oil recovery zone and cut the ripening time in half.
[0057] The conventional oil reservoir with the pay zone 24 is assumed to contain 10 cP oil and have 100 millidarcies perm. The heavy oil reservoir is assumed to have 1 darcy permeability and oil viscosity of 10,000 cP and bitumen example is assumed to be 5 darcies permeability and 6 million cP bitumen. The duration of time for the ripening step 54 is set by the speed that a concentration shock front will propagate through the reservoir. The propagation speed is derived from the correlation presented in the inventor's previous U.S. Pat. No. 2,591,354.
[0058] FIG. 6 also shows another curve 75 labeled stagnant countercurrent diffusion, which is a second way of estimating the solvent diffusion rate within the reservoir. The curve 75 assumes that the solvent penetration or propagation distance is proportional to square root of ripening time for this estimation model. The countercurrent model has somewhat faster penetration rates at short distances and much slower penetration rates at longer distance for a particular heavy oil. Although the particular choice of solvent penetration rate model requires field calibration, one conclusion from both models, is that the solvent penetration time can be extremely long (years to decades) for relatively short propagation distances. Consequently, the benefits of the present invention, in getting a widespread dispersal of the solvent by removing solvent blockers, and to minimize the distance the solvent must travel to contact stranded heavy oil can now be appreciated.
[0059] FIG. 7 shows a plot 76 of the expected gravity drainage oil production rate for a 800 m long horizontal well with 10 m of pay for a heavy oil that is 10,000 cP at original reservoir conditions. This graph shows that for an average perm of 1 Darcy, the expected oil rate is only about 10 m3/day. FIG. 7 shows the importance of achieving a sufficient concentration of solvent in the oil; doubling the solvent concentration from 10% to 20% by volume in the oil increases the oil production rate by 15 fold. Furthermore, solvent volume fractions below 10% appear to be totally futile.
[0060] FIG. 8 shows a plot 78 of the expected gravity drainage oil production rate for the same well and oil of FIG. 7 but having an average reservoir permeability of 7 Darcies. FIG. 8 shows that a for a 10% volume solvent charge with average reservoir permeability of 7 Darcy, the expected oil recovery rate is as high as 100 m3/day. This figure shows that pay zones with higher permeability are highly preferred, for the present invention because they reduce the amount of solvent required to achieve a given production rate. It is preferred that most of the solvent be recovered and recycled, in which case the solvent cost can be largely recovered.
[0061] FIG. 9 depicts with plot 80 the calculated solvent cost for the 7 Darcy heavy oil reservoir of FIG. 8 , assuming the solvent is eventually recovered, either from the produced solvent/oil blend or during the final blowdown. FIG. 9 shows that the solvent cost per m3 of oil production is reduced as the volume fraction of solvent increases in the produced solvent oil/blend. This is a surprising result and shows that the larger solvent inventory cost is more than offset by the reduced (faster) recovery time (based on the time value of money) to produce the stranded oil. Consequently, it shows that a process which aims to be frugal with the amount of solvent used, like much of the prior art, is not cost effective for maximizing value. FIG. 9 further reinforces the benefit of the initial voidage creation step according to the present invention, which permits the volume of solvent is delivered in close proximity to the stranded oil to be maximized.
[0062] FIG. 10 shows a graph line 82 of the reservoir pressure versus time in the case where the solvent which is co-produced with the oil is not subsequently reinjected back into the reservoir formation. As shown by the slope of the graph the reservoir pressure declines slightly over time during the production phase. It will be understood that this decline is not attributed to further dilution of the solvent into the oil, but rather by reason of the removal of the produced fluid volume from the pay zone in a well confined reservoir as taught by this invention.
[0063] FIG. 11 shows with plot 84 the cumulative solvent injection and production volumes as a function of time for the present invention when applied to a reservoir having an active aquifer or other type of pressure support. This type of reservoir is less desirable since the quality of the solvent dilution into oil and the appropriate ripening time cannot be assessed by means of remotely sensing the reservoir pressure because the reservoir pressure is effectively constrained at a constant value. It will be understood that the present extraction process invention can still be usefully applied to this type of reservoir but the assessment of the appropriate ripening time will be more uncertain, may rely more on the evaluation of the solvent to oil ratio of the produced fluids and will benefit from a detailed assessment of reservoir heterogeneity.
[0064] The advantages of the present invention can now be more clearly understood. Although the volume of solvent introduced into the reservoir is maximized by the precondition step of the present invention, the solvent concentration in the produced fluid is quite small, as the primary and secondary recovery is frequently in the 10% to 20% range of the original oil in place. Consequently, the amount and value of the solvent that is co-produced with the oil is greatly reduced over other prior art processes such as 2,299,790. The present invention comprehends that it may be cost effective to completely ignore solvent recovery in some cases to minimize field plant capital cost. Another advantage of the present invention is little or no asphaltene deposition is expected due to the relatively low solvent to oil ratio. On the other hand, little or no upgrading of the crude oil is expected. As well, the present invention is not a continuous process, as the full solvent charge is required almost from the start—during the ripening step no significant plant operating expenses are going to be incurred.
[0065] In addition, it is possible to use a variety of solvents. FIG. 6 shows that a ripening time of one month might allow a preferred solvent to propagate 5 meters in a conventional oil reservoir. However, it is expected that 6 or more years would be required for unheated solvent to diffuse 5 meters in very viscous bitumen of the oil sands. Additional commercial advantages include the potential of acquiring land with wells and production facilities for a low cost if a particular depleted heavy oil reservoir is perceived to be uneconomic to operate.
[0066] Additional novel aspects include, among other things, the following:
[0067] The cleanup/decontamination step to create void volume and get rid of undesirable contamination such as water and methane;
[0068] Use of solvent detectors to monitor solvent breakthrough in decontamination step;
[0069] a pressurization step to achieve bubble point condition, so the voids can be charged with highest possible solvent loading;
[0070] a ripening step with the tracking of reservoir pressure decay to monitor the progress of the mixing; and
[0071] monitoring solvent/oil ratio to detect and mitigate solvent coning and bypassing
[0072] The benefit of the present invention in using gravity drainage is that it can enable 60% or higher recovery of initial oil in place. If the primary only recovers 10% of the original oil in place then subsequent solvent assisted gravity drainage could allow 5 or more times cumulative oil production than was achieved in the primary and secondary production cycles.
[0073] Example: Consider a Lloydminster heavy oil with a native reservoir viscosity of 10,000 cP and a reservoir permeability of 7 Darcy and a pay thickness of 10 m. Recovery after primary CHOPS and subsequent water flood is 270 kbbls which is 15% of initial oil in place. In the first step of the present invention the reservoir pressure is dropped to 500 kPAa as solvent blockers consisting of water brine and methane are removed. Solvent vapour is then injected to help displace mobile water and methane from the reservoir and to permit the solvent vapour to spread out through the accessible reservoir voids.
[0074] This drainage step creates a void volume of 15% of the pore space, which can be subsequently filled with solvent. Sufficient ethane solvent is injected to fill this 15% void volume with liquid equivalent solvent (i.e. 270 kbbl liquid equivalent barrels of ethane). Assuming the voidage that was created during primary extraction was created primarily at the bottom of the pay zone, then the solvent must diffuse about 10 meters to homogenize across the full height of the reservoir. The required ripening time is estimated to be approximately one year. After the solvent injection, the reservoir pressure is measured until a decline from 4600 kPa to 3000 kPa is detected.
[0075] The reservoir is then put on production via the horizontal well and the initial oil rate is calculated to be 250 m 3 /day (1500 bopd) or more. The production fluids are carefully monitored to make sure that solvent isn't short circuiting. Assuming uniform solvent dilution of the stranded heavy oil, approximately 820,000 additional barrels of heavy oil are calculated to be available to be produced over the next 3 years. Towards the end of the production cycle the oil production rate will decline and the blowdown cycle is commenced to recover as much remaining solvent as can be had. At the end of the production cycle, it is calculated that each barrel of solvent injected has enabled the recovery of 3 additional barrels of oil. At current prices the ethane solvent cost is $13/bbl and the oil can be sold at $60 per barrel. Thus the solvent cost, with no solvent recovery at all, is about $4 per bbl of oil or −6% of the oil value.
[0076] It will be appreciated by those skilled in the art that although the invention has been described above with respect to certain preferred embodiments, that various alterations and variations are comprehended within the broad scope of the appended claims. Some of these have been discussed above, while others will be apparent to those skilled in the art. For example, while the solvent may be injected initially through a vertical well, it may also be injected through a horizontal well or both even at the same time during the solvent charging step. The present invention is intended to be only limited by scope of the claims as attached.
[0000] The embodiments of the invention in which an exclusive property or Privilege is claimed are defined as follows: | There is disclosed a multi-step in situ extraction process for heavy oil reservoirs using a solvent having various steps, including, removing, from areas in contact with said heavy oil, solvent blockers to create voids and to increase an interfacial area of unextracted heavy oil contactable by said solvent and injecting solvent in vapour form into the voids to raise the reservoir pressure until sufficient solvent is present in a liquid form to fill the voids and to contact said increased interfacial area of said heavy oil. Next the reservoir is shut in for a period of time to permit said solvent to diffuse into said unextracted oil across said interfacial area from the solvent filled voids in a ripening step to create a reduced viscosity blend of solvent and oil and one or more reservoir characteristics is measured to confirm the extent of solvent dilution that has occurred of the unextracted oil in the reservoir. Then gravity drainage based production is started from the reservoir once the blend has a viscosity low enough to permit the blend to drain through said reservoir to a production well. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to optical fibers and to apparatus and methods for splicing groups of such fibers formed in cables.
There is currently a great deal of interest in the use of cables of solid core dielectric fibers operating at optical frequencies and such cables are now being laid or are practically in use. Connectors for frequently connecting and disconnecting optical fiber cable sections, which automatically align the fibers, have been developed. These connectors are expensive precision devices.
When an optical fiber cable is being laid, it is not necessary to connect by means of disconnectable connectors the cable sections since the sections have not to be disconnected after laying except perhaps to lengthen one of them or to repair a break. Therefore, the cable sections can be connected by merely splicing the fibers. 2. Description of the Prior Art
An optical fibers splicing method has been proposed in the prior art. According to this method, the fibers are arranged in groups, each fiber group comprising a plurality of fibers secured to a ribbon-like tape. The fiber group segments to be spliced are mounted on the holders of a splicer such that each of the fibers of one segment is aligned approximately coaxially with a fiber on the other segment. The individual fiber ends and the tape ends are cut flat; bonding material, of matching refractive index, is placed on each fiber end of at least one segment, and the two segments placed in contact. To insure accurate alignment of the respective fibers, a cover plate, accurately dimensioned to fit over the fibers, is placed over the adjacent ends of the fibers and left in position until the bonding material sets. Alternatively, the fibers can be spliced to each other by the application of heat.
This splicing method only applies to optical fiber disposed parallel to one another and forming a plane structure.
It is the broad object of the invention to splice optical fibers formed in cables in which the fibers are disposed around a cable core, either parallel to the core axis or helically wound around said core.
SUMMARY OF THE INVENTION
According to the invention, the optical fiber cable, manufactured at the factory by a continuous process, is cut up into sections of predetermined lengths, after being provided with connecting devices. The sections must be numbered or otherwise identified so that they can be connected at the laying site in the order which they occupy in the cable. The sections must therefore necessarily be identified or numbered, although this is not the case with the prior art devices.
The splicing method according to the invention is therefore characterized in that it is applied to a cable whose structure is adapted to these kinds of operations and which is manufactured continuously or in sections of long enough lengths. The method is characterized in that it comprises, at the places determined by the subsequent cable-laying conditions: an operation of unsheathing the cable over a certain length; a rigid connection without any regulation of the fibers to the cable core, for instance, by the gluing of the optical fibers to the core; a rigid attachment to the core and fibers by gluing under pressure or flanging and gluing of two half-shells, an upper and a lower half-shells, preferably of plastics material; a sawing at a predetermined place through the cable and the two half-shells in a direction perpendicular to their longitudinal axis whereby each half-shell is divided into two segments, this being followed or not by a quick polishing optional operation. When the operations for preparing the connection have been completed, each section end is cleaned and protected by means of a grease or oil whose refractive index is adapted to ensure the best possible optical continuity during the connection, the cable end then being given a protective hood. Connection is carried out on the site after removing the protective hood from the two sections whose marking indicates that they must be connected to one another. Assembly is carried out, for instance, by means of four stepped columns which extend into calibrated bores in the half-shell segments. One of the columns has a diameter different from that of the three others, for instance, a smaller diameter, so as to avoid false turning through 180° during assembly. Resilient washers disposed beneath the stepping of the columns enable a slight pressure to be exerted at the splicing plane when the segments are assembled together. An internal circular groove and a feed channel enable the lubrication of the splice to be completed and maintained in time, thus ensuring satisfactory stability during transmission. Two very rigid half-hoods fit over the splice assembly and are secured to the jacket of the two cable sections by flanging or gluing to each section. They prevent forces exerted on the cable from having repercussions at the splice.
The invention will be more clearly understood from the following detailed description of embodiments thereof, with reference to the accompanying drawings, wherein :
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A - 1D are diagrams showing four possible causes of insertion loss at the connection between two optical fibers formed by a core and a cladding of different refractive indices;
FIG. 2 is a diagram showing an optical fiber cable stripped over a certain length L at the place of the future joint;
FIG. 3 is a longitudinal view, in axial half-section taken along the line 3--3 in FIG. 4, showing the stripped cable provided with two half-shells ;
FIG. 4 is a cross-sectional view, taken along the line 4--4 in FIG. 3;
FIG. 5 is a plan view of the cable having two assembled half-shells;
FIG. 6 is a view in axial half-section of a prepared and protected cable section terminal, after sawing, but before the connecting operation;
FIG. 7 is a view in longitudinal and radial cross-section showing the ends of two sections after the connecting operation on the site;
FIGS. 8-11 are cross-sectional views of FIG. 7, taken along the lines 8--8, 9--9, 10--10 and 11--11 in FIG. 7 respectively;
FIGS. 12 and 13 are cross-sectional views of optical fiber cables which are particularly well adapted to the kind of connection shown in FIGS. 2-11;
FIG. 14 is a diagram of an optical fiber cable in which the optical fibers are inclined to the cable axis;
FIG. 15 is a cross-section of a cable of optical fibers which are inclined in relation to the axis, showing the two half-shells of the connection for sawing; and
FIG. 16 is a longitudinal section through the half-shells illustrated in FIG. 15, taken along the line 16--16 in FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiments illustrated in FIGS. 2-11, the optical fibers are parallel with the cable axis. When two optical fibers 1, 2 have to be interconnected, an attempt is made to reduce the three following faults to the minimum:
The linear error of connection δ (FIG. 1A)
The angular error of connection α (FIG. 1B)
The longitudinal linear error of connection β (FIG. 1C).
During manufacture, it seems ecomonically prohibitive to avoid a certain tolerance Δφ e on the outer diameter of the fibers and differences of refraction index gradients which results in a difference in core diameter Δφ c (FIG. 1D) for two fibers taken at random from manufacturing lots.
The known optical fiber transmission cable connecting members, often using complicated means, allow the first three conditions to be met, some of the connecting devices even taking into account differences in outside diameters, but they are never able to compensate differences in the refractive index radial gradients although in the long run they may form the main source of losses.
The method for connecting optical fiber cables according to the invention enables all these conditions to be met, since after sectioning for purposes of warehousing, transportation and transmission cable laying, the connecting method and device according to the application enable the cable to be reconstituted with the minimum of losses.
In FIG. 1, a cable 10 comprising a protective jacket 11 is stripped over a certain portion 12 of length L to show the fibers 13 parallel with the cable axis around the place where a splice between two sections is to be made, something which can be done only when the splicing plane of the optical fiber cable to be laid is precisely known.
Referring to FIGS. 3-5, the stripped portion 12 of the cable is then surrounded by two half-shells 14, 15, after the fibers 13 have been rigidly held in place by placing a drop of bonding material on the stripped portion. The two half-shells 14, 15 are secured to the bonding material and therefore the fibers 13 by gluing under pressure.
The two half-shells 14 and 15 have the general shape of two half-cylinders and accomodate to each other over a diametral plane. A flexible joint 19 in this plane ensures the sealing tightness of the assembly. A channel 22 terminating in an interval groove 21 allows the introduction under pressure of the bonding material. When the bonding material has set, the half-shells are sawn off along a slight groove 20 which indicates the place of sawing.
Splicing consists in fitting together the half-shell segments resulting from the sawing operation. The half-shells 14 and 15 comprise four longitudinal bores 16 1 to 16 4 serving to reconstitute which accurate registration the half-shells from the half-shell segments. One of the bores 16 1 has a smaller diameter than the three other ones. A longitudinal groove 23 extends on the surface of the upper half-shell for indicating the location of this small diameter bore 16 1 . To make a splice, the half-shell segments terminating the two cables sections to be spliced are fitted together by aligning the bores 16 1 -16 4 of the two half-shell segments and introducing in the same calibrated columns.
The half-shells also have two other bores 17 which are perpendicular to the cable axis and adapted to receive two centering rods 18 to ensure the accurate assembly of the two half-shells.
FIG. 6 shows a cable terminal 14'-15' (only the part 14 is shown in transverse cross-section) after the half-shell sawing operation and polishing operation. After sawing, the terminal is effectively cleaned, for instance, by passing it through an ultrasonic basin and its front part 21 is greased using, for instance, a silicone grease or oil whose refractive index is such that when the splice is made such grease ensures optimum optical continuity between the fibers and protects their ends against any pollution. The terminal is then given a protective hood formed by two halfhoods 24, 25 rigidly attached by a flanging to the unstripped portion 11 of the cable 10, thus affording effective protection against impact and dust during the transportation of the cable section. The hood is attached to the cable by means of bolts with nuts 27.
As illustrated in FIGS. 7-11, the complete device for splicing in situ two cable sections is formed by terminals 14'-15' and 14"-15" from which the protective hoods have first been removed. The terminals are assemblied by means of four calibrated stepped columns 26 1 -26 4 which extend into the corresponding bores 16 1 -16 4 of the half-shell segments. One 26 1 of the columns has, as already said, a smaller diameter than the others, to avoid wrong accomodation between the half-shell segments, one of them being turned through 180° from its true registration. The assembly position is facilitated by the presence of the locating groove 23 mentioned hereinbefore. After longitudinal locking by means of, for instance, circlip-type washers 31, the resilient O rings 29 disposed beneath the steps 30 1 to 30 4 of the columns 26 1 -26 4 enable a slight pressure to be exerted at the place of the splice plane. The resulting splice in fact reconstitutes the sectioned fibers and thus meets all the conditions which must be brought together to achieve very low insertion losses. Two grated half-hoods 34, 35, attached by flanging, anchoring, or even gluing in the case of a non-detachable connection, to the unstripped portions of the two spliced cable sections ensure the mechanical rigidity of the assembly and the protection of splice against forces exerted on the cable.
In FIGS. 7-11, the half-hoods 34, 35 are attached by means of bolts with nuts 32 1 , 32 2 ; 33 1 . 33 2 .
FIGS. 12 and 13 show two types of prior art optical fiber cable structures, in which the fibers are wound helically, which are particularly suitable for the connecting method illustrated in FIGS. 2 to 11, when the helix pitch is relatively large.
The first structure (FIG. 12) comprises a central core 36 receiving in each of a plurality of peripheral grooves 37 a fiber 13 having a fine elementary protection jacket enabling it to be handled during cable manufacture, and a protection envelope 11. Clearly, therefore, by the method according to the invention, once the outer envelope 11 has been stripped over a certain length, it is easy to attach each fiber in its recess by gluing under pressure and then to proceed to all the splicing operations.
The second structure (FIG. 13) is a more conventional structure. It comprises a central carrier 38, fibers 13 helically would on the central carrier, and a protective envelope 11. The fibers 13 have an individual jacket 39 for protective purposes during cable manufacture. The splicing method is applied under the same conditions as previously. Obviously, these examples of cables are not restrictive, and of course the connecting principle according to the invention can be applied to numerous other optical fiber cable structures.
In some types of cables, the fibers have a direction substantially parallel with the cable axis or can be brought into such a direction by simple handling, in which case the embodiment disclosed in relation to FIGS. 2 to 11 is adequate. On the other hand, as shown by FIG. 14, the fibers 39 can have a known inclined direction in relation to the cable axis 40. This may be the case, inter alia, with the examples of structures illustrated in FIGS. 12 and 13 if the helix pitch is relatively small. FIG, 14 shows that unless simple handling operation has been carried out to align the fibers parallel with the cable axis, the inclined orientation of fibers at an angle α in relation to the cable axis taking account of the thickness e of the material removed by sawing and polishing which is of the order of several microns, causes an offsetting d = etgα between the two extremities of the fiber in the splicing plane. In such a case, therefore, the recesses for the stepped columns which position the cable half-shell segments in relation to one another after sawing must correct the offsetting of the fibers.
Referring to FIGS. 15 and 16, bores 16 1 -16 4 adapted to act as recesses receiving the columns 26 1 -26 4 in the half-shell segments 14'-15' and 14"-15" are replaced by bores 16 1 '-16 4 ' in the half-shell segment 14'-15' and by bores 16 1 "-16 4 " in the half-shell segment 14"-15". The centers of the bores 16 1 '-16 4 ' are on the same circumference of radius R as the centers of the bores 16 1 "-16 4 ", but offset by the amount d 1 . If L 1 is the length of the half-shell segments, the bores have a length ρ 1 slightly greater than L 1 . When, after the sawing and separation of the two couples of half-shells, they are reassembled by inserting the columns, the assembly 14'-15' is given a rotation in relation to the assembly 14"-15" corresponding to the offsetting d 1 of the centers of the bores, with d 1 = d × (R/r) where d and R are as defined above and r denotes the mean radius of the circle on which the axis of the helical fibers are situated. | Method for splicing optical fiber cables which applies to those cables having an axial core and fibers disposed around the core, parallel to the cable axis or having a slight slant with respect thereto. At the places where splicing will have to be made, when the cable is laid down, the jacket of the cable is removed the fibers are glued on the core and two half-shells are disposed round the glued fibers and encase them. The half-shells are bonded to the core and fibers by gluing under pressure. When the glue has set, the half-shells together with the fibers and cable core are sawn perpendicularly to the cable axis which gives two half-shell segments. These segments have registering bores and splicing is achieved by inserting calibrated columns or pins into these bores. | 6 |
REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM
This application claims the priority of Provisional Patent Application No. 61/078,135, filed on 3 Jul. 2008, the entire content of which is incorporated herein by reference.
TECHNICAL FIELD
The subject matter of this disclosure relates to internal combustion engines, especially diesel engines like those used to propel large trucks. In particular it relates to a strategy for inferring temperature of exhaust gas at an engine exhaust manifold from a measured temperature of exhaust gas entering a diesel oxidation catalyst (DOC) and using the inferred temperature as an engine control parameter, such as for control of recirculation of exhaust gas through an exhaust gas recirculation (EGR) system.
BACKGROUND OF THE DISCLOSURE
A representative diesel engine comprises an exhaust system through which diesel exhaust gas is conveyed from the engine's cylinders to the tailpipe where it enters the surrounding atmosphere. Before passing through and out of the tailpipe, the exhaust gas is treated by an after-treatment system that comprises one or more after-treatment devices. Examples of such devices are diesel oxidation catalysts (DOC's) and diesel particulate filters (DPF's).
Diesel engines that are manufactured today for use in automotive vehicles such as trucks are typically turbocharged. Heat energy in exhaust gas leaving an engine exhaust manifold is converted into mechanical energy as it passes through a turbine portion of a turbocharger to operate a compressor in the compression portion that draws air into the intake system to deliver charge air to the engine cylinders.
For controlling NOx content in the exhaust gas, a portion of the exhaust gas can be recirculated from the exhaust system through an EGR system to the intake system. When the entrance to an EGR system is upstream of the turbocharger turbine, it may be appropriate for the EGR system to comprise one or more heat exchangers for cooling the exhaust gas being recirculated. Cooling of the exhaust gas can increase the effectiveness of the EGR system in limiting the generation of NOx.
However, it is recognized in the industry that cooling of recirculated exhaust gas creates the potential for condensation of certain gaseous constituents in the exhaust gas. Over time such condensates may accumulate sufficiently to have a detrimental effect on performance and/or components. For example, coolant passageways in coolers may become restricted, components may corrode, and moving parts may stick.
Condensation may be more extreme and/or perhaps even unavoidable at certain times, such as when a cold-soaked engine is warming after having been started and portions of its EGR system have not yet reached operating temperature. When condensation occurs along an EGR flow path and temperature of surrounding parts is sufficiently low, condensate may freeze and consequently restrict, or even block, the flow until the parts warm sufficiently to thaw the frozen condensate.
Condensation may also occur regardless of whether any cooler is present in the EGR system, for example when the engine is running at low idle and exhaust gas temperatures are low.
To address such situations, known practices in EGR control strategies include delaying and/or limiting EGR when conditions are conducive for condensation, and while such measures may be helpful in slowing the accumulation of condensates as an engine ages, they do impact the quantity of NOx in tailpipe emissions.
SUMMARY OF THE DISCLOSURE
A temperature sensor associated with a diesel oxidation catalyst, or DOC, provides a measurement of the temperature of engine exhaust gas entering the DOC as an input to a processor in an engine controller. The present disclosure describes a model that enables the temperature of exhaust gas at the exhaust manifold to be inferred, or estimated, from the temperature measured by the sensor. The model is embodied, by way of illustration, as an algorithm that is executed by the processor.
Briefly, the model processes data for a number of parameters related to engine operation, to ambient conditions, and to exhaust system characteristics such as its geometry. Some parameters are constants; others are variables, such as engine speed and load, that are taken into account because exhaust gas temperature will vary as engine operation changes, and variables, such as air temperature and barometric pressure, which change with changing ambient conditions.
A general aspect of the disclosure relates to an internal combustion engine comprising an exhaust system which conveys exhaust gas created in engine combustion chambers to atmosphere and which comprises an exhaust manifold through which exhaust gas enters from the combustion chambers, an after-treatment device for treating exhaust gas before passing into the atmosphere, and a sensor providing data for temperature of exhaust gas entering the after-treatment device.
A processor comprises an algorithm that models temperature of exhaust gas at the exhaust manifold as a function of the data from the sensor and other data, including certain thermodynamic constants, certain geometry of the exhaust system, and certain variables related to operation of the engine, and that when executed, processes the data from the sensor and the other data to calculate temperature of exhaust gas at the exhaust manifold.
Another general aspect relates to a method for inferring temperature of exhaust gas at an exhaust manifold of an internal combustion engine that has an exhaust system comprising an after-treatment device for treating exhaust gas passing through the exhaust system from the exhaust manifold and a sensor providing data for temperature of exhaust gas entering the after-treatment device.
The method comprises processing the data from the sensor and other data to infer temperature of exhaust gas at the exhaust manifold by executing an algorithm that models temperature of exhaust gas at the exhaust manifold as a function of data from the sensor and the other data, including certain constants, certain geometry of the exhaust system, and certain variables related to operation of the engine.
The foregoing summary, accompanied by further detail of the disclosure, will be presented in the Detailed Description below with reference to the following drawings that are part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general schematic diagram that is representative of portions of a diesel engine in a motor vehicle.
FIG. 2 is a general block diagram of the strategy that is the subject of this disclosure.
FIGS. 3A and 3B are schematic diagrams showing more detail of one of the blocks of FIG. 2 .
FIG. 4 is a schematic diagram showing more detail of another block of FIG. 2 .
FIG. 5 is diagram defining certain parameters that appear in various Figures.
FIGS. 6 through 10 are enlarged views of correspondingly numbered blocks in the block diagram of FIG. 3 .
DETAILED DESCRIPTION
FIG. 1 shows an example of a turbocharged diesel engine 10 having an intake system 12 , including an intake manifold 14 , through which charge air enters, and an exhaust system 16 , including an exhaust manifold 18 , through which exhaust gas resulting from combustion exits, not all details of those two systems that are typically present being shown.
Engine 10 also comprises a number of cylinders 20 forming combustion chambers into which fuel is injected by fuel injectors to combust with the charge air that has entered from intake manifold 14 . Energy released by combustion in cylinders 20 powers the engine via pistons connected to a crankshaft (not specifically shown).
When used in a motor vehicle, such as a truck, engine 10 is coupled through a drivetrain to driven wheels that propel the vehicle. Intake valves control the admission of charge air into cylinders 20 from intake manifold 14 , and exhaust valves control the outflow of exhaust gas into exhaust manifold 18 , through exhaust system 16 , and ultimately to ambient atmosphere via a tailpipe.
Turbocharging is provided by a turbocharger 22 that comprises a turbine 22 T for converting heat energy in exhaust gas passing through the turbine after leaving exhaust manifold 18 into mechanical energy as to operate a compressor 22 C that draws air into intake system 12 through an air cleaner 23 to deliver charge air for cylinders 20 . Because the compression of the air elevates its temperature, the compressed air flows through a charge air cooler 24 where some of the heat is rejected before the charge air enters cylinders 20 .
After leaving turbine 22 T and before entering the atmosphere, the exhaust gas is treated by one or more after-treatment devices in an after-treatment system 26 that includes a DOC 28 and a temperature sensor 30 for measuring temperature of exhaust gas entering the DOC.
Engine 10 also comprises an EGR system 32 for recirculating some exhaust gas from exhaust system 16 successively through a cooler 34 and an EGR control valve 36 to intake system 12 for entrainment with the charge air flow to cylinders 20 . EGR valve 36 meters an appropriate amount of exhaust gas into fresh air passing through intake system 12 so that the air is diluted, consequently limiting in-cylinder temperatures and the quantity of NOx in the exhaust gas created by combustion.
For inferring the temperature of exhaust gas leaving manifold 18 to enter EGR system 32 , the temperature of exhaust gas measured by sensor 30 is processed by a processor 38 according to a mathematical model that will be described with reference to FIGS. 2 through 10 .
For modeling temperature of exhaust gas at exhaust manifold 18 , heat lost during passage through the turbo down pipe from turbine 22 T and heat lost in turbine 22 T are modeled, as indicated by the respective heat-loss models shown in blocks 40 and 42 respectively of FIG. 2 . Exhaust manifold temperature T ExhMnf is considered to equate to the sum of temperature measured by sensor 30 , temperature lost during passage through the turbo down pipe, and temperature lost during passage through turbine 22 T.
Heat loss through the turbo down pipe comprises a radiant component and a convective component. The convective component is large in comparison to the radiant component. Heat loss through turbine 22 T is due predominantly to work that it performs to operate compressor 22 C.
FIGS. 3A and 3B show detail of the heat-loss model represented by block 40 in FIG. 2 . The model is implemented in processor 38 as an algorithm that when executed calculates a value for a parameter TSTACK that represents exhaust gas temperature leaving turbine 22 T to enter the down pipe. The algorithm uses certain constants and variables to perform various preliminary calculations that include calculating an external heat transfer coefficient, h ext , and calculating an internal heat transfer coefficient, h int .
External heat transfer coefficient h ext is calculated using a mathematical model 44 . The variables used in the calculation are the nominal outside diameter of the turbo downpipe DO, velocity of the exhaust gas flowing through the downpipe U, and the temperature measurement T DOC provided by sensor 30 . The model uses a parameter DOC_In_Temp Signal corresponding to T DOC as the input to each of two converters 46 , 48 for converting the DOC inlet temperature into a parameter V representing the kinematic viscosity of air and a parameter K representing thermal conductivity of air.
Internal heat transfer coefficient h int is calculated using a mathematical model 50 . The variables used in the calculation are the nominal inside diameter of the turbo downpipe DI, the nominal internal transverse cross sectional area of the downpipe A in — cross — section , ambient air temperature Ambient_Temp_Signal, engine speed N, engine torque TQI_SP, and ambient air pressure Ambient_Pres_Signal. Constants used in the calculation are the specific heat of air C p , the viscosity of air μ, and the Prandtl number P r .
Ambient air temperature Ambient_Temp_Signal, engine speed N, engine torque TQI_SP, and ambient air pressure Ambient_Pres_Signal are used in a mathematical model 52 for calculating the mass flow rate of exhaust gas M exh that is one of the parameters in model 50 .
In addition to the external heat transfer coefficient h ext and the internal heat transfer coefficient h int , ambient air temperature Ambient_Temp_Signal, the nominal transverse cross sectional area bounded by the outer surface of the downpipe Across_section, and DOC inlet temperature DOC_In_Temp Signal are used in a mathematical model 54 to yield a value, Q, for heat lost in the down pipe due to convection. Because the radiant heat loss is small in comparison to the convective heat loss, the former is not worth modeling.
The lost heat Q, the mass flow rate of exhaust gas M exh , the DOC inlet temperature DOC_In_Temp Signal, and the specific heat of air C p are used in a mathematical model 56 for calculating a data value for T STACK representing the temperature of exhaust gas leaving turbine 22 T.
FIG. 4 shows detail of the model represented by block 42 in FIG. 2 . The model is implemented as an algorithm in processor 38 that uses the calculated value for T STACK as one variable used in a mathematical model 58 for calculating a value for T ExeMnf that represents exhaust gas temperature at exhaust manifold 18 . The calculation also uses DOC inlet temperature DOC_In_Temp Signal to map a parameter □ representing Specific Heat Ratio of gases, exhaust back-pressure measured by a sensor at exhaust manifold 18 and converted to a corresponding value for a parameter P exh — mnf , ambient air pressure measured by a barometric pressure sensor and converted to a corresponding value for a parameter P amb , and pressure loss across a diesel particulate filter that is downstream of DOC 30 in after-treatment system 26 , P dpf .
A calculation 60 sums P dpf and P amb to provide the pressure parameter P stack. The efficiency of turbine 22 T is a parameter ηt.
FIG. 5 is a chart that gives definitions of and units for thermodynamic constants that appear in the mathematical model that has been described. | An engine processor ( 38 ) processes data for inferring temperature of exhaust gas at an exhaust manifold ( 18 ) of an internal combustion engine ( 10 ) whose exhaust system ( 16 ) contains an after-treatment device ( 26, 28 ) for treating exhaust gas and a sensor ( 30 ) for providing data for temperature of exhaust gas entering the after-treatment device. The processor processes data from the sensor and other data to infer temperature of exhaust gas at the exhaust manifold by executing an algorithm (FIGS. 3 and 4 ) that models temperature of exhaust gas at the exhaust manifold as a function of data from the sensor and the other data, including certain constants, certain geometry of the exhaust system, and certain variables related to operation of the engine. | 5 |
This application claims the priority of Japanese Patent Application No. 2-312500 filed on Nov. 16, 1990 which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a cutting head for a cord type mower. More particularly, the present invention relates to a cord feeding system for extending a cord wound on a bobbin in a rotary casing to a length necessary for mowing.
2. Description of the Related Art
Many conventional cord type mowers have systems in their cutting heads for feeding new cord when the current cord length is insufficient. Also, manual-type cutting heads are known which permit manual extension of the cord wound on a bobbin.
At present, the so called tap-and-go type and automatic type cutting heads are popular. For the tap-and-go type, the cord is feed the required length by releasing an interlock between a bobbin and a rotary casing. The interlock is released either by hitting or strongly pressing the rotary casing against the ground. This type of cutting head is disclosed in, for example, Japanese Utility Model Publication No. 2-16595, Japanese Patent Publication No. 2-26922, U.S. Pat. No. 4,161,820, U.S. Pat. No. 4,183,138, and U.S. Pat. No. 4,189,833.
For the automatic type, the interlock between the bobbin and rotary casing is released by the centrifugal force which changes according to the length of the cord that extends from the rotary casing. Thus, the desired cord length can be maintained. This type of cutting head is disclosed in, for example, Japanese Patent Publication No. 59-22484, Japanese Patent Laid-open No. 60-83508, Japanese Patent Laid-open No. 63-79522, Japanese Patent Laid-open No. 2-163003, U.S. Pat. No. 4,347,666, U.S. Pat. No. 4,607,431, U.S. Pat. No. 4,660,286, and U.S. Pat. No. 4,817,288.
For the tap-and-go type, it is necessary for the operator to frequently check the length of the cord consumed during mowing and extend the cord by hitting the rotary casing against the ground at times or strongly pressing it. Otherwise, the mowing efficiency greatly decreases. Therefore, the operator always has to execute checking and hitting. The checking and hitting give a large mental burden and physical load to the operator.
However, the tap-and-go type has the advantage that the operator can freely set the cord length according to the state of the material (such as grass) being cut. For example, when grass is soft, it is possible to improve the operation efficiency by extending the cord length which permits to the cutter to mow at a faster rate. When grass is hard, it is possible to insure that the grass is cut by setting the cord length to a relatively small value, which increases the cutting force of the cord. Therefore, some operators prefer the advantage of optionally setting the cord length according to the situation to the labor saving advantages of the automatic feeding devices.
Automatic type feed mechanism automatically extends the cord after it has been worn to a predetermined length. Because the extending length depends on the characteristics of the elastic body and heavy bob set in the rotary casing, it is limited to a predetermined range. Therefore, to change the extending length, the elastic body and heavy bob should be changed. However, it is very troublesome to change the parts according to the type of operation. Therefore, the cord length is normally preset to an average length required during operation in a variety of situations.
Because the cord is automatically extended when the cord is worn due to mowing, the automatic-type cutting head does not require hitting by the operator and is therefore easier to operate. However, because the operator cannot optionally select the cord length, it is impossible to extend the cord longer than the set length or keep the cord shorter than the set length.
Thus, the tap-and-go type and the automatic type each have their own features. However, each of the features appears as both an advantage or disadvantage. Because the tap-and-go type allows the operator to optionally select the cord length, it easier for professional operators to use because it operates more efficiently.
The tap-and-go type, however, requires the operator to always pay attention to the cord length and also requires that the rotary casing be hit when the remaining cord becomes short. Therefore, during prolonged mowing, this type gives a larger burden and physical load to the operator. Thus, the request (or demand) for the automatic type has recently been increasing in the professional market.
SUMMARY OF THE INVENTION
Accordingly, it is a primary objective of the present invention to provide a compact automatic-type cutting head that can optionally incorporate a tap-and-go function, which can compensate for the disadvantages of the both types.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, an improved cutting head for a cord-type mower is provided. The cord-type mower has an engine for driving the cutting head. The cutting head includes a rotor which can rotate about an axis and a bobbin on which a cord is wound. The bobbin is mounted in the rotor so that it can rotate relatively to the rotor about the axis. A cord feed slot for leading the distal end of the cord from the bobbin to the outside of the rotor is formed on the periphery of the rotor. Moreover, the cutting head has two types of cord feeding systems.
The first cord feeding system automatically feeds the cord in response to cord wear. The first cord feeding system is arranged to selectively disengage one of the bobbin and rotor from the engine to feed a predetermined length of the cord through the cord feed slot. The disengaged one of the bobbin and rotor slips relative to the other when it is disengaged.
The second cord feeding system feeds the cord in response to a tapping operation that is executed while the cutting head is being driven. The second cord feeding system disconnects one of the bobbin and rotor from the engine in response to the tapping operation. Again, this causes the disengaged one of the bobbin and rotor to slip relative to the other.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with the objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIGS. 1 through 13 show a first embodiment of the present invention;
FIG. 1 is a side view of a first embodiment of a cord-type mower in accordance with the present invention;
FIG. 2 is a sectional view of a cutting head;
FIG. 3 is a partial sectional view of the cutting head showing a position different from the cutting position in FIG. 2;
FIG. 4 is a sectional view of the cutting head of FIG. 2, taken along the line 4--4 of FIG. 2;
FIG. 5 is a sectional view of the cutting head of FIG. 2, taken along the line 5--5 of FIG. 2;
FIG. 6 is a sectional view of the cutting head of FIG. 2, taken along the line 6--6 of FIG. 2;
FIG. 7 is an exploded perspective view of the cutting head;
FIG. 8 is a perspective view of the control plate constituting the cutting head;
FIG. 9 is a perspective view of the bobbin constituting the cutting head;
FIG. 10 is a sectional view of the cutting head performing the tap-and-go operation;
FIG. 11 is a sectional view of the cutting head of FIG. 10, taken along the line 11--11 of FIG. 10;
FIG. 12 is a sectional view of the cutting head of FIG. 10, taken along the line 12--12 of FIG. 10;
FIG. 13 is a partially sectional view of a cutting head corresponding to FIG. 3, in which the cutting head serves as one dedicated to the tap-and-go operation using a stopper pin;
FIGS. 14 through 22 show a second embodiment of the present invention;
FIG. 14 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 15 is a partially sectional view of a cutting head corresponding to FIG. 3 of the first embodiment;
FIG. 16 is a sectional view of the cutting head of FIG. 14, taken along the line 16--16 of FIG. 14;
FIG. 17 is a sectional view of the cutting head of FIG. 14, taken along the line 17--17 of FIG. 14;
FIG. 18 is a sectional view of the cutting head of FIG. 14, taken along the line 18--18 of FIG. 14;
FIG. 19 is a sectional view of a cutting head corresponding to FIG. 10 of the first embodiment;
FIG. 20 is a sectional view of the cutting head of FIG. 19, taken along the line 20--20 of FIG. 19;
FIG. 21 is a sectional view of the cutting head of FIG. 19, taken along the line 21--21 of FIG. 19;
FIG. 22 is a partially sectional view of a cutting head corresponding to FIG. 13 of the first embodiment;
FIGS. 23 through 30 show a third embodiment of the present invention;
FIG. 23 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 24 is a sectional view of the cutting head of FIG. 23, taken along the line 24--24 of FIG. 23;
FIG. 25 is a sectional view of the cutting head of FIG. 23, taken along the line 25--25 of FIG. 23;
FIG. 26 is a sectional view of a cutting head automatically feeding cords;
FIG. 27 is a sectional view of the cutting head of FIG. 26, taken along the line 27--27 of FIG. 26;
FIG. 28 is a sectional view of the cutting head of FIG. 26, taken along the line 28--28 of FIG. 26;
FIGS. 29 and 30 are sectional views of the cutting head serving as one dedicated to the tap-and-go operation using a stopper pin;
FIGS. 31 through 39 show a fourth embodiment of the present invention;
FIG. 31 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 32 is a partially sectional view of a cutting head corresponding to FIG. 3 of the first embodiment;
FIG. 33 is a sectional view of the cutting head of FIG. 31, taken along the line 33--33 of FIG. 31;
FIG. 34 is a sectional view of the cutting head of FIG. 31, taken along the line 34--34 of FIG. 31;
FIG. 35 is a sectional view of the cutting head of FIG. 31, taken along the line 35--35 of FIG. 31;
FIG. 36 is a sectional view of a cutting head corresponding to FIG. 10 of the first embodiment;
FIG. 37 is a sectional view of the cutting head of FIG. 36, taken along the line 37--37 of FIG. 36;
FIG. 38 is a sectional view of the cutting head of FIG. 36, taken along the line 38--38 of FIG. 36;
FIG. 39 is a partially sectional view of a cutting head corresponding to FIG. 13 of the first embodiment;
FIGS. 40 through 49 show a fifth embodiment of the present invention;
FIG. 40 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 41 is a partially sectional view of a cutting head corresponding to FIG. 3 of the first embodiment;
FIG. 42 is a sectional view of the cutting head of FIG. 40, taken along the line 42--42 of FIG. 40;
FIG. 43 is a sectional view of the cutting head of FIG. 40, taken along the line 43--43 of FIG. 40;
FIG. 44 is a sectional view of the cutting head of FIG. 40, taken along the line 44--44 of FIG. 40;
FIG. 45 is a sectional view of a cutting head corresponding to FIG. 10 of the first embodiment;
FIG. 46 is a sectional view of the cutting head of FIG. 40, in which drive rinks are moved from the state in FIG. 42 due to the centrifugal force;
FIG. 47 is a sectional view of the cutting head of FIG. 45, taken along the line 47--47 of FIG. 45;
FIG. 48 is a sectional view of the cutting head of FIG. 45, taken along the line 48--48 of FIG. 45;
FIG. 49 is a partially sectional view of a cutting head corresponding to FIG. 13 of the first embodiment;
FIGS. 50 through 58 show a sixth embodiment of the present invention;
FIG. 50 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 51 is a partially sectional view of a cutting head corresponding to FIG. 3 of the first embodiment;
FIG. 52 is a sectional view of the cutting head of FIG. 50, taken along the line 52--52 of FIG. 50;
FIG. 53 is a sectional view of the cutting head of FIG. 50, taken along the line 53--53 of FIG. 50;
FIG. 54 is a sectional view of the cutting head of FIG. 50, taken along the line 54--54 of FIG. 50;
FIG. 55 is a sectional view of a cutting head corresponding to FIG. 10 of the first embodiment;
FIG. 56 is a sectional view of the cutting head of FIG. 55, taken along the line 56--56 of FIG. 55;
FIG. 57 is a sectional view of the cutting head of FIG. 55, taken along the line 57--57 of FIG. 55;
FIG. 58 is a partially sectional view of a cutting head corresponding to FIG. 13 of the first embodiment;
FIGS. 59 through 66 show the seventh embodiment of the present invention;
FIG. 59 is a sectional view of a cutting head corresponding to FIG. 2 of the first embodiment;
FIG. 60 is a partially sectional view of the cutting head in FIG. 59, viewed in a position 45° displaced from the sectional position in FIG. 59;
FIG. 61 is a sectional view of the cutting head of FIG. 59, taken along the line 61--61 of FIG. 59;
FIG. 62 is a sectional view of the cutting head of FIG. 59, taken along the line 62--62 of FIG. 59;
FIG. 63 is a sectional view of the cutting head of FIG. 59, taken along the line 63--63 of FIG. 59;
FIG. 64 is a sectional view of a cutting head automatically feeding cords;
FIG. 65 is a sectional view of a cutting head during tapping;
FIG. 66 is a sectional view of the cutting head of FIGS. 64 and 65, taken along the line 66--66 of FIGS. 64 and 65;
FIGS. 67 through 72 show the eighth embodiment of the present invention;
FIG. 67 is a partially sectional view of a cutting head;
FIGS. 68 and 69 show a cutting head viewed from the bottom of it without a cover constituting the casing of the cutting head;
FIG. 70 is a partially sectional view of a cutting head during tapping;
FIG. 71 is a partially sectional view of a cutting head serving as one dedicated to the tap-and-go operation using a stopper pin; and
FIG. 72 is a partial view of the cutting head in FIG. 71 viewed from the bottom of it.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first through eighth embodiments of the present invention will be described below with reference to the accompanying drawings.
First embodiment
The first embodiment of the present invention is described below according to FIGS. 1 through 13. As shown in FIG. 1, the cord type mower has a cutting head 1, an engine 3, and a shaft tube 2. The shaft tube 2 connects the head 1 with the engine 3 and transmits the power of the engine 3 to the head 1. The head 1 is operated by the engine 3 through the tube 2. The following is the detailed description of the head 1.
As shown in FIG. 2, a rotary casing 4 of the head 1 has a housing 5 and a protective cover 6. The casing 4 is connected to a drive shaft (not illustrated) rotatably installed in the tube 2 by a center bolt 7 at the center of the housing 5. Therefore, the housing 5 and the cover 6 are rotated together around an axis 7a of the center bolt 7.
A bobbin 8 and a control plate 9 coupled to the bobbin 8 are stored in the casing 4 so that they can rotate around the axis 7a independently of the casing 4. A pair of cord feed slots 10 are provided on the outer periphery of the housing 5 and are spaced apart by an interval of 180°.
The bobbin 8 has upper and lower section and one of two cords 11 is wound about each bobbin section. The end of each cord 11 passes through an associated one of the slots 10 and extends outside the housing 5.
As shown in FIGS. 2 and 7, four drive links 12 are installed in the housing 5 such that they are positioned around the axis 7a at 90° intervals. Each link 12 can move in the radial direction of the housing 5 within the housing.
As shown in FIG. 4, a groove is provided in the top surface of the plate 9. The groove is composed of eight radial groove sections 13 and eight guide groove sections 14 that connect the radial grooves 13. The radial grooves 13 extend generally in the radial direction of the plate 9 and are provided at equal angular intervals about the center bolt 7. Adjacent radial and guide grooves 13 and 14 cooperate to form an inner step 13a nearer to the center bolt 7 and an outer step 13b farther from the center bolt 7.
A link stud 12a protrudes from the lower surface of each link 12. These link studs 12a extend into the plate groove. Thus, they are typically positioned in four of the radial groove sections 13. That is, in every other radial groove. Each link 12 is biased in the direction of the axis 7a by a compression coil spring 15 such that the link stud 12a is normally pressed against the step 13a of the groove 13 by the pressure of the spring 15. When the casing 4 is rotated under the above state, the plate 9 is rotated together with the casing 4 in the same direction due to the engagement with each link 12.
When the links 12 move radially outward against the pressure of the spring 15, the stud 12a of each link 12 moves from a position that engages the step 13a (i.e. stop position) toward the step 13b. When the stud 12a is released from the step 13a, the plate 9 relatively rotates in the direction opposite to the rotational direction of the casing 4 and the stud 12a moves to the linking position of the next radial groove 13 by following the guide groove 14.
As shown in FIG. 7, eight projections 16 are provided on the top surface of the bobbin 8 at equally spaced intervals. Each projection includes a tapered surface 16a which tilts in the same direction as the projection. As shown in FIG. 9, eight projections 17 are provided on the bottom surface of the bobbin 8 at equally spaced intervals. The projections 17 thus each include a tapered surface 17a. Each projection 16 at the top and each projection 17 at the bottom are installed corresponding to the same angular position in a concentric circle. The surfaces 16a and 17a tilt in the opposite direction to each other.
As shown in FIG. 8, eight tapered recesses 18 are formed on the bottom surface of the plate 9 at equally spaced intervals. The recesses 18 each include a tapered surface 18a. As shown in FIGS. 2 and 7, eight tapered recesses 19 are also formed on the inside bottom surface of the cover 6 at an equally spaced intervals. The recesses 19 also each include a tapered surface 19a.
As shown in FIGS. 5 and 6, each tapered recess 18 of the plate 9 and each recess 19 of the cover 6 are arranged along the periphery so that the former are staggered from the latter by 2π/16 radians. In addition, the tapered surface 18 and the surface 19a tilt in the opposite directions.
The bobbin 8 can slide along the axis 7a in the casing 4 and is pressed upward by a compression coil spring 20 supported by the cover 6. As shown in FIGS. 2, 5, and 6, the pressure of the spring 20, pushes the projections 16 into the recesses 18 of the plate 9. At the same time, the projections 17 on the bottom surface of the bottom surface of the bobbin 8 are separated from the recesses 19 of the cover 6.
As shown in FIGS. 10, 11, and 12, when the bobbin 8 moves downward against the biasing force of the spring 20, the projections 16 on the top surface of the bobbin 8 separate from the recesses 18. At the same time, the projections 17 engage the recesses 19 in the cover 6.
As shown in FIG. 7, a pair of bores 22 are formed in the upper surface of housing 5 at positions separated by an interval of 180°. A pair of holes 23 are formed on the plate 9 such that they are aligned with the bores 22.
As shown in FIG. 3, when a short pin 24 is inserted into the bore 22 of the housing 5, the plate 9 can rotate independently of the housing 5. As shown in FIG. 13, however, when a long stopper pin 25 is inserted into the bore 22 of the housing 5 it extends into the hole 23 of the plate 9. Thus, the housing 5 always rotates together with the plate 9.
As shown in FIG. 3, when the short pin 24 is used, the head 1 has the automatic and tap-and-go feeding functions. In this configuration, when the casing 4 is rotated in the state shown in FIGS. 2 and 4, the plate 9 is rotated therewith due to its engagement with the link stud 12a. Moreover, the bobbin 8 is also rotated due to the fact that the top projections 16 engage the recesses 18 in plate 9. In this case, the cord 11 which extends through the slot 10 is also rotated to cut grass or the like.
When the cord 11 is consumed during mowing, the rotating resistance of the casing 4 decreases. Thus, the rotational speed of the casing 4 increases when compared to the speed attained when a normal length of the cord 11 extends from the casing (given a constant engine output). Therefore, the centrifugal force acting on the links 12 increases causing the links 12 to move radially outward against the pressure of the spring 15. Accordingly, the studs 12a move from the stop position in their corresponding radial grooves 13 to the release position.
In the release position, the stud 12a slides along the groove 14 due to the rotation of the casing 4. Specifically, since the rotation of the casing 4 is not transmitted to the plate 9. The bobbin 8 slips relative to the casing 4. Accordingly, the bobbin 8 rotates relatively to the casing 4.
The cord 11 is wound in a direction that is opposite to the rotational direction of the casing 4. When the plate 9 and the bobbin 8 slip relative to the casing 4, the slot 10 rotates together with the casing 4. Therefore, the distal end of the cord 11 follows the rotation of the casing 4. Thus, the cord 11 is feed into the internal space of the casing 4 a distance equivalent to the distance the bobbin 8 slips relative to the casing 4. Centrifugal force then draws the feed cord 11 outside of the casing through the slot 10.
As the cord 11 is feed, the rotational resistance of the casing 4 gradually increases which reduces the speed of the casing 4. As the speed of the casing 4 decreases, the centrifugal force working on the link 12 decreases and the link 12 returns toward the axis 7a by the force of the spring 15. Thus, the stud 12a of the link 12 reaches the stop position of the adjacent groove 13. As a result, the casing 4 has been rotated a distance of 2π/8 radians (45°) relative to the bobbin 8. Then, the plate 9 and the bobbin 8 rotate together with the casing 4 until the cord 11 is again worn due to use.
In this type of automatic system, after a predetermined length of the cord 11 has been worn, the extending operation is repeated and the cord 11 is automatically extended. It is possible to control the distance that the cord 11 extends beyond the slot after a feeding operation by adjusting the force provided by spring 15. That is, when the spring tension is set relatively high, the automatic feeding operation will not be executed until the length of cord extending from slot 10 is relatively short. Thus, the length of the cord after the feeding operation has been completed will be relatively shorter.
When the head 1 is used in the automatic mode, the length of the cord 11 to be feed from the slot 10 is normally set to a constant value in this type of automatic feeding. On the other hand, when the head is used in the tap-and-go mode, it is possible to extend the cord 11 a total distance that is longer than the above set value.
In the tap-and-go mode, the cord is feed by hitting the casing 4 against the ground. More specifically in the state shown in FIGS. 2, 5, and 6, the casing is hit against the ground while it rotates. The impact drives the bobbin 8 against the pressure of the spring 20 as shown in FIGS. 10, 11, and 12. The bottom projections 17 of the bobbin 8 thus contact the recesses 19 in the cover 6 in an offset manner. Thus, a part of the tapered surface 17a of the projection 17 contacts a part of the tapered surface 19a of the recess 19. The casing 4 and the plate 9 then rotate relative to the bobbin 8 by the amount the bottom projections 17 are offset from the recesses 19. That is 2π/16 radians. At this point, the bobbin 8 again rotates together with the casing 4 and the plate 9. While the bobbin 8 slips relative to the casing 4, the cord 11 is feed a corresponding amount.
Since the spring 20 is compressed by the downward moving bobbin 8 due to the inertia created by the hitting actions, the bobbin 8 is thereafter pushed upward by the action of the spring 20. The top projection 16 of the bobbin 8 is thus inserted into the recess 18 of the plate 9 and a part of the surface 16a of the projection 16 contacts a part of the surface 18a of the recess 18.
Then, similarly to the above mentioned, the casing 4 and the plate 9 rotate 2π/16 radians relative to the bobbin 8 which feeds the cord 11 accordingly. When the surface 16a completely fits with the surface 18a, the bobbin 8 again rotates together with the casing 4 and the plate 9. By using the described tap-and-go function, the cord 11 is extended from the bobbin 8 by the length corresponding to 4π/16 radians each time the casing is tapped.
The head 1 having both the automatic and tap-and-go systems makes it possible to set the length of the cord 11 longer than the extending length set by the automatic system by hitting the casing 4 against the ground as desired.
In another mode shown in FIG. 13, pins 25 are inserted into the housing bores 22 and the plate holes 23, the plate 9 does not rotate relatively to the casing 4 and the cord 11 is not automatically extended. Therefore, it is possible to operate only the tap-and-go system independently of the automatic system. In this case, the length of the cord 11 to be extended is determined according to the number of times the case is tapped.
As described above, because the head 1 of the first embodiment has both the automatic and tap-and-go systems, the operator can use both or either one of the two systems according to the situation. Therefore, the disadvantages of the conventional cutting heads having only one of the automatic and tap-and-go system are eliminated. Moreover, this embodiment makes the head compact by arranging both of the systems along the axis 7a.
Second embodiment
The second embodiment of the present invention is described below with reference to FIGS. 14 through 22. It is noted that in many respects the design is similar to the design described above with reference to the first embodiment. Therefore, the discussion below primarily stresses the differences from the first embodiment.
The second embodiment is different from the first embodiment in the construction of a drive link 12 and its urging system. That is, for the second embodiment, just two links 12 are provided. As seen in FIGS. 14 and 16, the links are located 180° apart from each other relative to the housing axis 7a. Each link 12 is rotatably supported on the housing 5 by a pivot pin 26.
A link stud 12a protrudes from the bottom end of each link 12. The stud 12a, similarly to the procedure in the first embodiment, is inserted into a radial groove 13 of a control plate 9. A rotary sleeve 27 is positioned at the center in the housing 5. A torsion coil spring 71 for rotatably urging the sleeve 27 in FIG. 16 is journaled about the sleeve 27.
As shown in FIG. 16, gear type teeth on the link 12 engage similar teeth on the outer periphery of the sleeve 27. Therefore, the studs 12a of the links 12 are urged by the spring 71 such that they press against an associated inner step 13a.
Other portions of the second embodiment are basically the same as those of the first embodiment. Therefore, a portion corresponding to that of the first embodiment is provided with the same number as the first embodiment. FIGS. 14, 15, 16, 17, 18, 19, 20, 21, and 22 of the second embodiment correspond to FIGS. 2, 3, 4, 5, 6, 10, 11, 12, and 13 of the first embodiment respectively.
This construction rotates each link 12 against the action of the spring 71 through the sleeve 27 so that the stud 12a moves outward when the centrifugal force acting on each link 12 increases as the speed of a rotary casing 4 increases. Thus, the stud 12a moves from the stop position to the release position within the radial groove 13.
When cords 11 are extended up to a certain length similarly to procedure in the first embodiment, the speed of the casing 4 decreases and the centrifugal force acting on the link 12 decreases. Therefore, the links 12 are returned by the action of the spring 71. Thus, the automatic feeding of the cords 11 is controlled.
Third embodiment
The third embodiment of the present invention is described with reference to FIGS. 23 through 30. Again the differences from the first embodiment are stressed in the following description.
As shown in FIG. 23, the third embodiment does not have the control plate 9 used for the first embodiment. Rather a bobbin 8 is located in the casing 4 so that it can rotate relative to the casing 4 around an axis 7a. Because the plate 9 of the first embodiment is not used, the construction of a drive link 12 is also different from that of the first embodiment.
That is, an aperture 28 is formed at the center of the bobbin 8 and the internal surface of the aperture 28 serves as a surface 28a. The surface 28a gradually tilts outward from the axis 7a. A center pin 29 is positioned at the center of the bobbin so that it can be vertically moved. A support plate 30 is mounted to the center pin 29 above the aperture 28.
As shown in FIG. 24, four drive links 72 are located between the plate 30 and aperture 28 at 90° intervals so that they surround the center pin 29. The bottom surface 72b of each link 72 extends diagonally. The surface 72b of each link 72 contacts the surface 28a of the aperture 28. Each link 72 is mutually connected by an extension coil spring 73 so that it approaches the center pin 29.
As shown in FIGS. 23 and 24, eight teeth 31 are mounted on the top surface of the bobbin 8 at equally spaced intervals. Also, as shown in FIGS. 23 and 25, eight teeth 32 are mounted on the bottom surface of the bobbin 8 at equally spaced intervals. Each top tooth 31 is displaced from each bottom tooth 32 by 2π/16 radians under the state shown in FIGS. 24 and 25.
Eight teeth 33 are located inside the housing 5 at equally spaced intervals and eight teeth 34 are located on a protective cover 6 at equally spaced intervals. Each tooth 33 of the housing 5 and each tooth 34 of the cover 6 are located at the same angular position.
The bobbin 8 is slidably mounted along the axis 7a and is urged upward by a compression coil spring 20 supported on the cover 6. As shown in FIGS. 23, 24, and 25, the teeth 32 under the bobbin 8 are vertically separated from the teeth 34 of the cover 6 by the action of the spring 20. The spring also urges the teeth 31 above the bobbin 8 to engage with the teeth 33 of the housing 5.
As shown in FIGS. 26, 27, and 28, centrifugal force will urge the links 72 outward from the axis 7a against the action of the spring 73 when the casing 4 rotates. Outward movement of the links presses the bobbin 8 downward. That is the bobbin's aperture surface 28a is pressed downward by the link surfaces 72b. As a result, the bobbin 8 moves downward. When this occurs, the top teeth 31 of the bobbin 8 separates from the teeth 33 of the housing 5 and the bottom teeth 32 of the bobbin 8 engage the teeth 34 of the cover 6.
As shown in FIG. 23, four bores 36 are formed on the housing 5 at the intervals of 90°. Four bores 37 are also formed on a support plate 30 at positions corresponding to the bores 36 of the housing 5. Therefore, as shown in FIGS. 23 and 26, when short pins 38 are inserted into the bores 36 of the housing 5, the links 72 are able to move in the radial direction independently of the short pins 38. However, as shown in FIGS. 29 and 30, when stopper pins 39 are inserted into the bores 36 and 37, the bottom end of the stopper pins 39 enter the aperture 28. Therefore, the stopper pins 39 prevent the links 72 from moving radially outward.
As shown in FIG. 23, when the short pins 38 are inserted into only the bores 36 of the housing 5, a cutting head 1 has both the automatic and tap-and-go functions. When the casing 4 under the state shown in FIGS. 23, 24, and 25 rotates, the bobbin 8 also rotates because the teeth 33 of the housing 5 are engaged with the top teeth 31 of the bobbin 8. In this case, a cord 11 extended from a cord feed slot 10 of the casing 4 also rotates to execute mowing.
When the cords 11 are consumed due to mowing, the speed of the casing 4 increases as described in the first embodiment. Thus, the centrifugal force acting on each link 72 increases and the links 72 move radially outward against the spring 73. Thus, the bobbin 8 is pressed downward at surfaces 28a by the links 72.
In this case, as shown in FIGS. 26, 27, and 28, the bobbin 8 moves downward against the action of the spring 20 and rotation of the casing 4 is not transmitted to the bobbin 8 because the top teeth 31 of the bobbin 8 separate from the teeth 33 of the housing 5. Thus, the bobbin 8 slips relative to the casing 4, and the cord 11 is extended outward from the slot 10 by the length corresponding to the difference of rotational angle between the casing 4 and the bobbin 8, similarly to the first embodiment.
When the casing 4 slips by approximately 2π/16 radians relatively to the bobbin 8, the bottom teeth 32 of the bobbin 8 are engaged with the teeth 34 of the cover 6 and the bobbin 8 rotates again by following the casing 4. However, when the rotational resistance of the casing 4 increases after the cord 11 is extended, the speed of the casing 4 decreases. Accordingly, the centrifugal force acting on each link 72 also decreases and the links 72 are returned toward the axis 7a by the action of the spring 73. Accordingly, the bobbin 8 is raised by the action of the spring 20 and the bottom teeth 32 of the bobbin 8 separate from the teeth 34 of the cover 6. As a result, rotation of the casing 4 is not transmitted to the bobbin 8.
Then, the bobbin 8 slips relative to the casing 4, while, as described above, the cords 11 are extended outward by the length corresponding to the difference of rotational angle between the casing 4 and the bobbin 8. When the casing 4 slips by approximately 2π/16 radians relatively to the bobbin 8, the top teeth 31 of the bobbin 8 engage with the teeth 33 of the housing 5 and the bobbin 8 rotates again together with the casing 4.
In accordance with this embodiment, when the cords 11 wears off by a certain length, they are automatically fed by a length corresponding to 4π/16 radians each time the bobbin 8 vertically reciprocates.
The following is the description for use of the tap-and-go system. When the casing 4 under the state shown in FIGS. 23, 24, and 25 is hit against the ground, the bobbin 8 is moved downward by the hitting impact against the spring 20 as shown in FIG. 26. Thus, the cords 11 are fed similarly to the procedure in the automatic system. The spring 20 is compressed as the bobbin 8 is lowered due to the hitting operation. When the inertia of the bobbin is absorbed, the bobbin 8 is pushed upward due to the action of the spring 20 and the cords 11 are fed similarly to the procedure in the automatic system.
Thus, the head 1 of this embodiment makes it possible to set the length of the cord 11 longer than the extending length set by the automatic system by hitting the casing 4 against the ground as desired.
In another mode shown in FIGS. 29 and 30, the stopper pins 39 are inserted into the housing 5. In this mode, the links 12 cannot move and the cords 11 can not be automatically extended. Therefore, in this case, only the tap-and-go system operates similarly to the procedure in the first embodiment.
Fourth embodiment
The fourth embodiment of the present invention is described below with reference to FIGS. 31 through 39. Again the differences from the first embodiment are stressed.
In the first embodiment, the bobbin 8 and the plate 9 are rotatably supported independently of the casing 4. In contrast, in the fourth embodiment, the bobbin 8 always rotates together with a protective cover 6 as shown in FIG. 31.
A shifter 40 is set between the bobbin 8 and a control plate 9. The shifter 40 rotates relatively to a rotary casing 4. A pair of cord feed slots 10 are provided on the outer periphery of the shifter 40 and are spaced apart by an interval of 180°. The end of a cord 11 passes through the slots 10 and extends beyond a housing 5.
As shown in FIGS. 31 and 34, eight projections 41 are provided on the top surface of the shifter 40 along the periphery at equally spaced intervals. As shown in FIGS. 31 and 35, eight projections 42 provided on the bottom surface of the shifter 40 along its periphery at equally spaced intervals. Each top projection 41 and each bottom projection 42 are located at the same angular position.
Eight recesses 43 are provided on the bottom surface of the plate 9 at equally spaced intervals. Eight recesses 44 are provided on the upper surface of the cover 6 at equally spaced intervals. In the state shown in FIGS. 34 and 35, each recess 43 of the plate 9 is displaced from each recess 44 of the cover 6 by 2π/16 radians in the circumferential direction.
The bobbin 8 and the shifter 40 are slidable along an axis 7a and urged upward by a compression coil spring 20 supported by the cover 6.
As shown in FIGS. 31, 34, and 35, the top projections 41 of the shifter 40 are received by the recesses 43 of the plate 9 and the bottom projections 42 of the shifter 40 are separated the corresponding recesses 44 of the cover 6 by the action of the spring 20 respectively. FIGS. 36, 37, and 38 show the state in which the bobbin 8 and the shifter 40 move downward against the action of the spring 20. In this case, the bottom projections 42 are received by the cover recesses 44 and the top projections 41 are spaced from the plate recesses 43.
As shown in FIG. 32, when a short pin 24 is inserted into only a bore 22 of the housing 5, a cutting head 1 has both the automatic and tap-and-go functions. In this case, the casing 4 under the state shown in FIGS. 31 and 33 rotates together with the bobbin 8. The plate 9 is rotated due to engagement with link studs 12a of drive links 12. Moreover, the shifter 40 is rotated due to engagement between the plate recesses 43 and the top projections 41 of the shifter 40. In this case, the cords 11 also rotates to cut grass.
When the cords 11 are worn off due to mowing, the speed of the casing 4 increases and the centrifugal force acting on the links 12 increases, similarly to the situation described in the first embodiment. Accordingly, the links 12 separate from the axis 7a against a compression coil spring 15 and the projection 12a of each link 12 moves from a stop position to a release position in their radial groove 13 of the plate 9.
In the above state, the rotation of the casing 4 is not transmitted to the plate 9. Therefore, the shifter 40 slips relative to the casing 40 as the casing 4 rotates. Because the bobbin 8 rotates together with the casing 4, the cords 11 extend beyond the casing 4 by the length corresponding to the difference of rotational angle between the shifter 40 and the casing 4 (or bobbin 8).
When the bobbin 8 slips by approximately 2π/8 radians relative to the shifter 40 and the cords 11 are extended, the speed of the casing 4 decreases in a manner similar to the situation described in the first embodiment. Accordingly, the centrifugal force acting on the link 12 decreases and the link 12 returns toward the axis 7a due to the action of the spring 15. Thus, each projection 12a reaches a stop position of the adjacent slide groove 13, and the plate 9 and the shifter 40 rotate again together with the casing 4 and the bobbin 8.
As described above, the head 1 of this embodiment is similar to that described in the first embodiment in that it automatically feeds the cords 11 by a predetermined length when they are worn to a predetermined length.
The following is the description of the use of the tap-and-go system. When the casing 4 in the state shown in FIGS. 31, 34, and 35 is hit against the ground, the bobbin 8 and the shifter 40 move downward against the action of the spring 20. Then, the bottom projections 42 of the shifter 40 are inserted into the recesses 44 of the cover 6.
When the casing 4, bobbin 8, and plate 9 rotate by approximately 2π/16 radians relative to the shifter 40, the bottom projections 42 of the shifter 40 engage the recesses 44 of the cover 6. Then, the shifter 40 rotates again together with the casing 4, bobbin 8, and plate 9. Therefore, the cords 11 are fed by the length corresponding to the difference of rotational angle between the shifter 40 and the casing 4.
Once the downward inertia of the bobbin 8 and the shifter 40 has been overcome by the compression of spring 20 the bobbin 8 and the shifter 40 are moved upward by the action of the spring 20. As the shifter 40 moves upward, the top projections 41 of the shifter 40 are inserted into the recesses 43 of the plate 9.
When the casing 4, bobbin 8, and plate 9 slip by approximately 2π/16 radians relative to the shifter 40, the cords 11 are extended by the length corresponding to the difference of rotational angle between the shifter 40 and the casing 4 as mentioned above. When the top shifter projections 41 engage with the plate recesses 43, the shifter 40 rotates again together with the casing 4 and the plate 9. Thus, the fourth embodiment allows the operator to set the length of the cord 11 longer than the extending length set by the automatic system by hitting the casing 4 against the ground as desired.
In the mode shown in FIG. 39, when stopper pins 25 are inserted into the bores 22 of the housing 5 and the bores 23 of the plate 9, automatic feed of the cord 11 is prohibited and only the tap-and-go system operates, similarly to the situation described in the first embodiment.
Fifth embodiment
The fifth embodiment of the present invention is described below with reference to FIGS. 40 through 49. Again the differences from the first embodiment are stressed.
For the fifth embodiment, a housing 5 and a protective cover 6 which constitute a rotary casing 4 are assembled inversely to those of the first embodiment as shown in FIG. 40. Therefore, a shaft tube 2 is mounted on the cover 6. Accordingly, the positions of a bobbin 8, a control plate 9, and each drive link 12 are changed.
As shown in FIGS. 41 and 42, eight teeth 46 are provided on the bottom surface of the plate 9 at equally spaced intervals. Eight teeth 47 are also provided on the bottom surface of the plate 9 at equally spaced intervals. The teeth 46 and the teeth 47 are displaced from each other by 2π/16 radians.
Each drive link 12 is urged toward an axis 7a by a compression coil spring 15 and the link stud 12a of each link 12 is ready to engage with the inside teeth 46 of the plate 9. When the casing 4 rotates, the plate 9 also rotates in the same direction as the casing 4 due to engagement between the studs 12a and the inside teeth 46 of the plate 9.
As shown in FIG. 46, when the links 12 move radially outward from the axis 7a against the action of the spring 15, the studs 12a separate from the inside teeth 46 of the plate 9 and such that then can engage the outside teeth 47 of the plate 9.
As shown in FIGS. 40 and 43, eight teeth 48 are provided on the bottom surface of a bobbin 8 at equally spaced intervals. As shown in FIGS. 40 and 44, eight teeth 49 are provided on the top surface of the bobbin 8 at equally spaced intervals. The bottom teeth 48 and the top teeth 49 are located at the same angular positions.
Eight recesses 50 are formed on the top surface of the plate 9 at equally spaced intervals. Eight holes 51 are formed on the top wall of the cover 6 at equally spaced intervals. Under the state shown in FIGS. 43 and 44, the recesses 50 of the plate 9 and the holes 51 of the cover 6 are displaced by 2π/16 radians.
As shown in FIG. 40, a center boss 52 is mounted at the center of the bottom surface of the bobbin 8, which is exposed to the outside through the center of the housing 5. The bobbin 8 and the boss 52 are supported so that they can move along the axis 7a and are urged downward by the spring 20. By the action of the spring 20, the top teeth 49 of the bobbin 8 separate from the cover holes 51 and the bottom teeth 48 of the bobbin 8 are inserted into the plate recesses 50.
As shown in FIGS. 45, 47 and 48, when the bobbin 8 and the boss 52 are moved upward against the action of the spring 20, the bottom teeth of the bobbin 8 separate from the recesses 50 of the plate 9 and the top teeth of the bobbin 8 are inserted into the holes 51 of the cover 6.
As shown in FIG. 41, when short pins 24 are inserted into the bores 22 of the housing 5, the cutting head 1 has both automatic and tap-and-go functions. In this case, when the casing 4 under the state shown in FIGS. 40 and 42 rotates, the plate 9 is rotated due to engagement between the link studs 12a and the inside teeth 46 of the plate 9. Moreover, the bobbin 8 is rotated due to engagement between the plate recesses 50 and the bottom teeth 48 of the bobbin 8. The cords 11 rotate together with the casing 4 and the bobbin 8.
When the cords 11 are worn due to mowing, the centrifugal force acting on each link 12 increases similarly to the situation described in the first embodiment. Then, the links 12 separate from the axis 7a against the spring 15 and the link stud 12a separates from the inside teeth 45 of the plate 9 to enter the rotational route of the outside teeth 47.
When the link studs 12a are not engaged with the inside teeth 46 of the plate 9, rotation of the casing 4 is not transmitted to the plate 9. Therefore, the bobbin 8 and the boss 52 slip relative to the casing 4. Then, the cords 11 are extended outward due to the centrifugal force while the difference of rotational speed occurs between the plate 9, bobbin 8, and boss 52 on one hand and the casing 4 on the other.
When the casing 4 slips by approximately 2π/16 radians relatively to the bobbin 8, the link stud 12a engage the outside teeth 47 of the plate 9. Thus, the plate 9, bobbin 8, and boss 52 rotate again together with the casing 4.
When the cords 11 are fed by a designated length, the speed of the casing 4 decreases and the centrifugal force acting on each link 12 also decreases. Then, each link 12 is moved toward the axis 7a by the action of the spring 15. As a result, the stud 12a of each link 12 separates from the outside teeth 47 of the plate 9 and enters the rotational route of the inside teeth 46 of the plate 9.
As above mentioned, when the link studs 12a are not engaged with the outside teeth 47 of the plate 9, rotation of the casing 4 is not transmitted to the plate 9. Therefore, the bobbin 8 and the boss 52 slip. Thus, while the difference of rotational speed occurs between the plate 9, bobbin 8, and boss 52 on one hand and the casing 4 on the other, the cords 11 are extended outward by the centrifugal force.
When the casing 4 slips by approximately 2π/16 radians relatively to the bobbin 8, the link studs 12a engage with the inside teeth 46 of the bobbin 8, and the plate 9. At that point, bobbin 8 and boss 52 rotate together with the casing 4. Therefore, this embodiment automatically feeds the cords 11 of a certain length by repeating the operation previously mentioned when the cords 11 wear off by a certain length.
The following is the description for use of the tap-and-go system. When the boss 52 of the head 1 under the state in FIGS. 40, 43, and 44 is hit against the ground, the boss 52 moves upward together with the bobbin 8 against the action of the spring 20. Then the top bobbin teeth 49 are inserted into the cover holes 51 as shown in FIGS. 45, 47, and 48. At this point casing 4 slips relative to the bobbin 8 and boss 52 by approximately 2π/16 radians. Accordingly, the top bobbin teeth 49 engage the cover holes 51, and the bobbin 8 and boss 52 rotate together with the casing 4. Thus, like in the automatic function, the cords 11 are fed while the difference of rotational speed occurs between the bobbin 8 and boss 52 on one hand and the casing 4 on the other.
When the boss 52 and bobbin 8 move downward by the action of the spring 20, the bottom bobbin teeth 48 are inserted into the recesses 50 of the plate 9. Then, the casing 4 and the plate 9 slip by approximately 2π/16 radians relative to the bobbin 8. Then, as previously mentioned, the cords 11 are fed while the bobbin 8 slips relative to the casing 4. When the bottom bobbin teeth 48 engage the recesses 50 of the plate 9, the bobbin 8 and the boss 52 again rotate together with the plate 9 and the casing 4.
Therefore, the fifth embodiment allows the operator to freely set the length of the cord 11 by hitting the boss 52 against the ground as desired.
In another mode shown in FIG. 49, stopper pins 25 are inserted into the bores 22 of the housing 5 and the bores 23 of the plate 9. The stopper pins 25 prevent the cords 11 from being automatically fed and allow only the tap-and-go system to operate.
Sixth embodiment
The sixth embodiment of the present invention is described below with reference to FIGS. 50 through 58. Again the differences from the first embodiment are stressed.
As shown in FIG. 50, a center boss 54 is movably located at the center of a bobbin 8 and a control plate 9 along an axis 7a. The boss 54 is exposed outside through the center of a cover 6. As shown in FIGS. 50 and 53, a plurality of engaging projections 54a protrude from the boss 54 and slidably engage the plate 9. The boss 54 can always rotate together with the plate 9 due to the projections 54a.
As shown in FIG. 53, eight teeth 55 are formed on the top margin of the inner periphery of the bobbin 8 at equally spaced intervals. As shown in FIG. 54, eight teeth 56 are also formed on the bottom margin of the inner periphery of the bobbin 8 at equally spaced intervals. The top teeth 55 and the bottom teeth 56 are located at the same angular positions along the periphery.
Eight teeth 57 are formed on the top margin of the outer periphery of the boss 54 at equally spaced intervals and eight teeth 58 are formed at the bottom side of the outer periphery of the boss 54 at equally spaced intervals. The top teeth 57 are displaced from the bottom teeth 58 by 2π/16 radians.
The boss 54 is urged downward by the spring 20 supported by the housing 5. The top teeth 57 of the boss 54 are engaged with the top teeth 55 of the bobbin 8 by the action of the spring 20. The bottom teeth 56 of the bobbin 8 are separated from the bottom teeth 58 of the boss 54.
As shown in FIGS. 55, 56, and 57, when the boss 54 is moved upward against the action of the spring 20, the top teeth 57 of the boss 54 are separated from the top teeth 55 of the bobbin 8. The bottom teeth 58 of the boss 54 then engage with the bottom teeth 56 of the bobbin 8.
As shown in FIG. 51, when pins 24 are inserted into only bores 22 of the housing 5, a cutting head 1 has the automatic and tap-and-go functions simultaneously. When the casing 4 under the state shown in FIGS. 50 and 53 rotates, the plate 9 is rotated due to engagement between the link stud 12a of each link 12 and the inner step 13a of each radial groove 13.
Accordingly, the boss 54 rotates together with the plate 9 through the projections 54a. The bobbin 8 is also rotated together with the boss 54 due to engagement between the top teeth 57 of the boss 54 and the top teeth 55 of the bobbin 8. Cords 11 are rotated due to rotation of the casing 4 and the bobbin 8 to execute mowing.
When the cords 11 are worn off due to mowing, the speed of the casing 4 increases and the centrifugal force acting on each link 12 increases similarly to the procedure in the first embodiment. Then, the links 12 separate from the axis 7a against the action of a compression coil spring 15. The link studs 12a move from the stop position of each radial groove 13 to the release position.
In this case, rotation of the casing 4 is not transmitted to the plate 9, and the boss 54 and the bobbin 8 slip relative to the casing 4. This actions feeds, the cords 11.
When the bobbin 8 slips by approximately 2π/8 radians relative to the casing 4 and the cords 11 are extended by a corresponding length, the speed of the casing 4 decreases and the centrifugal force acting on each link 12 decreases. Accordingly, the links 12 moved toward the axis 7a by the action of the spring 15 and the link stud 12a move to the stop position of the adjacent radial groove 13. Then, the plate 9, boss 54 and bobbin 8 rotate again together with the casing 4. Thus, the sixth embodiment automatically feeds the cords 11 when the cords 11 wear off by a certain length, similarly to the first embodiment.
The following is the description for use of the tap-and-go system. When the boss 54 under the state shown in FIGS. 50, 53 and 54 is hit against the ground, the boss 54 moves upward against the action of the spring 20. Then, the bottom teeth 58 of the boss 54 enter the rotational route of the bottom teeth 56 of the bobbin 8 as shown in FIGS. 55, 56 and 57.
When the plate 9, boss 54 and casing 4 slip by approximately 2π/16 radians relatively to the bobbin 8, the bottom teeth 56 of the bobbin 8 engage the bottom teeth 58 of the boss 54. Then, the bobbin 8 rotates again together with the casing 4. Thus, the cords 11 are fed while the bobbin 8 slips relatively to the casing 4, similarly to the procedure in the automatic system.
When the boss 54 is moved downward by the action of the spring 20, the top teeth 57 of the boss 54 enter the rotational route of the top teeth 55 of the bobbin 8. When the plate 9, boss 54 and casing 4 slip by approximately 2π/16 radians relatively to the bobbin 8, the cords 11 are fed from the casing 4 as above mentioned. When the top teeth 55 of the bobbin 8 engage with the top teeth 57 of the boss 54, the bobbin 8 rotates again together with the plate 9 and the boss 54. Therefore, the sixth embodiment allows the operator to freely set the length of the cord 11 by hitting the boss 54 against the ground as desired.
In another mode in FIG. 58, when stopper pins 25 are inserted into the bores 22 of the housing 5 and the bores 23 of the plate 9, automatic feed of the cords 11 is prohibited and only the tap-and-go system operates.
Seventh embodiment
The seventh embodiment of the present invention is described below with reference to FIGS. 59 through 66. Again the differences from the first embodiment are stressed.
As shown in FIGS. 59 and 60, a drive link ring 65 is rotatably provided at the center of a rotary casing 4 about an axis 7a. As shown in FIG. 63, a center boss 61 is provided around the shaft of the ring 65. The boss 61 is spline-fitted with the ring 65. Therefore, the boss 61 can rotate together with the ring 65 and vertically move along the axis 7a.
A bobbin 8 is provided on the outer periphery of the boss 61. Spline grooves 66 are formed on the inner periphery of the bobbin 8. Spline keys 61a are formed on the outer periphery of the boss 61. The boss 61 can rotate together with the bobbin 8 and vertically move along the axis 7a due to engagement between the spline grooves 66 and the keys 61a.
The boss 61 is urged downward by a compression coil spring 20. The boss 61 is held in the casing 4 due to engagement between a step 63 constituting the spline grooves 66 of the bobbin 8 and the keys 61a of the boss 61.
As shown in FIGS. 61 and 62, four guide grooves pairs 65a extending in the radial direction of the ring 65 are formed on the ring 65. As shown in FIG. 59, a pin 62 protrude radially inward from the ring 65 between every pair of guide grooves 65a. A drive link 12 is slidably placed in each guide groove pair 65a.
A compression coil spring 15 is positioned between each link 12 and the ring 65 around each pin 62. Each spring 15 urges each link 12 toward the shaft of the ring 65. Each link 12 placed and each spring 15 housed in the ring 65, and the ring 65, boss 61 and bobbin 8 rotate together in the casing 4.
As shown in FIGS. 59, 64 and 65, tapered guide surface 61b are formed on the top end of the boss 61. The surfaces 61b extend up to the top of the keys 61a. A tapered surface corresponding to the tilt of the surface 61b is formed at the end of each link 12. Under the normal state shown in FIG. 59, the end of the boss 61 slightly enters the gap between each link 12 and the ring 65 while the end of the surface 61b of the boss 61 contacts a part of the surface 64 of each link 12.
As shown in FIGS. 59 and 61, radial grooves 13 and guide grooves 14 which are the same as those formed on the plate 9 of the first embodiment are formed on the inner surface of the housing 5. A link stud 12a mounted on the top of each link 12 is inserted into each radial groove 13 of the housing 5.
When the casing 4 under the state shown in FIGS. 59 and 61 rotates, the bobbin 8 is rotated together with the casing 4 due to engagement between the link studs 12a and the inner steps 13a of the radial grooves 13. Then mowing is executed by cords 11 extended from cord feed slots 10.
When the speed of the casing 4 increases due to wearing of the cords 11, the centrifugal force acting on each link 12 increases similarly to the procedure in the first embodiment. In this case, each link 12 separates from the axis 7a against the action of the spring 15 as shown in FIGS. 64 and 66. Then, the stud 12a of each link 12 moves from the stop position to the release position of each radial groove 13. The bobbin 8 is ready to slip relative to the casing 4.
Thus, similarly to the procedure in the first embodiment, when the bobbin 8 slips relative to the casing 4, the cords 11 are fed out of the casing 4 by the length corresponding to the difference of rotational angle between the bobbin 8 and the casing 4.
When the speed of the casing 4 decrease due to feed of the cords 11 and the centrifugal force acting on each link 12 decreases, each link 12 is returned to the position shown in FIGS. 59 and 61 by the action of the spring 15. Then, the bobbin 8 rotates again together with the casing 4. Thus, the seventh embodiment makes it possible to automatically feed the cords 11 when the cords 11 are consumed, similarly to the first embodiment.
The cords 11 can also be fed by hitting the boss 61 against the ground, similarly to the procedure in the first embodiment. That is, during tapping of the boss 61, the boss 61 moves upward against the action of the spring 20. And the top end of the boss 61 deeply enters the gap between each link 12 and the shaft of the ring 65 as shown in FIG. 65.
As the boss 61 moves upward, each link 12 is pushed out against the action of the spring 15 so that it separates from the axis 7a due to engagement between the surface 61 of the boss 61 and the surface 64 of each link 12. Thus, engagement between the stud 12a of each link 12 and the inner step 13a of each radial groove 13 is released. The bobbin 8 is ready to slip relatively to the casing 4. Therefore, the cords 11 are fed out of the slot 10, similarly to the procedure in the automatic feed.
When the state of hitting the boss 61 against the ground is released, the boss 61 is returned to the position shown in FIG. 59 by the action of the spring 20. As the boss 61 moves downward, the links 12 are pushed back by the action of the springs 20 so that they approach the axis 7a. When the links 12 return to the position shown in FIG. 59, the bobbin 8 rotates again together with the casing 4. Thus, the seventh embodiment allows the operator to freely feed the cords 11 by tapping as desired, similarly to the first embodiment.
Eighth embodiment
The eighth embodiment of the present invention is described below with reference to FIGS. 67-72.
As shown in FIGS. 67 and 68, a bobbin 8 is provided in a rotary casing 4 consisting of a housing 5 and a protective cover 6. The bobbin 8 can rotate about and vertically slide along an axis 7a of the casing 4.
The bobbin 8 is constructed by connecting an upper flange 75 with a lower flange 77 by a cylindrical body (not illustrated). Eight teeth 75a-75h are formed on the outer periphery of the upper flange 75 at equally spaced intervals. Similarly, eight teeth 77a-77h are formed on the outer periphery of the lower flange 77 at equally spaced intervals. The upper flange teeth 75a-75h are displaced from the lower flange teeth 77a-77h of the lower flange 77 by the angle of 2π/16 radians respectively.
A center boss 78 is located at the bottom center of the bobbin 8. A compression coil spring 79 is provided in the cylindrical body of the bobbin 8. The top end of the spring 79 contacts the housing 5 and the bottom end of it contacts the lower flange 77. The spring 79 urges the bobbin 8 and the boss 78 downward, and the bottom end of the boss 78 protrudes under the cover 6.
As shown in FIGS. 67 and 68, a swing lever 80 is rotatably supported between the housing 5 and the cover 6 in the casing 4. The lever 80 has a first arm 81 at the position approximately corresponding to the height of the upper flange 75 and a second arm 82 at the position slightly lower than the lower flange 77. The arms 81 and 82 have approximately equal length and extend in the approximately opposite direction.
Latching legs 81a and 82a are protruded at the end of the first arm 81 and that of the second arm 82 respectively so that they are parallel with the axis 7a and approach each other. As shown in FIG. 67, the length of the leg 81a of the first arm 81 is slightly shorter than the interval between the flanges 75 and 77. The bottom end of the leg 81a does not contact the lower flange 77.
The leg 81a of the first arm 81 is longer and heavier than the leg 82a of the second arm 82, and the moment of inertia of the first arm 81 is larger than that of the second arm 82. Therefore, when centrifugal force acts on the lever 80 due to rotation of the casing 4, the lever 80 is swung so that the first arm 81 separates from the bobbin 8. A torsion coil spring 83 is wound on the lever 80. As shown in FIG. 68, the torsion spring 83 urges the lever 80 so that the leg 81a of the first arm 81 approaches the bobbin 8.
As shown in FIG. 67, a partition plate 76 is located between the flanges 75 and 77 of the bobbin 8. A cord 11 is wound between the upper flange 75 and the plate 76 and between the plate 76 and the lower flange 77 respectively. As shown in FIG. 68, the upper cord 11 is led to a cord feed slot 10 via the leg 81a of the first arm 81 and extended to the outside of the casing 4.
When the cords 11 are extended by a certain length or more out of the slots 10, the end of the first arm 81 engages with the tooth 75a of the upper flange 75 as shown in FIGS. 68. Therefore the bobbin 8 rotates together with the casing 4.
The force F1 acts on the lever 80, which swings the lever 80 so that the first arm 81 separates from the bobbin 8 due to rotation of the casing 4. A tensile force of the cord 11 tends to further extend the cord 11 outward on the basis of the centrifugal force due to rotation of the casing 4 and the resistance produced when the cord 11 collides with grass. Then, the tensile force acts on the lever 80 as the force F2 for swinging the lever 80 so that the first arm 81 approaches the bobbin 8.
When the extended length of the cord 11 is secured at a certain value or more, the speed of the casing 4 is kept at the normal speed range (4,000 to 6,000 rpm). In this case, the sum of the force F2 caused by the tension of the cord 11 and the urging force F3 of the spring 83 is larger than the force F1 caused by the centrifugal force acting on the lever 80. Therefore, as shown in FIG. 68, the lever 80 is held at the position where the first arm 81 engages with the tooth 75a of the upper flange 75. As a result, the casing 4 rotates together with the bobbin 8.
Under the above state, the cord 11 is not fed from the bobbin 8. The leg 82a of the second arm 82 is placed outside the rotational route of the teeth 77a-77h of the lower flange 77.
When the cord 11 is worn off due to mowing, the speed of the casing 4 increases similarly to the procedure in the first embodiment and the centrifugal force acting on the lever 80 increases. Then, the force F1 caused by the centrifugal force acting on the lever 80 gets larger than the sum of the force F2 caused by the tension of the cord 11 and the urging force F3 of the spring 83. Accordingly, as shown in FIG. 69, the lever 80 is swung so that the first arm 81 separates from the bobbin 8. According to the swing, the leg 82a of the second arm 82 is brought into the rotational route of the teeth 77a through 77h of the lower flange 77.
When the end of the first arm 81 disengages from the tooth 75a of the upper flange 75, the bobbin 8 slips relative to the casing 4. When the bobbin 8 slips by 2π/16 radians relative to the casing 4, the tooth 77b of the lower flange 77 engages with the leg 82a of the second arm 82. The bobbin 8 rotates again together with the casing 4. According to relative rotation between the bobbin 8 and the casing 4, the cords 11 are fed outside the casing 4 by the length corresponding to the difference of rotational angle between the bobbin 8 and the casing 4.
When the speed of the casing 4 decreases because the cord 11 is fed outward, the centrifugal force acting on the lever 80 decreases and the force F1 for the lever 80 to push back the cord 11 decreases. Then, the sum of the force F2 caused by the tension of the cord 11 and the urging force F3 of the spring 83 gets larger than the force F1. The lever 80 returns from the position in FIG. 69 to the position in FIG. 68.
When the leg 82a of the second arm 82 disengages from the tooth 77b of the flange 77, the bobbin 8 slips relative to the casing 4 similarly to the above mentioned embodiments. When the bobbin 8 slips by 2π/16 radians relatively to the casing 4, the end of the first arm 81 engages with the tooth 75h of the upper flange 75. Thus, the cords 11 are fed outside the casing 4 by the length corresponding to the difference of rotational angle between the bobbin 8 and the casing 4. Therefore, as the cords 11 are worn off, they are automatically fed outside the casing 4 by the length corresponding to the angle of 4π/16 radians.
The following is the description for feed of the cords 11 by the tap-and-go function. When the boss 78 of a cutting head 1 under the state shown in FIGS. 67 and 68 is hit against the ground, the boss 78 and the bobbin 8 move upward against the action of the spring 79 as shown in FIG. 70. Accordingly, the tooth 75a of the upper flange 75 disengages from the end of the first arm 81, the bobbin 8 is ready to slip relatively to the casing 4. According to rotation of the casing 4, the bobbin 8 slips by 2π/16 radians relatively to the casing 4. Then, as shown in FIG. 70, the tooth 77a of the lower flange 77 engages with the leg 81a of the first arm 81. Thus, the cords 11 are fed outside the casing 4 by the length corresponding to the difference of rotational angle between the bobbin 8 and the casing 4.
When the state of hitting the boss 78 against the ground is released, the boss 78 and the bobbin 8 are moved downward by the action of the spring 79 and return to the state shown in FIG. 67. In this case, the tooth 77a of the lower flange 77 disengages from the leg 81a of the first arm 81. Then, similarly to the above mentioned, the bobbin 8 slips relatively to the casing 4 until the end of the first arm 81 engages with the tooth 75h of the upper flange 75. The cords 11 are fed outside the casing 4 by the length corresponding to the difference of rotational angle between the bobbin 8 and the casing 4.
Thus, the head 1 of this embodiment has both the automatic and tap-and-go cord feed functions. For this embodiment, only one lever 80 is used in the housing 5. However, it is possible to use a plurality of levers 80 corresponding to the number of slots 10.
In another mode shown in FIGS. 71 and 72, a bore 84 is formed on the housing 5 and a stopper pin 85 is inserted into the bore 84. The pin 85 has the length from the housing 5 to the first arm 81 of the lever 80. The pin 85 engages with the first arm 81 to inhibit the swing of the lever 80 caused by the centrifugal force. Therefore, insertion of the pin 85 into the bore 84 prevents the cords 11 from being automatically fed and allows only the tap-and-go system to operate.
Although eight embodiments of the present invention have been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. For example, the present invention may be executed in the following modes.
It is possible to arrange the long stopper pins used for some of the above embodiments so that they can move between the position where their ends stop within the bores of the housing and the position where their ends reach up to the bores of the control plate. In this case, a remote-controller may be combined with the cutting head to control the position of the pins.
Only one slot 10 or multiple slots 10 may be provided on the cutting head 1. Then the number of cords 11 can be changed according to the number of slots 10.
Eight radial grooves 13 and guide grooves 14 of the plate 9 are used for some of the above embodiments. However, the number of those grooves can be changed in the range of 6 to 12. Also, the number of links 12 can be changed according to the number of the grooves. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details giving herein, but may be modified within the scope of the appended claims. | A cutting head for a cord-type mower driven by an engine is disclosed. The cutting head includes a rotor capable of rotating about an axis and a bobbin with a cord wound on it. The bobbin can rotate relatively to the rotor about the axis in the rotor. The cutting head includes two types of cord feeding systems. The first cord feeding system automatically feeds a cord in response to cord wear. The second cord feeding system feeds a cord in response to a manual tapping operation executed during driving of the cutting head. The second cord feeding system disconnects one of the bobbin and rotor from the engine in response to the tapping operation. | 0 |
FIELD OF THE INVENTION
This invention relates generally to pressure sensitive and velocity sensitive safety valves for controlling the flow in well production and other flowlines in the event an unsafe flow condition is sensed. More particularly, the invention also relates to safety valve mechanisms that are controllably actuatable for purposes of selective flow control and are automatically actuatable as a storm choke or safety valve responsive to sensing a predetermined fluid flow condition at the valve. Even more particularly, the valve mechanism relates to a valve apparatus defining a straight through unobstructed flow passage that allows objects to be passed therethrough in the open condition of the valve.
The term "storm choke" is typically utilized in the well completion and production industry where deep wells are completed for the purpose of producing petroleum products, such as gas, oil, etc. A storm choke is typically located in a production tubing string within a well for the purpose of automatically shutting off production from the well when conditions arise that are potentially hazardous to the operation and safety of the well or when the operator of the well desires to cease production through closure of a valve located within the well itself. For example, in the event a flowline should rupture at the wellhead or immediately downstream thereof, it is desirable to provide means for insuring that production is shut in as rapidly as possible. Obviously, certain abnormal flow conditions which occur, such as by rupture of a flowline or the like, develop a potentially hazardous condition to personnel and equipment. In cases where petroleum products are being produced, a potential fire hazard exists when a flowline rupture occurs, especially in land based well operations. Where production of petroleum products is accomplished in an offshore or marine environment, the additional hazards of this environment due to wave action, debris, moving equipment, etc. makes the provision of storm chokes in wells even more necessary. It is desirable that production of petroleum products be allowed to continue even though the wells may be left unattended for long periods of time and even though a potentially dangerous condition, such as a storm, for example, might exist. In the event, however, the flowlines or other fluid production components of the well should become damaged to the extent that leakage occurs, this leakage is automatically sensed and results in automatic shutin of the well by virtue of the storm choke. It is desirable that a well, thus shut in, will remain out of production until such time as repairs are made. Properly functioning storm choke systems will prevent undesirable loss of production fluid will protect the environment against pollution by petroleum products and protect other equipment from becoming damaged or destroyed such as might otherwise occur if a damaged well production facility should flow in uninterrupted manner for an extended period of time.
Often, it is necessary or desirable to shut off a well for maintenance work at the wellhead or for other reasons. Hence, it is desirable that the well may be readily placed back in production after operation of the storm choke without the necessity of killing the well with fluids followed by swabbing, back-circulation, or other well completion procedures.
It is desirable that a storm choke be capable of being used with conventional well completion methods and wellhead equipment. The storm choke can also be dimensionally suitable for installation in standard casing sizes employed in wells and still provide full opening ports which will offer no restrictions preventing the running of instruments or other tools through the device. The ports through which production fluid from the well flows should be sufficiently large in dimension to minimize cutting by sand that might be carried with the production fluid.
In many cases, down hole production control devices such as storm chokes are subjected to a highly erosive and/or corrosive environment, depending upon the nature of the production fluid. In many cases it is desirable to periodically remove such apparatus from the well for repair or replacement, thereby insuring that the apparatus is always maintained in serviceable condition. In order to limit the expense involved in such repair and replacement operations, it is desirable to connect storm choke apparatus to wire line tool systems so that it will not be necessary to remove an entire production tubing string from the well in order to change out a storm choke. Moreover, in multiple completion systems, it may be desirable to cease production from a particular well zone while production is allowed to continue from different production formations. It may be desirable therefore to provide independent tubing strings for producing different production zones with a storm choke system being provided for each of the tubing strings. The storm chokes can be installed and retrieved by means of wire line systems thereby simplifying repair operations and maintaining repair costs at an acceptably low level.
In most cases, storm chokes and other down hole valve equipment define a rather circuitous flow path for the production fluid medium. Also, in some cases it is desirable to run well servicing tools through the valve mechanism in order to achieve down hole servicing operations. In such cases it is desirable to provide a valve mechanism having a straight through flow passage and yet being capable of closing in response to sensing an abnormal flow condition requiring automatic valve shutoff.
In many cases, storm chokes remain open responsive to forces developed by a compression spring and, when the force of the spring is overcome by the abnormal flow position, the valve mechanism will be moved to its closed position and it will remain closed until such time as pressure is supplied through the tubing string from the wellhead. It is desirable to provide a valve mechanism that functions automatically responsive to sensing an abnormal flow condition to shut off production flow through the tubing string and yet provide effective control of the valve mechanism by appropriate manipulation of surface control equipment. Further, it is desirable to provide a valve mechanism that is capable of mechanical closure in the event the automatic control mechanism of the valve should be inoperative for any reason, thus providing a mechanism back up for automatic closure of the storm choke.
Most storm choke type valve mechanisms incorporate a valve element such as a ball valve, check valve, etc. which is exposed to the flowing production fluid medium. Since the production fluid will typically contain quantities of particulate, such as sand and other debris, such valve mechanisms can easily become eroded or fouled to such extent that proper operation of the valve mechanism is not possible. It is desirable to provide a storm choke type valve mechanism incorporating a valve element that is completely shielded from the flowing production fluid during operation.
In cases where valve leakage is not allowed, it is desirable to provide a valve mechanism incorporating a valve element, which valve mechanism is not in any way exposed to the environment outside of the valve body. In cases where leaked fluid may be hazardous to the environment, or hazardous from the standpoint of fire, etc., it may be desirable to provide a valve body structure that completely encloses the valve mechanism and precludes any leakage whatever exteriorly of the flowline.
THE PRIOR ART
Subsurface safety valves, commonly referred to as storm chokes, are quite well known in the well production industry, having been employed for many years in pressurized petroleum well systems. In some cases, the storm choke is located in the wellhead structure, as shown by U.S. Pat. No. 3,724,501, and, in other cases, storm chokes are located within a tubing string as shown by U.S. Pat. Nos. 3,799,192 and 2,785,755. In some cases, storm chokes are located at the lower extremity of a string of production tubing as shown by U.S. Pat. No. 3,035,808. Subsurface safety valves have also been developed that function solely in response to conditions sensed within the well, as in U.S. Pat. No. 3,757,816, while other subsurface valve mechanisms are controllable from the surface as well as being responsive to abnormal well conditions, as in U.S. Pat. No. 4.069,871.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is a primary feature of the present invention to provide a novel valve mechanism that may be efficiently utilized as a down hole valve mechanism or storm choke or may conveniently take the form of an inline safety valve for general flowline used.
It is also a feature of the present invention to provide a novel valve mechanism incorporating a valve element having both linear and rotary components of movement within a valve body to allow direct seating and unseating movement and to allow the valve element to be freely rotated between the open and closed positions thereof.
It is an even further feature of the present invention to provide a novel valve mechanism incorporating a pivotal valve element that may be pivotally moved out of the flowstream to allow uninterrupted flow of fluid in the open position thereof and to further allow passage of tools and other devices through the valve mechanism as desired.
Among the several objects of the present invention is noted the contemplation of a novel valve mechanism incorporating a valve element that is retractable or positionable within a protective enclosure and is protected against contact with the flowing fluid during operation of the valve.
It is an even further feature of the present invention to provide a novel valve mechanism that functions efficiently as a safety valve responsive to sensing abnormal flow conditions and also functions as a controllable valve to achieve controlled operation as desired.
An important feature of the present invention includes the provision of means for imparting mechanical movement to the valve mechanism, thus insuring positive closure of the same in the event the valve mechanism does not respond properly to the sensing of an abnormal flow condition.
It is an even further feature of the present invention to provide a novel valve mechanism that may be installed and removed by wire line equipment, thus precluding any necessity for removing a tubing string in order to achieve servicing of the valve mechanism.
Another important feature of this invention concerns the provision of a flow line control valve that prohibits any possibility of leakage to the environment surrounding the valve and which may be controlled from a remote location.
It is also a feature of the present invention to provide a novel valve mechanism that functions as a controllable surface flowline valve providing absolute protection against leakage and which valve also functions as a safety valve responsive to the sensing of an abnormal flow condition.
SUMMARY OF THE INVENTION
These and other features of the present invention are attained in accordance with the concept of the present invention through the provision of a valve mechanism incorporating a valve body that is connectable to a flowline or tubing string in any desired manner. A valve element is movably positioned within a valve chamber defined within the valve body and is movable with both rotary and linear components of movement so as to be linearly movable into and away from seated engagement with a valve seat and is pivotally movable from a position within the flow passage to a protected, retracted position within a protective receptacle also defined within the valve body. Actuation of the valve element between its open and closed positions is accomplished by means of an elongated sleeve type piston actuator element that cooperates with the valve element to define a rack and pinion gear type valve actuating system, with the clam-shell pinion element being movable by the piston sleeve element and the pinion gear accomplishing rotation of the valve element responsive to linear movement of the piston sleeve.
Within the valve mechanism may be provided a compression spring that is adapted to maintain the valve mechanism in the closed position thereof in absence of an opposing force supplied in the form of hydraulic fluid introduced into the piston chamber and acting upon one extremity of the piston element. For down hole application, closure of the valve mechanism is also enhanced by formation pressure or line pressure that acts upon the opposite extremity of the sleeve piston element and enhances the force developed by the closure spring.
For application of the invention in a flow line control valve, a hydraulically energized piston may be positively actuated for opening and closing movements responsive to hydraulic fluid supplied from a remote power and control system.
Other and further objects, advantages and features of the present invention will become apparent to one skilled in the art upon consideration of this entire disclosure, including this specification and the annexed drawings. The form of the invention, which will now be described in detail, illustrates the general principles of the invention, but it is to be understood that this detailed description is not to be taken as limiting the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the Drawings:
The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a pictorial representation, partly in section, illustrating a storm choke type down hole safety valve mechanism installed within a well by means of a wire line retrieval mechanism.
FIG. 2A is a sectional view of the upper section of a down hole type safety valve or storm choke constructed in accordance with the present invention and showing the valve mechanism in registered but unseated relation with the valve seat.
FIG. 2B is a sectional view of the lower portion of the down hole valve mechanism of FIG. 2A.
FIG. 3 is a fragmentary sectional view of the valve mechanism of FIGS. 2A and 2B taken along line 3--3 of FIG. 2B.
FIG. 4 is a sectional view of the valve mechanism taken along line 4--4 of FIG. 3 and illustrating the valve element as being rotated 90° and being out of blocking relation with the flow passage of the valve.
FIG. 5A is a partial sectional view of the safety valve mechanism illustrated in FIG. 2 and illustrating the valve element in its fully closed position.
FIG. 5B is a partial sectional view of the valve mechanism illustrated in FIG. 2 with the valve element being linearly retracted from the valve seat and being positioned for 90° rotation.
FIG. 5C is a partial sectional view of the valve mechanism of FIG. 2 illustrating the valve element at the end of its 90° rotational movement.
FIG. 5D is also a partial sectional view of the valve mechanism of FIG. 2 illustrating the valve element in its fully retracted position within the protective receptacle and showing the masking tube in its fully seated position, thus isolating the valve element from the path of the flowing fluid through the valve mechanism.
FIG. 6A is a partial sectional view of an alternative embodiment illustrating a down hole type safety valve mechanism constructed in accordance with this invention and being arranged for both hydraulic and mechanical actuation as well as mechanical and pressure actuation toward the closed position thereof.
FIG. 6B is a partial sectional view of an intermediate portion of the valve mechanism of FIG. 5A and illustrating the mechanical and hydraulic actuation features in detail.
FIG. 7 is a partial sectional view of a mechanical actuator device that may be manipulated to maintain the valve in an open condition as desired.
FIG. 8 is a transverse sectional view of the mechanical actuator mechanism illustrated in FIG. 7 and taken along line 8--8 of FIG. 7.
FIG. 9 is an outside view of the mechanical actuator mechanism of FIG. 7.
FIG. 10 is a partial sectional view of a multiple spring type spring capsule, representing a part of an alternative embodiment of the present invention.
FIG. 11 is a transverse sectional view taken along line 11--11 of FIG. 10.
FIG. 12 is a sectional view of a packingless, hydraulically energized control valve constructed in accordance with the principles of this invention.
FIG. 13 is a transverse sectional view taken along line 13--13 of FIG. 12.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings and first to FIG. 1, a down hole check valve installation is illustrated pictorially and partially in section. Within the earth formation 10, a well bore 12 is formed which bore is lined with a casing 14 that traverses the formation being produced. A string of production tubing 16 extends downwardly through the casing to the vicinity of the production formation and extends through a packer element 18. The lower portion of the production tubing is open to the casing in typical manner and the casing is perforated at the production zone in order to allow production fluid, including gas, oil and other fluid, to enter the casing and thus enter the production tubing. The packer element 18 seals off the production interval from the well casing thereabove.
Down hole safety valves are typically installed above a packer element in the manner illustrated in FIG. 1, especially where wire line installation is desired. Such wire line installation typically incorporates a landing nipple 20 that is connected into the tubing string 16 by means of collars 22 and 24. The down hole safety valve, illustrated generally at 26 and constructed in accordance with this invention, is secured to the lower extremity of a wire line setting and retrieving mandrel 28 that is capable of being seated and locked with respect to the landing nipple by means of locator keys 30 and locking dogs 32 that are provided on the mandrel and are received within appropriate grooves within the landing nipple 20. The upper portion of the mandrel is typically provided with a wire line running and receiving neck.
Referring now to FIG. 2a of the drawings, the safety valve mechanism of the present invention is shown to include a connection and support body 34 having an internally threaded bore 36 formed at the upper extremity thereof for threaded connection to a wire line locking mandrel such as illustrated in FIG. 1. The connection and support body is formed to define an internally threaded portion 38 that receives the externally threaded portion 40 of a packing retainer and body support sub 42. A sleeve element 44 is positioned about a reduced diameter portion 46 of the sub 42 and is secured in fixed relation with the sub by means of a circular weld 48. An elongated groove in the sub 42, the sleeve element 44 or both defines an elongated channel or passage 50 through which hydraulic fluid may flow in the manner described hereinbelow. A packing assembly illustrated generally at 52 is positioned about the sleeve element 44 and functions to establish a sealed relationship with the wire line mandrel 28. Annular sealing element 54 establishes a seal to prevent leakage at the threaded connection between the connection support body 34 and the sub 42. A circular weld 56 secures the upper portion of sleeve 44 to the sub 42.
The sub 42 is formed to define an internally threaded increased diameter portion 58 within which is threadedly received an externally threaded portion 60 of an inner tubular housing portion 62. The outer housing structure of the safety valve mechanism 26 is formed by an elongated tubular housing element 64 having an internally threaded portion 66 at the upper extremity thereof that establishes threaded engagement with an externally threaded portion 68 of the packing retainer and body support sub 42. An annular sealing element 70 is supported within an annular groove formed within the outer tubular body element 64 and establishes fluid tight sealing engagement between the outer tubular body element and the lower portion of the sub 42.
The inner tubular housing portion 62 is sealed with respect to the sub 42 by means of an annular sealing element 72 supported within an annular groove defined within sub 42. The inner tubular housing portion 62 cooperates with the lower structure of the sub 42 to define an annular piston chamber 74 within which is received a generally cylindrical piston element 76 that is sealed with respect to the sub 42 by means of an annular sealing element 78 and sealed with respect to the inner tubular housing portion 62 by means of an annular sealing element 80. Hydraulic fluid may be introduced into the piston chamber 74 by way of the fluid supply passage 50 that is in turn connected in any suitable manner to a source of pressurized and controlled hydraulic fluid, not shown. The sub element 42 may be drilled to form an elongated fluid supply passage segment 82 that communicates with an annulus 84. The sub may also be formed to define a connector opening 86 in communication with the annulus 84 and a hydraulic fluid supply connection 88 may establish connection of a supply conduit 90 between the source of hydraulic fluid and the safety valve mechanism. To eliminate any projections from the exterior of the valve mechanism, hydraulic fluid supply may be accomplished by a fluid supply system essentially as illustrated in FIGS. 6A and 6B.
The piston element 76 is formed to define an annular abutment flange 92 and defines a lower externally threaded portion 94 receiving the upper internally threaded portion 96 of a valve actuator sleeve 98. A sealed relationship is established between the valve actuator sleeve 98 and the piston 76 by means of an annular sealing element 100 retained within an annular groove formed in the piston element 76. As the piston element 76 is moved downwardly under the influence of hydraulic pressure within the piston chamber 74, the valve actuator sleeve element 98 is also moved downwardly by virtue of its threaded connection with the piston element. It is desirable to provide a mechanism for imparting upward movement to the piston element to thus return the valve actuator sleeve 98 to its upper position. One suitable means for accomplishing return of the piston and the valve actuating sleeve may be conveniently accomplished in the manner illustrated in FIG. 2 by a compression spring 102 that is located within an annular spring chamber 104 defined between the valve actuator sleeve 98 and the inner tubular housing portion 62. A valve seat and guide sub 106 is formed to define an upper internally threaded portion 108 that receives the lower externally threaded portion 110 of the inner tubular housing portion 62. At the upper portion of the valve seat and guide sub 106 is defined an annular flange structure 112 defining a thrust shoulder 114 that is engaged by the lower extremity of the compression spring 102. The lower extremity of the piston element 76 defines an upper annular thrust shoulder 116 positioned for engagement by the upper extremity of the compression spring. As the piston element and valve actuator sleeve are moved downwardly under the influence of hydraulic fluid pressure, the compression spring 102 is compressed and thus stores mechanical energy sufficient to force the piston element 76 and the valve actuator sleeve 98 upwardly when hydraulic fluid pressure within the chamber 74 is relieved.
With regard now to FIGS. 2, 3 and 4, the valve actuator sleeve 98 is bifurcated at its lower extremity defining a pair of opposed support arms 118 and 120 defining pivot apertures 122 and 124 that receive valve pivot elements 126 and 128, respectively. A valve element generally illustrated at 130 is also constructed of bifurcated configuration defining a pair of opposed support elements 132 and 134 that are formed to define pivot apertures 136 and 138, respectively. The central portion of the valve element 130 defines a convex sealing surface 140 that may be of partially spherical configuration and is adapted for seating engagement with an annular seat surface 142 defined at the lower extremity of the valve seat and guide sub 106. The seat surface 142 may also be of partially spherical configuration, if desired.
It is desirable that the valve element 130 have a certain degree of limited linear movement in respect to the valve seat 142 and that the valve element be capable of rotating 90° to a position where the valve element is clear of a straight through elongated flow passage that is defined by the internal cylindrical bores of the various internal components of the valve mechanism. This straight through cylindrical bore enables production fluid to flow with least resistance through the valve mechanism and further allows servicing tools to be run through the valve mechanism in the event down hole servicing is required below the level of the safety valve mechanism. 90° rotation of the valve mechanism may be conveniently accomplished by means of a rack element 146 that is supported within the housing structure by means of an end cap element 148 that is threadedly received at the lower extremity of the outer tubular body element 64. The rack element is formed of partially cylindrical configuration, as illustrated in FIG. 4, and defines opposed sets of rack gear teeth 150 and 152 that are engageable by opposed sets of pinion gear teeth 154 and 156 defined on the opposed valve support elements 132 and 134, respectively. As the valve actuator sleeve 98 moves downwardly, during a certain portion of such downward movement the pinion gear teeth of the valve element will engage the teeth of the rack element 146 and will cause 90° rotation of the valve element from the position illustrated in FIGS. 2 and 5B to the position illustrated in FIG. 5C.
It is a feature of this invention that the valve element 130 be capable of moving linearly into and away from contact with the annular seat surface 142. This is conveniently accomplished in the manner shown in FIGS. 2B, 5A and 5B. With the valve element 130 in or near the closed position as shown in FIGS. 5A and 5B, segmented coplanar valve guide surfaces 158 and 160 are oriented in substantially parallel relation with the axis of the flow passage extending through the valve mechanism. Guide surfaces 158 and 160 are positioned for guiding engagement with opposed substantially planar surfaces 162 defined by the rack element 146. Surfaces 158 and 160 are also oriented in substantially parallel relation with the axis of the flow passage extending through the valve mechanism. With the valve element seated as shown in FIG. 5A, both of the guide surfaces 158 and 160 are disposed in guiding engagement with surfaces 162 of the rack element 146. In the position shown in FIG. 5A, the pinion gear tooth 164 is out of contact with the first one of the rack gear teeth 166. Contact between teeth 164 and 166 will be made only when the valve element has moved linearly from the position shown in FIG. 5A to the position shown in FIG. 2B. After the valve actuator sleeve has moved the valve element to the position shown in FIG. 2B, continued movement of the valve actuator sleeve in a downward direction, through interengagement between the pinion gear teeth and rack gear teeth, causes 90° rotation of the valve element from the position shown in FIGS 2B and 5B to the position shown in FIG. 5C.
The lower portion of the valve mechanism is designed to form a valve chamber 168 having a lower portion 170 thereof separated from the flowing fluid medium by means of a tubular partition 172. Between the tubular partition 172 and the outer tubular body portion of the valve mechanism, the lower portion of the valve chamber 168 defines a protective receptacle within which the arcuately curved head portion 139 of the valve element 130 is capable of being protectively located. After the valve element has been moved to the 90° rotated position illustrated in FIG. 5C, it is again appropriate to impart linear movement to the valve element to position the head portion 139 and the support elements 132 and 134 of the valve element within the protective enclosure. This feature is accomplished, as illustrated in FIGS. 5C and 5D. As shown in FIG. 5C, substantially planar elongated surfaces 174 are defined by the rack element 146, being disposed in substantially coplanar relation with opposed elongated surfaces 162. The opposed support elements 132 and 134 are formed to define substantially coplanar guide surfaces 176 and 178 that, in the position shown in FIG. 5C, are disposed in substantially parallel relation with the longitudinal axis of the valve flow passage. Guide surfaces 176 and 178 are capable of being positioned in sliding engagement with the elongated surfaces 174, thereby functioning to maintain the valve elements 132 and 134 in the position shown in FIG. 5C as it is moved linearly to the position illustrated in FIG. 5D.
As the valve element is moved in the opposite direction by the return spring 102 which imparts upward movement to the valve actuator sleeve 98, pinion gear tooth 180 will engage rack gear teeth 182 and will initiate rotation of the valve element from the position illustrated in FIG. 5C to the position illustrated in FIG. 5B as the valve element is moved upwardly by the valve actuator sleeve 98 under influence of the compression spring 102. After the valve element has been rotated to the position shown in FIG. 5B, continued upward movement of the valve actuator sleeve 98 will impart upward linear movement to the valve element 130 causing the sealing surface 140 of the head portion 139 of the valve element to move into direct sealing engagement with the annular sealing surface 142 of the valve seat and guide sub 106.
It is considered desirable to isolate the protective receptacle 170 from the flowing production fluid to prevent the valve element from being filed or eroded by the production fluid. It is well known that oil and gas that is produced typically contains a certain amount of sand or other particulate that is eroded from the formation. Where safety valve elements are subjected to flowing production fluid, it is expected that wear may occur as sand and other particulate flows through the valve mechanism along with flowing production fluid. In accordance with the present invention, a pair of opposed pin elements 176 and 178 extend through apertures 180 and 182 formed in the valve actuator sleeve 98. Pins 176 and 178 extend through elongated slots 184 and 186 defined in the valve seat and guide sub 106 with the inner extremities of each of the pins being received within apertures 188 and 190 defined in a masking tube 192. Pin elements 176 and 178 function to establish a mechanical interconnection between the valve actuator sleeve 98 and the masking tube 192, causing the masking tube to be moved linearly along with the valve actuator sleeve 98. The cooperative relationship between the pin elements 176 and 178, the valve actuator sleeve 98 and the elongated slots 184 and 186 prevent the valve actuator sleeve from rotating within the valve housing and thereby confine the valve actuator sleeve solely to linear movement within limits defined by the length of the slots. The lower surfaces 194 and 196 of the slots define stop surfaces for engagement by the pins to thus limit downward travel of the valve actuator sleeve during full opening movement and retraction of the valve element into its protective receptacle 170.
The lower extremity of the masking tube 192 is formed to define a tapered annular seating surface 198 that is slightly spaced from the sealing surface 140 of the valve element when the valve is closed. The tapered seating surface 198 is primarily provided for seating engagement with an oppositely tapered annuular seating surface 200 defined at the upper extremity of tubular element 172. As the valve element moves to the position illustrated in FIG. 5D, the masking tube 192 will move downwardly sufficiently to bring seating surfaces 198 and 200 into engagement. Although it is not intended that a positive seal be established when seating surfaces 198 and 200 are in engagement, it is intended that these surfaces fit sufficiently close that discernible fluid flow from the flow passage 144 into the valve chamber 168 and protective receptacle 170 will not occur. Thus, any particulate contained within the flowing production fluid will not enter the valve chamber and protective receptacle and the valve element will be protected against the contamination or erosion by contaminants within the flowing production fluid.
It is desirable to provide a valve mechanism whereby formation pressure functions to assist the sealing ability of the valve and functions to assist in imparting closing movement to the valve mechanism. This feature is conveniently accomplished in the valve mechanism illustrated in FIGS. 1-4. The valve actuator sleeve 98 is provided with inner and outer annular sealing elements 202 and 204 that are retained, respectively, within inner and outer annular grooves defined in the valve actuator sleeve. The inner sealing element 202 establishes a seal between the valve actuator sleeve 98 and the valve seat and guide sub 106 while outer sealing element 204 establishes a seal between the valve actuator sleeve and the inner surface 206 of the outer tubular body element 64. Formation pressure entering the valve mechanism through opening 208, defined by the end cap 148, acts upon the exposed surface area defined by the lower extremity 210 of the cylindrical valve actuator sleeve 98, thus developing an upward force on the valve actuator sleeve that assists the return spring 102 in moving the valve mechanism to its closed position. Thus, closing movement of the valve mechanism occurs automatically under emergency conditions such as might occur through rupture of a flowline forces developed by the compression spring 102 and formation pressure acting upwardly on the valve actuator sleeve will very rapidly move the valve mechanism to its closed position. This movement is instantaneous and relatively little flow will occur through the valve mechanism during the automatic closing sequence of the valve mechanism.
The masking tube 192 is sealed with respect to the valve seat and guide sub 106 by an annular sealing element 212 that is retained within an annular internal groove defined within the sub 106. Sealing of the movable components of the valve mechanism is further enhanced by annular sealing elements 214 and 216 that are retained, respectively, within inner and outer annular grooves defined in the upper portion of the sub 106. Sealing element 214 establishes a seal between the valve seat and guide sub and the masking tube 192 while sealing element 216 establishes a seal between the sub 106 and the valve actuator sleeve 98. An O-ring type sealing element 218 is provided to establish a seal at the joint between the inner tubular housing portion 62 and the valve seat and guide sub 106.
OPERATION
With regard to the valve construction illustrated in FIGS. 1-4, opening and closing movements of the valve mechanism may best be understood with reference to FIGS. 5A-5D. With the valve mechanism in its closed position as illustrated in FIG. 5A, opening movement occurs as hydraulic pressure is introduced into the piston chamber, driving the valve actuator sleeve 98 downwardly, thus causing the valve element 130 to move downwardly in linear manner until the first teeth of the pinion gear portions of the valve element engage the first teeth of the rack element 146. As downward movement of the valve actuator sleeve 98 continues from this point, the rack and pinion gear teeth will interact causing pivotal movements of the valve element from the position illustrated in FIG. 5B to the position illustrated in FIG. 5C. The valve element is thus positioned for entry into its protective receptacle 170 defined by the annulus between the tubular body element 64 and the inner tubular portion 172. The masking tube, being interconnected with the valve actuator sleeve 98 by means of the connector pins 176 and 178, will move downwardly along with the valve actuator sleeve during opening movement of the valve mechanism. As shown in FIG. 5A, the masking tube 192 is fully retracted while the sealing surface of the valve element 130 is in sealing engagement with the annular seat surface 142. As the valve actuator sleeve 98 moves downwardly, as shown in FIG. 5B, the masking tube will also initiate its downward movement. Upon rotation of the valve element to the position illustrated in FIG. 5C, the masking tube 192 will have moved further downwardly toward the upwardly extending tubular element 172. At the full open position as shown in FIG. 5D with the valve element fully retracted within its protective receptacle 170, the masking tube 192 will have moved downwardly sufficiently to bring its seating surface 198 into engagement with the opposing seating surface 200 of the tubular element 172.
In the event the valve mechanism should become automatically closed responsive to sensing of a low pressure condition downstream and should it become desirable to reopen the valve mechanism, such can be conveniently accomplished simply by introducing hydraulic pressure into the piston chamber 74, thus driving piston element 76 and valve actuator sleeve 98 downwardly in the manner described above. In the event the hydraulic system should fail, thus releasing pressure within the piston chamber 74, the compression spring 102, together with the force induced by formation pressure, will urge the valve mechanism to its closed position. Should it become desirable to reopen the valve mechanism even though a hydraulic failure exists, it is desirable to provide a mechanical override system having the capability of opening the valve against the influence of spring and pressure induced forces. A mechanical override system capable of opening the valve may conveniently take the form illustrated in FIGS. 6A and 6B, each being partial views of a unitary down hole safety valve mechanism. The structure illustrated in FIG. 6A, except for the mechanical actuation mechanism, is essentially identical with respect to the structure set forth in FIGS. 2A and 2B, and therefore identical reference characters are utilized to indicate corresponding parts. As shown in FIG. 6A, a connector sub 220 is provided having an internally threaded portion 222 that is adapted to receive the externally threaded lower extremity of a conventional wire line locking mandrel such as illustrated in FIG. 1. The lower portion of the connector sub is internally threaded as shown at 224 and receives the upper externally threaded portion 226 of a body and actuator connector element 228 having an elongated internal tubing section 230 and defining an annular shoulder 232. A mechanical actuator section 234 is positioned about the elongated tubular section 230 of the body and actuator connector element and is retained in intimate immovable engagement with connector element 228 by virtue of being interposed between shoulder 232 of the connector element and annular shoulder 236 of the connector sub 220. The mechanical actuator section includes a generally cylindrical body 238 defining an internally cylindrical surface 240 that fits closely about the cylindrical tubular portion 230 of the body and actuator connector element. The cylindrical body 238 is formed to define a pair of internal, generally parallel bores 242 and 244, each receiving elongated rack pins 246 and 248, respectively, having rack teeth 250 and 252 formed respectively thereon. Rack pins 246 and 248 are movable within the respective bores.
Each of the elongated bores 242 and 244 intersects a centrally located pinion gear recess 254 within which is rotatably received a pinion gear 256 having a bearing shaft 258 extending therefrom. The bearing shaft is receivable within a bearing opening 260 defined in an elongated retainer plate 262. The pinion gear retainer plate is secured in assembly with the cylindrical body 238 by means of a pair of cap screws 264 and 266 as shown in FIG. 9. The teeth of the pinion gear are maintained in engaged relation with the teeth of each of the rack pins 246 and 248. This relationship causes the rack pins to move in opposed direction upon rotation of the pinion gear. Thus, upward movement of the rack and pin 248 induces the pinion gear 256 to cause downward movement of the rack pin 246.
At the upper portion of the mechanical actuator is provided a cable connector element 270 of the same external dimension as the cylindrical body 238. Cable connector 270 is formed to define a partial bore 274 being axially registered with bore 244 of the body 238. Partial bore 274 is interconnected with bore 244 by a cable opening 276 through which a bowden cable 282 extends. A bowden cable connector 280 is received within the internally threaded bore or opening 274 and secures bowden cable 282 in assembly with the cable connector element. The bowden cable is connected to the rack pin 248 in any suitable manner, thereby causing the rack pin to be moved upwardly responsive to upward movement of the bowden cable 282.
Referring now to FIG. 6B, the mechanical actuator 234 is simply placed over the elongated sleeve portion 230 of the body and actuator connector element 228. The rack pin 246, extending below the lower extremity of the cylindrical body 238, is received in closely fitting engagement within a bore 284 defined in the body and actuator connector element 228. A sealing element 286, such as an O-ring or the like, is received within an annular groove defined in the rack pin 246 and establishes sealing engagement between the rack pin and bore 284. The lower extremity of the rack pin 246 is cut away as shown at 288 to define an offset piston actuating portion 290 that is positioned in registry with the piston chamber 74. After limited downward movement, the lower extremity of the piston actuating portion 290 will contact the upper extremity of the piston element 76 and, upon continued downward movement of the rack pin 246, the piston actuating portion will drive the piston 76 downwardly. As the piston element is moved downwardly by the mechanical actuator mechanism with sufficient force to overcome the force of the compression spring 102 and the force developed by formation pressure acting upon the valve actuator sleeve, the valve element 130 will be caused to move its open, protected position as illustrated in FIG. 5D.
For the purpose of providing pressurized hydraulic fluid for pressurization of the piston chamber 74, the body portion 238 of the mechanical actuator 234 will be formed to define an elongated slot 292 and the cable connector element 270 will be provided with a registering external slot 294. A hydraulic fluid supply conduit 296 is received within slots 292 and 294 and within a slot 298 defined in the connector sub 220. This conduit will extend upwardly through the well bore and within the production tubing as illustrated in FIG. 1 where a pressurized source of hydraulic fluid will be located and will be provided with such controls as is appropriate for achieving controlled operation of the safety valve mechanism. The body and actuator connector element 288 is formed to define an enlarged connector receptacle 300 communicating with a hydraulic fluid supply bore 302 that communicates with the annular piston chamber 74. An enlarged connector element 304 is received within the receptacle 300 and is restrained in position within the receptacle by the lower surface 306 of the mechanical actuator body 238 which bears against an annular shoulder 308 defined by the conduit connector element 304. Thus, upon assembly of the mechanical actuator mechanism, the hydraulic supply conduit is positively interconnected with the body and actuator connector element for the supply of pressurized hydraulic fluid to the piston chamber. An annular sealing element 310 is retained within an annular chamber to insure a positive seal between the connector element 304 and the body and actuator connector element 228. Thus, it is apparent that provision of the mechanical actuator mechanism 234 allows the piston element 76 to be operated either hydraulically or mechanically to the open position thereof. Closing movement in either case is controlled by the stored energy of the compression spring 102 and the force induced to the actuating sleeve 98 by formation pressure. The mechanical actuator mechanism provides a mechanical override backup system for achieving valve opening under circumstances where the hydraulic system may be rendered inoperative.
In view of the fact that the safety valve mechanism of the present invention is designed for insertion through the tubing string of a well, it is obvious that the maximum outside dimension of the valve mechanism is critical. The maximum outside dimension could, in some circumstances, require the compression spring 102 to be of restricted size and it may be difficult to provide a single helical compression spring capable of developing the desirable force for valve closing movement. As shown in FIGS. 10 and 11, a modified spring package may be provided wherein a plurality of compression springs are utilized to provide a designed closing force for the valve mechanism. The spring capsule, illustrated generally at 312, is dimensioned for insertion into the spring chamber 104 for replacement of the single compression spring 102. A pair of generally cylindrical spring receptacles 314 and 316 are provided, each being drilled or otherwise formed to define a plurality of elongated, slotted spring retainer receptacles 318. A plurality of compression springs 320 are provided having the extremities thereof disposed within the spring receptacles of respective ones of the spring capsule sections 314 and 316. In order to provide a more clear understanding of the present invention, the upper portion of the spring capsule illustrated in FIG. 10 is broken away showing only one of the compression springs 320 together with the relationship of the compression spring to the spring receptacle 318.
Within each of the compression springs is provided an inner support rod 322 that is of sufficient length to bridge the space between spring retainer elements 314 and 316 at the widest separation thereof. The inner support rods provide against transverse beinding of the compression springs, thereby allowing each of the compression springs to develop maximum resistance upon being compressed by downward movement of the piston and actuating sleeve. Obviously, the maximum force potential of the spring capsule will be achieved when compression springs are retained within each of the receptacles. The force resistance of the spring capsule may be modified by eliminating some of the compression springs, thereby promoting a valve design incorporating a spring package that can be calculated to provide designed force resistance. The receptacles move into abutment under maximum force and prevent over compression of the springs. Also, the fully collapsed spring capsule provides a mechanical stop function to limit movement of the valve actuating sleeve 98, thus preventing severe forces from acting on the pin elements 176 and 178.
Although the present invention has been discussed heretofore in its application particularly to its service as a safety valve in a down hole well environment, it is not intended in any manner whatever to restrict utilization of the present invention to such use. In the embodiment illustrated in FIG. 12, a valve mechanism incorporating the basic features of the present invention may be utilized as a controllable flowline valve which may be utilized in hazardous environments where valve stem leakage from typical valves cannot be tolerated. The flowline valve which is illustrated generally at 324 incorporates a generally cylindrical body portion 326 having end sections 328 and 330 secured thereto by means of bolts or cap screws 332 or by any other suitable form of connection. The end closure elements 328 and 330 are sealed with respect to the cylindrical body 326 by means of annular sealing elements 334 and 336 that are retained within end grooves formed in the body 326. A pair of connector flanges 338 and 340 are formed integrally with the end closure elements 328 and 330 and provide means for establishing connection between the valve mechanism and a flanged flowline, not shown. Obviously, any other suitable means for connecting the valve mechanism to a flowline may be incorporated within the spirit and scope of the present invention.
Each of the end closure elements defines respective inwardly projecting cylindrical hubs 342 and 344 which cooperate with inner cylindrical surface 346 of the body 326 to define a pair of spaced piston chambers 348 and 350. An elongated piston element 352 is provided having each extremity thereof received within respective one of the piston chambers 348 and 350. A piston element is sealed with respect to the valve structure by outer sealing elements 354 and 356 that engage the internal cylindrical surface 346 of the body and by inner annular sealing elements 358 and 360 that engage the cylindrical surfaces 362 and 364 of the inwardly extending hubs.
The piston element is formed to define an internal support flange 366 that defines a plurality of threaded holes 368 receiving bolts or cap screws 370 for the purpose of securing a valve support body 372 in supported relation with the internal flange 366. The bolts or cap screws 370 extend through apertures in a connection flange 374 of the valve support body and positively secure the flange and the valve support body in immovable engagement with the internal support flange 366.
The valve support body 372 is of generally cylindrical cross-sectional configuration and includes a bifurcated extremity defining a pair of support arms 376 each having pivot apertures 378 formed therein and adapted to receive pivot elements 380 to establish pivotal engagement between the support arms 376 and a pair of pivotal support elements 382 of a valve element illustrated generally at 384.
Hub member 342 establishes an internal receptacle 386 adapted to receive a rack body 388 that is secured in assembly with the end closure element 328 by a plurality of bolts or cap screws 390. The lower portion of the rack element 388 is formed to define opposed pairs of planar guide surfaces 392 and 394 with rack teeth 396 being defined between the planar guide surfaces. Each of the pivotal portions 382 of the valve element 384 are formed to define pinion gear teeth 398 interposed between planar guide surfaces 400 and 402, the guide surfaces 400 and 402 being disposed in normal relation to each other in order to facilitate 90° rotation of the valve element. As the valve element is moved longitudinally along with the valve support body 372 and piston element 352, the valve element will have an initial increment of linear movement followed by 90° rotational movement resulting from interaction of the pinion gear teeth with the rack teeth and subsequently followed by another increment of linear movement as the valve element is retracted to a protected piston. Valve actuation is substantially identical as compared to the down hole safety valve structure described above in connection with FIGS. 1-4.
For the purpose of protecting the valve element from erosion and to define a through conduit type flow path, an elongated tubular element 404 is positioned within the valve and cooperates with the annular hub 342 to define a protected receptacle 406 within which the sealing portion of the valve element may be retracted in essentially the same manner as discussed above in connection with tubular element 172 of FIG. 2. The elongated tubular element 404 is provided with an annular flange 408 at one extremity thereof which is adapted to be received within a flange recess 410 defined at one extremity of the rack body 388. The flange 408 is retained by a rack body against the end surface 412 to maintain the tubular element 404 in proper position within the valve chamber so as to align the internal flow passage 414 thereof with the straight through flow passage 416 of the valve mechanism.
At the right hand portion of the valve mechanism shown in FIG. 12, an elongated tubular element 418 is provided which is secured to the end closure element 330 by means of bolts or cap screws 420 that extend through apertures formed in an annular connection flange 422. The tubular element 418 is formed at the free extremity thereof to define an annular seat surface 424 that is positioned for sealing engagement by a sealing surface 426 formed on the valve member 384. Sealing surface 426 and seat member 424 may be of partially spherical configuration if desired, or may take any other convenient form for establishment of proper sealing engagement. The tubular element 418 is also formed to define a pair of elongated opposed slots 428 and a pair of connector pins 430 extend through the slots 428 and establish connection between the movable valve support body and a masking tube 432 that is movably received within a cylindrical recess 434 defined cooperatively by end closure element 330 and tubular element 418. As the valve support body 372 is moved linearly by the piston element 352, the masking tube 432 will move linearly along with the valve support body by virtue of its pinned connection therewith. The opposed slots and connector pins may be of similar configuration and operation as those illustrated and described in conjunction with FIGS. 2B and 3. One extremity of the masking tube 432 is formed to define a seat surface 436 which is capable of establishing seating engagement with a mating seat surface 438 defined by the free extremity of the tubular element 404. Upon full rotation and retraction of the valve element 384 into the protective receptacle 406, the masking tube 432 will have moved linearly sufficiently to bring the seating surface 436 into engagement with seating surface 438 of tubular element 404. Fluid will be allowed to flow through the flow passage 416 of the valve and any erosive substance contained within the flowing fluid will not erode or file the valve element.
For the purpose of imparting operative movement to the piston element 352, the valve body 326 is formed to define a pair of bosses 440 and 442, each being formed to define internally threaded openings 444 and 446, respectively. Fluid supply conduits 448 and 450 may be interconnected within the threaded openings 444 and 446 for the purpose of supplying pressurized hydraulic fluid to piston chambers 348 and 350 as required for operation of the valve. Conduits 448 and 450 are interconnected with a control system schematically illustrated at 5C, which control system may take any convenient form for selectively and controllably introducing hydraulic fluid into piston chambers 348 and 350 or receiving hydraulic fluid from these chambers. The internally threaded openings 444 and 446 are communicated with piston chambers 348 and 350 by means of fluid ports 452 and 454.
From the standpoint of operation, it should be borne in mind that the valve mechanism of FIG. 12 is typically a unidirectional valve with flow being shown in the direction of the flow arrow located at the left hand portion of the flow passage 416. The valve can function, however, with flow in the opposite direction.
In view of the foregoing, it is readily apparent that I have provided a valve mechanism that may be efficiently utilized either in a down hole well environment as a safety valve or storm choke or as a packingless hydraulically or pneumatically controllable valve for flowlines. In each case, a valve mechanism is employed incorporating a valve element that may be retracted to a protected position where it may not be contacted by erosive materials contained within the flowing fluid handled by the valve mechanism. In the down hole well environment, the valve mechanism may function as a safety valve or storm choke incorporating combined forces of stored energy from a compression spring and force developed by formation pressure to achieve automatic closure of the valve in the event a hazardous predetermined condition occurs.
As a flowline control valve, a hydraulic actuating system may be provided for inducing opening and closing controlling to the valve mechanism and it will not be possible for the valve mechanism to leak fluid as might otherwise occur upon failure of a conventional operating stem packing. This feature promotes a valve mechanism that satisfactorily functions in hazardous environments and may be efficiently controlled at a substantial distance from the site of the valve itself.
I have provided a spring package that may be substituted for a single compression spring for a valve operating in a down hole well environment. The maximum force developed by the spring package may be selectively adjusted simply by selective deletion of springs, thereby promoting automatic valve control responsive to designed pressure and well conditions.
It is clearly evident that I have provided a valve mechanism which incorporates all of the features and objects hereinabove set forth together with other features and objects which are inherent in the construction of the valve mechanism itself. Although the present invention has been described in its particular application to down hole safety valves and flowline valves, it is not intended to limit the invention in any manner whatever. | An actuatable safety valve for the production tubing of wells and/or fluid flowlines includes a valve element having both linear and rotary components of movement within a valve body and is actuated by a lost-motion rack and pinion gear actuating mechanism. The clam-shell pinion gear is moved linearly within the valve body by a hydraulic sleeve piston actuator for causing control valve movement responsive to hydraulic control of the sleeve piston. The sleeve piston is also responsive to upstream pressure for pressure actuation of the valve to its closed position. The valve element is also mechanically movable to its closed position. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to mobile support structures and, more specifically, to mobile support structures to be used as break walls and flood walls.
During floods, storms and bad weather, it may be necessary to quickly construct and erect levees, dams or the like along river banks and other water sources to protect against flood damage. Similarly, during particularly rainy seasons or heavy spring thaws it may be necessary to construct a temporary flood wall or dam until the water levels subside. Conventionally, this has been done by stacking sand bags upon one another to form a wall or barrier. However, this can be an arduous and difficult process. Thus, artificial walls have been designed that are easier to assemble and construct.
Some contemplated structures have included inflatable walls. While these bladder-type walls do form a barrier to keep water away, the size of the formed dam cannot be easily adapted to accommodate different sized areas. Thus, if the area that needs to be dammed is larger than expected, it is not easy to stack such structures upon one another, thereby limiting their utility in emergencies. Similarly, such structures are generally space intensive, which is inhibitive for use by individuals.
Other structures have been designed that comprise interconnectable blocks that can be stacked to form a wall structure. As an example, Zetzsch, U.S. Pat. No. 5,984,576, shows a mobile barrier that has blocks that can be connected using S-shaped block ends that fit together. The blocks form an airtight structure that stacks vertically upward. However, the blocks are not interconnectable horizontally, or side to side, which limits the efficiency of using the blocks for areas that do not correlate directly to the size of the blocks. If the length of the wall needs to be extended, the wall will not easily form a complete sealing structure.
Lefebvre, U.S. Pat. No. 6,394,705, discusses a modular flood wall that has interlocking blocks having hollow interiors that can be filled with material to give the wall added support. Thus, the wall is light-weight for transportation and assembly purposes, but will form a solid, sturdy structure when it becomes filled. Still, the modular blocks are not designed so that they can be stacked in an upwardly interlocking fashion, which limits the height of the wall. If it was necessary to stack the blocks upon one another, they would not necessarily form a tight seal, and it may be difficult to fill lower level blocks with material.
Arnett, U.S. Pat. No. 422,901, discusses the use of blocks that may be stacked upon one another to form a dam. However, the discussed blocks are not lightweight, which does not make the wall as useful as necessary in emergency situations. The system is not designed as a lightweight portable structure that may be easily erected in emergency situations.
Thus, it would be advantageous to devise a portable flood wall that provides adequate protection against flooding, while being easy to erect and transport. The wall should also evenly disperse the pressure that comes from the retained water pushing against the wall. A lightweight, yet durable wall that can be used to fix flood leaks of varying sizes is thus contemplated.
SUMMARY OF THE INVENTION
The present invention comprises interlocking, stacking blocks having a hollow interior that can be easily filled with water so that the wall will have added strength and stability when holding back flood waters. Ideally, this modular flood wall structure will be used in place of sandbags that are commonly used to prevent flooding in those certain areas.
The invention comprises a base and a series of variously shaped modular building elements or blocks that fit together in much the same way as Legos™ blocks. One or more protuberances are formed in the upper surfaces of each block and one or more mating receptacles are formed on the lower surfaces. Alternatively, this arrangement could be spatially reversed. In order to act as a retaining wall, these blocks are actually hollow vessels that are filled with water in order to lend strength and stability to the wall structure itself. Ideally, the walls will themselves be watertight and, to that end, each of the blocks is provided a seal structure on its adjoining surfaces to prevent the passage of water therebetween. One such structure includes a series of interlocking ribs formed in the abutting surfaces of the blocks, though other types of structures may be envisioned. In addition, the present invention may be used alone or in conjunction with sandbags and/or watertight membranes to form a wall that will hold back floodwaters.
Each of the blocks comprises a hollow vessel having a generally cubic/rectangular shape in a first embodiment. The upper surface of each of the blocks is provided with a series of projections or protuberances that are constructed and arranged to be received within a series of complementary receptacles or receptacles formed into the bottom surfaces of the blocks. The base of the flood wall structure is essentially an elongate sheet having raised ribs formed on its edges. The elongate base is typically staked to the earth in a desired location and the blocks are placed thereon between the ridges on the base's edges. It is preferable to fill each course of blocks with water prior to placing a subsequent course of blocks thereover. In order to support the weight of the blocks and water, it is preferred to emplace various support structures within the blocks themselves. The support structures typically comprise a series of posts or columns disposed around the exterior edges of the interior walls of the blocks with at least one center support also being placed therein. Alternatively, the supporting structures or columns may be formed as a rigid structure exterior to the blocks themselves.
Alternatively, the assembled wall may also include blocks that are not composed of cubical or parallelepiped shaped blocks. Such an arrangement of blocks may be advantageous for constructing a wall on a sloped surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away perspective view of a modular flood wall assembly according to the present invention.
FIG. 2 is a perspective view of a support base according to the present invention.
FIG. 2A is an elevated side view of the support base of FIG. 2 .
FIG. 2B is an elevated side view of an alternate embodiment of a support base according to the present invention.
FIG. 3 is a perspective view of a building block according to the present invention.
FIG. 4 is a bottom perspective view of the block of FIG. 3 .
FIG. 5 is a cross-sectional view of the building block taken along line 5 - 5 of FIG. 3 .
FIG. 6A is a cross-sectional view of the building block taken along line 6 A- 6 A of FIG. 3 showing the internal support structures of the block.
FIG. 6B is a cross-sectional view of a building block showing an alternate internal support structure to that shown in FIG. 6A .
FIG. 7 is a partially cut-away view of the modular flood wall assembly.
FIG. 8 is a cross-sectional view of the flood wall assembly taken along line 8 - 8 of FIG. 7 .
FIG. 9 is a perspective view of an alternate embodiment of a building block and flood wall assembly used in the present invention.
FIG. 10 provides a perspective view of a block according to the present invention.
FIG. 11 is a perspective view of another embodiment of the present invention.
FIG. 12 is a perspective view of an alternate arrangement of the modular flood wall assembly of the present invention.
FIG. 13 is a perspective view of an alternate sized building block according to the present invention.
FIG. 14 is a perspective view of an alternate embodiment of a building block according to the present invention.
FIG. 15 is an overhead view of a further embodiment of a building block according to the present invention.
FIG. 16 is an overhead view of a flood wall assembly using building blocks shown in FIG. 15 .
FIG. 17 is another alternate flood wall assembly according to the present invention.
FIG. 18 is further flood wall assembly according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
FIG. 1 shows a perspective view of a modular wall assembly 10 . The assembly generally comprises a base member 12 and a plurality of stackable blocks 14 . Each of the blocks 14 has a plurality of protuberances 16 . The protuberances 16 are arranged so that the blocks 14 can be easily mated with one another in an interlocking fashion to form a solid wall. As shown, the blocks 14 can be of differing sizes from one another. The base member 12 preferably is secured to the ground or other external force with stakes, rods, or other possible securing devices (not shown).
As shown in FIGS. 2 , 2 A, and 2 B, the base member 12 also has a plurality of ribs 17 , designed similarly to the protuberances 16 located on the blocks 14 . The ribs 17 allow the blocks 14 to be secured upon the base member 12 to form the eventual wall assembly 10 (see FIG. 8 ). The base member 12 is preferably an elongated sheet of flexible material, possibly a rubber, vinyl, or plastic material, but any other suitable materials, such as a lightweight tin or aluminum material, may be used. As previously stated, the base member 12 will be secured to the ground using stakes or other conventional securing devices. An extension 19 may be located on the base member 12 , preferably integral as one piece with the base, to prevent flood water from seeping under the base member 12 . The extension 19 will be angled downward, which will assist in preventing the water from eroding away the dirt underneath the base member 12 . Various designs can be seen as extension 19 a ( FIG. 2A ), which has a curved or hook shape, and an extension 19 b ( FIG. 2B ), having a shape designed for digging into the ground surface. Preferably, the base member 12 is long enough that it will accommodate several blocks 14 . As a way of example, the base member 12 may consist of a long length of pliable material that could then be sized accordingly, by folding or cutting, to the required size of the flood wall.
FIG. 3 shows a perspective view of an individual block 14 . The block 14 has a top surface 18 and a bottom surface 20 . It should be understood that the use of a top surface and a bottom surface should not limit the blocks 14 to any specific spatial arrangement, but rather to distinguish one side from the other. The protuberances 16 extend outwardly from the top surface 18 of the block 14 . As shown in FIG. 3 , the block 14 is shown having a generally cubical arrangement with four identical sides 22 . However, the blocks 14 could be rectangular or another geometrical shape, provided that the blocks could be interlocked and stacked as described herein. As a comparison, FIG. 1 shows blocks 14 having a more elongated rectangular shape compared to the cubical shape shown in FIG. 3 . The symmetrical arrangement of the block 14 allows for easy orientation when erecting the wall assembly 10 . The protuberances 16 are hollow, thereby allowing access into the interior 24 of the block 14 (see FIGS. 5 , 6 A, 6 B and 8 ). This allows the block 14 to be filled with water when constructing the wall assembly 10 , which gives the wall additional strength and support when buttressing flood waters (see FIG. 7 ).
FIG. 4 is a bottom perspective view of the block 14 . The bottom surface 20 also has a plurality of receptacles 26 located thereon. The receptacles 26 extend inwardly into the interior 24 of the block 14 , which provides an area for the protuberances 16 on the top surface 18 to mate with the receptacles 26 on the bottom surface 20 (see FIG. 8 ). The receptacles 26 can generally be described as inverted protuberances 16 , which allows for a secure mating arrangement. The receptacles 26 and protuberances can be of any shape or size, provided they form a sufficient mating arrangement. As with the protuberances 16 , the receptacles 26 are also hollow, which allows access into the interior 24 of the block 14 .
FIGS. 3 and 4 can be viewed as showing an inverted embodiment of the block 14 , as well. That is, FIG. 3 could be showing the bottom surface of a block, where the protuberances 16 are located on the bottom surface, and FIG. 4 would then be depicting the top surface of a block, where the receptacles 26 are located on the top side. Alternatively, the top surface 18 and the bottom surface 20 could have protuberances and receptacles located on each respective side. An example of such an embodiment is shown in FIG. 11 . The block 214 has both protuberances 16 and receptacles 26 on each side of the block 214 . Provided that the arrangement of the protuberances 16 and receptacles 26 on the top and bottom surfaces will allow an individual block to mate with a corresponding block, the arrangement would fall within the scope of the present invention.
FIG. 5 provides a cross-sectional view of the block 14 . The block 14 has a center support 28 that extends from the bottom surface 20 to the top surface 18 . The block also has a plurality of side supports 30 that are preferably symmetrically arranged for further stability of the block 14 . The supports 28 and 30 add stability and rigidity to the blocks 14 without significantly increasing the mass of the empty blocks 14 and without preventing the flow of water throughout the interior 24 of the blocks 14 when filling the blocks 14 with water.
FIG. 6A shows a cross-sectional view of the block 14 taken along line 6 A- 6 A of the block 14 of FIG. 3 . As previously stated, the center support 28 extends from the bottom surface 20 to the top surface 18 . The side supports 30 reinforce the strength in the corner of the blocks 14 , without adding significant weight to the blocks 14 . It is understood that depending on the size of the blocks 14 , there may be more or fewer supports located within the interior 24 of the block 14 . As can also be seen in FIG. 6A (and FIG. 6B ), the hollow design of the protuberances 16 and the receptacles 26 will allow water to pass through the interior to a block located below the block 14 . This will be more evident with respect to FIGS. 7 and 8 . FIG. 6B shows an alternate arrangement for a center support 128 and side supports 130 . The supports 128 and 130 are designed of angled braces 132 , which provide a structural support for the block 14 , but will be lighter. This may be advantageous in moving and arranging larger sized blocks.
Referring again to FIGS. 3-5 , the sides 22 of the block 14 further comprise coupling areas 32 . The coupling areas 32 allows side by side blocks to be connected to one another, thereby strengthening the wall and further preventing leaking in between the individual blocks 14 . The coupling areas 32 can be of any size or shape that will allow side by side blocks 14 to be joined together. Each side 22 preferably has a coupling area 32 . As shown, the coupling areas 32 preferably have a simple, symmetrical shape, with both a male area 34 and a female area 36 within each coupling area 32 . The coupling areas 32 are designed with sufficient depth and interconnectability to prevent water from seeping between two blocks 14 . Having a coupling area on each side of the block 14 provides for an overall easier construction of the assembly 10 , since the blocks 14 can be connected or locked together with an adjacent block 14 from any side 22 . It is also possible to design the blocks 14 with only one set of opposing sides having coupling areas 32 . Preferably, the coupling areas 32 are formed of a material that is flexible enough so that the blocks will seal easily when filled with water.
FIG. 7 shows a partially cut-away view of the wall assembly 10 . The interior 24 of the blocks 14 are shown containing water, which gives the wall assembly 10 added strength and stability. The blocks 14 are also stacked with each tier of blocks 14 alternating in alignment so that the blocks 14 in one tier overlap the blocks 14 in the tier above and below that tier. This provides further stability for the wall assembly 10 . Also, because of the hollow protuberances 16 and receptacles 26 , the staggered arrangement allows all of the blocks 14 in a tier to be evenly filled with water in a simple fashion. Essentially, the arrangement allows the individual interiors 24 of each of the blocks 14 to act as a single interior, which makes filling with water a straightforward process and, also, evenly distributes weight within the wall. Because the water will evenly flow through the blocks 14 , weight will be evenly dispersed throughout the wall. Prior art modular structures that do have hollow interiors may not be filled with water quickly and efficiently as can be accomplished in the present invention.
FIG. 8 shows a cross-sectional cut-away view of the assembly of FIG. 7 . Because the receptacles 26 and the protuberances 16 are open, water may flow between the blocks 14 , which allows for each tier of the blocks 14 to be evenly filled. The blocks 14 are depicted as being symmetrical, with the protuberances 16 and the cavities 26 being vertically aligned with one another on each block 14 , which also allows for vertical alignment of the protuberances and cavities 26 on corresponding blocks 14 . The open water way consisting of the interiors 24 of the blocks 14 provides a much easier and more efficient arrangement for filling the wall assembly with water or other fluid than prior art arrangements. While it is understood that all of the protuberances 16 and receptacles 26 are preferably hollow, it is understood that in some embodiments some of the protuberances and/or receptacles may be sealed. The bottom protuberances 26 a are preferably sealed so that water will not flow between the base member 12 and the bottom row of blocks 14 .
FIG. 9 shows another embodiment 110 of the present invention. The wall assembly 110 is similar to the assembly 10 , except that blocks 114 do not have a parallelepiped shape or cubical shape. A side wall 122 a is not parallel to a side wall 122 b . Because the ground or other external surface that the wall 110 is situated between may be sloped, a wall using only square blocks 14 would not allow for even stacking of successive rows. Preferably, a top surface 118 is parallel to a bottom surface 120 . The blocks 114 allow a wall to be erected quickly on a variety of surface contours while still providing for a vertical wall assembly 110 . The shape of the blocks 114 could be designed for any shape necessary for a respective area of ground. The angle θ formed between the side wall 122 b and the bottom surface 120 may be any desired angle. The remaining area of the assembly 10 would use blocks 14 , as previously discussed.
FIG. 10 shows the block 14 having an inlet 38 containing a plug 40 . The inlet 38 allows for an alternate place to fill the blocks 14 with water. The inlet 38 may be located anywhere on the side 22 and may be of any design, such as a spigot that could be coupled to a hose. The inlet 38 would make draining of the blocks 14 quicker once the wall assembly 10 is no longer needed. Also, the protuberances 116 have a circular shape, compared to the square protuberances 16 previously depicted. The protuberances 116 demonstrate that any shaped protuberance (and cavity) will fall within the scope of the present invention.
FIG. 12 shows a perspective view of an alternate wall assembly 310 . The assembly 310 is essential as the assembly 10 previously discussed, except the assembly 310 is shown forming a corner. Because of the symmetrical arrangement and design of the protuberances 16 and the coupling areas 32 on the blocks 14 , a corner is easily formed, while still providing sealing arrangement. The design of the blocks 14 would allow for a wall arrangement having a T-shaped or L-shaped arrangement.
FIG. 13 shows an alternate block 414 . The block 414 demonstrates that the blocks can be designed of any size depending on specific needs. Because the blocks are of lightweight material, the blocks may be designed of larger sizes than prior art blocks. For example, the block 414 may be easily constructed as 4′×4′×4′ blocks, and still be easy to move and construct. While the size of the blocks may be designed of any dimensions, symmetrical blocks as discussed would be most advantageous for manufacturing and wall assembly purposes.
FIG. 14 shows a yet further embodiment of a block 514 . The block 514 is similar to the previous embodiments except that protuberances 16 are located on the side wall 22 as well as on the top surface 18 . Receptacles 26 (not shown) would be located on the opposing side wall 22 to mate with the protuberances 16 in the same fashion as previously described with respect to the previous figures and blocks. The use of the protuberances 16 further allows water to flow through the blocks 514 so that water within the blocks 514 will be evenly distributed throughout the blocks 514 , similarly to the description of the wall assembly 10 in FIGS. 7 and 8 . The blocks 514 are shown with a coupling area 32 . However, because the protuberances 16 and the receptacles 26 will further secure and seal the block 514 to a corresponding block 514 , the coupling area 32 could be optional, and the protuberances 16 and the receptacles 26 would act as a coupling area. Also, the protuberances 16 could be placed in other places on the side walls 22 , such as centrally located where the coupling area 32 is shown in FIG. 14 . When the blocks 514 are used to construct a wall, it is preferable that the protuberances 16 located on the outermost blocks either be sealed, or the outermost side walls 22 could be designed without protuberances 16 (as in blocks 14 ), to prevent leaking.
FIGS. 15 and 16 depict blocks 614 having a different protuberance 616 and receptacle 626 (shown in phantom) arrangement. Previously, the protuberances 16 and receptacles 26 (see FIG. 8 ) were of relatively the same size, so that they would have a tight fitting relationship. While the mating principles are similar to those previously discussed, the protuberances 616 are designed to be of a smaller diameter/cross-sectional area than the corresponding receptacles 626 , so that an upper row of blocks 14 can be arced or turned, to adjust for the need of a curved wall. The difference in the area of the protuberances 616 and the receptacles can be varied as necessary. However, it is preferable that the differences in the areas of the protuberances 616 and the receptacles 626 are not too great, to still allow the wall to form an adequate retention structure.
FIGS. 17 and 18 provide alternate designs that provide curved or arced walls. In FIG. 17 a corner block 714 allows the wall to be angled. In the row or tier of blocks below the corner block 714 are mating angled blocks 714 a and 714 b (shown in phantom) to allow the corner block 714 to fit upon the angled blocks 714 a and 714 b . The angle or angles of the blocks 714 , 714 a , and 714 b can be of any desired angle. The remaining blocks can be of the structure as previously described in the preceding Figures. FIG. 18 provides a similar arrangement to that of FIG. 17 except a curved block 814 is used in place of the block 714 . Likewise, curved angled mating blocks 814 a and 814 b (shown in phantom) are used in place of blocks 714 a and 714 b . Provided that a wall having an internal water pathway is formed as described, the angles and shapes of the blocks should not limit the scope of the present invention. The mating principles for the protuberances 16 and the receptacles 26 , to allow flow of water through the interiors 24 of the blocks, are the same as previously discussed.
Preferably the blocks are filled with water after each layer of blocks is laid down for support purposes. However, because of the fact that all of the individual interiors 24 are preferably open to one another, it may also be possible to fill the blocks after the wall is completed. This flexibility further enhances the novelty of the present invention. As the wall is filled with water, the weight of the water will not only provide extra stability to the wall, but will also assist in the necessary sealing between adjacent blocks.
It is preferred that the blocks be fabricated from a plastic material as by injection molding or blow molding or other known molding procedures. Rotational molding may also be used for forming the blocks. Given the size of these blocks, and given the need to emplace support structures therein, one process of constructing the individual blocks is to form the block in two halves and thereafter weld the halves together with known plastic welding techniques.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. | A modular flood wall assembly having a relatively flat base member having a plurality of ribs extending therefrom. The assembly further comprises a plurality of interconnectable blocks, with each block having a top surface with at least one hollow protuberance, at least one side wall, a hollow interior, and a bottom surface having at least one hollow cavity. The cavities on the bottom surface of the blocks are matable with the ribs on the base member. The protuberances on the top surface of the blocks are matable with the receptacles on the bottom surface of a corresponding block. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims the benefit of U.S. Provisional Patent Application No. 61/544,821, entitled “Scalable Quantum Computer Architecture with Coupled Donor-Quantum Dot Qubits,” filed on Oct. 7, 2011, which is expressly incorporated by reference herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with government support under Contract No. DE-AC02-05CH11231 awarded by the United States Department of Energy to The Regents of the University of California for management and operation of the Lawrence Berkeley National Laboratory. This invention was also made with U.S. Government support under the National Security Agency Contract No. 100000080295. The government has certain rights in this invention.
BACKGROUND
1. Field
The present disclosure relates to quantum computing and, more particularly, to scalable computing architectures with coupled donor-quantum dot qubits.
2. Description of Related Art
Electron and nuclear spins of donors in silicon have long been recognized as promising qubit candidates. In isotopically purified 28 Si they exhibit long coherence times on the order of seconds and their integration can benefit from the great fabrication finesse of silicon nanotechnology. Several concepts for scalable quantum computer architectures with donor spin qubits have emerged. In one proposed aspect of quantum computing (QC), quantum information may be stored in the nuclear spin of phosphorus atoms. Electrostatic gates facilitate transfer of quantum information from nuclear to electron spins and between electron spins, by modulating the contact hyperfine interaction (A-gates), and the Heisenberg exchange coupling (J-gates), respectively. Recently, reliable detection of single electron spins and the control of single electron and nuclear spin states has been observed. For the development of a large scale quantum computer, elements of quantum memory, quantum logic and efficient quantum communication channels may be integrated. While single donor electron and nuclear spin readout and control have been demonstrated, the mastering of spin qubit coupling so that two and multiqubit logic operations can be implemented is still needed. In early concepts of donor qubits, coupling was envisioned along 1D chains of nearest neighbor coupled qubits. While this may suffice for two or three qubit logic demonstrations, severe limitations of nearest neighbor coupling have been noted. Coherent shuttling of electrons between donors has been proposed as a path to circumvent the nearest neighbor coupling challenges or supplement nearest neighbor coupling with a longer range coupling option. For electron shuttling, two important aspects include spin coherence of donor electron and nuclear spins during cycles of ionization and recombination. Other potential paths for long range transport of quantum information from donor spins include concepts of a spin bus, virtual phonon mediated coupling, coupling via nano-mechanical resonators and spin-to-photon coupling in optical cavities or via high Q microwave resonators.
In parallel to single donor spin control, control of electron spins in silicon and Si—Ge based quantum dots has developed. Here, quantum information can be encoded, e. g., in the spin state of a coupled pair of electrons in a double quantum dot structure. For spin based quantum computers with donors, the nuclear spin represents a promising mode for quantum memory. Electrons of donors and dots allow fast single qubit operation and nearest neighbor two-qubit interactions through controlled exchange coupling. Cluster state quantum computer approaches offer an alternative approach e. g. with nuclear spin memory that “only” require nearest neighbor interactions and reliable single qubit control and readout.
SUMMARY
Disclosed is a quantum computer architecture where donor nuclear spins are coupled via donor electron spins to spins of electrons in quantum dots, enabling further coupling, e. g., to high Q resonators for quantum communication or enabling cluster state QC implementations without need for donor ionization and coherent recombination. Practical implementation of such a donor-dot architecture may be considered, i. e., fabrication of back gated, vertical aligned quantum dots-to single donors in a semiconductor layer that may be isotopically purified 28 Si, a Si—Ge heterostructure, or the like, which may be epitaxially grown.
In an aspect of the disclosure, a quantum bit computing architecture includes a substrate, a buried oxide layer on the substrate, a semiconductor layer on the buried oxide layer, a dielectric insulator on the semiconductor layer, one or more spin memory donor atoms embedded in the semiconductor layer, and a quantum dot embedded in the semiconductor layer above and aligned with each of the donor atoms. A one or more top gate electrodes above and adjacent to the dielectric layer are aligned to control the quantum dots. A back gate opposite the one or more donor atoms and adjacent to the buried oxide are provided, wherein a voltage applied between the top gates and the back gates controls the donor-quantum dot coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows, in an aspect of the disclosure, a schematic of a spin qubit architecture;
FIG. 2 shows, in an aspect of the disclosure, a more detailed schematic of a spin qubit architecture.
DETAILED DESCRIPTION
Various aspects of the present invention will be described herein with reference to drawings that are schematic illustrations of idealized configurations of the present invention. As such, variations from the shapes of the illustrations as a result, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, the various aspects of the present invention presented throughout this disclosure should not be construed as limited to the particular shapes of elements (e.g., regions, layers, sections, substrates, etc.) illustrated and described herein but are to include deviations in shapes that result, for example, from manufacturing. By way of example, an element illustrated or described as a rectangle may have rounded or curved features and/or a gradient concentration at its edges rather than a discrete change from one element to another. Thus, the elements illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the precise shape of an element and are not intended to limit the scope of the present invention.
It will be understood that when an element such as a region, layer, section, substrate, or the like, is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be further understood that when an element is referred to as being “formed” on another element, it can be grown, deposited, etched, attached, connected, coupled, or otherwise prepared or fabricated on the other element or an intervening element. In addition, when a first element is “coupled” to a second element, the first element may be directly connected to the second element or the first element may be indirectly connected to the second element with intervening elements between the first and second elements.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of an apparatus in addition to the orientation depicted in the drawings. By way of example, if an apparatus in the drawings is turned over, elements described as being on the “lower” side of other elements would then be oriented on the “upper” side of the other elements. The term “lower” can therefore encompass both an orientation of “lower” and “upper,” depending of the particular orientation of the apparatus. Similarly, if an apparatus in the drawing is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The terms “below” or “beneath” can therefore encompass both an orientation of above and below.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this disclosure.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term “and/or” includes any and all combinations of one or more of the associated listed items.
The scalable quantum computer architecture based on coupled donor-quantum dot Qubits relies on integration of several modules and interaction processes: a single donor nuclear spin memory coupled to the donor electron spin through the contact hyperfine interaction for storage and retrieval of quantum information, where the donor electron spin couples to the spin of an electron in a vertically aligned quantum dot, with a voltage gate controlling the exchange coupling. In effect, electron spins in quantum dots are coupled to a nuclear spin memory. Readout of quantum information can be performed on either the donor or quantum dot electron spins, e. g., through spin dependent tunneling. Single qubit operations can be performed on the donor electron spin and on the dot electron spin with pulsed microwaves, which can be delivered locally or globally by placing devices into microwave cavities. Two qubit operations can be implemented between spins of donor and dot electrons and on electron spins of adjacent dots. Here, a large enough magnetic field (e.g., >10 mG/nm) may be applied to detune the spin resonance lines for adjacent donor-dot devices, e. g., through the presence of micro-magnets or local inductors.
FIG. 1 shows a schematic of a spin qubit architecture 100 with vertically coupled donors 105 and quantum dots 110 formed, e. g., in SOI (silicon 101 on insulator) where the insulator is a thin buried oxide 115 (box). The box 115 may be, for example, SiO 2 , Al 2 O 3 , or the like. Top gates 120 on a high quality dielectric layer 118 define quantum dots with single electron occupancy control in the semiconductor layer 101 . Quantum dots 110 are aligned to donors 105 ˜20 to 30 nm below the quantum dots. Local back gates 130 below the buried oxide layer allow tuning of the donor-dot exchange coupling 140 and control electron transfer between a dot and a donor atom. The donor-donor distances may be about ˜100 nm, large enough to avoid spurious direct donor-donor coupling 150 , while Heisenberg exchange (J coupling) and charge transfer coupling 160 between dots may be gate controlled.
The quantum computer architecture includes integrating the following modules and interactions: a single donor nuclear spin memory coupled to the donor electron spin through the contact hyperfine interaction for storage and retrieval of quantum information, wherein the donor electron spin couples to the spin of an electron in a vertically aligned quantum dot, with a gate controlled exchange coupling.
A voltage V is applied between a back gate 130 beneath the donor and one or more of the top gates 120 above an aligned pair of donor 105 and quantum dot 110 . The voltage alters the overlap of the donor electron wave function 125 and quantum dot electron spin wave function 165 , and therefore controls the exchange coupling.
FIG. 2 shows FIG. 1 with more detail. In an embodiment, the entire architecture, including top gates 120 , dielectric layer 118 , silicon 101 on box 115 , embedded single atom donors 105 , are formed on a substrate 170 , such as, for example, silicon. Back gates 130 may be formed, for example, by etching vias in the silicon substrate 170 , followed by deposition of conductive electrodes.
Further integration for mid and long range quantum communication through electron shuttling between dots or coupling to superconducting resonators is possible by combining all three critical architecture elements of quantum memory, logic and communication.
An alternative approach of cluster state quantum computing may also be implemented without the need for cycles of coherent donor ionization and recombination. Ionizing the donor protects the nuclear spin from de-coherence through uncontrolled interaction with the donor electron, if coherence can be preserved in the recombination step that is necessary to retrieve the quantum information from the nuclear spin and transfer it back to the donor electron spin for further processing. Inter-dot coupling can effectively entangle donor nuclear spins and enable implementation of cluster state quantum computing.
While key elements of this donor-dot architecture have been experimentally tested—at least in ensemble measurements—challenges remain, e.g., efficient quantum information transfer between donor electron and nuclear spins has been demonstrated with ensembles of phosphorus donors in 28 Si. Also, quantum dots with a high degree of control have also been demonstrated in silicon and Si—SiGe hetero-structures, i.e. in a materials system that can be prepared with minimal nuclear spin background. Further, these nuclear spin free matrixes can be prepared on insulator layers, enabling back gating of devices in SOI (silicon on insulator, including 28 SOI) and SGOI (Silicon-Germanium on insulator).
Device integration of donors in a transistor paradigm, e. g. with local gate control of single and two qubit interactions, requires integration with electrodes, which can be isolated from the matrix with thin dielectrics. The underlying physical mechanisms at the Si—SiO 2 interface appear to limit coherence of donor electron spins and are not well understood. However, ion implanted antimony (Sb) shows promise as a nuclear spin donor. Even at a few tens of ms, the antimony nuclear spin near the Si—SiO 2 interface makes an attractive quantum memory, provided that reliable quantum information transfer between the donor electron and nuclear spin is accomplished at least 10 4 times faster to enable application of error correction schemes.
When donor electrons are exposed to conduction electrons, e. g. from a two dimensional electron gas (2DEG) in the channel of a field effect transistor, spin coherence times can be expected to be even shorter than in the presence of an SiO 2 interface only. The quality of the SiO 2 —Si interface is of critical importance, especially also quantum dots, both for electron spin coherence and for control of single electron dot occupancy. While it can be expected that the coherence limiting noise source, such as magnetic fluctuators at the interface, will freeze out to some degree at lower temperatures, it is clear that interface quality is a critical factor for both donor and quantum dot electron spin qubit integration. Hydrogen passivated silicon provides the highest quality interface with the longest electron spin coherence times of nearby donors but technical challenges exist to integrate it with 20 to 50 nm scale top gates and e. g. a ˜10 nm scale vacuum gap.
A promising substrate for donor-dot device fabrication may be 28 SOI, i.e., silicon on insulator where a 28 Si enriched epi-layer is grown on a thin natural silicon device layer. Top gates formed by standard e-beam lithography may define quantum dots. Careful annealing re-oxidation steps are required to enhance the oxide quality.
Single ions can be implanted into double quantum dot devices. Gate electrodes are formed from metals that can sustain the required post-implantation anneals. Back gate formation may require back etching of the silicon substrate to the box and lithography on the back side. Alignment to features on the top can be achieved with common vias through the device layer and box.
For donor spin qubit applications, implant energies have to be selected so that placement uncertainties from range straggling are within tolerances set by the qubit architecture. For a quantum computer model with nearest neighbor coupling of donors spaced 10 to 20 nm apart, this control of donor placement by ion implantation is important. For ion implantation, the position accuracy is limited by three factors: range straggling, ion beam spot size and diffusion during annealing.
Range straggling results from statistical energy loss process in the gradual slow down of ions in the target matrix. Range straggling is reduced for lower ion implantation energies and is reduced for higher projectile mass in a given target matrix. E.g., for implantation of group V donors into silicon, straggling is highest for phosphorus (P), intermediate for arsenic (As) and lowest for bismuth (Bi) donors.
The required control of donor depth below a quantum dot is stringent and is given by limits of the tunability of the exchange coupling between donors and an electron in a quantum dot. The characteristic length scale for (Heisenberg exchange) J coupling is set by the extent of the dot electron wave function, which is set by the confinement potential and is ˜5 to 10 nm in typical top gated quantum dots, similar to the extent of 2DEG's in field effect transistors. For donors, Bohr radii range from ˜1.8 in P and Sb to 1.5 nm in Bi. J coupling between an electron in a dot and an electron on a donor below the dot can be tuned to have appreciable strengths needed for fast and precise exchange gate execution for distances of ˜20 to 40 nm. The requirement for gate execution time is set by the applicability of quantum error correction codes at a given gate fidelity and electron spin coherence time. For dot electron spin coherences times of a few tens of μs gates should preferably execute within a few ns, requiring J>10 μeV. Both top and back gates can be tuned to displace both the donor and dot electron wave functions in order to turn exchange coupling on and off. The donor depth must be controlled within the J-tuning range and ion implantation of donors into a depth of ˜25 nm with a FWHM of 20 nm may enable this with high yield. A 60 keV Sb implant from has a FWHM of ˜33 nm, and 60% of donors would be placed in a 30 nm wide depth window from 10 to 40 nm below a quantum dot. Using Bismuth, range straggling is further reduced.
Donor placement tolerances in a coupled donor-quantum dot architecture are relaxed compared to requirements for nearest neighbor donor-donor coupling or coupling along a donor chain.
The various aspects of this disclosure are provided to enable one of ordinary skill in the art to practice the present invention. Modifications to various aspects of forming quantum memory, quantum logic and quantum communications channels presented throughout this disclosure will be readily apparent to those skilled in the art of quantum structures and nuclear spin physics, applications to other technical arts, and the concepts disclosed herein may be extended to such other applications. Thus, the claims are not intended to be limited to the various aspects of a quantum bit computing architecture presented throughout this disclosure, but are to be accorded the full scope consistent with the language of the claims. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” | A quantum bit computing architecture includes a plurality of single spin memory donor atoms embedded in a semiconductor layer, a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, wherein a first voltage applied across at least one pair of the aligned quantum dot and donor atom controls a donor-quantum dot coupling. A method of performing quantum computing in a scalable architecture quantum computing apparatus includes arranging a pattern of single spin memory donor atoms in a semiconductor layer, forming a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, applying a first voltage across at least one aligned pair of a quantum dot and donor atom to control a donor-quantum dot coupling, and applying a second voltage between one or more quantum dots to control a Heisenberg exchange J coupling between quantum dots and to cause transport of a single spin polarized electron between quantum dots. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation application of U.S. Ser. No. 11/844,813, filed Aug. 24, 2007, which claims the benefit of U.S. Ser. No. 60/823,588, filed Aug. 25, 2006, the disclosure of which incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to power meters and, more particularly, to a power meter to which the collective current draw of multiple loads is measured using a measuring circuit composed entirely of analog components.
Whether it be as a matter of general interest or to determine the size needed for an auxiliary power supply, such as an electric generator, homeowners are increasingly interested in the energy use associated with the electric load of the home and, more particularly, of selected electrical loads. The total electrical load of a home may be determined through monitoring the utility power meter typically located exteriorly of the home. However, determining the electrical load, i.e., current draw, of selected electrical loads is more difficult.
One approach is to electrically isolate all loads except those to be tested and then visually inspect the utility power meter. A drawback of such an approach is that all loads not to be measured, of which there may be dozens for a single home, must be electrically isolated. Alternately, the circuit breakers for the circuit branches loaded by the electrical devices not to be measured may be thrown OFF. In the case of the latter, the homeowner would still be required to electrically isolate loads of a given circuit branch if other electrical devices that load the given circuit are to be measured. Regardless of which approach is taken, it can be time-consuming to electrically isolate the appropriate electrical devices. Moreover, if the homeowner wanted to measure the energy usage over time, the electrical isolation would be required throughout the measurement interval, which may be undesirable and impractical.
As such, a number of in-line power meters have been designed that allow current to be supplied to an electrical device through the power meter itself when interconnected between a wall outlet and the electrical device. These devices typically include rather complex digital circuits that measure various electrical parameters associated with the energy usage of an electrical device, such as an appliance. These parameters include instantaneous values, such as instantaneous current, as well as time-based values, such as average current. Moreover, some power meters may be programmed to include cost information associated with energy usage so that a homeowner can monitor the cost of the energy usage of a given electrical device.
These conventional power meters, which can be quite costly to the consumer because of the complexity of the measuring circuitry and the functionality provided, are designed to be wall-connected devices. That is, the power meter will include a back-mounted electrical plug that plugs into a conventional wall outlet. The power meter will also include a single front mounted outlet into which the electrical plug of an electrical device to be measured can be plugged. Outside their cost, these conventional power meters are generally practical if the outlet to which the power meter is connected is accessible and viewable.
For example, most homeowners connect the power cord of a refrigerator to a wall outlet that is positioned behind the refrigerator. Thus, to make use of a conventional power meter, the homeowner would be required to wheel the refrigerator away from the wall a sufficient distance for the homeowner to connect the power meter. To be able to read the power meter, the homeowner would also be required to wheel the refrigerator out a sufficient distance so that the display panel of the power meter could be viewed. For a typical refrigerator, this may require that the homeowner wheel the refrigerator several feet away from the wall outlet. To measure the energy usage over time and be able to visually read the display panel, the homeowner would be need to keep the refrigerator wheeled away from the wall outlet or wheel the refrigerator away each time the homeowner desired to read the power meter.
Another drawback of conventional power meters is that a single outlet is provided for connecting a single electrical device to the power meter. To measure the electrical usage of multiple electrical devices requires the homeowner to connect each of the electrical devices to a multi-outlet receptacle and then connect multiple electrical devices to the multi-outlet receptacle. The power meter may measure the collective energy usage, but the power meter would have to be positioned in sufficient proximity to all of the electrical devices to be measured. Alternately, multiple extension cords could be used to link the electrical devices to the wall-mounted power meter with the additional cost and disruption associated with multiple extension cords strewn about the home.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is directed to a power meter having a measuring circuit composed entirely of analog components that measures the instantaneous current draw of one or more electrical devices, such as home appliances. The power meter may be in the form of a hand-held device, which includes elongated connections that allow a homeowner to measure and monitor a value of the current draw of an electrical device without significant displacement of the electrical device. In addition to measuring current draw, the power meter may measure an estimated wattage consumed by the measured electrical devices. Since the measuring circuit lacks any digital circuitry, such as microprocessors, the power meter may be light, small, and highly portable while providing a cost savings relative to predecessor digital-based power meters.
In one aspect of the invention, a power meter includes a plug insertable into a conventional outlet and a receptacle adapted to receive one or more plugs extending from various electrical appliances or other loads. Between the plug and the receptacles, the power meter includes an analog measuring circuit that can modify the electrical signal passing through the measuring device to determine the amperage drawn or watts consumed by the electrical device(s) connected to the power meter. This measured or determined value for the particular electrical parameter is then displayed by the power meter in a manner that can be readily viewed by a homeowner or other user.
In accordance with a further aspect, the invention contemplates a power meter that includes a housing and a current measuring circuit disposed in the housing. The power meter further includes a first cord extending from the housing and electrically connected to the measuring circuit. The first cord has a plug adapted to engage a conventional electrical outlet. The power meter further includes a receptacle formed in the housing and electrically connected to the current measuring circuit, wherein the receptacle is adapted to receive a conventional three-prong plug of an electrical device.
According to another aspect of the invention, the present invention contemplates a power meter that includes a plug adapted to be engaged with a conventional electrical outlet and an outlet adapted to receive a plug of an electrical device. A measuring circuit composed entirely of analog components and electrically interconnected between the plug and the outlet is adapted to measure an instantaneous current draw of the electrical device.
Numerous other aspects, features, and advantages of the present invention will be made apparent from the following detailed description together with the drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate the best mode currently contemplated of practicing the present invention.
In the drawings:
FIG. 1 is a rear perspective view of a plug-in power meter constructed according to one embodiment the present invention;
FIG. 2 is a front perspective view of the power meter of FIG. 1 ;
FIG. 3 is a side perspective view of the power meter of FIG. 1 ;
FIG. 4 is a circuit diagram of the power meter of FIG. 1 ;
FIG. 5 is an elevation view of another embodiment of a power meter according to the present invention; and
FIG. 6 is an end view of a portion of the power meter shown in FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
With regard now to the drawing figures in which like reference numerals designate like parts throughout the disclosure, a plug-in power meter constructed according to a first embodiment of the present invention is indicated generally at 10 in FIG. 1 . The power meter 10 includes a plug 12 disposed at one end that may be engaged with a conventional electrical outlet (not shown), and a cord 14 extending outwardly from the plug 12 . The cord 14 contains conductive wires (not shown) that enable electrical power to be supplied from the outlet to which the plug 12 is connected, through the cord 14 to a receptacle 16 attached to the cord 14 opposite the plug 12 . The receptacle 16 includes a number of openings 18 in a configuration similar to that of a conventional outlet, such that a plug (not shown) connected to a suitable electric device or appliance (not shown), such as a furnace, air conditioner, sump pump, microwave oven, refrigerator, freezer, toaster, coffee maker, computer, radio, and the like, can be inserted into the openings 18 in order to connect the device or appliance to the outlet using the power meter 10 , such that the device or appliance can be operated on power supplied through the power meter 10 .
The receptacle 16 also includes a housing 20 in which the openings 18 are formed. The housing 20 can include an extension 21 projecting outwardly from the housing 20 and in which the openings 18 are disposed. The openings 18 are electrically connected to a measuring circuit 24 (best shown in FIG. 4 ) such that, when power is supplied to the device or appliance through engagement of the plug within the openings 18 , the electrical power passes through the measuring circuit 24 for measurement of the desired electrical parameter.
As best shown in FIG. 2 , the housing 20 also includes a display 22 generally opposite the openings 18 . The display 22 is also operably connected to the measuring circuit 24 such that the value for an electrical parameter as measured or determined by the circuit 24 can be represented on the display 22 . As best shown in FIG. 3 , a switch 26 is located on the housing 20 , preferably on one side of the housing 20 between the openings 18 and the display 22 . The switch 26 is also operably connected to the measuring circuit 24 and selectively changes the mode of operation of the circuit 24 , such that the circuit 24 can measure and display one of two electrical parameters that can be determined by the measuring circuit 24 . For example, in one embodiment, the switch 26 toggles the power meter between measuring current (amperage) draw and power (wattage) consumption of the connected electrical devices.
Referring now to FIG. 4 , an exemplary circuit configuration 24 for the power meter 10 includes an amperage measuring circuit 28 that is connected to the power source or outlet via the plug 12 , and to the electrical device that is to be tested via the openings 18 . The amperage drawn by the appliance when operated is measured in an analog fashion by an amplifier 30 and resistors 32 - 38 . The measured or determined value for the amperage is then directed to an analog-to-digital converter 40 that functions only as a driver for the display 22 . That is, the converter 40 does not form part of the amperage/wattage measuring circuit 28 . The signal received by the converter 40 is converted into a format that can readily be represented on the display 22 to illustrate the amperage or wattage value of the device or appliance plugged into the power meter 10 . When the switch 26 is in the proper position to indicate that the value for the amperage drawn by the appliance is to be represented, this value is illustrated in a readable manner on the display 22 .
Alternatively, when the switch 26 is moved to the position indicating that the value for the watts consumed by the electrical device is to be represented on the display 22 , the measuring circuit 24 arrives at this value by altering, or multiplying the measured or determined amperage value by a factor of 120 to provide an estimated value for the watts being drawn by the device or appliance being tested. More particularly, when switch 26 is moved to the “WATT” position, the output of the amplifier 30 is presented across a feedback loop comprised generally of resistors 34 , 36 . This causes the gain of the amplifier 30 to be changed from a unity gain to a gain factor of 120. In other words, the measured current draw is multiplied by the amplifier by 120 to provide an estimated power consumption for the connected electrical devices. One skilled in the art will appreciate that the gain factor of the amplifier may be varied by selecting a resistor 36 with different impedance. Preferably, the value of resistors 32 , 34 should be equal so that the amplifier 30 has a unity gain when switch 26 is the “AMP” position.
One skilled in the art will appreciate that the exemplary circuit shown in FIG. 4 includes additional electronic components that provide line buffering and conditioning not specifically described herein. Additionally, one skilled in the art will appreciate that other circuit configurations using electronic components other than those shown in the circuit are possible and considered within the scope of the present invention.
In a second embodiment on the present invention as shown in FIGS. 5-6 , in which like components are designated with primed reference characters, the power meter 10 ′ includes the plug 12 ′, the cord 14 ′, and the housing 20 ′ with the display 22 ′ and the switch 26 ′ as in the previous embodiment. The cord 14 ′ is preferably formed to have a length similar to that for a normal extension cord. However, the power meter 10 ′ also includes a second cord 42 ′ that extends away from the housing 20 ′ opposite the cord 12 ′ to a receptacle 16 ′. It is understood that either of the cords 14 ′ or 42 ′ may have any desired length. The receptacle 16 ′ includes multiple sets of openings 18 ′ in the configuration of a conventional electrical outlet, such that multiple plugs from multiple electric devices or appliances can be simultaneously connected to the receptacle 16 ′ for determining a combined amperage or wattage for all of the appliances when in operation. Additionally, the receptacle 16 ′ can include a selector device (not shown) that enables the power meter 10 ′ to determine the amperage or watt value for any combination of the appliances connected to the receptacle 16 ′.
Various additional embodiments of the present invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention. | A power meter has a measuring circuit composed entirely of analog components that measures the instantaneous current draw of one or more electrical devices, such as home appliances. The power meter may be in the form of a hand-held device that includes elongated connections that allow a homeowner to measure the current draw of an electrical device without significant displacement of the electrical device. In addition to measuring current draw, the power meter may provide an estimated wattage consumed by the measured electrical devices. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CN2010/077636 with an international filing date of Oct. 12, 2010, designating the United States, now pending. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an antiviral transdermal patch and a method for producing the same.
[0004] 2. Description of the Related Art
[0005] Conventional antiviral drugs for treatment of viral diseases, for example, hepatitis B, AIDS, influenza virus, and herpes, include entecavir, adefovir, dipivoxil, lamivudine, acyclovir, ribavirin, and zidovudine.
[0006] Conventional dosage forms of the nucleoside antiviral drugs include oral formulations or injections. The administration modes often cause time fluctuation of blood concentrations of active ingredients. Too low concentration of active ingredients in blood cannot exhibit desired effects. Too high concentration of active ingredients in blood, however, may be poisonous to human body. Furthermore, through the administration modes, the active ingredients are easily hydrolyzed by enzymes in the gastrointestinal tract and have to experience the first pass effect of the liver, thereby reducing the efficacy.
SUMMARY OF THE INVENTION
[0007] In view of the above-described problems, it is one objective of the invention to provide an antiviral transdermal patch that eliminates enzymolysis of administered drugs in the gastrointestinal tract and the first pass effect of the liver and reduces side effects of administered drugs.
[0008] To achieve the above objectives, in accordance with one embodiment of the invention, there is provided an antiviral transdermal patch comprising a backing layer, a viscous polymer layer, and a protection film layer, wherein the viscous polymer layer comprises an antiviral agent, a viscous polymer, and a transdermal enhancer.
[0009] In a class of this embodiment, the antiviral agent is a nucleoside antiviral drug with a daily delivery of less than 100 mg.
[0010] In a class of this embodiment, the nucleoside antiviral drug is selected from the group consisting of entecavir, adefovir dipivoxil, lamivudine, stavudine, or a mixture thereof.
[0011] In a class of this embodiment, the content of the antiviral agent per square centimeter of the antiviral transdermal patch is between 0.1 and 50 mg, preferably between 1.5 and 40 mg, more preferably between 5 and 30 mg, particularly between 10 and 25 mg, and more particularly between 15 and 20 mg.
[0012] In a class of this embodiment, the antiviral agent accounts for between 0.1 and 15.0 wt. % of the viscous polymer layer, preferably between 0.5 and 13.0 wt. %, particularly between 1.0 and 9.0 wt. %, and more particularly between 5.0 and 7.0 wt. %.
[0013] In a class of this embodiment, the viscous polymer is selected from the group consisting of a polyacrylate pressure sensitive adhesive, polyisobutylene, polyisoprene, and a silicone copolymer.
[0014] In a class of this embodiment, the polyacrylate pressure sensitive adhesive is selected from the group consisting of polyacrylic resin II, polyacrylic resin III, polyacrylic resin IV, ammonio methacrylate copolymer I, ammonio methacrylate copolymer II, and acrylic resin-EUDRAGIT E100; the acrylic resin-EUDRAGIT E100 is a copolymer of butyl methacrylate-dimethylamino ethyl methacrylate-methyl methacrylate (1:2:1).
[0015] In a class of this embodiment, the viscous polymer accounts for between 50.0 and 96.0 wt. % of the viscous polymer layer, preferably between 65.0 and 90.0 wt. %, particularly between 75.0 and 85 wt. %, and more particularly between 78.0 and 82.0 wt. %.
[0016] In a class of this embodiment, the transdermal enhancer is selected from the group consisting of laurocapram, essential oils, dimethyl sulfoxide, thymol, eucalyptus oil, and a traditional chinese medicine comprising terpenes or phenols, or a mixture thereof.
[0017] In a class of this embodiment, the transdermal enhancer is laurocapram.
[0018] In a class of this embodiment, the transdermal enhancer is a mixture of laurocapram and essential oil with a weight ratio of 1:0.5-2.
[0019] In a class of this embodiment, the transdermal enhancer is a mixture of laurocapram and dimethyl sulfoxide with a weight ratio of 1:0.5-2.
[0020] In a class of this embodiment, the transdermal enhancer accounts for between 2.0 and 12.0 wt. % of the viscous polymer layer, preferably between 4.0 and 11.0 wt. %, particularly between 6.0 and 10 wt. %, and more particularly between 8.0 and 9.0 wt. %.
[0021] In a class of this embodiment, the viscous polymer layer further comprises an organic solvent, for example, propylene glycol or ethyl lactate.
[0022] In a class of this embodiment, an adhesive layer is disposed between the viscous polymer layer and the protection film layer.
[0023] In a class of this embodiment, a raw material of the adhesive layer is selected from a polyacrylate pressure sensitive adhesive, polyisobutylene, or a silicone copolymer.
[0024] In a class of this embodiment, the backing layer is selected from the group consisting of high-density polyethylene, low density polyethylene, polypropylene, polyvinyl chloride, an ethylene-vinyl acetate copolymer, polyester, polyvinylpyrrolidone, polyvinyl alcohol, poly urethane, aluminum foil, or a mixture thereof.
[0025] In a class of this embodiment, the backing layer is a composite film formed by mixing an aluminum foil with high-density polyethylene, low density polyethylene, polypropylene, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyester, polyvinylpyrrolidone, polyvinyl alcohol, poly urethane, or a mixture thereof.
[0026] In a class of this embodiment, the backing layer is a three-layered composite film with an aluminum foil in the middle and low density polyethylene, poly urethane, or a mixture thereof at both sides.
[0027] In accordance with another embodiment of the invention, there is provided a method for producing the antiviral transdermal patch comprising the steps of a) uniformly mixing the antiviral agent, the viscous polymer, the transdermal enhancer, and a solvent to yield a mixture; b) coating the mixture to the backing layer to yield the viscous polymer layer; c) drying and cooling; and d) coating the protection film layer to the viscous polymer layer.
[0028] In another aspect, the invention provides a method for treatment of viral diseases comprising administering to a patient in need thereof the antiviral transdermal patch.
[0029] Advantages of the invention are summarized below. In the invention, the viscous polymer functions as a delayed-release framework material. The antiviral agent is dissolved in the transdermal enhancer (laurocapram or a mixture thereof) uniformly distributed in the framework in the form of liquid micro-rooms through solvent evaporation. The release rate of the antiviral agent of the patch is regulated by controlling the concentration of drugs, the density of the liquid micro-rooms, and the proportion of the transdermal enhancer.
[0030] Laurocapram or a mixture thereof functioning as the transdermal enhancer effectively promotes the penetration of the nucleoside antiviral agent into skin, and then the agents is assimilated via capillary vessels and enters the blood circulation, thereby inhibiting the replication of target viruses and reducing viral DNA level in the serum. In addition, the transdermal administration avoids the enzymolysis of gastrointestinal tract and the first pass effect of the liver and reduces side effect of drugs. The resulting antiviral transdermal patch can releases active ingredients sustainably and stably for 3-5 consecutive days. The raw materials involved in the invention are simple and available from market, with a low cost.
[0031] Pharmacology and toxicology research have shown that allergy test and skin irritation test of the patch is negative. That is to say, the patch has no irritation on skin, and no hemolysis and allergy occur. Thus, the patch is safe.
[0032] Clinical studies have shown that the patch accelerates the penetration of nucleoside antiviral agent into skin, and the efficacy can be maintained for 3-5 consecutive days. The time of administration is reduced. Thus, the patch of the invention is a safe, long-term effective and convenient transdermal formulation for treatment of viral diseases.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0033] For further illustrating the invention, experiments detailing an antiviral transdermal patch and a method for producing the same are described below. It should be noted that the following examples are intended to describe and not to limit the invention.
EXAMPLE 1
[0034] To a jar, 185 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 0.5 g of entecavir as an antiviral agent, 9 g of laurocapram as a transdermal enhancer, a mixture of 6 g of eucalyptus oil and 8.9 g of propylene glycol, and 100 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising polythene-aluminum-polyethylene to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 2 cm 2 to yield an antiviral transdermal patch I with 2.5 mg of entecavir per square centimeter. The antiviral transdermal patch I comprised 75.2 wt. % polyacrylate pressure sensitive adhesive, 0.5 wt. % entecavir, 9.1 wt. % laurocapram, 6.1 wt. % eucalyptus oil, and 9 wt. % propylene glycol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 15 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 2
[0035] To a jar, 225 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 10 g of adefovir dipivoxil as an antiviral agent, a mixture of 9 g of laurocapram and 3 g of thymol as a transdermal enhancer, and 150 g of dichloromethane as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising low-density polyethylene to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 20 cm 2 (4 cm×5 cm) to yield an antiviral transdermal patch II with 35 mg of adefovir dipivoxil per square centimeter. The antiviral transdermal patch II comprised 80.4 wt. % polyacrylate pressure sensitive adhesive, 9 wt. % adefovir dipivoxil, 8 wt. % laurocapram, and 2.6 wt. % thymol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 20 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 3
[0036] To a jar, 128 g of polyisobutylene as a viscous polymer, 14 g of lamivudine as an antiviral agent, a mixture of 6 g of laurocapram and 10 g of essential oil as a transdermal enhancer, 42 g of ethyl lactate, and 134 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising poly urethane to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 200 cm 2 to yield an antiviral transdermal patch III with 15 mg of lamivudine per square centimeter. The antiviral transdermal patch III comprised 64 wt. % polyisobutylene, 7 wt. % lamivudine, 3 wt. % laurocapram, 5 wt. % essential oil, and 21 wt. % ethyl lactate. The permeation rate of the patch measured using upgraded Franz diffusion cell was 55 μg/cm 2 /h, and the release time of the active ingredients exceeded 96 hrs. Thus, the patch was suggested for use of up to 4 days.
EXAMPLE 4
[0037] To a jar, 87.5 g of polyisoprene as a viscous polymer, 15 g of stavudine as an antiviral agent, a mixture of 6 g of laurocapram and 6 g of dimethyl sulfoxide as a transdermal enhancer, and 147 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising poly urethane to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 100 cm 2 to yield an antiviral transdermal patch IV with 10 mg of stavudine per square centimeter. The antiviral transdermal patch I comprised 76.5 wt. % polyisoprene, 13.1 wt. % stavudine, 5.2 wt. % laurocapram, and 5.2 wt. % dimethyl sulfoxide. The permeation rate of the patch measured using upgraded Franz diffusion cell was 34 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 5
[0038] To a jar, 88 g of silicone copolymer as a viscous polymer, 6 g of adefovir dipivoxil as an antiviral agent, a mixture of 7 g of laurocapram and 4.4 g of menthol as a transdermal enhancer, and 147 g of ethyl acetate were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising poly urethane to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 30 cm 2 to yield an antiviral transdermal patch V with 40 mg of adefovir dipivoxil per square centimeter. The antiviral transdermal patch V comprised 83.5 wt. % silicone copolymer, 5.7 wt. % adefovir dipivoxil, 6.6 wt. % laurocapram, and 4.2 wt. % menthol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 18 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 6
[0039] To a jar, 225 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 0.5 g of entecavir as an antiviral agent, 3.77 g of laurocapram as a transdermal enhancer, and 147 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising poly urethane to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A layer of polyacrylate was coated on the other surface of the viscous polymer layer, dried and cooled following the process mentioned above, and then a non-adhesive paper was coated. The product was cut into patches with an area of 4 cm 2 (2 cm×2 cm) to yield an antiviral transdermal patch VI with 3.25 mg of entecavir per square centimeter. The antiviral transdermal patch VI comprised 95.5 wt. % polyacrylate pressure sensitive adhesive, 0.5 wt. % entecavir, and 4 wt. % laurocapram. The permeation rate of the patch measured using upgraded Franz diffusion cell was 10 μg/cm 2 /h, and the release time of the active ingredients exceeded 48 hrs. Thus, the patch was suggested for use of up to 2 days.
EXAMPLE 7
[0040] To a jar, 225 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 0.2 g of entecavir as an antiviral agent, 9.8 g of laurocapram as a transdermal enhancer, 6.38 g of propylene glycol, and 160 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising polythene-aluminum-polyethylene to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A layer of silicone copolymer was coated on the other surface of the viscous polymer layer, dried and cooled following the process mentioned above, and then a non-adhesive paper was coated. The product was cut into patches with an area of 4 cm 2 (2 cm×2 cm) to yield an antiviral transdermal patch VII with 2.2 mg of entecavir per square centimeter. The antiviral transdermal patch VII comprised 84.6 wt. % polyacrylate pressure sensitive adhesive, 0.19 wt. % entecavir, 9.21 wt. % laurocapram, and 6 wt. % propylene glycol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 12 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to days.
EXAMPLE 8
[0041] To ajar, 170 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 0.8 g of entecavir as an antiviral agent, a mixture of 4 g of laurocapram and 5.4 g of eucalyptus oil as a transdermal enhancer, 5 g of propylene glycol, and 100 g of ethyl acetate were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising poly urethane to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 2 cm 2 (1 cm×2 cm) to yield an antiviral transdermal patch VIII with 6 mg of entecavir per square centimeter. The antiviral transdermal patch VIII comprised 82 wt. % polyacrylate pressure sensitive adhesive, 1 wt. % entecavir, 4.5 wt. % laurocapram, 6.5 wt. % eucalyptus oil, and 6 wt. % propylene glycol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 15 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 9
[0042] To a jar, 200 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 1 g of entecavir as an antiviral agent, a mixture of 8 g of laurocapram and 8.5 g of eucalyptus oil as a transdermal enhancer, and 100 g of ethyl acetate as a solvent were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising polythene-aluminum-polyethylene to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A non-adhesive paper was coated on the other surface of the viscous polymer layer. The product was cut into patches with an area of 2 cm 2 (1 cm×2 cm) to yield an antiviral transdermal patch IX with 7 mg of entecavir per square centimeter. The antiviral transdermal patch IX comprised 82 wt. % polyacrylate pressure sensitive adhesive, 1.5 wt. % entecavir, 8 wt. % laurocapram, and 8.5 wt. % eucalyptus oil. The permeation rate of the patch measured using upgraded Franz diffusion cell was 12 μg/cm 2 /h, and the release time of the active ingredients exceeded 96 hrs. Thus, the patch was suggested for use of up to 4 days.
EXAMPLE 10
[0043] To a jar, 150 g of polyacrylate pressure sensitive adhesive (EUDRAGIT E100, from Germany, pre-dissolved with ethyl acetate, in which solid EUDRAGIT E100 accounts for 40 wt. %) as a viscous polymer, 0.5 g of entecavir as an antiviral agent, a mixture of 10 g of laurocapram and 10 g of eucalyptus oil as a transdermal enhancer, 9.5 g of propylene glycol, and 100 g of ethyl acetate were added. The jar was sealed and oscillated for 15 hrs, and then stood until bubbles disappeared. The resulting mixture was coated to a backing layer comprising low density polythene to yield a viscous polymer layer which was further dried at 40° C. for 4 min, at 60° C. for 2 min, at 90° C. for 2 min, and then cooled. A layer of polyisobutylene was coated on the other surface of the viscous polymer layer, dried and cooled following the process mentioned above, and then a non-adhesive paper was coated. The product was cut into patches with an area of 1 cm 2 (1 cm×1 cm) to yield an antiviral transdermal patch X with 0.8 mg of entecavir per square centimeter. The antiviral transdermal patch X comprised 66.4 wt. % polyacrylate pressure sensitive adhesive, 0.6 wt. % entecavir, 11 wt. % laurocapram, 11 wt. % eucalyptus oil, and 11 wt. % propylene glycol. The permeation rate of the patch measured using upgraded Franz diffusion cell was 22 μg/cm 2 /h, and the release time of the active ingredients exceeded 72 hrs. Thus, the patch was suggested for use of up to 3 days.
EXAMPLE 11
Irritation Test of Entecavir Transdermal Patch
[0044] Drug to be tested: entecavir
[0045] Patch to be tested: a patch prepared by Example 7
[0046] Patch for control groups: a patch prepared by Example 7 but no entecavir and transdermal enhancer added.
[0047] Method: 40 healthy guinea pigs (180 g±20 g), half male and half female, were collected and carried out with left/right self comparison experiments. At 24 hrs prior to the experiments, the hair of drug administration area (on the back) of guinea pigs was removed, with an area of 3 cm×3 cm at both sides. The patch to be tested was pasted on one side and the patch for the control pasted on the other side. The patches were pasted for 8 hrs per day in 3 consecutive weeks. When the patches were removed, the drug administration area was cleaned with warm water or a non-irritating solvent. After one hour of patch removal as well as prior to next pasting, the guinea pigs were examined whether there were erythema, edema, pigmentation, blood spots, rough skin, or thin skin in the drug administration area. After 30-60 min, 24 hrs, 48 hrs, and 72 hrs of the final patch removal, the guinea pigs were examined with naked eyes whether there were erythema and edema in the drug administration area.
[0048] Results and conclusions: During the experiments, the appearance, behavior, feeding, and excretion of the guinea pigs were as normal as before, no abnormal pruritus occurred. The body weight of all guinea pigs increased, and no erythema, edema, pigmentation, blood spots, rough skin, or thin skin observed in the drug administration area. No guinea pig died. Thus, the patch had no obvious irritation.
EXAMPLE 12
Irritation Test of Lamivudine Transdermal Patch
[0049] Drug to be tested: lamivudine
[0050] Patch to be tested: a patch prepared by Example 3
[0051] Patch for control groups: a patch prepared by Example 3 but no lamivudine and transdermal enhancer added.
[0052] Method: 30 healthy rabbits, half male and half female, were collected and carried out with left/right self comparison experiments. At 24 hrs prior to the experiments, the hair of drug administration area (on the back) of the rabbits was removed, with an area of 4 cm×4 cm at both sides. The patch to be tested was pasted on one side and the patch for the control pasted on the other side. The patches were pasted for 8 hrs per day in 3 consecutive weeks. When the patches were removed, the drug administration area was cleaned with warm water or a non-irritating solvent. After one hour of patch removal as well as prior to next pasting, the rabbits were examined whether there were erythema, edema, pigmentation, blood spots, rough skin, or thin skin in the drug administration area. After 30-60 min, 24 hrs, 48 hrs, and 72 hrs of the final patch removal, the rabbits were examined with naked eyes whether there were erythema and edema in the drug administration area.
[0053] Results and conclusions: During the experiments, the appearance, behavior, feeding, and excretion of the rabbits were as normal as before, no abnormal pruritus occurred. The body weight of all rabbits increased, and no erythema, edema, pigmentation, blood spots, rough skin, or thin skin observed in the drug administration area. No rabbit died. Thus, the patch had no obvious irritation.
EXAMPLE 13
Irritation Test of Stavudine Transdermal Patch
[0054] Drug to be tested: stavudine
[0055] Patch to be tested: a patch prepared by Example 4
[0056] Patch for control groups: a patch prepared by Example 4 but no stavudine and transdermal enhancer added.
[0057] Method: 30 healthy rabbits, half male and half female, were collected and carried out with left/right self comparison experiments. At 24 hrs prior to the experiments, the hair of drug administration area (on the back) of the rabbits was removed, with an area of 4 cm×4 cm at both sides. The patch to be tested was pasted on one side and the patch for the control pasted on the other side. The patches were pasted for 8 hrs per day in 3 consecutive weeks. When the patches were removed, the drug administration area was cleaned with warm water or a non-irritating solvent. After one hour of patch removal as well as prior to next pasting, the rabbits were examined whether there were erythema, edema, pigmentation, blood spots, rough skin, or thin skin in the drug administration area. After 30-60 min, 24 hrs, 48 hrs, and 72 hrs of the final patch removal, the rabbits were examined with naked eyes whether there were erythema and edema in the drug administration area.
[0058] Results and conclusions: During the experiments, the appearance, behavior, feeding, and excretion of the rabbits were as normal as before, no abnormal pruritus occurred. The body weight of all rabbits increased, and no erythema, edema, pigmentation, blood spots, rough skin, or thin skin observed in the drug administration area. No rabbit died. Thus, the patch had no obvious irritation.
EXAMPLE 14
Allergy Test of Entecavir Transdermal Patch
[0059] Drug to be tested: entecavir
[0060] Patch to be tested: a first patch whose entecavir concentration was four times that of a patch prepared by Example 7 as a sensitizer; a second patch whose entecavir concentration was eight times that of a patch prepared by Example 7 as an activator.
[0061] Negative control group: a patch prepared by Example 7 but no entecavir and transdermal enhancer added.
[0062] Positive control group: 1% mercapto thiazole as a sensitizer and 2% mercapto thiazole as an activator.
[0063] Method: 30 healthy adult guinea pigs, either male or female, were divided into an experimental group (20), a positive control group (5), and a negative control group (5). At 24 hrs prior to the experiments, the hair of drug administration area (on the back) of the guinea pigs was removed, with an area of 4 cm×4 cm at both sides. Buehler test (BT) was carried out as follows. The guinea pigs were administered with a sensitizer for 10-14 days to induce immunoreactions, and then an activator was administered. Observe whether there were allergic reactions. The skin response and response degree thereof at the induction period and attack period were compared, and the results were compared with those of the negative control group.
[0064] During the Buehler test (BT), entecavir transdermal patches were pasted at the 0, 6 th , and 13 th days on one side of the abdomen for induction, and at the 27 th day pasted on the other side for 6 hrs for activation. At one hour and 24 hrs after sensitization and 24 and 48 hrs after activation, observe whether there were erythema, edema, and other abnormal reactions, and evaluate the erythema and edema. The results were listed as Table 1.
[0000]
TABLE 1
Skin allergy rate (%)
Groups
0 h
24 h
48 h
72 h
Evaluation on sensitization
Mercapto thiazole
60
80
90
80
Allergenic
Negative control
0
0
0
0
Nonallergenic
Entecavir
0
0
0
0
Nonallergenic
[0065] The results showed that, the patch of the invention had no obvious allergenicity.
[0066] While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. | An antiviral transdermal patch including a backing layer, a viscous polymer layer, and a protection film layer. The viscous polymer layer includes an antiviral agent, a viscous polymer, and a transdermal enhancer. The transdermal enhancer is laurocapram or a mixture thereof. The antiviral agent is a nucleoside antiviral drug with a daily delivery rate of less than 100 mg/day. The patch effectively promotes the penetration of a nucleoside antiviral agent into the blood circulation and avoids enzymolysis in the gastrointestinal tract and the first pass effect of the liver and reduces side effect of drugs, thereby inhibiting the replication of target viruses and reducing viral DNA level in the serum. A method for producing the patch is also provided. The raw materials involved in the invention are easily purchased from the market at a low cost. | 0 |
BACKGROUND
[0001] The present invention relates to a tactile device and method for providing information to an aircraft, motor vehicle or equipment operator.
[0002] Devices and methods for providing information tactually to aircraft operators are known.
[0003] U.S. Pat. No. 2,078,982, hereby incorporated by reference herein, for example, describes a tactile device for registering airspeed, altitude or a turn indicator. The information is provided tactually via the operator grasping the tactile device, and is not provided passively.
[0004] U.S. Pat. No. 3,902,687, also hereby incorporated by reference herein, describes an aircraft indicator system having a seat cushion and a leg clamp with left and right vibrators which indicate to the aircraft operator a deviation from a course selected via a radio navigational aid receiver. A frequency of vibration is indicative of the magnitude of the deviation.
[0005] The United States Navy at http://www.namrl.navy.mil/TSAS/, the entire description of which is also hereby incorporated by reference herein, describes a tactile situation awareness system (TSAS) which provides aircraft operators with a vest with tactors arranged in a grid fashion. The tactors provide pitch and roll information via absolute actuating of the tactors. In other words, to convey information regarding pitch, only one tactor at a time is actuated.
BRIEF SUMMARY OF THE INVENTION
[0006] An object of the present invention is to improve the ability to convey information tactually to aircraft operators. An alternate or additional object of the present invention is improve the ability to convey information tactually to motor vehicle or equipment operators.
[0007] The present invention provides a tactile device for an aircraft operator which has a plurality of tactors passively attached to an aircraft operator, the plurality of tactors including a first tactor and a second tactor neighboring the first tactor. A control system controls actuation of the tactors as a function of a variable representing a characteristic of the operation of the aircraft and actuates the first tactor when the variable reaches a first predetermined value. The control system then actuates both the first and second tactor when the variable reaches a second predetermined value different from the first predetermined value.
[0008] By providing for actuation of both the first and second tactors as the variable changes value, the operator obtains a relative sensation between the first tactor and the second tactor which improves the ability of the operator to detect the actuation of the second tactor. Advantageously, less powerful tactors or more closely spaced tactors may be provided to convey the information from the variable.
[0009] By having the tactors passively attached to the operator, as opposed to on a handle or at the seat where the position of the operator with regard to the tactors may change, the tactors also may convey information more effectively.
[0010] The tactile device may include a third tactor, the second tactor being located between the first and third tactors, the first, second and third tactors all being actuated when the variable reaches a third predetermined value, a difference between the first predetermined value and the third predetermined value being greater than a difference between the first predetermined value and the second predetermined value. In other words, the direction of actuation of the tactors and of the value of the variable are the same. Thus for example if the characteristic is altitude, as the altitude reaches a first level, the first tactor may be actuated, as it reaches a higher second level, the first and second tactors are actuated, and as it reaches yet a higher third level, the first, second and third tactors are actuated.
[0011] The first, second and third tactors may be arranged linearly, and may be spaced equidistantly, and the difference between the first predetermined value and the second predetermined value may be the same as the difference between the second predetermined value and the third predetermined value.
[0012] Preferably, the characteristic is one of altitude or airspeed. These characteristics are well suited to expression via a row of tactors. The characteristic also could be the proximity of the aircraft in relation to a threat, for example a surface-to-air missile or another nearby aircraft.
[0013] The tactors for example may be spaced within two centimeters of each other, or more preferably within one centimeter or less of another. Since a forearm, which is an advantageous location for the tactors of the present invention, typically provides about 20 centimeters of tactile space, up to twenty or more tactors may be able to be provided on the forearm. Each individual tactor may be 1.0 cm or less in length and width, and even less than 0.5 cm in length and width. Small piezoelectric tactors for example may advantageously be used with the present invention.
[0014] Preferably, the tactors are supported by a longitudinal strip of material, which may be fastened for example via perpendicular VELCRO or adhesive tape strips to the forearm. This permits easier attachment of a plurality of tactors. The tactors also may be fastened by a longitudinal strip of adhesive tape or by other means.
[0015] The present invention also provides a tactile device for an aircraft operator in which a plurality of tactors are passively attached to an aircraft operator, the plurality of tactors including a first tactor and a second tactor neighboring the first tactor. A control system controls actuation of the tactors as a function of a variable representing a characteristic of the operation of the aircraft, the control system actuating the first tactor as a marker, and actuating the first and second tactors when the variable reaches a first predetermined value.
[0016] The marker, which for example may be actuated when the device is first turned on or the aircraft started and always left on, advantageously also provides for relative sensation when the second tactor is actuated.
[0017] The present invention also provides a tactile device for an aircraft operator comprising a strip-shaped tactor passively attached to the aircraft operator over a longitudinal surface and infinitely variable in the longitudinal direction. A control system controls actuation of the strip-shaped tactor as a function of a variable representing a characteristic of the operation of the aircraft, the control system actuating the strip-shaped tactor longitudinally as a function of the variable.
[0018] The strip-shaped tactor functions similarly to the plurality of tactors but provides for infinitely variable sensation, for example via a spring-loaded inflatable device.
[0019] The control system may actuate the strip-shaped tactor longitudinally in a direct linear relation to a value of the variable, but may also proceed logarithmically or in other related fashion.
[0020] The present invention also provides a tactile device for an aircraft operator with a tactor passively attached to an aircraft operator, the tactor having a characteristic infinitely variable between two points. A control system controls the infinitely-variable characteristic of the tactor as a function of a variable representing a characteristic of the operation of the aircraft, the characteristic being independent of signals generated outside the aircraft. Thus altimeter and airspeed signals, generated onboard, may be provided via the infinitely-variable tactor characteristic.
[0021] The infinitely-variable characteristic may be for example a vibration of the tactor, a temperature of the tactor, an electric voltage of the tactor, or a pressure provided by the tactor to the operator.
[0022] The present invention also provides a method for actuating a plurality of tactors passively attached to an aircraft operator, the plurality of tactors including a first tactor and a second tactor neighboring the first tactor. The method includes actuating a first tactor when a variable reaches a first predetermined value or as a marker, the variable being a function of a variable representing a characteristic of the operation of the aircraft and actuating the second tactor when the variable reaches a second predetermined value.
[0023] The present invention also provides a method for actuating a strip-shaped tactor passively attached to an aircraft operator, the strip-shaped tactor being longitudinally actuable. The method includes actuating the strip-shaped tactor to provide a signal at a first tactile location when a variable reaches a first predetermined value or as a marker, the variable being a function of a variable representing a characteristic of the operation of the aircraft and actuating the strip-shaped tactor to provide further signals longitudinally downstream from the first tactile location as a value of the variable changes.
[0024] Any of the tactile devices according to the present invention above may also be provided for a motor vehicle or equipment operator to provide information regarding a motor vehicle or other equipment operating characteristic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Various embodiments of the present invention are described with respect to the figures in which:
[0026] FIG. 1 shows a tactile device having a plurality of tactors for attachment to a forearm of an aircraft, motor vehicle or equipment operator;
[0027] FIG. 2 shows a tactile device have a strip-shaped tactor;
[0028] FIG. 3 shows an alternate tactile device in circular form; and
[0029] FIG. 4 shows an alternate tactile device similar to FIG. 1 with transverse marker strips.
DETAILED DESCRIPTION
[0030] FIG. 1 shows a tactile device having a plurality of tactors for attachment to a forearm of an aircraft, motor vehicle or equipment operator. A plurality of tactors 11 , 12 , 13 , 14 , 15 , 16 and 17 are arranged linearly and spaced at equal distances on a longitudinal strip of material 20 , which can be attached via VELCRO or adhesive tape strips 22 , 24 for example to the forearm of an aircraft operator. Preferably, the tactors directly contact the skin of the operator. The strip of material 20 or tactors 11 may for example be about 0.25 inches wide. The strip of material preferably is made of cloth or other flexible natural or synthetic material.
[0031] The tactors may be piezoelectric or pneumatic tactors for example, or may be vibrating motors, for example those manufactured by ALCOM or JAMECO, or may be tactors which provide heat or a minor electric charge to the skin. The tactors may contact the skin directly through cutouts in the strip 20 , or if appropriate through the strip 20 . A lubricant or gel may be used to increase electric sensitivity to the charge.
[0032] A voltage source 50 may provide electricity to the tactors through a flexible connection 40 . A battery source alternately could be located directly on the strip 20 .
[0033] A controller 30 may receive inputs from an airspeed detector 60 and/or an altimeter 62 , and/or other components of the aircraft or of a motor vehicle or other equipment.
[0034] As a function of theses inputs, controller 30 controls individual actuation of the tactors via connection 40 and a flexible control line 32 . Each tactor may be connected to a bus 42 and has an individually addressable location for a header for control signals from the controller 30 . For example, with eight tactor system shown, a three bit header can be used, as well as a single bit on/off control signal. The connections between the controller 30 and tactors and aircraft operating signal inputs may be wireless. Each tactor may also be connected via an individual wire or other connection to the conroller 30 , instead of through the bus 42 .
[0035] As an example, tactor 10 may function as an initiation tactor, and is actuated for example when the operator inputs a control to the aircraft controller 30 indicating that the strip 20 is attached to the operator. As the aircraft increases in speed, for example to 100 miles per hour, tactor 11 is actuated. When the aircraft reaches 200 miles per hour, tactor 12 is actuated, and tactors 10 and 11 remain actuated. At 300 miles per hour, tactor 13 is actuated, and so on until at 700 miles per hour tactor 17 , and thus all tactors 10 to 17 are actuated. As the aircraft slows the tactors are deactivated, starting with tactor 17 .
[0036] The tactile device thus provides a sensitive tactile device for airspeed, which can aid in reducing or eliminating the need for the aircraft operator to view the airspeed indicator. The present invention has particular applicability to military aircraft where the pilots often face visual and aural information overload.
[0037] A second strip with tactors could be provided for the other arm for indicating altitude, and controlled by controller 30 in a similar manner as the altitiude varies.
[0038] If the tactors operate via electronic signals to the skin surface of the aircraft operator, the present invention also provides that controller 30 can send a known electric charge to one of the tactors and measure the electric charge delivered via another, for example, neighboring, tactor so as to determine the skin resistance. Thus as the skin resistance of the aircraft operator varies, for example via perspiration, the electric charges delivered via the tactors can be varied. The operator also may control the electric charge strength, for example through input to controller 30 .
[0039] FIG. 2 shows an alternate tactile device with an infinitely variable tactor, here made up of an inflatable device and a spring. A rectangular frame 130 with an open bottom may be attached to the strip 20 , which may have a cutout 148 . Frame 130 for example may be made of thin plexiglass. An inflatable bladder 142 may move a stopper 146 back and forth against springs 144 , and may be inflated via a pneumatic pressure device 140 , for example. The bladder 142 may be felt by the operator through its pressure through the strip 20 , and if present, directly on the skin through cutout 148 . The longitudinal extent of the bladder may increase or decrease as a function of the airspeed, so that for example the location of stopper 146 shown in FIG. 2 may indicate an airspeed of 455 miles per hour. The location of stopper 146 is infinitely variable within the frame 130 . As airspeed decreases, pressure from pressure device 140 decreases and springs 144 force the stopper 146 and thus bladder 142 to move downwardly, as oriented in FIG. 2 . The pneumatic connection between 140 and bladder 142 is flexible.
[0040] FIG. 3 shows an alternate embodiment in which tactors 210 , 212 , 214 , 216 , 218 , 220 , 222 , 222 , 224 , 226 , 228 , 230 and 232 are arranged in a circular or expanding pattern. Thus for example when the aircraft speed is 200 miles per hour, tactor 210 is actuated, at 300 miles per hour, tactors 210 , 212 , 214 , 216 and 218 are actuated, and at 300 miles per hour, all tactors are actuated. More tactors outside the ring of tactors 220 to 234 may be provided to provide even a larger expansion area. However other linearly-laterally expanding tactor patterns may be used, for example a V-shaped or inverted triangle pattern where the tip of the V represents a first speed or variable value, and the top of the V, which may be for example twelve or more tactors across a highest speed or variable value. A cross-shaped pattern is another example of a linearly-laterally expanding tactor pattern.
[0041] FIG. 4 shows an alternate embodiment in which a main tactor strip 300 is supplemented with individual transverse marker tactor strips 310 , 312 , 314 spaced apart, for example on a forearm. The marker strips 310 , 312 , 314 may be spaced more then five centimeters apart. The marker strips 310 , 312 , 314 may be activated at all times or be triggered as the tactors on strip 300 are activated in linear fashion to reach the marker strip. Tactor marker strip 310 for example may indicate an aircraft speed of 200 miles per hour. Marker strip 312 may indicate 300 miles per hour. Marker strip 314 may indicate a speed of 400 miles per hour. The marker strip may have an actuating length of for example 1 to 1.5 inches in the transverse direction, and may be a single tactor or a plurality of tactors as described above. The individual tactors on strip 300 thus may be provide a finer feeling for the variable changes and operate similar to the FIG. 1 embodiment, while the marker strips 310 , 312 , 314 may aid the operator in determining the value of the variable.
[0042] It should also be noted that in an alternate embodiment of the present invention a single tactor could provide variable information in some cases. For example in the FIG. 1 embodiment, tactor 10 could vibrate at a frequency or amplitude indicative of airspeed 60 , be heated or cooled to a temperature, or provide a pressure or an electric voltage indicative of airspeed 60 .
[0043] The embodiments of FIGS. 1, 2 , 3 and 4 could also be used for example to provide motor vehicle or equipment operating information, for example vehicle speed information or proximity information, for example the proximity of a crane to an object. | A tactile device for an aircraft operator has a plurality of tactors for being passively attached to an aircraft operator, the plurality of tactors including a first tactor and a second tactor neighboring the first tactor. A control system controls actuation of the tactors as a function of a variable representing a characteristic of the operation of the aircraft, the control system actuating the first tactor when the variable reaches a first predetermined value, and actuating both the first and second tactor when the variable reaches a second predetermined value different from the first predetermined value. Other tactile devices and methods for actuating tactile devices are also provided. | 1 |
FIELD OF THE INVENTION
The invention relates generally to vehicle braking systems, and in particular to braking systems aboard electrically powered vehicles in which regenerative braking can be employed on some powered wheels and conventionl friction braking on other unpowered wheels.
BACKGROUND OF THE INVENTION
Electrically powered vehicles are commonly used in urban transportation systems in which the vehicles travel along rails and obtain power either directly from the rails or from the rails in combination with an overhead power line. Such vehicles are commonly provided with two types of braking systems: a "regenerative braking system" in which the electric motor normally driving the vehicle is conditioned during braking to operate as a generator thereby permitting recapture of the vehicle's kinetic energy during braking, and a "friction braking system" which normally involves frictional engagement of a braking member between stationary and rotating members of the vehicle's wheels. Friction braking merely dissipates the vehicle's kinetic energy as heat, and therefore use of friction braking is preferably minimized. Another consideration is to ensure proper braking under poor rail conditions, particularly the low adhesion characteristic of rain-dampened rails.
According to a known system, when an operator aboard an electrically powered urban transit vehicle depresses his brake pedal, he provides a brake demand signals which is initially responded to by the regenerative braking system. The regenerative braking system provides a braking effect in general proportion to the magnitude of the brake demand signal until that signal exceeds a predetermined level which normally corresponds in substance to the limit of the regenerative braking available. At that point, the friction braking system is actuated to provide any additional demand required. In typical applications, regenerative braking associated with a particular powered truck supporting the vehicle may be used to provide braking up to for example, 3.5 miles per hour per second (mph/sec) with no braking from friction sources being used. This will effectively call for adhesion of the powered trucks of around 4.8 mphs, for a typical vehicle. These figures will depend of course in large measure on the adhesion available between the vehicle wheels and the rails and also the distribution of weight throughout the vehicle. On a wet track, regenerative braking might typically be limited to 2.0 mph/sec, the wheels then tending to spin or slide relative to the track with further regenerative braking. To accommodate the sliding associated with poor rail conditions, such a braking system has been equipped with a slide detector which together with associated control circuitry applies essentially anoscillatory brake demand signal to the braking system, causing the regenerative braking system to repeatedly brake until sliding is detected and then reduce braking to a level below the threshold at which sliding occurs. Because the brake demand signal has been reduced below the level required for actuation of the friction braking system, only regenerative braking is available, and the braking capability of the vehicle is very significantly impaired. If an emergency situation arises in which the operator requires additional braking, such as a vehicle stopped on the rails, the operator will normally have available to him a track brake which physically engages the rails of the track to provide emergency braking. Use of such a track brake is very undesirable because of attendant damage to the track.
As an object of the invention in the context of a transportation system of the type described is to provide a vehicle with an improved braking system which can be adapted if desired to maximize regeneration under good rail conditions and to provide more effective, balanced braking under poor, slippery rail conditions.
BRIEF SUMMARY OF THE INVENTION
In a vehicle supported for rolling movement by a multiplicity of wheels including a first set of wheels which are driven by an electric motor and a second set of wheels (which will normally be undriven), the invention provides an improved braking system. The braking system includes means operable by an operator aboard the vehicle for generating a brake demand signal indicative of the level of braking required by the operator, a regenerative braking system associated with the electric motor, a friction braking system associated with the second set of wheels, and means for detecting slippage of the wheels relative to a surface on which the vehicle rolls, during regenerative braking. Control means which respond to the slippage detecting means and the brake demand signal regulate the operation of the regenerative and friction braking systems. The control means serves normally to actuate the regenerative braking system in response to the brake demand signal and to actuate the friction braking system when a brake demand signal exceeds a predetermined level (normally selected to correspond to the maximum regenerative braking which can be obtained). When slippage is detected during regenerative braking, normally an indicator of slippery rail conditions, the control means responds by thereupon actuating the friction braking system to supplement the regenerative braking system, thereby overriding normal operation and providing more balanced and effective braking to accommodate the slippage problem.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 shows diagramatically a side view of a vehicle;
FIG. 2 shows schematically a braking system of a vehicle;
FIG. 3 shows a graph of braking effort against braking demand;
FIG. 4 shows a further graph of braking effort against braking demand; and
FIG. 5 shows a diagram showing how the braking effort is provided in different cases.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, there is shown a vehicle, which in this case is a railway vehicle, the vehicle being denoted by the reference 1. The vehicle 1 is arranged for travel along tracks 2. Although a railway vehicle is shown, it is to be appreciated that the invention is applicable to other types of vehicle as well. Here, the railway vehicle 1 is articulated, and it has first and second sections 2, 3 mounted on three trucks 4, 5 and 6. Truck 4 is a first power truck P1, whilst truck 6 is a second power truck P2. The truck 5 is a center truck C, on which ends of both the sections 2, 3 of the vehicle 1 are pivotally mounted. In contrast to the powered trucks 4, 6, the center truck 5 has unpowered wheels.
With reference to FIG. 2, there is shown the circuit of a braking system for the vehicle 1. The braking system is generally denoted by the reference 10. The braking system 10 includes a controller 12, which is connected to an input device 14, such as foot-operated pedal, which supplies a brake request signal to the controller 12. The controller 12 in turn is connected to braking logic 16, and supplies a brake command signal to it. The braking logic 16 in this embodiment, has three outputs 18, 20, 22, corresponding to the three trucks 4, 5 and 6. The two outputs 18, 22 are connected to the two powered trucks 4, 6. As the control arrangement for each of the powered trucks 4, 6 is the same, it is only shown in detail for the first, powered truck 4; it is the same for the powered truck 6.
The output 18 of the braking logic 16 is connected to a propulsion control unit 24. This propulsion control unit 24 controls a motor 26 of the powered truck 4. Although not shown, the propulsion control unit also includes an input for at least a drive signal command, when normal tractive effort is required from the motor. The propulsion unit 24 controls the motor 26, according to the control signals received A feedback line 28 feeds back to the braking logic 16 information on the braking effort provided by the motor 26. The braking logic 16 can then adjust the regenerative braking provided by the motor 26, as controlled by the propulsion control unit 24. A spin-slide control 30 is also provided, with a view to preventing the wheels of the trucks locking and sliding, and provides a means for detecting slippage during regenerative braking. It is connected to a further input of the braking logic 16. As indicated by a dotted line, the spin-slide control can be connected to the motor 26, to detect the occurrence of a slide condition, although this can be detected by other means.
The output 20 of the braking logic 16 is connected to a friction brake control 32, which in turn controls a friction brake 34 for the central truck 5.
A description of the operation of the braking system 10 will now be given, with reference to FIGS. 3-5.
Referring first to FIG. 3, there is shown a graph of the braking effort or force provided against the brake command or desired vehicle braking right. This is shown for good conditions with dry rails. Curve A shows the combined regenerative braking from both power trucks 4 and 6. As the brake command is increased, the braking effort increases linearly in response, until a maximum is reached. This maximum is determined by the friction and the load on the particular truck. Thereafter, even if the brake command is increased, the braking effort cannot be increased. This braking using a power truck is achieved by regenerative braking, which effectively recovers the kinetic energy of the vehicle. If further braking is required, then friction braking is used on the center truck 5. The curve B shows the behaviour of the friction brake for this center truck 5, and how it co-operates with the regenerative braking represented by curve A. When the maximum of the regenerative braking is reached, if further braking effort is demanded, then the friction brake is brought in. As shown by the slope of the first part of curve B, a progressive increase in the friction braking effort is provided, as the brake demand is further increased. Again, the friction brake effort provided will eventually reach a maximum, and no further increase in braking effort is then available. Assuming the load on each truck is the same and as indicated by curves A and B, the combined maximum braking effort from the two trucks 4, 6 is approximately twice the maximum braking effort available from the center truck 5. Curve C represent the ccmbined effect of the regenerative braking and the friction braking, i.e. curves A and B combined. Thus, as the brake demand is increased, braking is first provided by regenerative braking on the power trucks. When this reaches a maximum, to further increase the brake effort, the friction brakes are applied to the central, unpowered truck 5.
To effect braking, the foot pedal 14 is operated, to send a brake request signal to the controller 12. The controller 12 in turn sends a brake command signal to the braking logic 16, dependent on the depression of the foot pedal 14. The braking logic 16 is turn controls the various braking devices. Thus, at the onset of braking, the braking logic initially controls the propulsion units for the two power trucks 4, 6, to provide only regenerative braking. Feedback from the propulsion control units enables the braking logic 16 to maintain the required level of braking. The braking logic will take the regenerative braking up to a maximum, as determined by various factors. For example, the braking logic 16 can be such as to consider one or more of the following factors:
(a) The weight of the vehicle, and the weight on each truck;
(b) Rail condition-if rail condition is poor then the braking available from each truck is reduced;
(c) Partial failure or shortfall in electric or regenerative brakes.
Once the maximum regenerative braking is achieved, as determined by the braking logic, any further demand for braking effort is met by applying the brakes to the center truck 5. Thus, a further increase in the brake command signal will cause the braking logic 16 to actuate the friction brake control 32 and thus the friction brake 34.
A particular problem arises, if poor rail conditions are present. Typically poor rail conditions result from rain, etc., which reduces friction between the wheels and track. This reduces the maximum available regenerative braking from the powered trucks. Any attempt to increase the braking effort above the available maximum, simply causes the wheels to lock and slide, which is highly undesirable.
A known spin-slide system simply backs off the brakes if the wheels lock and slide, to release the wheels. Whilst this enables the wheels to rotate again, it reduces the braking effort. No provision is made for replacement of the braking effort from another braking source because the conventional "preferred" braking mode will not allow the demand to rise high enough to call in friction braking on the center truck. Thus, even if the operator is increasing the brake command signal, the control system may simply be maintaining the braking effort at a constant level consistent with that which will not cause a slide on the power trucks. In the known system, the friction braking is only applied when the regenerative braking reaches a maximum. As, for poor rail conditions, this maximum can never be achieved, the friction braking is never applied. As a result, the total braking effort is limited not only by the poor rail conditions but also by the absence of friction braking.
Reference will now be made to FIG. 4, which shows the variation of braking tractive effort with vehicle braking rate, for both good and poor rail conditions. In FIG. 4 the solid lines indicate the braking effort provided by two powered trucks (P1 and P2) and the center, unpowered truck (C), under good conditions. This represents a "preferred" mode, as all the braking is regenerative. Under this condition, as the braking command or desired vehicle braking rate is increased, then the braking tractive effort for each of the power trucks 4, 6 is progressively increased, until it reaches the maximum A. For normal conditions, this should provide ample braking capacity, and friction braking from the center truck should not be required.
Now, if poor rail conditions obtain, then the maximum braking tractive effort available from the two powered trucks is represented by the line B. When the braking effort reaches this level, sliding will commence. This is detected by the spin-slide control 30, which then causes the braking logic 16 to switch from the "preferred" mode to a "balanced" mode. Whereas in the preferred mode only the power trucks 4, 6 provide braking effort, in the balanced mode all the trucks 4, 5 and 6 will contribute towards the braking effort. This is shown by the dotted lines. The top dotted line shows the braking effort that will be provided by the two powered trucks 4, 6 and is marked P1' and P2'. The braking effort from the center truck 5 will be slightly less than that available from each powered truck as it is less heavily loaded than the end trucks 4, 6; it is marked C'. In this balanced mode, as shown by the dotted lines, the braking effort is distributed in the same proportion, for all required braking rates. This is in contrast to the arrangement of FIG. 3, where the regenerative braking is always used to a maximum, and only when the maximum is reached is the friction braking introduced.
Once the control system is switched to balanced braking, the vehicle will stay in balanced braking whilst in the braking configuration. Usually, the braking configuration will obtain, until foot pedal 14 is released and positive traction reapplied. Thus, once in balanced braking, the braking effort to the trucks will follow lines P1' and P2', and C' down to zero. As an alternative, when sliding occurs, the corresponding braking effort of the powered trucks can be noted. Then, once in balanced braking, if the braking demand is reduced, the braking effort of all the trucks can be reduced uniformly until the total braking effort is below that which could be supplied by regenerative braking of the powered trucks without slipping. Then, the braking system reverts to regenerative braking. At all times, the spin-slide control monitors wheel slippage and will revert to balanced braking if slippage of the wheels of trucks 4, 6 is detected. In this respect it is to be noted that the maximum braking effort under poor rail conditions can vary considerably. Thus, the value of the maximum braking effort B, and hence the difference, 2×, between it and the maximum, good rail, braking effort A can vary greatly. It will depend on such factors as water on the rails and debris, eg. leaves on the rails.
As shown on the left-hand side of FIG. 6 with good rail conditions the two power trucks 4, 6 provide all the braking effort, indicated by P1, P2. Under poor rail conditions for example, the power trucks can only provide a braking effort P1', P2', resulting in a shortfall of 2× (center column of FIG. 6), dependent on how poor the rail conditions are. Then, as shown on the right-hand side of FIG. 6, this short fall is made up by a braking effort C' from the center truck 5.
Whilst one can rely solely on a spin-slide control 30, to switch from the preferred to the balanced mode, other techniques are possible. For example, the vehicle can be provided with an override switch, to enable the operator to switch the braking logic 16 to the balanced mode. For example, for a particular journey, the operator might know or anticipate that he will be encountering many patches of bad rail conditions, and it is therefore desirable to have the braking logic 16 permanently in the balanced mode. | A vehicle supported for rolling movement on a track by a first set of wheels driven by an electric motor and a second unpowered set of wheels is provided with an improved braking system. The braking system includes a brake pedal which can be depressed to generate a brake demand signal, a regenerative braking system associated with the electric motor, and a friction braking system attached to the unpowered wheels. Control circuitry which regulates the operation of the two brake systems serves normally to actuate the regenerative braking system in response to the brake demand signal and to actuate the friction braking system only when the brake demand signal exceeds a predetermined level which corresponds normally to the maximum regenerative braking available. Under slippery rail conditions, a detector indicates slippage of the wheels relative to the rails during regenerative braking, and immediately actuates the friction braking system to produce additional braking in proportion to the brake demand signal. The braking system thus maximizes regeneration under optimal rail conditions and enhances braking under poor rail conditions. | 8 |
CROSS-REFERENCE TO RELATED U.S. PATENT APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser. No. 09/854,975 filed May 14, 2001, hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to semiconductor manufacture, and more particularly to facet etching useful for improving subsequent dielectric layer step coverage.
BACKGROUND OF THE INVENTION
[0003] A major goal of any dielectric deposition system is good step coverage. Step coverage refers to the ability of subsequent layers to evenly cover layers (“steps”) already present on the substrate. Facet etches are frequently used to provide superior step coverage. The standard facet etch uses a high energy argon ion which physically bombards the material being etched and thereby etches the oxide at an angle to allow subsequent material to have the best step coverage possible. However, if the argon ions etch through the oxide and reach metal or another conductor, they disperse their energy into the metal line or other conductor. This energy finds its way to a ground through a weak spot in the gate oxide thereby resulting in a blown gate.
[0004] In sputter etching, ions which impinge on horizontal surfaces have a minimal effect on etch rate and profile. However, the sputter yield of the etch at the corners is approximately four times that of the etch rate of a horizontal surface, thereby creating an extreme etch profile. The effect is the wearing away of the corners of a feature at approximately 45 degree angles. The material removed by the sputter etch is redeposited along the sides of the feature and along the surface of the substrate.
[0005] An issue associated with sputter etching is that some of the sputtered material redeposits frequently on the inside surfaces of the etching chamber. This redeposited material must be removed at intervals, thereby taking the etching chamber off-line.
SUMMARY OF THE INVENTION
[0006] The process of the present invention employs a two-step etching sequence wherein an insulating layer deposited on top of a plurality of conductive structures is first etched by a high energy inert gas ion to physically sputter the oxide material and form a faceted etch. The first step etch is terminated prior to reaching a predetermined target depth. The second step etch is conducted with a reactant gas to further remove the insulating material down to the target depth.
[0007] In a preferred embodiment, the method of the invention comprises forming a first layer comprising an insulating material superjacent a substrate comprising a plurality of conductive structures, at least some of the conductive structures being placed apart to form spaces between the conductive structures, such that the first layer forms in at least some of the spaces between the conductive structures and the first layer is formed to a thickness at least equal to the target depth. Next, the first layer is etched by directing a plasma of an inert gas at the first layer formed in at least some of the spaces between the conductive structures. The plasma is of sufficient energy to sputter material from the first layer thereby forming a facet etch in the first layer formed in the spaces between the conductive structures. The first etch is terminated when the first layer has been etched to a predetermined depth which is less than the target depth. Next, the first layer is etched, in a second etch, by contacting the first layer with a reactive chemical gas/plasma. The second etch is terminated when the first layer has been etched to the target depth.
[0008] Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Preferred embodiments of the invention are described below with reference to the following accompanying drawings, which are for illustrative purposes only. Throughout the following views, reference numerals will be used in the drawings, and the same reference numerals will be used throughout the several views and in the description to indicate same or like parts.
[0010] [0010]FIG. 1 is a schematic view of a semiconductor device having a plurality of conductive structures.
[0011] [0011]FIG. 2 is a schematic view of the semiconductor device of FIG. 1 at a later stage in the process.
[0012] [0012]FIG. 3 shows a schematic view of a portion of the semiconductor device of FIG. 2.
[0013] [0013]FIG. 4 shows the semiconductor device of FIG. 2 at a later stage in the process.
[0014] [0014]FIG. 5 shows a portion of the semiconductor device of FIG. 4.
[0015] [0015]FIG. 6 shows the semiconductor device of FIG. 4 at a later stage of the process.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In the following detailed description, references made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention.
[0017] [0017]FIG. 1 shows a semiconductor device 1 suitable for use in a preferred embodiment of this invention. The semiconductor device 1 comprises a plurality of conductive structures 12 overlying a substrate 10 . The conductive structures 12 are positioned in close proximity to each other to form spaces 14 between the conductive structures 12 .
[0018] Conductive structures 12 can be any conductive element of semiconductor device 1 but are typically metal lines, runners, leads or interconnects. Conductive structures 12 typically comprise at least one of titanium, tungsten, tantalum, molybdenum, aluminum, copper, gold, silver, nitrides thereof and silicides thereof.
[0019] The substrate 10 includes any semiconductor-based structure having a silicon base. The base of substrate 10 is to be understood as including silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, previous process steps may have been used to form regions or junctions in the base semiconductor structure or foundation. Typically, the substrate 10 will comprise at least one layer of material deposited on top of the silicon base. In one preferred embodiment, the uppermost layer of material of substrate 10 , which contacts conductive structures 12 , will be a dielectric material such as silicon dioxide or boron phosphosilicate glass (BPSG).
[0020] A first layer 16 is formed over the substrate 10 and conductive structures 12 as shown in FIG. 2. First layer 16 comprises a dielectric material 17 , preferably silicon dioxide or BPSG. First layer 16 may be conveniently formed by chemical vapor deposition or any other suitable means.
[0021] As shown in FIG. 3, the spaces 14 between the conductive structures 12 are not completely or uniformly filled during the formation of first layer 16 . In particular, the bottom 37 and lower corners 36 of space 14 are covered with a thinner depth of dielectric material 17 than are the sidewalls 38 and upper corners 35 . This nonuniform coverage of dielectric material 17 leads to the formation of undesirable voids, known as keyholes within the first layer 10 or between the first layer 10 and subsequent layers.
[0022] A facet etch is performed to provide a lower aspect opening for subsequent layers as shown in FIG. 4. The facet etch is conveniently performed by placing the semiconductor device 1 in a high vacuum reactor on a cathode for which a power source creates a radio frequency (RF) of 13.56 Mhz, while controlling the introduction of the etchant gases.
[0023] The walls of the reactor are grounded to allow for a return RF path. This chamber configuration is generally referred to as a Reactive Ion Etcher (R.I.E.). The RF power source acts to create a plasma condition within the chamber, thereby allowing for the creation of charged particles or ions 40 .
[0024] Due to the physics of the RF powered electrode, a direct current self-bias voltage condition is created at the semiconductor device 1 location. This self-bias condition acts to direct the charged particles or ions 40 toward the semiconductor device 1 in a direction perpendicular to the device surface 1 .
[0025] If the pressure is in a range being slightly less than 30 mtorr, the mean free path of the charged particles or ions 40 will be great enough to allow for physical sputtering of dielectric material 17 when the ions 40 impinge on the surface of the first layer 12 . It is important to note that a wide variety of systems and parameters can be used to effect a facet etch, as long as the pressure limit is not violated. As the pressure nears and exceeds 30 mtorr, the results of the process are effected.
[0026] Typical parameters for facet etching using an Applied Materials 5000. Series equipment are as follows:
[0027] RF power: 300-700 watts
[0028] pressure: 10-30 mtorr
[0029] etchant: 30-70 sccm.
[0030] The facet etch is performed for a time sufficient to obtain holes with sloping sides 42 in first layer 16 as shown in FIG. 4. The facet etch is terminated at depth 51 prior to removing the dielectric material 17 to a predetermined target depth 53 as shown in FIG. 5. The facet etch is terminated at a depth at least half of the target depth. For example, if the target depth is 300 Å, the facet etch will be at least 150 Å. Preferably, the facet etch is as deep as possible, as constrained by the possibility of etching through first layer 12 , in order to allow the second etch to maintain the facet contour. Typically, the facet etch is terminated less than about 150 Å, preferably no more than about 100 Å, more preferably, not more than about 50 Å prior to the target depth 53 . Some of the sputtered dielectric material 17 redeposits 55 in bottom corners 36 .
[0031] Subsequent to the termination of the facet etch, a chemical reactive ion etch (RIE) is performed on first layer 16 . The RIE is a directional etch which removes dielectric material 17 along the profile established by the facet etch. The RIE is terminated when sufficient dielectric material 17 is removed to reach the target depth 53 . This two-stage etch therefore results in a profiled etch of the desired depth.
[0032] As shown in FIG. 6, a second layer 64 may then be formed over first layer 10 with the formation of only minimized keyholes 66 . Additionally, the upper surface 68 of the second layer is relatively even.
[0033] As is typical with any sputter process, some of the sputtered dielectric material redeposits onto the interior surfaces of the etching chamber. The sputtered material which redeposits onto the chamber surfaces gradually builds up to a depth sufficient to impair the operation of the etching chamber. At that time, the etching chamber must be taken off-line for cleaning and reconditioning. An additional benefit to the current two-stage process is that the second stage reactive ion etch also etches the material building up on the chamber surfaces. As such, the etching chamber is at least partially cleaned on-line and the time between off-line cleaning and reconditioning is greatly extended.
[0034] In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | A modified facet etch is disclosed to prevent blown gate oxide and increase etch chamber life. The modified facet etch is a two-stage process. The first stage is a plasma sputter etch to form a facet profile. The first stage etch is terminated prior to reaching the target depth for the etching process. The second stage etch is a reactive ion etch which directionally follows the facet profile to reach the target depth. | 7 |
FIELD OF THE INVENTION
This invention relates to a computer system and, more particularly, to a system in which crossbar switches for connecting CPUs and memory of a computer or for connecting the nodes in a computer system constituted by multiple nodes are provided with redundancy.
BACKGROUND OF THE INVENTION
In modern computer systems, crossbar switches are used to switchingly connect the CPUs and memory of a computer, for example, or the nodes in a computer system constituted by multiple nodes. Crossbar switches are constructed on a plurality of LSI chips or cards or on a single LSI chip, which includes a plurality of crossbar switch blocks, in accordance with the bit slice or byte slice, etc.
SUMMARY OF THE DISCLOSURE
In the prior art there are the following problems, if a crossbar switch develops a failure, the switch cannot be allowed to degrade as in the manner of a CPU or memory, etc. That is, a faulty CPU is detached from the system when the system is restarted. The remaining CPUs can then execute processing. If a faulty crossbar switch is allowed to degrade, however, the computer CPUs and memory or the nodes can no longer be connected. As a consequence, the system will not operate.
Thus, a problem with the conventional crossbar switch is that system recovery cannot be achieved until the faulty parts of the crossbar switch are replaced. The result is prolonged system downtime.
Though a system in which all of the crossbar switch components are provided with redundancy, i.e., duplicated in order to avoid the foregoing problem is available, the system is high in cost and impractical.
An example of a crossbar switch having redundancy is disclosed in the specification of Japanese Patent Kokai (Laid-Open) Publication JP-A-7-264198. Here an N×N crossbar switch device is provided with an (N+1)th standby input line to construct an (N+1)×N cross-bar switch device. If an abnormality is detected in one of the N-number of working lines, a changeover is made to the standby line by a spatial switch, thereby furnishing data with an alternative path. Further, the specification of Japanese Patent Kokai (Laid-Open) Publication JP-A-11-331374 discloses a device serving as a cross-bar switch device used in an ATM switch or the like, wherein problems associated with the redundant cross-bar switch device (i.e., the fact that the switch is left in operation with no measures being taken to restore a faulty location) described in the aforesaid specification of JP-A-7-264198 are intended to be solved. In this device, a crossbar switch unit, which accommodates N-number of ports and implements a function for switching between any two of these ports, comprises a plurality of N×N cross-bar switch cards. The device further includes N-number of ports connected to the cross-bar switch unit by a plurality of working lines and at least one standby line, and a connection controller for outputtinga switch-abnormality detection signal upon detecting a switch abnormality in the cross-bar switch unit set in response to a switch signal. A port responds to the switch-abnormality detection signal by changing over at least one working line to at least one standby line. The entire disclosure of JP-A-7-264198 is herein incorporated by reference thereto.
In the cross-bar switch device described in the specification of JP-A-11-331374, packet data transmitted to an N×N cross-bar switch card detected to be abnormal is detoured to a standby line and is switched to a standby cross-bar switch card. When a crossbar switch card develops a failure, the destination to which the packet data is detoured (the switching destination) becomes the predetermined standby crossbar switch. Consequently, a problem which arises is delay time for data transfer, depending upon how the original cross-bar switch card and standby cross-bar switch that is the destination of the detour are disposed. A fluctuation in this data-transfer delay time is a major problem in computers in which the operating frequency is very high. The entire disclosure of JP-A-7-331374 is herein incorporated by reference thereto.
Accordingly, an object of the present invention is to provide a crossbar switch system in which rapid recovery of the system can be achieved at low cost when a crossbar switch fails.
According to an aspect of the present invention, there is provided a crossbar switch system comprising N+1 crossbar switches of which N is required and one is redundant. When the system develops a failure, a failure processing circuit recognizes that a crossbar switch is faulty and controls selection circuits, which are provided at input/outputs of the crossbar switches, after the system is restarted. As a result, the faulty crossbar switch is taken out of service and the redundant crossbar switch is placed in service.
According to a second aspect of the present invention, there is provided a cross-bar switch system with redundancy having a cross-bar switch set of a redundant structure comprising a plurality of cross-bar switches necessary for effecting connections between nodes of a plurality of nodes, and at least one additional redundant cross-bar switch;
(a) wherein a first cross-bar switch of said cross-bar switch set receives at input terminals thereof, first outputs among multiple N outputs of each of the plurality of nodes, and said one redundant cross-bar switch receives Nth outputs among N outputs of each of said plurality of nodes applied to input terminals thereof, N being an integer of 2 or more;
(b) each of the remaining cross-bar switches has M selection circuits to each of which receives two consecutive outputs of an order corresponding to that of the cross-bar switch, among N outputs of each of said plurality of nodes, the outputs of these M selection circuits being input to the cross-bar switch provided that M is an integer of 2 or more;
(c) each node of said plurality of nodes has N selection switches, which are provided at input terminals thereof, each of said selection switches receives two consecutive outputs of an output order corresponding to that of the node, among outputs of two mutually adjacent cross-bar switches, two by two, of said cross-bar switch set; and
(d) in response to a selection control signal output from a failure processing circuit that executes cross-bar switch failure processing, each of said selection circuits selects and outputs one of its two inputs and, when one cross-bar switch fails, takes the failed cross-bar switch out of service.
More specifically, according to a third aspect of the present invention, there is provided a cross-bar switch system having N+1 cross-bar switches inclusive of redundancy wherein one cross-bar switch is provided in addition to N cross-bar switches required for connecting of nodes among first to Mth nodes (where M is a prescribed integer equal to or greater than 2); the first cross-bar switch receiving each first output among N outputs of each of the first to Mth nodes at M input terminals thereof; the (N+1)th cross-bar switch receiving each Nth output among N outputs of each of the first to Nth nodes at M input terminals thereof; an Ith (where I is an integer of 2 or more and not more than N) cross-bar switch having M selection circuits, which are provided at respective ones of M input terminal thereof, to each of which are input consecutive (I−1)th and Ith outputs, which correspond to the Ith cross-bar switch, among outputs of each of the first to Mth nodes; and a Jth (where J is an integer of 1 or more and not more than M) node having N selection switches, which are provided at input terminals of the node, to each of which are input Jth outputs of two mutually adjacent cross-bar switches among the first to (N+1)th cross-bar switches (N is integer≧2); wherein in response to a selection control signal output from a failure processing circuit that executes cross-bar switch failure processing, each of selection circuits selects and outputs one of the two inputs and, when one cross-bar switch fails, takes the failed cross-bar switch out of service.
According to a fourth aspect of the present invention, there is provided a cross-bar switch system with redundancy,
(a) comprising N+1 cross-bar switches wherein one cross-bar switch is redundantly provided in addition to N cross-bar switches required for connecting of nodes among first to Mth nodes, where M and N are prescribed integers of 2 or more, respectively;
(b) each node of said first to Mth nodes outputting first to Mth output signals from output terminals thereof and receiving first to Nth input signals applied to input terminals thereof;
(c) the first cross-bar switch receiving each first output signal of each of said first to Mth nodes at M input terminals thereof;
(d) the (N+1)th cross-bar switch receiving each Nth output signal of each of said first to Mth nodes at M input terminals thereof;
(e) an Ith, where I is an integer of 2 or more and not more than N cross-bar switch having M selection circuits, which are provided at respective ones of M input terminals thereof, to each of which are input two signals, namely an (I−1)th output signal and an Ith output signal, of each of said first to Mth nodes; and
(f) a Jth, where J is an integer of 1 or more and not more than M, node having N selection circuits, which are provided at N input terminals thereof, to each of which are input outputs of a Jth output port of each of mutually adjacent cross-bar switches among said first to (N+1)th cross-bar switches, namely of Kth and (K+1)th cross-bar switches, where K is an integer of 1 or more and not more than N;
(g) wherein in response to a selection control signal output from a failure processing circuit that executes cross-bar switch failure processing, each of said selection circuits selects and outputs one of two signals and, when one cross-bar switch fails, takes the failed cross-bar switch out of service.
In the present invention, the crossbar switches connect CPUs and a memory within a computer or perform switching between nodes of a multinode system having CPUs and memories wherein the memories of remote nodes are accessed via the crossbar switches.
Namely, in a system having cross-bar switches for connecting CPUs and a memory within a computer system or for connecting nodes in a computer system composed of a plurality of nodes, a cross-bar switch system with redundancy according to a fifth aspect comprises;
(a) N+1 cross-bar switches inclusive of N cross-bar switches that are indispensable for the system and one redundant cross-bar switch;
(b) selection circuits provided at inputs and outputs of said cross-bar switches; and
(c) means, operable when the system fails, for performing control in such a manner that a cross-bar switch that has failed is taken out of service and the redundant cross-bar switch is placed in service by controlling said selection circuits by a failure processing circuit after the system is restarted, said failure processing circuit recognizing that said cross-bar switch has failed.
Each of said nodes inputs and outputs N bytes of data preferably on a byte-by-byte basis.
The failure-processing circuit includes: an (N+1)-bit cross-bar switch failure information register for storing whether failure has occurred or not with regard to the first to (N+1)th cross-bar switches; a selection-circuit control output circuit for outputting a selection control signal to each of the selection circuits based upon values in the cross-bar switch failure information register; and a multiple-failure detector for informing a system controller of occurrence of multiple failure when multiple cross-bar switches fail. M and N may be equal values.
Other aspects, features and advantages of the present invention will be apparent from the entire disclosure 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
FIG. 1 is a diagram illustrating the configuration of a crossbar switch system according to an embodiment of the present invention;
FIG. 2 is a block diagram illustrating the arrangement of CPUs according to the embodiment of the present invention;
FIG. 3 is a block diagram illustrating the structure of a failure processing circuit according to the embodiment of the present invention; and
FIG. 4 is a diagram illustrating the relationship between faulty crossbar switches and crossbar switches traversed by the bytes of transfer data.
PREFERRED EMBODIMENTS OF THE INVENTION
A mode for carrying out the present invention will be described below.
According to an embodiment of the crossbar the crossbar switch system according to the present invention, the system is provided with N+1 crossbar switches of which N are required and one is redundant. If a failure processing circuit recognizes failure of a cross-bar switch when such a failure occurs in the system, the failure processing circuit controls selection circuits, which are provided at inputs and outputs of the cross-bar switches, after the system is restarted, to thereby take the faulty cross-bar switch out of service and place the redundant cross-bar switch in service.
More specifically, according to a preferred mode for carrying out the present invention, a cross-bar switch system has first to (N+1)th cross-bar switches wherein one cross-bar switch is provided in addition to N cross-bar switches (N=8 holds in FIG. 1 ) required for connecting of nodes among first to Mth (M=8 in FIG. 1 ) nodes; each node outputs first to Nth output signals from output terminals thereof and has first to Nth input signals applied to input terminals thereof; the first cross-bar switch (cross-bar switch 10 in FIG. 1 ) has first output signals of each of the first to Mth nodes input thereto; the (N+1)th cross-bar switch (cross-bar switch 8 in FIG. 1 ) has Nth output signals of each of the first to Mth nodes input thereto; an Ith (where I is an integer equal to or greater than 2 and not more than N) cross-bar switch (cross-bar switches 11 to 17 in FIG. 1 ) has first to Mth selection circuits ( 11 - 0 to 11 - 7 , . . . , 17 - 0 to 17 - 7 ), which are provided at the input thereof, to each of which are input two signals, namely an (I−1)th output signal and an Ith output signal, of each of the first to Mth nodes; a Jth (where J is an integer equal to or greater than 1 and not more than M) node has M selection circuits ( 0 - 0 to 0 - 7 , 1 - 0 to 1 - 7 , . . . , 7 - 0 to 7 - 7 ), which are provided at N input terminals thereof, to each of which are input outputs of a Jth output port of each of mutually adjacent cross-bar switches among the first to (N+1)th cross-bar switches, namely of Kth and (K+1)th (where K is an integer equal to or greater than 1 and not more than N) cross-bar switches; and the selection circuits ( 11 - 0 to 11 - 7 , . . . , 17 - 0 to 17 - 7 , 0 - 0 to 0 - 7 , 1 - 0 to 1 - 7 , . . . , 7 - 0 to 7 - 7 ) each select and output one of two signals in response to a selection control signal output from a failure processing circuit ( 20 ) for cross-bar switch failure processing, whereby control is performed so as to take a cross-bar switch that has failed out of service and place the redundant cross-bar switch in service.
In this mode of carrying out the invention, each node inputs and outputs first to Nth items of data on a byte-by-byte basis.
The failure processing circuit has an (N+1)-bit cross-bar switch failure information register ( 200 ) for storing failure information, which is output from a system controller, regarding the N+1 cross-bar switches; a selection-circuit control output circuit ( 201 ) for outputting a selection control signal to the selection circuits; and a multiple-failure detector ( 202 ) for informing the system controller of occurrence of multiple failure when multiple cross-bar switches fail.
DETAILED DESCRIPTION OF EMBODIMENTS
Embodiments of the present invention will now be described in greater detail with reference to the drawings.
FIG. 1 is a diagram illustrating the configuration of a crossbar switch system according to an embodiment of the present invention. As shown in FIG. 1 , the system includes eight nodes 0 to 7 , nine cross-bar switches 10 to 18 , a failure processing circuit 20 , and selection circuits 0 - 0 to 0 - 7 , . . . , 7 - 0 to 7 - 7 , 11 - 0 to 11 - 7 , . . . , and 17 - 0 to 17 - 7 .
The nodes 0 to 7 are identically constructed and so are the crossbar switches 10 to 18 . Each of the cross-bar switches 10 to 18 has eight input ports, eight output ports, an 8×8 cross-bar switch unit (not shown) and a connection controller (not shown) for controlling switching of the input and output ports to the cross-bar switch unit. Each port is constructed to input or output data on a per-byte (8-bit) basis. FIG. 1 is mainly for the purpose of describing the principle of the present invention; the number of nodes, for example, is not limited to eight, as a matter of course. As for the cross-bar switches and the failure detection, reference is made to JP-A-11-331374 which is incorporated herein by reference thereto.
Data communicated between any two nodes of the nodes 0 to 7 is transferred from the source node to the destination node by the crossbar switches 10 to 18 .
The data width of data communication between two nodes is eight bytes (8×8=64 bits), by way of example.
Byte- 0 data of the 8-byte data output from respective ones of the nodes 0 to 7 is input to the crossbar switch 10 at a respective one of the eight input ports.
With regard to cross-bar switch 11 , byte- 0 data and byte- 1 data output from node 0 is input to the selection switch 11 - 0 , the output of the selection switch 11 - 0 is applied to the first input port of the cross-bar switch 11 , byte- 0 data and byte- 1 data output from node 1 is input to the selection switch 11 - 1 , and the output of the selection switch 11 - 1 is applied to the second input port of the cross-bar switch 11 . Similarly, byte- 0 data and byte- 1 data output from node 7 is input to the selection switch 11 - 7 and the output of the selection switch 11 - 7 is applied to the eighth input port of the cross-bar switch 11 .
In response to a control signal from the failure processing circuit 20 , the selection circuits 11 - 0 to 11 - 7 select one of byte- 0 data and byte- 1 data in the 8-byte data output from the nodes 0 to 7 and output the selected data to the cross-bar switch 11 . The selection circuits 11 - 0 to 11 - 7 select the byte- 1 data in the absence of a failure and select the byte- 0 data when the crossbar switch 10 fails (see FIG. 4 , described later).
With regard to cross-bar switch 17 , byte- 6 data and byte- 7 data output from node 0 is input to the selection switch 17 - 0 , the-output of the selection switch 17 - 0 is applied to the first input port of the cross-bar switch 17 , byte- 6 data and byte- 7 data output from node 1 is input to the selection switch 17 - 1 , and the output of the selection switch 17 - 1 is applied to the second input port of the cross-bar switch 17 . Similarly, byte- 6 data and byte- 7 data output from node 7 is input to the selection switch 17 - 7 and the output of the selection switch 17 - 7 is applied to the eighth input port of the cross-bar switch 17 .
The byte- 7 data in the 8-byte data output from each of the nodes 0 to 7 enters respective ones of the eight input ports of crossbar switch 18 .
The data output from the cross-bar switches 10 to 18 is selected by the selection circuits 0 - 0 to 0 - 7 , 1 - 0 to 1 - 7 , . . . , 7 - 0 to 7 - 7 and input to the nodes 0 to 7 .
The selection circuit 0 - 0 corresponding to node 0 receives as inputs the byte- 0 data output from the first output port of cross-bar switch 10 and the byte- 0 data output from the first output port of cross-bar switch 11 , selects one of these inputs based upon the control signal from the failure processing circuit 20 and outputs the selected data to the node 0 . The selection circuit 0 - 7 corresponding to node 0 receives as inputs the byte- 7 data output from the first output port of cross-bar switch 17 and the byte- 7 data output from the first output port of cross-bar switch 18 , selects one of these inputs based upon the control signal from the failure processing circuit 20 and outputs the selected data to the node 0 .
Similarly, the selection circuit 7 - 0 corresponding to node 7 receives as inputs the byte- 0 data output from the eighth output port of cross-bar switch 10 and the byte- 0 data output from the eighth output port of cross-bar switch 11 , selects one of these inputs based upon the control signal from the failure processing circuit 20 and outputs the selected data to the node 7 . The selection circuit 7 - 7 selects byte- 7 data, which is output from the eighth output port of cross-bar switch 17 and the eighth output port of cross-bar switch 18 , based upon the control signal from the failure processing circuit 20 and outputs the selected data to the node 7 .
On the basis of failure information relating to a failure that has occurred, the failure processing circuit 20 outputs the selection control signal to the selection circuits 0 - 0 to 0 - 7 , 1 - 0 to 1 - 7 , . . . , 7 - 0 to 7 - 7 , 11 - 0 to 11 - 7 , . . . , 17 - 0 to 17 - 7 .
FIG. 2 illustrates an example of the internal structure of the node 0 to 7 show in FIG. 1 . Each node is composed of four CPUs 100 to 103 , a memory controller 104 , a memory 105 and an input/output (I/O) controller 106 .
Each of the CPUs 100 to 103 performs memory access and I/O access via the memory controller 104 .
In a case where a CPU accesses the memory 105 within its own node, the memory 105 is accessed from the memory controller 104 . However, when a memory within another node is accessed, the access re quest is sent from the memory controller 104 to a memory controller of the other node via a cross-bar switch, thereby accessing the memory within the other node.
FIG. 3 illustrates the internal structure of the failure processing circuit 20 shown in FIG. 1 . The failure processing circuit 20 outputs the selection control signal to the selection circuits 0 - 0 to 7 - 7 , 11 - 0 to 17 - 7 after the system is restarted, for example, whereby control is performed in such a manner that the faulty crossbar switch is taken out of service and the redundant crossbar switch is placed in service.
Failure information concerning the crossbar switches 10 to 18 output from a system controller enters a 9-bit crossbar switch failure information register 200 . Each bit of the register 200 holds information as to whether the respective one of the cross-bar switches 10 to 18 is faulty or not.
The information from the crossbar switch failure information register 200 is output to a selection-circuit control output circuit 201 . On the basis of this information, the selection-circuit control output circuit 201 outputs a selection control signal to each of the selection circuits 0 - 0 to 7 - 7 , 11 - 0 to 17 - 7 .
The information from the crossbar switch failure information register 200 is also output to a multiple-failure detector 202 . If two or more of the crossbar switches 10 to 18 fail, the multiple-failure detector 202 notifies the system controller of the occurrence of multiple failure.
FIG. 4 illustrates, in table form, which crossbar switches switch each byte of data transferred between nodes when the crossbar switches 10 to 18 fail.
Under normal conditions in the absence of failure, the data of bytes 0 to 7 are switched by the cross-bar switches 10 to 17 , respectively, as illustrated by the lowermost row of the table in FIG. 4 .
If the crossbar switch 10 , for example, develops a failure, the data of bytes 0 to 7 are switched by the crossbar switches 11 to 18 , respectively, as indicated by the second row of the table of FIG. 4 .
If any of the cross-bar switches 11 to 18 fails, then, in similar fashion, the data of each byte is switched by a respective one of the cross-bar switches indicated in FIG. 4 while the faulty cross-bar switch is avoided.
The operation of this embodiment of the invention will now be described.
As shown in FIG. 1 , the crossbar switches 10 to 18 are cross-bar switches in a redundant arrangement for effecting communication between nodes. If a failure has not occurred, the crossbar switches 10 to 17 are employed and the crossbar switch 18 is not used.
Under normal conditions, the byte- 0 data in the 8-byte data output from each of the nodes 0 to 7 is switched by the cross-bar switch 10 , the byte- 1 data is switched by the cross-bar switch 11 and the byte- 7 data is switched by the cross-bar switch 17 .
In a case where the CPU 100 in node 0 accesses the memory within node 1 , which is a remote node, the byte- 0 data in 8-byte request data is switched by the cross-bar switch 10 and is sent to node 1 .
Though the byte- 0 data is sent from node 0 to the selection circuit 11 - 0 , the latter responds to the control signal from the failure processing circuit 20 by selecting and outputting its other input, namely the byte- 1 data in the 8-byte data from node
The byte- 0 data output from the cross-bar switch 10 enters the selection circuit 1 - 0 which, in response to the selection control signal from the failure processing circuit 20 , selects the byte- 0 data and outputs this data to the node 1 .
If the system develops a failure and it is determined as a result of diagnostic processing executed after the occurrence of the failure that the cross-bar switch 10 is faulty, then, in response to the selection control signal output from the failure processing circuit 20 to the selection circuits after the system is restarted, the cross-bar switch 10 is taken out of service and the items of byte- 0 data, byte- 1 data and byte- 7 data in the 8-byte data output from nodes 0 to 7 are switched by the cross-bar switches 11 , 12 and 18 , respectively.
As for the transfer of data from node 0 to node 1 in this case, the byte- 0 data that was output from node 0 to selection circuit 11 - 0 is selected by the selection control signal from the failure processing circuit 20 and is delivered to the cross-bar switch 11 .
The byte- 0 data output from cross-bar switch 11 enters the selection circuit 1 - 0 , and the latter responds to the selection control signal from the failure processing circuit 20 by selecting the byte- 0 data and inputting it to the node 1 .
If a failure occurs in any of the cross-bar switches 11 to 18 , each byte of node transfer data is transferred by control similar to that set forth above via the cross-bar switches indicated in FIG. 4 .
If two or more of the crossbar switches 10 to 18 fail, then the crossbar multiple-failure detector 202 in the failure processing circuit 20 detects multiple crossbar failure and so informs the system controller. In this case, the system is not restarted and remains down until it is repaired.
According to the embodiment described above, each node outputs 8-byte data, and each selection circuit and each port of the crossbar switches inputs and outputs data in single-byte units. However, the present invention is not limited to this implementation and it goes without saying that an implementation in which data is input and output in word units or bit units may be adopted.
Further, the present invention is not only ideal for application to a multinode computer system but can be similarly applied to crossbar switches that control the connections between multiple CPUs and memories.
The meritorious effects of the present invention are summarized as follows.
The present invention has a number of advantageous effects, which will now be described.
First, in a case where cross-bar switches are provided with redundancy and a cross-bar switch fails, the failure processing circuit controls the selection circuits, which are provided at the inputs and outputs of each of the cross-bar switches, based upon failure information, thereby making it possible to achieve an operation in which the faulty cross-bar switch is avoided after the system is started up.
Second, it is possible to avoid a situation in which system recovery cannot be achieved until a faulty crossbar switch is repaired. Avoiding this situation does not require that all crossbar switches be made redundant.
Third, in a case where a cross-bar switch is designed to be inserted into and withdrawn from a live wire, it is possible for cross-bar switch components to be replaced on-line. This means that maintenance can be performed without shutting down the system.
Fourth, when switching is performed in the event of failure of a crossbar switch, the switching takes place between crossbar switches whose data branching inputs are mutually adjacent. As a consequence, the fluctuation in data delay time caused by detouring the data, which is a problem encountered with the system of JP-A-11-331374 described earlier, either does not occur or is so small as to be negligible. This has applications in computer systems that operate at high operating frequencies.
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.
It should be noted that other objects, features and aspects of the present invention will become apparent in the entire disclosure and that modifications may be done without departing the gist and scope of the present invention as disclosed herein and claimed as appended herewith.
Also it should be noted that any combination of the disclosed and/or claimed elements, matters and/or items may fall under the modifications aforementioned. | A crossbar switch system with redundancy has N+1 cross-bar switches. A first cross-bar switch has first outputs of each of a plurality of nodes applied to N input terminals thereof, an (N+1)th cross-bar switch has Nth outputs of each of the nodes applied to N input terminals thereof, and second to Nth (Ith) cross-bar switches each have first to Nth selection circuits, which are provided at respective input terminals thereof, to each of which are input mutually adjacent (I−1)th and Ith outputs among outputs of each of the nodes. Each (Jth) node has N selection switches, which are provided at input terminals thereof, to each of which are input Jth outputs of two mutually adjacent cross-bar switches among the first to (N+1)th cross-bar switches. In response to a selection control signal output from a failure processing circuit that executes crossbar switch failure processing, each of the selection circuits selects and outputs one of its two inputs. | 7 |
FIELD OF INVENTION
[0001] The invention relates to water soluble prodrugs in which the solubulizing groups are non toxic acids which are attached to paclitaxel as an ester functionality to the C2′- and/or C7-hydroxyl position. These prodrugs are stable in aqueous solution but are readily hydrolyzed at physiological conditions to the parent drug.
BACKGROUND OF THE INVENTION
[0002] Paclitaxel (1) is a natural diterpenoid, isolated from the Pacific yew tree ( Taxus brevifolia ) . Paclitaxel has been approved for treatment of patients with advanced ovarian cancer or breast cancer.
[0003] Although paclitaxel has demonstrated to be an unique antitumor agent, it has several disadvantages. One of the major problems is its poor solubility in water, which makes formulation difficult in relation to the intravenous administration. Due to this poor solubility, paclitaxel is formulated, using a 1:1 mixture of cremophor EL (a polyethoxylated castor oil) and ethanol (Rowinsky, E. K. et al. J. Natl. Cancer Inst. 1990, 82, 1247). This mixture is diluted with 5% dextrose in water or saline prior to lengthy infusion. Unfortunately, various hypertensive reactions have been reported in patients who were treated with paclitaxel, partly due to cremophor EL, which is responsible for histamine release, causing the effects (Rowinsky, E. K. et al. Ibid.) . Premedication, using antihistaminic drugs can deminish these side effects, but results in additional medication, cost and discomfort to the patient.
[0004] The solubility problems with paclitaxel could be overcome by the development of a more water soluble, chemically stable, and therefore more easily formulated analog/prodrug of paclitaxel. Prodrug strategies consist of temporary modification of the physiochemical properties of a compound through chemical derivatization. Such temporary chemical modification is usually designed to alter aqueous solubility and biodistribution while the pharmacological properties of the parent drug remain intact. Prodrugs can be designed to be converted in a predictable way, in vivo, to the active drug by either an enzymatic mechanism or by hydrolysis initiated under physiological pH conditions.
[0005] SAR studies have shown that some modifications at C7 of paclitaxel are allowed ((a) Mellado, W. et al. Biochem. Biophys. Res. Comm. 1984, 124, 329-336. (b) Kingston, D. G. I et al. New Trends in Nat. Prod. Chem. 1986, 26, 219-235. (c) Horwitz, S. B. et al. Ann. New York Acad. Sci. 1986, 466, 733-740. (d) Kingston, D. G. I. et al. J. Nat. Prod. 1990, 53, 1-12. (e) Ringel, I. et al. J. Pharmacol. Exp. Ther. 1987, 242, 692-698. (f) Chaudhary, A. G. et al. J. Org. Chem. 1993, 58, 3798-3799. (g) Chen, S. et al. J. Org. Chem. 1993, 58, 5028-5029).
[0006] For instance, 7-acetylpaclitaxel has shown to be as active as paclitaxel in microtubule assembly assays. SAR studies have also shown that introduction of an acetyl group at C2′ resulted in the loss of the ability to promote microtubule assembly. However the cytotoxic activity of 2′-acetyl-paclitaxel is almost the same as for paclitaxel, probably due to the fact that the C2′-acetyl group is either being hydrolyzed under the conditions of the bioassay or converted intracellularly to paclitaxel or an active paclitaxel metabolite. These observations suggest that the C2′- and C7-positions of paclitaxel are suitable for (temporary) structural modifications. The C2′-position seems more suitable for reversible derivatization.
[0007] Several research groups have reported the syntheses and biological evaluations of water soluble prodrugs of paclitaxel. These analogs have a polar substituent either at the C2′- or at the C7-hydroxyl group. In most cases the polar substituents are coupled to these hydroxyl groups via an ester, carbonate or carbamate functionality. Deutsch et al. (Deutsch, H. M. et al. J. Med. Chem. 1989, 32, 788-792) reported that some salts of 2′-succinylpaclitaxel and 2′-glutarylpaclitaxel had improved antitumor activities compared to the corresponding free acids. The triethanolamine and N-methyl-glucamine salts showed improved aqueous solubility and were more active than the sodium salts. Zhao et al. (Zhao, Z. et al. J. Nat. Prod. 1991, 54, 1607-1611) introduced sulfonate groups to improve the water solubility of paclitaxel. These sulfonate-paclitaxel analogs showed improved water solubility and had about the same (in vivo) activity compared to paclitaxel. Mathew et al. (Mathew, A. E. et al. J. Med. Chem. 1992, 35, 145-151) reported the synthesis and evaluation of some 2′- and 7-amino acid analogs of paclitaxel. The methane sulfonic salts of both 2′- and 7-amino acid esters of paclitaxel showed increased water solubility. The 2′-analogs showed activity to an extent similar to that of paclitaxel, while the others showed reduced activity. Vyas et al. (Vyas, D. M. et al. Bioorg. Med. Chem. Lett. 1993, 3, 1357-1360) synthesized and vevaluated 2′- and 7-phosphate paclitaxel analogs. These analogs showed improved water solubility. However in vitro as well as in vivo these derivatives were non-toxic compared to paclitaxel. Ueda et al. (Ueda, Y. et al. Bioorog. Med. Chem. Lett. 1993, 3, 1761-1766) synthesized 2′- and 7′-phosphonoxyphenylpropionatepaclitaxel, which both showed increased water solubility. The 2′-analog was inactive, whereas the 7-analog was as active as paclitaxel in vivo. Greenwald et al. ((a) Greenwald, R. B. et al. J. Org. Chem. 1995, 60, 331-336. (b) Greenwald, R. B. et al. J. Med. Chem. 1996, 39, 424-431) prepared some 2′- and 7-polyethyleneglycol esters of paclitaxel. These analogs were extremely water soluble. The 2′-analogs had in vitro and in vivo activities in the same extent as paclitaxel, whereas the 7-analogs showed reduced activity. Greenwald et al. claimed that by choosing the appropriate weight for the 2′-PEG moiety, a prodrug was produced that is as efficacious as paclitaxel/cremophor EL/ethanol in an in vivo model. Nicolaou et al. (Nicolaou, K. C. et al. Nature 1993, 364, 464-466) synthesized some 2′-(2-thio-aryl)ethylcarbonate analogs of paclitaxel as well as some 2′- and 2′,7-(bis)-C(O)CH 2 XCH 2 COOH (wherein X═O, S or SO 2 ) analogs of paclitaxel, which were all more water soluble and showed increased in vitro cytotoxic activities compared to paclitaxel. Nicolaou et al. ((a) Nicolaou, K. C. et al. Angew. Chemie 1994, 106, 1672-1675. (b) Paloma, L. G. et al. Chem. Biol. 1994, 1, 107-112) also synthesized 2′- and 7-methylpyridiniumacetate analogs of paclitaxel. Both compounds showed increased water solubility. The 2′-analog was as active as paclitaxel in in vivo models, whereas the 7-analog was far less cytotoxic. Kingston et al. (Kingston et al. US patent 1995, U.S. Pat. No. 5,411,984A) prepared some 2′- and 2′,7-bis-O-aroyl analogs. These analogs showed improved water solubility. The 2′-analogs showed in vivo activities in the same extent as paclitaxel and some even better.
[0008] Chemical stability is critical to the formulation and storage of any water soluble analog/prodrug of paclitaxel, since partial degradation to the poorly soluble parent drug is likely to lead to precipitation of paclitaxel. The enzymatic stability (in rat, human plasma or in vivo) is important in relation to the degradation of the prodrugs to paclitaxel or to an active metabolite of paclitaxel.
[0009] From the water soluble paclitaxel prodrugs described so far the pharmacological properties of the used solubilizing functionalities, which are released once paclitaxel is liberated have not been studied. It might be possible that these solubilizing moieties or their metabolites have some undesired and/or unknown side effects. The prodrugs described in this patent release after hydrolysis a non-toxic acid.
OBJECTS OF THE INVENTION
[0010] It is therefore an object of this invention to provide water soluble paclitaxel analogs/prodrugs, using a body innocuous solubulizing moiety, for the treatment of cancer.
[0011] A further object of this invention is to produce water soluble analogs of paclitaxel which possess (in vitro or in vivo) antitumor activity in the same extent as paclitaxel.
[0012] It is a further object of this invention to produce prodrugs of paclitaxel which are stable in aqueous solutions, but which upon hydrolysis at physiological (in vitro and/or in vivo) conditions exhibit the same or similar level of antitumor activity as paclitaxel.
SUMMARY OF THE INVENTION
[0013] The above and various other objects of the present invention are achieved by water soluble analogs/prodrugs having the following general formula:
[0014] Wherein:
[0015] R 1 ═C(O)CH 2 CH(OH)COOX
[0016] R 2 ═H, C(O)CH 2 CH(OH)COOX,
[0017] X═H, Li, Na or any other pharmaceutically acceptable counterion.
DESCRIPTION OF THE DRAWINGS
[0018] [0018]FIG. 1 illustrates the protection of one of the carboxylic acids together with the α-hydroxyl group of malic acid ( 2 ) as an isopropylidene functionality, resulting in compound 3 . In this figure also the synthesis of 2′-malylpaclitaxel ( 5 ), via coupling of 3 to the C2′-hydroxyl group of paclitaxel, leading to 4 , and removal of protective isopropylidine functionality, is presented. Finally it contains in conversion of 5 into the corresponding sodium salt 6 .
[0019] [0019]FIG. 2 illustrates the synthesis of 2′,7-bis(malyl)paclitaxel ( 8 ), carried out similar to the synthesis of 5 . The coupling reaction of 3 with paclitaxel, leading to 7 , was carried out at 40° C.
[0020] [0020]FIG. 3 illustrates the synthesis of 7-malylpaclitaxel ( 11 ), via 2′-Trocpaclitaxel ( 9 ), which was coupled to 3 , leading to 10 , followed by removal of the protecting groups.
DEFINITIONS
[0021] Unless clearly indicated by context or statement to the contrary, the terms used herein have the meanings as conventionally used in chemical arts, and definitions incorporate those used in standard texts.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Paclitaxel was obtained from Pharmachemie BV Haarlem. Proton magnetic resonance spectra were measured on a Bruker AC-100 or a Bruker AM-400 spectrometer. Chemical shift values are reported as δ-values relative to tetramethylsilane as an internal standard; deuterochloroform was used as solvent. Mass spectra were obtained with a double focusing VG 7070E spectrometer. Elemental analyses were carried out on a Carlo Erba Instruments CHNSO EA 1108 element analyzer. Melting points were determined with a Reichert Thermopan microscope and are uncorrected. Thin layer chromatography was carried out on Merck precoated silica gel 60 F-254 plates (thickness; 0.25 mm). Spots were visualized with UV or a 6.2 a H 2 SO 4 aqueous solution, (1L) containing ammonium molybdate (42 g) and ceric ammonium sulfate (3.6 g), followed by charring. Column chromatography was carried out using silica 60 or silica 60H (Merck). Unless otherwise stated, materials were obtained from commercial sources and used without further purification. When necessary, solvents were distilled and dried according to standard procedures. All reactions, if necessary, were carried out under argon atmosphere.
[0023] The synthesis of prodrugs from paclitaxel in which the 2′-OH or the 7-OH group is esterified by a dicarboxylic acid needs a protection strategy for one of the carboxylic acid groups.
[0024] With reference to FIG. 1, 1,2-O-(Propane-2,2-diyl)-malic acid ( 3 ) was obtained after treatment with malic acid ( 2 ) with acetone, in the presence of p-toluenesulfonic acid. Next, 2′-malylpaclitaxel ( 5 ) was synthesized by reaction of paclitaxel ( 1 ) with 1.1 equivalent of 3 in the presence of diisopropylcarbodiimide (DIPC) and 4-dimethylaminopyridine (DMAP) at 0° C. to afford 2′-(1,2-O-(propane-2,2-diyl)-malyl)paclitaxel ( 4 ), which reacted with a mixture of HOAc/THF/H 2 O: 4/1/2 at 45° C. to give 2′-malylpaclitaxel ( 5 ). This compound 5 was subsequently eluted with a mixture of H 2 O/acetone: 4/1 (v/v) from DOWEX 50W×2, pretreated with 1N NaOH, yielding sodium salt 6 .
[0025] With reference to FIG. 2, 1,2-O-(Propane-2,2-diyl)-malic acid ( 3 ) was coupled to paclitaxel ( 1 ) in the presence of DIPC and DMAP at 40° C. to yield 2′,7-bis(1,2-O-(propane-2,2-diyl)-malyl)-paclitaxel ( 7 ). This compound 7 was converted to 2′,7-bis(malyl)paclitaxel ( 8 ) by treatment with a mixture of HOAc/THF/H 2 O: 4/1/2. Compound 8 can be further converted into for example sodium salts analogously to the procedure described for compound 6 .
[0026] With reference to FIG. 3, the C2′-hydroxyl group of paclitaxel ( 1 ) was protected, using 2,2,2-trichloroethyl chloroformate (Troc-Cl) in pyridine, leading to 2′-Trocpaclitaxel ( 9 ) (Magri, N. F. et al. J. Org. Chem. 1986, 51, 797-802). Compound 9 was coupled to 1,2-O-(Propane-2,2-diyl)-malic acid (3), in the presence of DIPC and DMAP to give 2′-Troc-7- (1,2-O-(propane-2,2-diyl) -malyl)paclitaxel ( 10 ). This compound 10 was converted to 7-malylpaclitaxel ( 11 ) by treatment with a mixture of HOAc/THF/H 2 O: 4/1/2, in the presence of zinc powder (Zn).
EXAMPLES
[0027] The following nonlimiting examples provide specific synthesis methods for preparing prodrugs/analogs of paclitaxel of the present invention. All technical and scientific terms used herein have the same meaning as commonly understood by persons of ordinary skill in the art. Other methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention.
[0028] 2′-Malylpaclitaxel ( 5 )
[0029] a. 1,2-O-(Propane-2,2-diyl)-malic acid ( 3 )
[0030] To a solution of malic acid ( 2 ) (5.0 g, 37 mmol) and acetone (22 g, 0.37 mol) in pentane (300 ml), PTS (1.0 g, 5.8 mmol) and H 2 SO 4 (10 drops) were added. The reaction mixture was heated to reflux temperature and then stirred for 18 hours. The formed water is removed azeotropically and trapped by molecular sieves (4 Å), using a Dean-Stark apparatus. After 18 hours, the reaction mixture was concentrated in vacuo. The residue was purified via chromatography (CHCl 3 /CH 3 CN: 1/1), yielding 3 (3.78 g, 21.7 mmol, 59%). m.p. 113° C.; 1 H-NMR (100 MHz, CDCl 3 ): δ 4.51 (1H, m, CH-malyl), 2.68 (2H, m, CH 2 -malyl), 1.43 (3H, s acetonide) , 1.38 (3H, s, acetonide).
[0031] b. 2′-(1,2-O-(Propane-2,2-diyl)-malyl)-paclitaxel ( 4 ).
[0032] A solution of paclitaxel ( 1 ) (100 mg, 0.117 mmol) and 1,2-O-(Propane-2,2-diyl)-malic acid ( 3 ) (22 mg, 0.13 mmol) in CH 2 Cl 2 (10 ml) was stirred at 0° C. Next, DIPC (36 μl, 0.24 mmol) and DMAP (15 mg, 0.12 mmol) were added. After stirring for 3 hours at 0° C., the mixture was diluted with EtOAc (25 ml) and washed with a saturated NaHCO 3 solution. The organic layer was washed with water, dried over Na 2 SO 4 and concentrated in vacuo. The residue was purified via chromatography (EtOAc/hexane: 1/1), yielding 4 (103 mg, 0.102 mmol, 87%). m.p. 138° C.; 1 H-NMR (400 MHz, CDCl 3 ): δ 8.15 (2H, d, J=7.2 Hz, H-Ph), 7.80 (2H, d, J=7.4 Hz, H-Ph), 7.61 (1H, t, J=7.2 Hz, H-Ph), 7.45 (10H, m, H-Ph), 7.01 (1H, d, J NH-3′ =9.2 Hz, NH), 6.29 (1H, s, H10), 6.26 (1H, m, H13) , 6.00 (1H, dd, J 3′-NH =9.2 Hz, J 3′-2′ =3.0 Hz, H3′) , 5.69 (1H, d, J 2-3 =7.1 Hz, H2), 5.52 (1H, d, J 2′-3′ = 3.0 Hz, H2′), 4.97 (1H, d, J 5-6 =8.0, H5), 4.44 (1H, m, H7), 4.32 (1H, d, J 20a-20b =8.4 Hz, H20a), 4.21 (1H, d, J 20b-20a =8.4 Hz, H20b), 4.12 (1H, m, CH-malyl), 3.82 (1H, d, J 3-2 =7.1 Hz, H3), 2.96 (2H, m, CH 2 -malyl), 2.51 (1H, m, H6), 2.46 (3H, s, OCOCH 3 ) , 2.36 (1H, m, H14a), 2.23 (3H, s, OCOCH 3 ), 2.19 (1H, m, H14b), 2.03 (1H, m, H6), 1.93 (1H, s, H18), 1.69 (3H, s, H16), 1.57 (3H, s, acetonide), 1.51 (3H, s, acetonide), 1.25 (3H, s, H17), 1.13 (3H, s, H19); FAB-MS, 1010 [M+H] + , 1032 [M+Na] + .
[0033] c. 2′-Malylpaclitaxel ( 5 )
[0034] Compound 4 (100 mg, 0.099 mmol) was dissolved in a mixture of HOAc/THF/H 2 O (8/2/4 ml) . The mixture was stirred at 45° C. for 6 hours. Next, the organic solvents were removed by evaporation in vacuo. The residue was diluted by water (100 ml) and freeze dried, yielding 5 (91 mg, 0.093 mmol, 94%). m.p. 148-151° C. 1 H-NMR (400 MHz, CDCl 3 ): δ 8.16 (2H, d, J=7.6 Hz, H-Ph), 7;93 (2H, d, J=7.6 Hz, H-Ph), 7.61 (1H, t, J=7.3 Hz, H-Ph), 7.36 (11H, m, H-Ph and NH), 6.30 (1H, s, H10), 6.28 (1H, m, H13), 6.08 (1H, dd, J 3′-NH =9.2 Hz, J 3′-2′ =2.8 Hz, H3′), 5.68 (1H, d, J 2-3 =7.3 Hz, H2), 5.51 (1H, d, J 2′-3′ =2.8 Hz, H2′), 4.99 (1H, d, J 5-6 =8.0, H5), 4.46 (1H, m, H7), 4.33 (1H, d, J 20a-20b = 8.4 Hz, H20a), 4.27 (1H, m, CH-Malyl), 4.22 (1H, d, J 20b-20a =8.4 Hz, H20b), 3.82 (1H, d, J 3-2 =7.3 Hz, H3), 3.03 (2H, m, CH 2 -malyl), 2.55 (1H, m, H6), 2.53 (3H, s, OCOCH 3 ), 2.40 (1H, m, H14a), 2.23 (3H, s, OCOCH 3 ), 2.13 (1H, m, H14b), 1.93 (1H, s, H18), 1.88 (1H, m, H6), 1.69 (3H, s, H16), 1.21 (3H, s, H17), 1.14 (3H, s, H19); FAB-MS, 992 [M+Na] + .
[0035] Sodium salt of 2′-malylpaclitaxel ( 6 )
[0036] 2′-Malylpaclitaxel ( 5 ) (30 mg, 0.031 mmol) was brought on DOWEX 50W×2, which was pretreated with 1N NaOH (aq). Using a mixture of H 2 O and acetone (4/1, v/v) as eluent, sodium salt 6 (30 mg, 0.030 mmol, 98%) was isolated after removal of the acetone in vacuo and freeze drying. m.p. 195° C.; 1 H-NMR (400 MHz, CDCl 3 ): in accordance with the structure of compound 5 ; FAB-MS, 992 [M+H] + , 1014 [M+Na] + .
[0037] 2′,7-Bis(malyl)paclitaxel ( 8 )
[0038] a. 2′,7-Bis(1,2-O-(propane-2,2-diyl)-malyl)-paclitaxel ( 7 ) A solution of paclitaxel ( 1 ) (50 mg, 0.0586 mmol) and 1,2-O-(Propane-2,2-diyl)-malic acid ( 3 ) (51 mg, 0.29 mmol) in CH 2 Cl 2 (5 ml) was stirred at 0° C. Next, DIPC (100 μl, 0.064 mmol) and DMAP (7.5 mg, 0.061 mmol) were added. After 1 hour, the mixture was heated to reflux temperature and stirred for 3 days. The mixture was filtered over Hyflo. The filtrate was diluted with CH 2 Cl 2 (30 ml) and washed with a saturated NaHCO 3 solution. The organic layer was washed with water, dried over Na 2 SO 4 and concentrated in vacuo. The residue was purified via chromatography (EtOAc/hexane 1/1), yielding 7 (49 mg, 0.0421 mmol, 72%) . m.p. 139 ° C.; 1 H-NMR (400 MHz, CDCl 3 ) : δ 8.14 (2H, d, J=7.6 Hz, H-Ph), 7.80 (2H, d, J=7.6 Hz, H-Ph), 7.61 (1H, t, J=7.4 Hz, H-Ph), 7.39 (10H, m, H-Ph), 7.02 (1H, d, J NH-3′ =9.2 Hz, NH), 6.24 (1H, s, H10), 6.23 (1H, m, H13), 5.99 (1H, dd, J 3′-NH =9.2 Hz, J 3′-2′ =3.0 Hz, H3′), 5.69 (1H, d, J 2-3 6.9 Hz, H2), 5.66 (1H, m, H7), 5.55 (1H, d, J 2′-3′ =3.0 Hz, H2′), 4.97 (1H, d, J 5-6 =9.4, H5), 4.84 (1H, m, CH-malyl), 4.64 (1H, m, CH-malyl), 4.33 (1H, d, J 20a-20b =8.4 Hz, H20a), 4.19 (1H, d, J 20b-20a =8.4 Hz, H20b), 3.94 (1H, d, J 3-2 =6.9 Hz, H3), 3.10 (2H, m, CH 2 -malyl), 2.97 (2H, m, CH 2 -malyl), 2.60 (1H, m, H6), 2.45 (3H, s, OCOCH 3 ), 2.35 (1H, m, H14a), 2.25 (1H, m, H14b), 2.21 (3H, s, OCOCH 3 ), 1.97 (1H, s, H18), 1.85 (1H, m, H6), 1.81 (3H, s, H16), 1.58 (6H, s, acetonide), 1.56 (6H, s, acetonide), 1.21 (3H, s, H17), 1.16 (3H, s, H19); FAB-MS, 1166 [M+H] + .
[0039] b. 2′,7-Bis(malyl)paclitaxel ( 8 )
[0040] Compound 7 (40 mg, 0.0343 mmol) was dissolved in a mixture of HOAc/THF/H 2 O (4/1/2 ml). The mixture was stirred at 45° C. for 6 hours. Next, the organic solvents were removed by evaporation in vacuo. The residue was diluted by water (50 ml) and freeze dried, yielding 8 (33 mg, 0.0304 mmol, 89%) . m.p. 166-168° C.; 1 H-NMR (400 MHz, CDCl 3 ): δ 8.11 (2H, d, J=7.6 Hz, H-Ph), 7.84 (2H, d, J=7.5 Hz, H-Ph), 7.63 (1H, t, J=7.5 Hz, H-Ph), 7.37 (11H, m, H-Ph and NH), 6.25 (1H, s, H10), 6.16 (1H, m, H13), 5.99 (1H, dd, J 3′-NH =8.8 Hz, J 3′-2′ =2.9 Hz, H3′), 5.67 (1H, d, J 2-3 =6.4 Hz, H2), 5.66 (1H, m, H7), 5.63 (1H, d, J 2′-3′ =2.8 Hz, H2′), 4.94 (1H, d, J 5-6 =7.6, H5), 4.48 (2H, m, CH-malyl) , 4.32 (1H, d, J 20a-20b =7.9 Hz, H20a), 4.17 (1H, d, J 20b-20a =7.9 Hz, H20b), 3.88 (1H, d, J 3-2 =6.4 Hz, H3), 2.97 (4H, m, CH 2 -malyl), 2.51 (1H, m, H6), 2.44 (3H, s, OCOCH 3 ), 2.36 (2H, m, H14), 2.07 (3H, s, OCOCH 3 ), 1.93 (1H, S, H18), 1.86 (1H, m, H6), 1.79 (3H, s, H16), 1.20 (3H, s, H17), 1.18 (3H, s, H19); FAB-MS, 1108 [M+Na] + .
[0041] 7-Malylpaclitaxel ( 11 )
[0042] a. 2′-Trocpaclitaxel ( 9 )
[0043] A solution of paclitaxel ( 1 ) (80 mg, 0.0938 mmol) in CH 2 Cl 2 (2 ml) and pyridine (0.2 ml) was stirred at −23° C. Next, 2,2,2-trichloroethyl chloroformate (13 μl, 0.095 mmol) was added. After stirring for one hour at −23° C., the mixture was diluted with CH 2 Cl 2 (20 ml) and washed with 1N HCl (aq). The organic layer was washed with a saturated NaHCO 3 solution, with water, dried over Na 2 SO 4 and concentrated in vacuo. The residue was purified via chromatography (EtOAc/hexane: 1/1), yielding 9 (63 mg, 0.0612, 65%). m.p. 171° C. (dec); 1 H-NMR (400 MHz, CDCl 3 ): δ 8.15 (2H, d, J=7.4 Hz, H-Ph), 7.75 (2H, d, J=7.5 Hz, H-Ph), 7.61 (1H, t, J=7.4 Hz, H-Ph), 7.44 (10 H, m, H-Ph), 6.93 (1H, d, J NH-3′ =9.4 Hz, NH), 6.29 (1H, s, H10), 6.25 (1H, t, J 13-14 =8.8 Hz, H13), 6.05 (1H, dd, J 3′-NH =9.3 Hz, J 3′-2′ =2.8 Hz, H3′), 5.69 (1H, d, J 2-3 =7.3 Hz, H2), 5.54 (1H, d, J 2′-3′ =2.7 Hz, H2′), 4.97 (1H, dd, J=9.4 Hz, J= 1.6 Hz, H5), 4.78 (2H, d, J=8.0 Hz, CH 2 (Troc)), 4.43 (1H, m, H7), 4.32 (1H, d, J 20a-20b =8.4 Hz, H20a), 4.21 (1H, d, J 20b-20a =8.4 Hz, H20b), 3.82 (1H, d, J 3-2 =7.2 Hz, H3), 2.55 (1H, m, H6), 2.48 (3H, s, OCOCH 3 ), 2.40 (1H, m, H14a), 2.23 (3H, s, OCOCH 3 ), 2.20 (1H, m, H14b), 1.91 (3H, s, H18), 1.88 (1H, m, H6), 1.69 (3H, s, H16), 1.24 (3H, s, H17), 1.14 (3H, s, H19); FAB-MS, 1030 [M+H] + , 1052 [M+Na] + .
[0044] b. 2′-Troc-7-(1,2-O-(propane-2,2-diyl)-malyl)paclitaxel ( 10 )
[0045] A solution of 9 (63 mg, 0.0612 mmol) and 3 (21 mg, 0.12 mmol) in CH 2 Cl 2 (5 ml) was stirred at 0° C. Next, DIPC (125 μl, 0.80 mmol) and DMAP (20 mg, 0.16 mmol) were added. After 1 hour, the mixture was heated to reflux temperature and then stirred for 3 days. The mixture was filtered over Hyflo. The filtrate was diluted with CH 2 Cl 2 (50 ml) and washed with a saturated NaHCO 3 solution. The organic layer was washed with water, dried over Na 2 SO 4 and concentrated in vacuo. The residue was purified via chromatography (EtOAc/hexane: 2/5), yielding 10 (38 mg, 0.0320, 52%). m.p. 140-145° C.; 1 H-NMR (400 MHz, CDCl 3 ) : δ 8.14 (2H, d, J= 7.3 Hz, H-Ph), 7.76 (2H, d, J=7.5 Hz, H-Ph), 7.61 (1H, t, J=7.5 Hz, H-Ph), 7.45 (1OH, m, H-Ph), 6.92 (1H, d, J NH-3′ =9.5 Hz, NH), 6.26 (1H, s, H10), 6.25 (1H, m, H13), 6.04 (1H, dd, J 3′-NH =9.6 Hz, J 3′-2′ =2.8 Hz, H3′), 5.69 (1H, d, J 2-3 6.8 Hz, H2), 5.65 (1H, m, H7), 5.54 (1H, d, J 2′-3′ =2.8 Hz, H2′), 4.99 (1H, d, J 5-6 =8.4, H5), 4.84 (1H, m, CH-malyl), 4.78 (2H, d, J=9.4 Hz, CH 2 (Troc)), 4.33 (1H, d, J 20a-20b =8.4 Hz, H20a) , 4.20 (1H, d, J 20b-20a =8.4 Hz, H20b), 3.95 (1H, d, J 3-2 =6.8 Hz, H3), 3.07 (2H, m, CH 2 -malyl), 2.63 (1H, m, H6), 2.47 (3H, s, OCOCH 3 ), 2.40 (1H, m, H14a), 2.25 (1H, m, H14b), 2.16 (3H, s, OCOCH 3 ), 1.97 (1H, s, H18), 1.87 (1H, m, H6), 1.81 (3H, s, H16), 1.60 (3H, s, acetonide), 1.57 (3H, s, acetonide), 1.24 (3H, s, H17), 1.14 (3H, s, H19); FAB-MS, 1187 [M+Na] + , 1209 [M+Na] + .
[0046] c. 7-Malylpaclitaxel (11)
[0047] Compound 10 (28 mg, 0.0236 mmol) was dissolved in a mixture of HOAc/THF/H 2 O (4/1/2 ml). Zinc powder (20 mg) was added. The mixture was stirred for 3 hours at 45° C. Next, the organic solvents are evaporated in vacuo. The residue was diluted with water (50 ml) and freeze dried, yielding 11 (23 mg, 0.0237 mmol, 100%). m.p. 237-240° C.; 1 H-NMR (400 MHz, CDCl 3 ) : δ 8.13 (2H, d, J=7.3 Hz, H-Ph), 7.76 (2H, d, J=7.3 Hz, H-Ph), 7.61 (1H, t, J=7.4 Hz, H-Ph), 7.38 (1OH, m, H-Ph), 6.93 (1H, d, J NH=3′ =9.2 Hz, NH), 6.25 (2H, m, H10 and H13), 5.75 (1H, dd, J 3′-NH =9.2 Hz, J 3′-2′ =2.8 Hz, H3′), 5.69 (1H, d, J 2-3 =7.1 Hz, H2), 5.66 (1H, m, H7), 4.96 (1H, d, J 5-6 =8.4, H5), 4.83 (1H, d, J 2′-3′ =2.8 Hz, H2′), 4.74 (1H, m, CH-malyl), 4.28 (1H, d, J 20a-20b =8.0 Hz, H20a) , 4.14 (1H, d, J 20b-20a =8.0 Hz, H20b) , 3.95 (1H, d, J 3-2 =7.1 Hz, H3), 3.06 (2H, m, CH 2 -malyl), 2.60 (1H, m, H6), 2.47 (3H, s, OCOCH 3 ) , 2.38 (1H, m, H14a), 2.25 (1H, m, H14b), 2.16 (3H, s, OCOCH 3 ), 1.97 (1H, s, H18), 1.81 (3H, s, H16), 1.25 (3H, s, H17), 1.14 (3H, s, H19); FAB-MS, 970 [M+H] + , 992 [M+Na] + .
[0048] Solubility and stability
[0049] Methods
[0050] Water Solubility: Paclitaxel or paclitaxel prodrugs ( 5 , 6 , 8 , 11 .) were suspended in water or PBS-buffer (pH 7.4) until a concentration was reached of 2 mg/ml. The suspensions were sonicated for 15 minutes and centrifuged (13000 g) for 10 minutes (Nicolaou, K. C. et al. Nature 1993, 364, 464-466). The above fluid was analyzed, using HPLC. The paclitaxel (prodrug) concentration was determined using paclitaxel standards in methanol.
[0051] HPLC: Rheodyne injection valve (20 μl loop); Lichrospher 5RP18 column (200×3 mm, Chrompack); UV-detector (Model 759A, Applied Biosystems); eluent: CH 3 CN/MeOH/H 2 O: 5/1/4 in 10 mM NH 4 OAc (pH 5.0) (Willey, T. A. J. Chromatography 1993, 621, 231-238). The detection of the (pro)drugs was performed at 226 nm, where it is supposed that the extinction coefficients of paclitaxel and paclitaxel prodrugs are equal. The concentrations were determined by measuring the relative area of paclitaxel or the paclitaxel prodrugs.
[0052] Stability in human plasma and PBS-buffer
[0053] The paclitaxel prodrugs ( 5 , 6 , 8 , 11 ,) were dissolved in water, sonicated and centrifuged. 100 μl of the above fluid was mixed with 400 μl of plasma (heparin) or PBS-buffer (pH7.4), respectively, in such way that the concentration of the prodrug was about 0.5 mg/mL. The plasma or PBS-buffer, respectively, was incubated at 37° C. and on different points in time (T=0, 0.5, 1, 4, 20, 48 hours) 50 μl was extracted with 150 μl of EtOAc. After mixing for 2 minutes (using a vortex), this mixture was centrifuged (2 minutes, 13000 g) and 100 μl EtOAc was evaporated (30 minutes, in vacuo) . The (pro)drugs were dissolved in 50 μl eluent and analyzed by HPLC (Longnecker, S. M. Cancer Treat Rep. 1987, 71, 53-59). The efficiency for the extraction of paclitaxel was about 80%.
[0054] Solubility and stability values for compounds of the present invention are shown in table I.
TABLE I Solubility and Stability of some Water-soluble Analogs of Paclitaxel Water T ½ a (hours) 2′-(R 1 ) paclitaxel 7-(R 2 ) paclitaxel Solubility Human No R 1 = R 2 = (mg/ml) pH 7.4 Plasma 1 H H 0.01 — — 5 C(O)CH 2 CH(OH)COOH H 0.2 >24 20 6 C(O)CH 2 CH(OH)COONa H 0.6 no pacl. b 4 8 C(O)CH 2 CH(OH)COOH C(O)CH 2 CH(OH)COOH 0.5 no pacl. b no pacl. b 11 H C(O)CH 2 CH(OH)COOH 0.003 no pacl. b no pacl. b
[0055] With the exception of 11, all prodrugs showed increased water solubility compared with paclitaxel. Best water solubility was found for the 21-malyl prodrug 6. All malyl prodrugs 5, 6, 8 and 11, showed sufficient stability in PBS buffer for prodrug applications. Prodrug 6 showed also a fast hydrolysis rate in human plasma. These results show that the most promising drug for further evaluation of the drugs presented in table I is the malyl prodrug 6.
[0056] Biological Evaluation
[0057] Material and Methods
[0058] Determination of the IC 50 -values for the new synthesized prodrugs have been determined with a variety of cell lines and have been compared with the IC 50 -value of paclitaxel 1 (see table II)
[0059] Compounds 1 , 5 , 8 , 11 ,
[0060] The following human tumor cell lines were used:
[0061] MCF7 Breast cancer
[0062] EVSA-T Breast cancer
[0063] WIDR Colon cancer
[0064] IGROV Ovarian cancer
[0065] M19 MEL Melanoma
[0066] A498 Renal cancer
[0067] HA266 non small cell lung cancer
[0068] MCF7 is estrogen receptor ER+/Progesterone receptor PgR+ and EVSA-T is ER-/PgR-.
[0069] Cell lines WIDR, M19 MEL, A498 and IGROV belong to the currently used anti-cancer screening panel of the National Cancer Institute, USA (Skeham et al., J. Nat. Cancer Inst. 85: 1107-1112, 1990).
[0070] Prior to the experiments a myocoplasma test was carried out on all cell lines and found to be negative. All cell lines, except ETSA-T, were maintained in a continuous logarithmic culture in RPMI medium with Hepes and Phenol red supplemented with 10% bovine calf serum (BCS), penicillin 111 IU/ml, streptomycin 111 μg/ml, gentamycin 46 μg/ml and insulin 10.6 μg/ml. EVSA-T was maintained in DMEM with 5% BCS and antibiotics as described. The cells were mildly trypsinized for passage and for use in experiments.
[0071] The Experiment
[0072] The compounds of this invention were dissolved to a concentration of 177147 ng/ml as follows:
Paclitaxel 5% DMSO in full RPMI growth medium 5 5% DMSO in full RPMI growth medium 8 5% DMSO in full RPMI growth medium 11 5% DMSO in full RPMI growth medium
[0073] On day 0, 200 μl of trypsinized tumor cells (2*10 3 cells/well) were plated in 96-wells flatbottom microtiter plates (Costar, no. 3799, Badhoevedorp, The Netherlands). The plates were preincubated 24 hr at 37° C,, 5% CO 2 to allow the cells to adhere.
[0074] On day 2, 100 μl of the highest drug concentration was added to the wells of column 12 and from there diluted 3-fold to column 3 by serial transfer of 100 μl using an 8 channel micropipette. The final volume of column 3 was adjusted to 200 μl with PBS. Column 2 was used for the blank. To column 1 PBS was added to diminish interfering evaporation.
[0075] On day 7 the incubation was terminated by washing the plates twice with PBS. Subsequently the cells were fixed with 10% trichloroacetic acid in Milli Q water (Millipore, Etten Leur, The Netherlands) and placed at 4° C. for one hour.
[0076] After five washings with tap water, the cells were stained for at least 15 min. with 0.4% SRB, dissolved in 1% acetic acid, and subsequently washed with 1% acetic acid to remove the unbound stain. The plates were air dried and the bound protein was dissolved by using 150 μl 10 mmol/l tris base. The absorbance was read at 540 nm using an automatic microplate reader (Titertec, Flow Laboratories LtD., Irvine, Scotland). Data were used for construction of concentration-response curves and determination of the IC 50 -value.
[0077] Compounds 1 , 6
[0078] The human tumor cell line OVCAR-3 was used. OVCAR is an ovarium carcinoma.
[0079] In vitro antiproliferative effects: paclitaxel or paclitaxel prodrugs were dissolved in DMSO to give a concentration of 5 mM. Concentrations were verified by measuring the OD at 226 nm. The antiproliferative effects of drugs and prodrugs were determined with the use of OVCAR-3 cells. Cells in supplemented tissue culture medium (DMEM, 10% fetal calf serum with 50 IU/ml penicillin and 50 microgram/ml streptomycin) were seeded in triplicate in 96-well culture plates (5000/well, 100 microliter). After 24 h, 100 microliter of culture medium containing drug or prodrug was added to give final concentrations ranging from 1 picomolar to 10 micromolar.
[0080] The cells were incubated for an additional 72 h, fixed with 10% trichoroacetic acid and stained with sulforhodamine B. The absorbance at 540 nm was read and the antiproliferative effects were expressed as IC 50 values, which are the (pro)drug concentration that give 50% growth inhibition when compared with control cell growth (Houba et al. Bioconj. Chem. 1996, 7, 606-611).
[0081] The IC 50 values of the compounds of this invention are given in table II.
TABLE II IC 50 a (ng/ml) IC 50 a (nM) Compound MCF7 EVSA-T WIDR IGROV M19 MEL A498 H226 OVCAR-3 paclitaxel <3 <3 <3 33 <3 5 <3 0.25 5 <3 <3 <3 <3 3 39 10 — 6 <3 <3 <3 233 <3 <3 <3 0.80 8 69 59 167 49 311 436 241 — 11 390 300 589 241 1344 1435 706 —
[0082] Evaluation and Conclusions
[0083] With exception of compound 11 , all the analogs of paclitaxel show increased water solubility relative to paclitaxel.
[0084] Compounds 8 and 11 showed reduced cytotoxic activity, when compared to paclitaxel, probably due to the functional group at C7-OH. The 7-analog ( 11 ) and the 2′,7-analog ( 8 ) is very stable: in PBS-buffer (pH 7.4) as well as in human plasma, no degradation to the parent drug was observed, since no liberated paclitaxel has been detected.
[0085] Compound 5 showed similar cytotoxic activity as paclitaxel, which can probably be explained by the degradation of these compounds to the parent drug, under the conditions used to determine the activity. The 2′-analog 5 is stable in PBS-buffer (pH 7.4). After 24 hours, only traces of paclitaxel were detected. Whereas in human plasma only after 20 hours 50% of the analog is degraded to paclitaxel.
[0086] Compound 6 showed a comparable against OVCAR-3 cells, when compared to paclitaxel. Of compound 6 about 50% was degraded to paclitaxel within 4 hours. Furthermore, compound 6 is sixty times more watersoluble than paclitaxel.
[0087] The present invention discloses a method for the preparation of paclitaxel analogs of paclitaxel having a malate moiety at C2′ and/or C7-position. It is apparent that many modifications of the present invention are possible, for example the use of counterions other than sodium, which may give rise to higher solubilities. It is therefore understood that the invention may be practiced otherwise than specifically described. | The invention relates to water soluble antitumor analogs of paclitaxel of formula (I) wherein R 1 ═C(O)CH 2 CH(OH)COOX, R 2 ═H, C(O)CH 2 CH(OH)COOX, X═H, Li, Naa or any other pharmaceutically acceptable counterion, as well as to a pharmaceutical composition comprising an antineoplastically effective amount of such analogs as an active ingredient. | 2 |
TECHNICAL FIELD
[0001] This invention relates to hydraulic fracturing of natural ground formations which may be on land or under a sea bed.
[0002] Hydraulic fracturing is a technique widely used in the oil and gas industry in order to enhance the recovery of hydrocarbons. A fracturing treatment consists of injecting a viscous fluid at sufficient rate and pressure into a bore hole drilled in a rock formation such that the propagation of a fracture results. In later stages of the fracturing treatment, the fracturing fluid contains a proppant, typically sand, so that when the injecting stops, the fracture closes on the proppant which then forms a highly permeable channel (compared to the permeability of the surrounding rock) which may thus enhance the production from the bore hole or well.
[0003] In recent years, hydraulic fracturing has been applied for inducing caving and for preconditioning caving in the mining industry. In this application, the fractures are typically not propped but are formed to modify the rock mass strength to weaken the ore or country rock.
[0004] One of the most important issues in the practice of the hydraulic fracturing technique is knowledge of the geometry (orientation, extent, volume) of the created fracture. This is of particular importance in order to estimate the quality of the treatment performed. However, operators presently have no direct measurement capability allowing them to verify the quality and effectiveness of their operations. It is only afterwards when production has restarted that the performance of the created fracture can be assessed.
[0005] In order to map hydraulic fractures, several types of indirect measurements can be carried out such as microseismic acoustic monitoring and tiltmeter mapping, but such surface tiltmeter techniques have not so far been capable of producing accurate information which can be used during the course of a hydraulic fracturing treatment and generally only provide data for later analysis. By the present invention, it is possible to obtain useful data on the effectiveness of a hydraulic treatment as the treatment progresses.
DISCLOSURE OF THE INVENTION
[0006] The invention broadly provides a method for estimating a fluid driven fracture volume during hydraulic fracturing treatment of a ground formation, comprising:
[0007] positioning a series of tiltmeters at spaced apart tiltmeter stations at which tilt changes due the hydraulic fracturing treatment are measurable by those tiltmeters;
[0008] obtaining from the tiltmeters tilt measurements at progressive times during the fracturing treatment; and
[0009] deriving from the tilt measurements at each of said times an estimate of the fluid driven fracture volume at that time by performing an analysis to produce estimates of the fluid driven fracture volume at each of said times as the treatment is in progress.
[0010] The method may further comprise the steps monitoring the volume of fluid injected during the treatment and comparing the estimate of the fracture volume at each of said times with the volume of injected fluid at that time to derive an indication of treatment efficiency.
[0011] The analysis may be performed sufficiently rapidly to provide real-time estimation of the fluid driven fracture volume.
[0012] The analysis may further produce estimates of fracture orientation as the treatment is in progress. The method may thus provide real-time estimates of fluid driven fracture volume, and, by making use of the measured injected volume, the treatment efficiency, and the detection in real-time of fracture orientation or changes in fracture orientation (both strike and dip).
[0013] The analysis at a given time may be based on minimisation of misfit between the tilt measurements at this given time and tilts predicted by a fracture model.
[0014] The fracture model may predict tilts by simulating a finite hydraulic fracture using, for example, a displacement discontinuity model. The computational cost of such model should be low, typically of the order of 1/10 second per prediction calculation. This can be achieved, for example, by using a fracture model consisting of a displacement discontinuity singularity with an intensity equal to the volume of the simulated fracture. Each tilt prediction computation may take of the order of 1/10 seconds. There may be of the order of 100 to 300 evaluations performed to complete the minimization analysis for deriving the fracture volume and fracture orientation at a given time. Therefore, typically, the analysis may be carried out at regular intervals of about every 10 seconds to 5 minutes, and typically of the order of 1 minute, throughout the fracturing treatment.
[0015] The tiltmeter stations may be located at the surface of the ground formation and/or within one or more bore holes within the ground formation or within tunnels in the case of a mine.
[0016] In order to ensure best accuracy of the analysis, the tiltmeter stations should be located sufficiently far from the fracture that only the orientation and volume of the fracture has an effect on the tilt fields. In that case, it is recognised that it is impossible to separate the effect of both the length and opening of the fracture so that only the volume of the fracture and it's orientation can be obtained by inversion of the tilt data.
[0017] The invention further provides apparatus for estimating a fluid driven fracture volume during hydraulic fracturing treatment of a ground formation, comprising:
[0018] a series of tiltmeters positionable at spaced apart tiltmeter stations to measure tilt changes due to the hydraulic fracturing treatment; and
[0019] a signal processing unit to receive tilt measurement signals from the tiltmeters at progressive times during the fracturing treatment and operable to derive at each of said times an estimate of the fluid driven fracture volume at that time by performing an analysis sufficiently rapid to produce estimates of the fluid driven fracture volume as the treatment is in progress.
[0020] The apparatus may further include a flow meter for measuring the flow of hydraulic fracturing fluid injected during a fracturing treatment and the signal processing unit may be operable to receive signals from the flow meter and to compare the estimate of fracture volume at each of said times with the volume of injected fluid as measured by the flow meter so as to derive an indication of treatment efficiency.
[0021] The signal processing unit may also be operable to derive from the tilt measurements estimates of fracture orientation at each of said times.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention and the manner in which it may be put into effect will now be described in more detail with the aid of the twenty two references listed at the end of this specification and the accompanying drawings, in which:
[0023] FIG. 1 illustrates the principle of tiltmeter measurement;
[0024] FIG. 2 shows the relation between inclinations (tilts) and uplift gradient;
[0025] FIG. 3 illustrates diagrammatically an inclined fracture and corresponding uplift at the ground surface;
[0026] FIG. 4 illustrates the evolution in time of the inclination recorded at a tiltmeter station during a fracturing treatment;
[0027] FIG. 5 illustrates tilt vectors at an array of tiltmeter stations at a particular instant of time during a fracturing treatment;
[0028] FIG. 6 is a sketch of a planar hydraulic fracture;
[0029] FIG. 7 is a sketch of a hydraulic fracture and the distance of a tiltmeter station to the injection point;
[0030] FIG. 8 illustrates an exemplary set up for real-time estimation of fracturing efficiency and orientation during treatment; and
[0031] FIG. 9 is an exemplary plot of real-time estimation of treatment efficiency.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] In order to explain the operation of the preferred method and apparatus and according to the invention, it will be necessary to analyse in some detail the current state of the art in the operation of tiltmeters and the modelling and resolution techniques required to derive meaningful data from tiltmeter measurements.
[0000] Tiltmeter State of the Art
[0033] A tiltmeter (which is installed tightly in the rock) measures, at it's location, changes in the surface tilt in two orthogonal directions (see FIGS. 1 and 2 ). The tilts are a direct measure of the horizontal gradient of the vertical displacement. High precision apparatus developed in the last 20 years can measure changes in tilt down to one nanoradian.
[0034] The propagation of a pressurized fracture of length L(t) and opening w(t) produces elastic deformation in the rock mass which, in turn result in a corresponding uplift and therefore a change of inclination at the location of the tiltmeter (see FIG. 3 for example). This inclination change is sampled sequentially in time at each tiltmeter and an array of tiltmeters is used to obtain tilts at several different locations remote from the hydraulic fracture. The tiltmeters can be located on the surface (surface tiltmeter array) or in a vertical borehole (borehole tiltmeter array) or in an underground tunnel.
[0035] FIG. 4 displays, for a given tiltmeter station, the two inclinations (north-south and east-west) recorded during a fracturing job. We clearly see the evolution of the inclination during injection as well as the slow return toward their initial values after the end of the injection. This return is associated with the hydraulic fracture closing back on itself after injection stops.
[0036] Another representation of tiltmeter measurements is given in FIG. 5 . The so-called tilt vectors are shown in this figure for a particular time during the injection. This plan-view representation contains all the tiltmeter stations. The tilt vector v is determined from a vector addition of the two orthogonal components of the horizontal gradient of the vertical displacement measured by the two bubbles in the tiltmeter:
v = ( ∂ u z ∂ x , ∂ u z ∂ y ) .
Modelling and Resolution
[0037] In contrast to the relative simplicity of the measurement, the modelling necessary to solve the related inverse problem which is required to analyse the tiltmeter data, pose difficult problems. Despite the now common use of tiltmeters to map hydraulic fractures in the petroleum industry, there is general misunderstanding of what information about the fracture can and cannot be obtained from such measurements. Based on practical experience Cipolla C. L and Wright C. A list in reference [3] some of the fracture quantities better resolved by surface or borehole tiltmeters. In addition, Larson et al in reference [20], Warpinski in reference [17] and Evans in reference [7]also list several difficulties in obtaining certain fracture parameters depending on the configuration. However, no clear statement and formal results concerning the resolution of geometrical characteristics of the fracture have been established by these papers.
[0038] The hydraulic fracture that produces the recorded tilts is most of the time modelled by using finite Displacement Discontinuities, also called dislocation models. The validity of this type of model has been extensively discussed (see references [10, 5, 7]) and many solutions for different geometries can be found in the literature (see references [12, 13, 10, 5, 4, 15]). All these solutions can be formalized within the framework of eigenstrain theory (see references [6, 9]) and the solutions for any finite dislocation can be obtained by superposition of DD singularities for the configuration of interest (half, full-space, layered medium . . . ). The displacements and stresses in the medium induced by a displacement jump across any finite surface can be determined either analytically (using any modern symbolic computation packages) or numerically from the knowledge of these fundamentals solutions. These fundamental solutions can be represented by a third-rank tensor U ijk (x,x′) for the displacement and a fourth rank tensor Σ ijk (x,x′) for the stresses.
[0039] Here, we restrict consideration to planar surf aces and denote by S the surface, with normal n, of a planar finite fracture (or fault) (see FIG. 6 ). The discontinuity surface can be, for example, a constant opening rectangular planar DD panel or a penny-shaped fracture under uniform pressure and characterized by a variable opening. The displacements u and stresses σ in the medium arising from this dislocation sheet can be obtained from the DD singularity by superposition.
u i ( x ) = ∫ S { U ijk ( x , x ′ ) n j n k D n ( x ′ ) + U ijk ( x , x ′ ) s j n k D s ( x ′ ) } ⅆ S ( 1 ) σ ij = ∫ S { Σ ijkl ( x , x ′ ) n k n l D n ( x ′ ) + Σ ijkl ( x , x ′ ) s k n l D s ( x ′ ) } ⅆ S
i , j , k , l = 1 , 2 , 3 ( 1 , 2 in 2 D ) ( 2 )
[0040] In our notation, (U ijk ·D jk ) denotes the displacement u i at x induced by a DD singularity of the form D jk located at x′. (D jk ·n k ) represents a displacement jump across an element oriented by its unit normal n k . We define D, n 32 D ij n i n j as the normal component of the displacement jump and D s =D ij s i n j as the shear component, with s a unit vector in the plane of the element (s i n i =0) indicating the direction of the shear (see FIG. 6 ). The fundamental solution Σ ijk for stress is a fourth-rank tensor and (Σ ijkl ·D kl ) represents the stresses σ ij induced by the DD singularity D kl . These fundamental kernels contain all the possible orientations for the DD. One has to remember that the DD singularity is restricted to the point x′ and has a unit intensity. The fundamental kernels U(x,x′), Σ(x,x′) are singular for x=x′ and regular otherwise. Evaluation of the integral (1) is therefore straightforward for any x outside the fracture surface S, but special techniques for singular integrals have to be used if x=x′ (see reference [8]). In the case of tiltmeter analysis, the measurements are always made outside the DD domain therefore simplifying the evaluation of eq. (1).
[0041] The tilts are directly related to the horizontal component of the gradient of the vertical displacement; in our notation ∂ x 1 u 3 and ∂ x 2 u 3 . Without loss of generality, we can define a DD singularity gradient tensor T ijkl (x,x′)=∂ x i U ijk (x,x′), from which it is possible to obtain the tilt components by superposition.
[0000] Far-Field Solution
[0042] An important result can be obtained by looking at the far-field behaviour of the displacement solution eq. (1). A point is located in the far-field of the fracture if its distance r from the fracture center is far greater than the fracture characteristic half-length r>>l. We have determined that under these conditions there is far-field equivalence of the displacement fields produced by a finite (tensile) fracture and a DD singularity with an intensity equal to the volume of the finite fracture. Similar results hold for a shear fracture. This equivalence is expected and is a direct illustration of St Venant's principle in elasticity. The far-field influence of fractures can thus simply be modelled using DD singularities of proper intensity by taking advantage of this intrinsic property of elasticity. Therefore, for any points x in the far-field of the fracture the integral (1) reduces to:
u i ( x ) =V×U ijk ( x,x c ) n j n k +S×U ijk ( x,x c ) s j n k (3)
σ ij ( x ) =V×Σ ijk ( x,x c ) n j n k +S×Σ ijkl ( x,x c )s j n k
where x c denotes the center of the fracture. The volume V of the fracture (i.e the integrated opening profile) and the integrated shear profile S are given by
V = ∫ S D n ( x ′ ) ⅆ S
S = ∫ S D s ( x ′ ) ⅆ S
[0043] An understanding of the intrinsic behaviour of the kernel U ijk (x,x′), independent of the elastic domain (infinite, semi-infinite medium . . . ), allows important conclusions to be made regarding the inverse problem of mapping a hydraulic fracture from tiltmeter measurements.
[0000] Length Scale Resolution
[0044] The major issue is to determine under what conditions tiltmeter data can be used to obtain both the width and size of the fracture modeled as a finite dislocation. As noted in reference [7], the effect of fracture dimensions on the displacement field is weak and the resolution improves for shallow fractures where the measurements are near the fracture. The same qualitative statement can be found in references [21], [3], and [19]. Reference [20] mentions non-uniqueness problems in a laboratory experiments where fracture dimensions are inverted from displacements. None of these references recognizes the issue of the remote location of the measurements in conjunction with the far-field equivalence. It is important to quantify when the far-field equivalence is reached in terms of the distance ratio r/l. In other words, we want to establish a limit function of r/e beyond which only the volume and orientation of the fracture can be resolved from tiltmeter measurements.
[0045] In order to investigate at what distance ratio r/l, the dimensions of the fracture can be determined from the displacement field, one can look at the next order terms of the series expansion of the far-field displacement. This far-field expansion for the 3D case can be rewritten as:
u i ∝ V × x i r 3 × ( 1 + α i ℓ 2 r 2 + O ( ( ℓ / r ) 3 ) ) i = 1 , 3 ( 4 )
where α i is a number of O( 1 ) and its value depends on Poisson's ratio.
[0046] We therefore see that the dimensions of the fracture start to have an effect on the displacement field when (l/r) 2 is of O( 1 ). When the measurements are at a distance 3 times the characteristic half-length of the fracture, this ratio (l/r) 2 is equal to 0.09 which is already negligible compared to 1. This implies that for any point such that r is greater than 3l, where r is the distance from the center of the finite DD of characteristic half-length l, it is practically impossible to distinguish both the opening and the length of a fracture. Under these conditions, only the volume of the fracture V and fracture orientation has an effect on the displacement and tilt fields. The same result holds for a shear fracture, in that case only the integrated shear S and fracture orientation has an effect on the displacement and tilt fields.
[0047] As a consequence, the tilt field only weakly reflects the dimensions of a finite fracture of characteristic half-length t if the measurements are further than 2 to 3l. More precisely, taking into account the effect of the fracture plane orientation and using the characteristic fracture size 2l as a reference, the limiting distance can be expressed as:
r /(2 l )>1.5+|cosβ| (5)
where β is the relative angle between the fracture plane and the measurement location. According to the previous examples, this bound is clearly optimistic and in some configurations the fracture dimensions already have no effect for (r/2l)=1 .
Resolution of Orientation
[0048] We have conducted a detailed investigation via spatial Fourier Transform of the resolution of the fracture orientation. This resolution mainly depends on the relative angle between the fracture plane and the plane where the tiltmeter array is located.
[0049] The orientation is better resolved for a relative angle of 45°. In summary:
A surface tiltmeter array better resolves sub-vertical fractures, A borehole tiltmeter array better resolves sub-horizontal fractures.
This confirms observations mentioned in the literature (see references [7, 3, 19].
Field Conditions
[0052] Field conditions are such that, in many cases, tiltmeter stations are located so that the condition (5) is satisfied. The recorded tilts therefore do not contain information about both the dimensions (length, height) and opening of the fracture. Attempting to retrieve both length and opening from the tilt data results in an ill-posed problem with an infinite number of solutions, all of which give the same fracture volume. This situation is typically the case for surface tiltmeter array in petroleum applications for monitoring hydraulic fracturing treatments. In the case of downhole tiltmeter arrays where the measurements are located in a monitoring well, the measurements may sometimes be sufficiently close to the fracture to be able to sense the near-field pattern. Unfortunately, if the measurements are located too close to the fracture (condition (5) violated), the proper modeling required to analyse tiltmeter measurements may become very complex and such an analysis can provide an incorrect estimation of the fracture parameters. It is more common and practical to locate the measurements relatively far from the fracture so that the condition (5) is satisfied. Then it is possible to accurately identify the volume and orientation of the fracture, by simply using a DD Singularity as the forward model. The computational efficiency of such a forward model also makes a real time analysis possible. Of course, the distance between the fracture and the measurements must remain compatible with the resolution of the type of tiltmeter used.
[0000] Real-Time Efficiency and Orientation
[0053] The following proposed analysis method is based on the understanding of the fundamental DD solution and conclusions arising from it described above. It takes advantages of the fact that the parameters with the most effect on tiltmeter are the fracture volume and fracture orientation.
[0054] Thus, from the estimation of the fracture volume at a particular time and the recorded injected volume V p (t) at the same time, we are able to estimate the fracturing efficiency, η, (in %) at t defined as the ratio between the fracture volume and the injected one.
[0000] Modelling and Inversion
[0000] Far-Field Tiltmeter Mapping
[0055] The tiltmeter stations are located at a distance r from the injection point sufficient for the condition (5) to hold. In that case, the tiltmeters are not able to resolve independently the dimensions of the fracture (width and length) but its volume V (and integrated shear S in the case of shear fracture) can be accurately estimated. On the other hand, this distance r has to be compatible with the resolution of the tiltmeters used. If the tiltmeters are too far away from the fracture or not very sensitive, one may end up recording nothing but ambient noise. If these conditions imposed on the tiltmeter array position and layout are fulfilled, we can take advantage of the far field equivalence between a finite fracture and a DD Singularity of equal volume to simulate the hydraulic fracture.
[0000] Near-Field Tiltmeter Mapping
[0056] As already pointed out, in most practical situation, we are in a case corresponding to far-field conditions for tiltmeter mapping which greatly simplify the modeling. Nevertheless, the situation of near-field tiltmeter mapping can occur. In that case the tiltmeter are closer to the fracture with regard to the fracture characteristic length (eq. (5) violated). A proper finite fracture model should be used in order to analyse tiltmeter data. Despite the effect of the fracture shape, the most resolvable parameters will remain the fracture volume and orientation, eventually others fracture parameters such as length and height can be obtained from such a near-field analysis.
[0000] Geological Conditions
[0057] We have to note that depending on the configuration, we may use different solutions. For example, one can either use the finite or semi-infinite elastic domain solution. Solutions are known in analytic form for these two domains. Solutions for a layered medium can also be used if necessary. In that case, the solution can be obtained numerically at a low computational cost using the method developed by Pierce and Siebrits (see references [11, 14]). Any other easily computed model may also be used in the analysis depending on the geological conditions. The only practical requirement is that the solution (tilt at the different stations) for a given fracture volume, orientation etc . . . can be computed in the order of 0.1 second. Therefore, once the analysis is complete in this time frame a real-time estimation of several important fracture parameters is possible.
[0000] Inversion
[0058] In all cases, the only parameters of the fracture that will be accurately determined are the volume and the orientation of the fracture plane (strike and dip). In most applications, the fracture model is typically centered at the injection point. If needed, this last restriction can be relaxed and the location of the fracture center can be identified.
[0059] The values for orientation and volume can be obtained from the recorded tilt at different location and at different times t throughout a fracture treatment. The analysis is based on a classical minimization scheme. As usual for parameter identification problem, the misfit between the measurements and the model are minimized starting from an initial guess for the volume and orientation of the model. The misfit can be for example defined as:
J ( c ( t ) ) = 1 2 ∑ i = 1 , N T model ( x i , c , t ) - T measure ( x i , t ) 2 ( 6 )
where N is the number of a tiltmeter station, x i is the location of the tiltmeter station, t the time for which the analysis is performed. T represents the tilt and c is a vector of unknown parameters (i.e. c=(Volume,Dip and strike) for far-field tiltmeter). T model (x i , c, t) are the tilts at the station x i induced by the fracture model with the values c for the orientation and volume parameters, whereas T measure is the corresponding measurement at station x i .
[0060] We can note that it is possible to incorporate a priori information in this type of functional. For example, the strike of the hydraulic fracture may be known from in-situ stress measurements. A comprehensive description of computational techniques for inverse problems is provided in reference [16]. Several minimization algorithms such as gradient based minimization, genetic programming etc. can be used to obtain the optimal parameters c.
[0061] The fastest technique will always be a gradient based minimization scheme (such as BFGS with line search) which require of the order of 10 to 100p 2 evaluations of the model. Note that this number increases dramatically with the number of parameters p to be identified. We are well aware that gradient based methods only converge to a local minima depending on the initial guess. In order to ensure that the solution obtained is a global minima, one simple method is to performed several identifications starting from different initial values for the parameters. This method is well suited to analysis of tilt data as there is a small number of parameters (p=3) involved. As a general rule we start from 4 different initial parameter guesses. In our experience using this approach, we always obtained the same minima.
[0000] Treatment Efficiency
[0062] As the tiltmeter data are recorded, the volume of the fracture can be estimated in real-time using a inversion procedure such as described above. The analysis procedure may also furnish an estimation of the fracture orientation (dip and strike). At time t during the fracture treatment, from the tiltmeter measurements we are able to obtain via an analysis procedure:
V(t) estimation of the fracture volume at time t, θ(t) estimation of fracture dip at time t, φ(t) estimation of fracture strike at time t. Moreover, from the known injected volume V p (t) at the same time, we are able to estimate the efficiency, η, (in %) at t:
η ( t ) = V ( t ) V p ( t ) × 100
Poroelastic Effect
[0066] In some cases, the rock mass is highly porous and the previous approach should incorporate poroelastic deformations.
[0067] The deformation due to the propagation of the hydraulic fracture in a porous reservoir comes on the one hand from the opening of the fracture itself and on the other hand from the poroelastic deformation induced by the fluid leaking into the formation. Under the assumption of zero fluid lag, the injected volume can be readily split in two parts: the volume of the fracture and the volume of fluid leaking into the formation. Introducing the efficiency η=V frac /V inj , the global volume balance reads at each time:
V inj = V frac + V leakoff = η V inj ︸ Fracture volume + ( 1 - η ) V inj ︸ Leak off volume ( 7 )
[0068] The total poroelastic deformation at a given time, is a combination of the two contributions: fracture opening and leak-off. This total deformation can be also decomposed in an instantaneous and transient part. The instantaneous component is due to the sudden change in deformation and pore pressure, while the transient response is controlled by the diffusion of pore pressure in the reservoir. We can estimate the importance of the transient response, by simply looking at the fundamental solutions in poroelasticity derived for the infinite medium (see reference [22]). The transient response is governed by a dimensionless variable ξ defined by:
ξ = r 4 c t ( 8 )
where c is the rock diffusivity, r the distance from the source and t is the time. For ξ>100, no transient effect is visible. This is typically the case for tiltmeter mapping. Indeed, typical value of the rock mass diffusivity is of the order of 10 −6 to 10 −8 m 2 .s −1 , while the average duration of a HF treatment is of the order of 1 hour and the measurement are always located at more than ten to hundreds of meters from the fracture. If we take these average values, we found that ξ is always above 100 such that only the instantaneous poroelastic deformation is important while analyzing tiltmeter data. When considering only this instantaneous response, the time dependence of the recorded tilts only comes from the propagation of the fracture and not the transient poroelastic effect. One has to keep in mind that for very permeable reservoir and long treatments, the transient effect can eventually become significant.
Combination of Fundamental Solutions
[0069] The deformation induced by the fracture opening and the fluid leak-off can be obtained by superposition of poroelastic fundamental solutions.
[0070] The effect of fracture opening is obtained using Displacement Discontinuity (DD) singularities as fundamental building blocks to construct solutions for any geometry of finite fracture as previously described for the non-porous case.
[0071] The effect of the fluid loss into the formation can be similarly obtained using the fundamental solution for an instantaneous point fluid source (see reference [21]). The displacement and stress at a point x in the medium due to a point fluid source located at x 1 are represented by u i s (x,x′) and respectively σ ij s (x,x′)
[0072] From knowledge of these fundamental solutions, the displacements and stresses in the medium induced by the combination of a displacement jump and a fluid loss across any finite surface S can be determined either analytically or numerically. Also, the tilts recorded by the tiltmeter can be directly obtained by simple differentiation of the displacement. Here, for clarity, we restrict consideration to planar and opening mode fractures (no shear). Let S denote the surface, with normal n, of a planar finite fracture (see FIG. 6 ). The displacement gradient (tilt) is given by superposition as:
u i , l = ∫ s U ijk , l ( x , x ′ ) n j n k D n ( x ′ ) ⅆ S + ∫ s u i , l 3 ( x , x ′ ) C ( x ′ ) ⅆ S ( 9 )
where D n (x′) is the intensity of the normal DDs along the fracture: the opening profile. C(x′) is the intensity of the fluid loss along the fracture. The surface S can be, for example, a rectangular DD or a penny-shaped crack.
[0073] As previously mentioned, we do not consider the effect of the diffusion of pore pressure in the rocks such that the time dependence of the poroelastic effect disappears. In this case, the solution U ijk for the DD is strictly equal to the classical solution in elasticity with undrained elastic parameters. The instantaneous fluid source solution u i s also reduces to the elastic solution for a center of dilation with an intensity weighted by a lumped poroelastic parameter χ instead of the classical elastic one. The instantaneous poroelastic effect only requires the knowledge of elastic solutions. However, the intrinsic difference with the classical elastic models lies in the combination of the fundamental solutions in order to take into account the effect of both fracture opening and fluid leak off on the deformation.
[0074] The importance of the instantaneous poroelastic effect due to fluid leak-off is governed by a dimensionless parameters χ defined as:
χ = n p S G ( 10 )
where η p is a lumped poroelastic parameter (reference [22]) (not to be mixed with the treatment efficiency), S the storage coefficient and G the shear modulus. It has been found that the poroelastic parameter η p has a value of ≈0.25 for the type of rocks encounter in petroleum geomechanics. For vanishingly small value of the parameter χ, the solution reduces to the elastic one: the influence of the fluid leak off is negligible, the poroelastic effect can be ignored.
Model
[0075] The resolution issue derived for the case of a purely elastic rock mass still holds as the poroelastic deformation induced by the fracture is a combination of elastic solutions. Therefore in the case of far-field measurements, the tilts can be simply modeled as:
u i,l ( x ) =V frac U ijk,l ( x,x c ) n j n k +V leakoff U i,l s ( x,x c ) (11)
where x c is the location of the fracture center. The fracture volume and leak-off volume are simply related to the treatment efficiency and injected volume using the global volume balance (7):
V frac = ∫ s w ( x ′ ) ⅆ S = η V inj
V leakoff = ∫ s C ( x ′ ) ⅆ S = ( 1 - η ) V inj
In the porous case, from the recorded tiltmeter data and the injected volume, the inverse analysis will directly estimate the fracture efficiency η together with the fracture orientation.
Practical Requirements
[0076] In order to successfully implement the method in practice, some additional requirements are needed. All the tiltmeter stations, as well as the measurement of the injected volume, may be connected to a central unit where all the data are collected (see FIG. 8 ). The data processing and the identification procedure may then run on this central unit or from a unit remotely connected to this unit where the data are gathered.
[0077] The sampling rate of the tiltmeters and injection pump can be sufficiently fast to allow enough data to be available for inversion: typically a sampling rate of 15 seconds should be enough. At least 6 tiltmeters stations, properly working will generally ensure that sufficient data is collected for robust operation. More stations may be used to improve the estimation.
[0000] Steps of the Analysis and Outcomes
[0078] For one time t, the steps of the method are the following:
Sample the injected volume at time t, Sample every tiltmeter at time t, Correct the drift for each tilt station (earth tides . . . ), express the two channels in the global coordinate system, Perform the minimization procedure to obtain fracture volume, treatment efficiency, fracture strike and dip at time t, Plot the efficiency history t=[0, t], Plot the fracture orientation history t=[0, t]. This analysis can be repeated every minute or so, using either the total tilt signals from the start of the injection or tilt increment between two sampling point in time.
[0085] By performing this analysis every minute during a treatment (which typically lasts between half an hour to several hours), we are able to produce a plot of the efficiency history η(t) (see FIG. 9 for example). We also get the fracture orientation history. This information is valuable in order to adjust in real-time the treatment parameters: injection rate, fluid type, proppant loading etc . . .
[0086] The robustness of the method is ensured by a sufficient amount of data in both space (approximately 6 to 10 tiltmeters properly placed) and time (sufficient sampling rate) together with a model that recognizes the fact that the volume is the only dimensional property available from practical tilt measurement located in the far field (condition (5)).
REFERENCES
[0000]
[1] Adachi J. I. Fluid-Driven Fracture in a permeable rock. PhD thesis, University Of Minnesota, 2001.
[2] Branagan P. T., Wilmer R. H., Warpinski N. R., and Steinfort T. D. Measuring a deformation of a rock mass around the vicinity of a fracture in a well drilled offset from proposed fracture region. US5934373-A, 1999. Assignee : GRI.
[3] Cipolla C. L. and Wright C. A. Diagnostic techniques to understand hydraulic fracturing: What ? why ? and how ? Soc. Petrol. Eng. 59735, 2000.
[4] Crouch S. L. and Starfield A. M. Boundary element methods in solid mechanics . George Allen & Unwin, 1983.
[5] Davis P. M. Surface deformation associated with a dipping hydrofracture. J. Geophys. Res., 88:5826-5838, 1983.
[6] Eshelby J. D. The determination of the elastic field of an ellipsoidal inclusion and related problems. Proc. Roy. Soc. series A, 241:376-396, 1957.
[7] Evans K. On the development of shallow hydraulic fractures as viewed through the surface deformation field: Part 1-principles. L. Petrol. Tech., 35(2):406-410, 1983.
[8] Hills D. A., Kelly P. A., Dai D. N., and Korsunsky A. M. Solution of Crack Problems . Kluwer Academic Publishers, 1996.
[9] Mura T. Micromechanics of Defects in Solids . Martinus Nijhoff Publisher, 1982.
[10] Okada Y. Surface deformation due to shear and tensile faults in a half plane. Bull. Seismol. Soc. Am., 75(4):1135-1154, 1985.
[11] Pierce A. P. and Siebrits E. Uniform asymptotic approximations for accurate modeling of cracks in layered elastic media. Int. J. Fracture , (110):205-239, 2001.
[12] Rongved L. Dislocation over a bounded plane area in an infinite solid. J. Appl. Mechanics, 24:252-254, 1957.
[13] Rongved L. and Frasier J. T. Displacement discontinuity in the elastic half-space. J. Appl. Mech., 25:125-128, 1958.
[14] Siebrits E. and Pierce A. P. An efficient multi-layer planar 3d fracture growth algorithm using a fixed mesh approach. Int. J. Numer. Meth. Engng, 53:691-717, 2002.
[15] Sun R. J. Theoritical size of hydraulically induced horizontal fractures and corresponding surface uplift in an idealized medium. J. Geophys. Res., 74(25):5995-6011, 1969.
[16] Vogel C. Computational Methods for Inverse Problems . SIAM, 2002.
[17] Warpinski N. R., Steinfort T. D., Branagan P. T., and Wilmer R. H. Apparatus and method for monitoring underground fracturing. U.S. Pat. No. 5,934,373, Jan. 1997. Assignee: GRI.
18] Wright C., Davis E., Ward J., Samson E., Wang G., Griffin L., Demetrius S. , and Fisher K. Treatment well tiltmeter system, for monitoring fluid motion in subsurface strata from active well, comprises tiltmeter array within borehole, with tiltmeter sensor. WO2001181724-A;WO2001181724-A1; AU2001157342-A, 2001. Assignee : Pinnacle Technologies Inc.
[19] Wright C. A., Weijers L., Davis E. J., and Mayerhofer M. Understanding hydraulic fracture growth: Tricky but not hopeless. Soc. Petrol. Eng. 56724, 1999.
[20] Larson M. C., Arthur Verges M., and Keat W. Q (1999) Non destructive identification of three dimensional embedded cracks in finite bodies by inversion of surface displacements. Eng. Frac. Mech., 63:611-629.
[ 21 ] Warpinski N. R (2000) Analytic crack solutions for tilt fields around hydraulic fractures. J Geophys. Res, 105(B10): 23463-23478.
[22] Cheng A.H.D and Detournay E (1998) On singular integral equations and fundamental solutions of poroelasticity. Int. J. Solids Structures, 35(34-35):4521-4555. | Method and apparatus for estimating a fluid driven fracture volume during hydraulic fracturing treatment of a ground formation. A series of tiltmeters are positioned at spaced apart tiltmeter stations at which tilt changes due to the hydraulic fracturing treatment are measurable by those tiltmeters. Tilt measurements obtained from the tiltmeters at progressive times during the fracture treatment are analysed to produce estimates of the fluid driven fracture volume at each of those times as the treatment is in progress. The analysis may be performed sufficiently rapidly to provide real time estimates of the fluid driven fracture volume and may also produce estimates of fracture orientation. The estimates of fracture volume may be compared with the volume of fluid injected to derive an indication of treatment efficiency. | 4 |
TECHNICAL FIELD
This invention pertains to winged needles for the administration of fluids to and the withdrawal of blood samples from patients.
BACKGROUND OF THE INVENTION
Winged needles (also known as butterfly needles) have long been a popular and simple means of gaining intravascular access for administering fluids and medicines to patients. Winged needles are also used for drawing blood samples or performing hemodialysis. The winged finger grips employed in their design offers maximum sensitivity which is important for successful venipuncture. In the relaxed (wings down) position, the wings also provide means for fixing the needle securely, close to the skin puncture site where it cannot be readily jarred.
Known safety shields (see U.S. Pat. Nos. 4,676,783 (Jagger), 4,781,692 (Jagger), 4,935,011 (Hogan), 4,943,283 (Hogan) and 5,137,515 (Hogan) and the Saf-T E-Z set available from Becton Dickinson Co., add considerable bulk to the basic butterfly needle design. For example Hogan patents 4,935,011 and 4,943,283 describe shields which are slidable along a length of tubing and sized to receive a needle and associated gripping means. The bulk added by such shields significantly interferes with the best features of the butterfly needle. It impedes the delicate needle tip control required while starting the needle into a vein. It also extends behind the puncture site, thus increasing the risk of needle dislodgement even by a slight bump.
The use of winged needles is still significant (albeit declining, due to the availability of thin walled catheters) especially for intravascular procedures which do not require long dwell times. Winged needles are often preferred, for example, for giving single bolus injections of medicines and diagnostic agents.
In many countries, price precludes use of intravascular catheters. Butterfly needles cost only $0.25 to $0.50, whereas intravascular catheters may cost $1.75 to $3.00. This price differential gains universal particular importance in this era of cost controls.
The present invention preserves the central features of butterfly needles while also providing a simple and effective safety needle shield slidable along a length of tubing to prevent accidental needle stick injuries.
SUMMARY OF THE INVENTION
This invention provides a safety shield slidable along a length of tubing which is initially in a retracted position away from the needle and associated winged needle gripping means where it does not interfere with the delicate control of the needle tip during venipuncture. In one embodiment of the invention the shield may be used to detach the gripping means from the needle as the needle is withdrawn into the shield.
During venipuncture the wings of the device of this invention are folded upward to pinch and compress the needle so that it is held securely while pushed through the skin and vessel wall. The wings are then allowed to return to a relaxed, flat position. It is a feature of this invention that, in the relaxed position, there is still sufficient friction provided by the wings to prevent passive motion of the needle or of the coupling of the needle to the tubing within the winged gripping means.
A winged needle gripping means is found in the Becton Dickinson Angioset, Intima, and Saf-T Intima catheters as well as the Menlo Care Landmark catheter. However, in these devices the gripping means is not in direct contact with the needle. Instead, the needle is within a catheter which in turn is in contact with the gripping means such that the needle elements cannot be withdrawn from the gripping means by pulling on the connection tubing. The device of this invention permits the needle to be passed back through the winged gripping means by pulling on the connection tubing.
In Jagger, patent 4,676,783, the needle is retracted into a shield by pulling on a special section of tubing. However, the forward end of the shield is prevented from moving backward beyond the base of the needle. The shield adds bulk to the needle end and cannot be retracted along the connection tubing away from the needle. The present invention is therefore an improvement over Jagger.
An important novel feature of this invention is that the movable needle shield can be slid from the initial retracted position along the tubing to a position immediately behind the winged gripping means. Here the needle shield is maintained in a steady position while the connection tube is pulled backward, thus overcoming the friction grip around the needle allowing the needle tip to be retracted from the blood vessel back through the winged gripping means and into the needle shield where it is fixed into position. This may be accomplished while the winged gripping means is still secured to the skin. This is an advantage since butterfly needles have been accidentally removed from veins while attempting to remove tape dressings.
Another advantage of the present invention is that only the needle shield with the enclosed needle and attached tubing needs to be placed in the sharps container. The winged gripping means may be placed in regular refuse cans. Embodiments of the invention wherein the wings are detached in use facilitate disposal of the used needle through narrow mouthed sharps containers.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 depicts one embodiment of the invention. The needle shield is shown in a retracted position on the tubing.
FIG. 2 illustrates the FIG. 1 embodiment of the invention in which the top of the needle gripping means is cut away to depict coupling of the needle to the tubing.
FIG. 3 depicts the same embodiment of the invention as FIG. 1. In FIG. 3, the needle shield has been advanced along the tubing to a forward position adjacent the back of a winged needle gripping means.
FIG. 4 depicts the same embodiment of the invention as that shown by FIGS. 1 and 3. In FIG. 4, the needle is shown retracted into the needle shield.
FIG. 5 depicts the winged gripping means separated from the remainder of the device. The needle base is shown secured in the back of the shield.
FIG. 6 is a longitudinal section of a portion of the device of FIG. 4 or 5, including the retracted needle in the needle shield.
FIG. 7 depicts the needle base embedded in a plastic needle coupling to which tubing is attached. The shield is shown in a position retracted from the needle coupling.
FIG. 8 illustrates another embodiment of the invention in which a winged needle coupling means is permanently fixed to the needle and couples the needle to the tube, whereas in the embodiment of the invention depicted by FIGS. 1 to 7, the winged needle gripping means may be separated from the remainder of the device. In the FIG. 8 embodiment, the wings may be sheared by the needle shield.
FIG. 9 is a cross-sectional view of the FIG. 8 embodiment taken on the line "a--a".
FIG. 10 illustrates the FIG. 8 device with the needle shield in a forward position containing the needle and needle coupling secured therein by internal threads. The wings are shown as sheared by the forward movement of the shield.
FIG. 11 illustrates a section of a portion of the needle shield of FIG. 8 including a recessed means for shearing the needle wings.
DETAILED DESCRIPTION OF THE INVENTION
The invention is first described by reference to the embodiment of the invention illustrated by FIGS. 1 to 7.
As shown by these figures, the device 10 of the invention comprises an intravascular needle 11 joined to a length of tube 12 through which blood or other fluids may pass. As best shown by FIGS. 2, 4 and 6, the needle 11 is preferably embedded in a plastic needle coupling 13 to which the tube 12 is attached.
The needle 11 is initially exposed in a forward position on the tube 12 in front of the needle gripping means 14 having wings 15. The needle gripping means 14 maintains the needle 11 in this initial position by friction fit.
A cylindrical needle shield 16 slidable along tube 12 is shown in various positions along the tube in FIGS. 1 to 7.
The distal end of the tube 12 may optionally be joined to an injection port and intravenous coupling device 17.
FIG. 4 shows the needle 11 and the needle coupling 13 drawn into the needle shield 16, for example, by pulling on the tube 12 while the shield 16 has been maintained in stationary position, thus overcoming the friction fit of the winged needle grip 14 around the plastic needle coupling 13 and permitting the needle 11 and the needle coupling 13 to slip backward through the winged needle grip 14 into the needle shield 16 in which it is secured. Thereafter, as shown by FIG. 5, the shield 16 containing the secured needle and needle coupling is separated, along with the tube 12 and the injection port 17 from the winged needle grip 14 which may, if desired, remain taped to the skin.
Referring to FIG. 6, the shield 16 containing a retracted needle 11 is shown in section. The back of the shield 16 is provided with an opening 18 sized to permit tube 12 to slide therethrough but to preclude passage of the plastic needle coupling 13 and the associated needle 11. As shown by FIG. 6, the distal end of the shield 16 is provided with internal threads 19 to engage and compress the tubing 12 which is stretched around the distal end of the plastic needle coupling 13. Engagement of the threads 19 compresses the tube 12 against the coupling 13 and secures the needle coupling 13 and the needle 11 in the shield 16.
Referring to the embodiment of the invention shown in FIGS. 1 to 7, during venipuncture, the wings 15 are folded upward to pinch and compress the coupling 13 surrounding the needle 11 within the winged gripping means 14 such that the needle 11 is held securely for passage through the skin and vessel walls.
The wings 15 are then returned or allowed to return to a relaxed flat position usually on the skin surface. The internal surfaces of the needle gripping means 14 provide friction adequate to prevent passive motion of the needle 11 and the needle coupling within the gripping means.
To remove the needle 11, the needle shield 16 is slid along the tube 12 from the retracted position shown by FIG. 1 to the advanced or forward position shown by FIG. 3. The needle 11 is then withdrawn into the shield 16 by pulling the tube 12 rearwardly. In this procedure, the needle shield 16 is maintained in a steady position while the tube 12 is pulled backward, thus overcoming the friction grip around the plastic needle coupling 13 allowing the needle tip to be retracted from the blood vessel back through the winged gripping means and into the needle shield 16 where it is fixed into position.
Many possible locking means could be employed to fix the needle 11 and the coupling means 13 within the needle shield. One preferred means is the internal thread 19 at the back of the shield 16 as shown in FIG. 6. The threaded gripping means 19 reliably holds the needle 11 and the needle coupling 13 within the needle shield 16 and offers the manufacturing advantage of allowing the shield to simply be made in an injection mold. The threaded locking means 18 is believed to be novel in this setting.
This may be accomplished while the winged gripping means is still secured to the skin. The risk of accidental removal of the needle from the vein while attempting to remove tape dressings is thus reduced as compared with prior art winged needles.
In the FIG. 8 embodiment 20 of the invention, a winged needle coupling means 21 having wings 22 is fixed permanently to a needle 25 which secures the needle 25 to tubing 27. Shear lines 23 are provided at the joinder of the wings 22 to the coupling means 21.
Referring to the embodiment 20 of the invention illustrated by FIGS. 8 to 11, the winged needle coupling means 21 has wings 22 joined by shear lines 23. The needle coupling means is permanently fixed to the needle 25. In use, the wings 22 are sheared off by the slidable needle shield 28 which is provided at its proximate or forward end with a blunt or dull leading edge 29 and a recessed shearing means 30. In use, when the needle shield 28 is slid along the tube 27 to a forward position in which it contains the needle 25 and needle coupling 21, the shearing means 30 of the shield 28 shears the wings 22 at the shear lines 23. The needle 25 and sheared needle coupling 21a may be secured in shield 28 by thread means 31. See FIGS. 8, 9 and 10. | An intravascular needle with a removable safety shield is disclosed. The arrangement is such that there is little or no impediment of the needle tip control required to efficiently start a needle into the vein. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to multi-purpose hangers and apparatus for hanging objects, and the like, and the methods of using same.
2. Background Information
Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Devices for hanging objects have been developed and used for years. Most objects, such as clothing hangers, utilize a hook apparatus, as well as an outer framework. The hook apparatus connects to a reciprocal apparatus which permits the hanger to hang, while the outer framework holds the object, such as clothing. In the case of an apparatus of hanging plants or lanterns, a hook-type apparatus is usually supplied at one end, again, with a reciprocal apparatus which permits the hanger to hang, while extending therefrom is a framework which permits objects, such as a container containing a plant, or a lantern, to be disposed in the framework.
In some instances, it can be difficult, or inconvenient, to find a reciprocating apparatus in which to “hook” the hanger. In doors, the reciprocating apparatus must be installed in ceilings or walls. Outside, it can be difficult to find an acceptable “natural” reciprocating apparatus, such as a tree limb, at either the right height or the right location.
Therefore, there is a need felt within the art for a multi-purpose hanger which would permit a number of different objects to be hung from such a hanger, and in which it is easier to find and/or utilize an artificial or natural reciprocating apparatus in which to connect the multi-purpose hanger.
Further, there is a need felt in the art to provide an easy to use, adjustable hanger for indoor or outdoor use. Moreover, there is a need felt in the art to provide an easy to use, adjustable hanger for hanging objects outdoors, such as, but not by way of limitation, a plant in a container, birdseed, backpacks, lanterns, food, trash, party decorations, and the like. Such a device would be economical to manufacture and supply, easy for a user to use, relatively light weight, and would provide ease of control in raising and lowering the item being hung by a user.
SUMMARY OF THE INVENTION
A multi-purpose hanger for connecting to a surface is disclosed. The multi-purpose hanger is formed from at least a connector member, at least one strap member, a hanger member, and an adjustable arm member. The connector member is connected to a surface via the strap member. The hanger member connects to and extends away from the connector member and the hanger member is adjustably positioned and held in the position via a connection between the hanger member, the adjustable arm member and the connector member.
In other configurations of the multi-purpose hanger, a strap member may not be needed. The hanger member and/or the adjustable arm member may be formed from telescoping parts. The configuration of the connector member may be flat, concave, convex, a ninety degree angle, or any combination thereof. The multi-purpose hanger may have a top portion, which may be square, round, or any operative configuration. The connector member has a plurality of elements, namely, notches, pegs, grooves and/or apertures, which hold the adjustable arm member in place once the unconnected end of the adjustable arm member is disposed adjacent at least one of the elements. This connection results in the placement of the hanger member as well. In an alternative, the hanger member may have a plurality of elements, namely, notches, pegs, grooves and/or apertures.
A method of connecting a multi-purpose hanger to a surface is also disclosed. In this method, a multi-purpose hanger is provided which has a connector member having at least one attachment element, and a hanger member pivotally connected to the connector member, the hanger member having an adjustable arm member. The connector member is disposed adjacent a surface such that the attachment element is disposed and positioned adjacent the surface. The attachment element is activated such that the connector member is held firmly against the surface. The hanger member is raised into a selected position, and the adjustable arm member is positioned to hold the hanger member in the selected position. The adjustable arm member is then connected to the connector member to hold the hanger member in the selected position.
It is an object of the present invention to provide an apparatus for hanging a number of different items, the apparatus which may be quickly and easily connected and disconnected to a number if different surfaces, i.e., round surfaces, flat surfaces, concave surfaces, convex surfaces, irregular surfaces, and/or any combination thereof. It is a goal of the present invention to provide a multi-purpose hanger which may be attached easily and quickly to living surfaces, such as, but not by way of limitation, a tree, or may be connected to artificial (non-living) surfaces, such as, but not by way of limitation, a post, a wall, and the like. It is an object of the present invention to provide a multi-purpose hanger that is relatively light weight and portable. It is a goal of the present invention to provide a multi-purpose hanger that can be easily moved, and contained in a backpack or daypack. It is an object of the present invention to provide a multi-purpose hanger that is formed such that it is easy for a smaller operator to position the apparatus on a surface, as well as easy for the operator to elevate the “arm” which holds an item, such as, for example, but not by way of limitation, a lantern, such that the item can easily be moved both above and below the operator's head. It is a goal of the present invention to provide a multi-purpose hanger which is easily and quickly connected to a surface and disconnected from a surface, all without causing any significant damage to the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more fully apparent from the following detailed descriptions of the preferred embodiments, the appended claims and the accompanying drawings in which:
FIG. 1 is a perspective view of the multi-purpose hanger connected to a tree trunk constructed in accordance with the present invention;
FIG. 2 is a side elevational view of the multi-purpose hanger of FIG. 1, but showing the positional change of the adjustable arm member via phantom lines and the resulting positional change of the hanger member via phantom lines; shown in FIG. 3 is a front elevational view of the multi-purpose hanger of FIG. 1;
FIG. 4 is a partial top plan view of the multi-purpose hanger of FIG. 1, but showing the ninety degree angel of the connector member in relation to the round tree trunk;
FIG. 5 is a partial top plan view of the multi-purpose hanger of FIG. 1, but showing the curved angle of the connector member;
FIG. 6 is a partial top plan view of the multi-purpose hanger of FIG. 1, but showing the flat angel of the connector member adjacent a flat surface;
FIG. 7 is a perspective view of another embodiment of the multi-purpose hanger of FIG. 1, but showing an alternative embodiment for the adjustable arm member, and showing the absence of the hinge assembly;
FIG. 8 is a sectional view of the alternative embodiment of the adjustable arm member of FIG. 7;
FIG. 9 is a perspective view of yet another embodiment of the multi-purpose hanger of FIG. 1, but showing another alternative embodiment for the adjustable arm member as well as the connector member and the hanger member, resulting in a different connection among these elements;
FIG. 10 is a side elevational view of still another embodiment of the multi-purpose hanger of FIGS. 1-2, but showing a telescoping hanger member and a telescoping adjustable arm member;
FIG. 11 is still yet another embodiment of the multi-purpose hanger of FIGS. 1-2, but showing the multi-purpose hanger connected to a square post, and a top portion having a square configuration connected to the square post; and
FIG. 12 is an embodiment similar to the one shown in FIG. 11, but showing the multi-purpose hanger connected to a round post, and a top portion having a round configuration connected to the round post.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Embodiments and Methods of FIGS. 1-4
Apparatus, and methods for hanging items, as noted above, have been known in the art. Most of these apparatus and methods, however, are only adapted to a specific surface, and require specific reciprocating apparatus to be connected to a surface first, and are not easy, quick, light weight and readily mobile. The present multi-purpose hanger overcomes the limitations of previous apparatus.
Referring to FIGS. 1-4, the multi-purpose hanger 10 comprises a connector member 12 . The connector member 12 has a dual flange member 14 which connects to a hanger member 16 via an upper aperture (not shown) in the hanger member 16 through which the dual flange member 14 is hingably, rotatably connected via a first nut and bolt assembly 20 , or any other hinge and/or rotatable means known in the art. The hanger member 16 has an adjustable arm member 22 which is connected to the hanger member 16 via a hinge assembly 24 . The hinge assembly 24 rotatably connects to the adjustable arm member 22 via a first lower aperture (not shown) and second nut and bolt assembly 28 and a second lower aperture (not shown) and a third nut and bolt assembly 30 . It will be understood that, alteratively to the aperture and nut and bolt assembly, a pin assembly, a slot with pin assembly, or any other apparatus which would operate and function as shown and described herein which is known in the art would suffice in this, and all similar embodiments shown and/or described herein.
The connector member 12 has a first side 34 , a second side 36 , an outer periphery 38 , a first end 40 and a second end 42 . The second side 36 is formed such that it may be disposed adjacent a selected surface 43 ; the second side optionally may comprise some type of padding known in the art as well. The first side 34 is formed to have a plurality of notches 44 (only one of the plurality of notches being designated by the numeral 44 ). It will be appreciated that notches, holes, pegs, grooves, and/or any combination thereof, or any other embodiment known in the art, may be utilized, so long as the multi-purpose hanger 10 operates in the manner shown and described herein. In the present embodiment shown in FIGS. 1-2, the first side 34 has a plurality of notches 44 .
The connector member 12 also has a first connecting strap 46 , a second connecting strap 48 and a connecting link 49 . The connecting link 49 permits the first connecting strap 46 to be connected to the second connecting strap 48 . At least one of the first or second connecting straps 46 and 48 will have a connector element 50 connected thereto, which permits the connector member 12 to be securely and tightly strapped to the selected surface 43 , such as, for example, but not by way of limitation, a tree or a pole. The first and second connecting straps 46 and 48 wrap about the selected surface 43 and connect together via the connecting link 49 . The connecting like 49 comprises a link with an opening. It will be understood that any apparatus which operates as shown and/or described herein may be utilized as a connecting link 49 . The connector element 50 tightens the connected first and second connecting straps 46 and 48 together, and permits tensioning of the first and second connecting straps 46 and 48 such that the connector member 12 is held firmly against the selected surface 43 . Such a connector element 50 may comprise, for example, but not by way of limitation, an adjustable buckle, adjustable rings, or any other apparatus known in the art.
In one alternative (not shown), the first and second connecting straps 46 and 48 are formed such that each connector strap has a connecting element 50 connected thereto to permit the first and second connecting straps 46 and 48 to be connected together. Such an example would be a hook and loop type of fastener, where, for example, but not by way of limitation, the first connecting strap 46 had the hook material, while the second connecting strap 48 had the loop material. In a further alternative (not shown), the connecting link 49 may also comprise various different fasteners, including, but not limited to, those described herein, as well as those known in the art. In still a further embodiment (not shown), the connector member 12 may comprise at least a portion of a connector element 50 , such as, but not by way of limitation, loop material, and the selected surface 43 may also comprise at least another portion of the connector element 50 , such as, but not by way of limitation, hook material, so that when the connector member 12 is disposed adjacent and in a connecting engagement with the selected surface 43 and the connector elements 50 thereon, the connector member 12 is held in a connecting engagement with the selected surface 43 . In this alternative embodiment, any apparatus described and/or shown herein, or any apparatus known in the art, may be utilized to create and form the connection between the connector member 12 and the selected surface 43 , so long as the multi-purpose hanger operates and functions as illustrated and/or described herein.
The hanger member 16 is usually cylindrically-shaped, but it will be appreciated that any shape may be utilized, so long as the hanger member 16 operates as described and/or shown herein. The hanger member 16 has a first end 52 , a second end 54 , and, in the present embodiment, but not by way of limitation, a cylindrical outer periphery 56 and a length 58 . The hanger member 16 may also have at least one hanger notch 60 , although it will be appreciated that any peg, hook, notch, aperture, or any combination thereof, or any other apparatus which would permit the hanger member 16 to function as illustrated and/or described herein, may be used. When the hanger member 16 has, for example, but not by way of limitation, a hanger notch 60 , the hanger notch 60 will often be positioned near the second end 54 of the hanger member 16 . It will be appreciated that more than one hanger notch 60 , that is, a plurality of hanger notches (not shown) may be utilized. It will further be understood that one or more hanger notches 60 may be located in various positions along the length 58 of the hanger member 16 (not shown). Further, any type of hanger notch 60 , described herein, may be utilized, either singularly, or in combination, and in any position. When a hook is utilized, it will be appreciated that the hook may be rotatable.
The adjustable arm member 22 is also usually cylindrically-shaped, but it will be appreciated that any shape may be utilized, so long as the hanger member 16 and the multi-purpose hanger 10 function as described and/or shown herein. The adjustable arm member 22 has a first end 62 , a second end 64 , an outer periphery 66 and a length 68 . An arm aperture (not shown) is formed in the first end 62 , permitting the third nut and bolt assembly 30 to connect the adjustable arm member 22 to the hinge assembly 24 .
The first end 62 of the adjustable arm member 22 is connected to the hinge assembly 24 via the third nut and bolt assembly 30 , the hinge assembly 24 is connected to the hanger member 16 via the second nut and bolt assembly 28 . The second end 64 of the adjustable arm member 22 is formed to connected to at least one of the plurality of notches 44 in the connector member 12 , although it will be appreciated that the adjustable arm member 22 may be formed to connect to, or through, one or more notches 44 , or the alternatives, such as, but not by way of limitation, apertures, pegs, and/or grooves. It will be understood that the hingeable engagement of the adjustable arm member 22 to the hanger member 16 , as shown in FIGS. 1-2, permits the higher and lower, vertical adjustment of the hanger member 16 .
In a method of use, the multi-purpose hanger 10 is connected to a selected surface 43 , such as, but not by way of limitation, a tree trunk. The second side 36 of the connector member 12 is disposed adjacent the tree trunk, and the first connecting strap 46 is extended about the tree trunk and connected to the connecting link 49 of the second connecting strap 48 . The connector element 50 is activated via an operator pulling the first connecting strap 46 , thereby tightening the engagement of the first connecting strap 46 , the second connecting strap 48 and the connector member 12 about the (tree trunk) selected surface 43 , resulting in a tight, non-slippable engagement between the connector member 12 and the selected surface 43 .
An item, such as, but not by way of limitation, a lantern (not shown), may be connected to the hanger member 16 by sliding the ring usually connected to the top of a lantern (not shown) over the second end 54 of the hanger member 16 and into the hanger notch 60 . The hanger member 16 is then lifted into a position by lifting the adjustable arm member 22 and disposing the second end 64 of the adjustable arm member (through which at least a portion of the second end 64 is formed at least a hollow portion) against one of the plurality of notches 44 , thereby engaging and holding the hanger member 16 in a fixed position selected by the operator. It will be appreciated, as shown in FIG. 2, that engaging the second end 64 of the adjustable arm member 22 in one of the higher notches of the plurality of notches 44 results in the higher position of the second end 54 of the hanger member 16 , while engagement of the second end 64 of the adjustable arm member 22 in one of the lower notches of the plurality of notches 44 results in the lower position of the second end 54 of the hanger member 16 . It will also be understood that the multi-purpose hanger 10 is easily and quickly connected to the selected surface 43 and also easily and quickly disconnected from the selected surface 43 , without causing any significant damage to the surface.
The Embodiments and Methods of FIGS. 5-6
The connector member 12 shown in FIGS. 1-4 has formed therein a ninety degree (90%) angle, which extends the length of the connector member 12 , namely, from the first end 40 to the second end 42 . However, it will be appreciated that the connector member 12 may, partially or totally, have a different configuration.
Referring to FIGS. 5-6, as shown herein and designated by the general reference numeral 10 a is a multi-purpose hanger and another connector member 12 a constructed in accordance with the previously disclosed multi-purpose hanger 10 . In an alternative, however, the connector member 12 a has a round configuration extending through a part or all of the connector member (as shown in FIG. 5 ), or the connector member 12 a may have, partially or totally, a flat configuration (a partial flat configuration is shown in FIG. 6 ). It will be appreciated that the connector member 12 may also have other convex, concave, or any other configuration shown and/or described herein, or known in the art, so long as the connector member 12 a operates as shown and/or described herein.
In these embodiments, the multi-purpose hanger 10 a will operate in the methods described and shown previously herein. For application to a selected surface 43 a which is flat, it will be appreciated that other elements may be utilized to connect the connector member 12 a to the flat surface. Such elements include, but are not limited to, screws, bolts, nails, hook and loop-type material, and any other elements known in the art which would permit the multi-purpose hanger 10 a to operate and function in the manner shown and/or described herein.
The Embodiments and Methods of FIGS. 7-8
Referring to FIGS. 7-8, as shown herein and designated by the general reference numeral 10 b is a multi-purpose hanger and another adjustable arm member 22 b constructed in accordance with the previously disclosed multi-purpose hanger 10 . In an alternative embodiment, however, the hinge assembly 24 (FIGS. 1-2) is eliminated, and, as shown in FIGS. 7-8, the first end 62 of the adjustable arm member 22 b is modified as illustrated (FIGS. 7-8) to permit rotation, or pivoting, of the adjustable arm member 22 b in its connection with the hanger member 16 b.
In a method of use of this alternative embodiment, it will be appreciated that the multi-purpose hanger 10 b will operate in the methods described and/or shown previously herein.
The Embodiments and Method of FIG. 9
Referring to FIG. 9, as shown herein and designated by the general reference numeral 10 c is a multi-purpose hanger and another alternate embodiment constructed in accordance with the previously disclosed multi-purpose hanger 10 . In this alternative embodiment, however, the hinge assembly (not shown), or the alternative adjustable arm member 24 c described immediately above, could be altered to permit the hinge assembly (not shown) and/or the adjustable arm member 24 c to be hingeably connected in the manner described and/or shown herein to the connector member 12 c rather than the hanger member 16 c . In the present embodiment, the hanger member 16 c has a plurality of notches 44 c . It will be understood that any alternative to a plurality of notches shown and/or described herein or known in the art may be utilized. This alternative embodiment permits the hanger member 16 c to be positioned via the adjustable arm member 22 c in a manner similar to the one shown and described previously herein.
In a method of use of this alternative embodiment, it will be appreciated that the multi-purpose hanger 10 c will operate in the methods described and shown previously herein, with the exception that the second end 64 c of the adjustable arm member 22 c is hingeably connected to the connector member 12 c , and the first end 62 c of the adjustable arm member 22 c is positioned adjacent at least one of the plurality of notches 44 c on the hanger member 16 c to position the hanger member 16 c in the desired position.
The Embodiments and Methods of FIG. 10
Referring to FIG. 10, as shown herein and designated by the general reference numeral 10 d is a multi-purpose hanger and another alternate embodiment constructed in accordance with the previously disclosed multi-purpose hanger 10 . In this alternative embodiment, however, the hanger member 16 d is formed as a telescoping hanger member 16 d , as shown in FIG. 10 . That is, the hanger member 16 d may have a plurality of hanger member parts 72 (only one of the plurality of hanger member parts designated by numeral 72 ) which form the hanger member 16 d , which may be connected together via an operator to form the hanger member 16 d (not shown), or, alternatively, each of the plurality of hanger member parts 72 may fit one inside the other and extend and lock into place to form the “telescoping”, i.e., elongated hanger member 16 d , as shown in FIG. 10 . Such telescoping parts of each type are known in the art, and various ways of locking such telescoping parts together are known in the art. Such an arrangement permits a collapsibility of the hanger member 16 d , permitting ease of use and/or transport.
Similarly, it will be appreciated that the adjustable arm member 22 d , as shown in FIG. 10, may also, optionally, be formed of any telescoping elements shown and/or described herein, or known in the art. The adjustable arm member 22 d illustrated in FIG. 10 has a plurality of adjustable arm member parts 74 which are interlocked together via any method described and/or shown herein, or known in the art.
In a method of use of either of these alternative embodiments, it will be appreciated that the multi-purpose hanger 10 d will operate in the methods described and/or shown previously herein.
The Embodiments and Methods of FIGS. 11-12
Referring to FIGS. 11-12, as shown herein and designated by the general reference numeral 10 e is a multi-purpose hanger and another alternate embodiment constructed in accordance with the previously disclosed multi-purpose hanger 10 . In this alternative embodiment, however, the connector member 12 e has a top portion 76 connected thereto. The top portion 76 fits over the top of, for example, but not by way of limitation, a fence post, a mail box post, or the like, when the multi-purpose hanger 10 e is connected thereto. Such a top portion 76 could comprise a square box-type shape having an opening (FIG. 11 ), a cylindrical shape having one closed end (FIG. 12 ), or any other shape or configuration, or combination of shapes and/or configurations, known in the art.
In a method of use of either of these alternative embodiments, it will be appreciated that the multi-purpose hanger 10 e will operate in the methods described and shown previously herein. It will be understood that the top portion 76 may be applied to the top of a post either before the connector member 12 e is firmly connected to the selected surface 43 e , or, alternatively, the top portion 76 may be applied to the top of a post after the connector member 12 is firmly connected to the selected surface 43 e . The top portion 76 may rest above the elements of the multi-purpose hanger 10 e , as shown in FIGS. 11-12. It will be appreciated, however, that the top portion 76 may extend over the upper portion of the multi-purpose hanger 10 e , namely, a portion of the first end 40 e of the connector member 12 e and over at least a portion of the first and second connecting straps 46 e and 48 e , respectively, including at least a portion of the connecting link 49 e and the connector element 50 e (not shown).
Changes may be made in the embodiments of the invention described herein, or in parts or elements of the embodiments described herein, or in the sequence of steps of the methods described herein, without departing from the spirit and/or scope of the invention as defined in the following claims. | A hanger including a connector member, a strap member, a hanger arm, and an adjustable support arm is provided. The connecting member has a surface configured to substantially conform to at least a portion of an upright support member. The strap member is connected to the connector member for holding the connector member against the support member. The hanger arm has a first end pivotally connected to the connector member and a free second end adapted to suspend an item therefrom. The adjustable support arm has a first end pivotally connected to the hanger arm and a second end matingly engageable against selective portions of the connector member to support the hanger arm in a selected angular relationship with respect to the upright support member. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of PCT/EP01/11100, filed Sep. 26, 2001, which is incorporated herein by reference in its entirety, and also claims the benefit of German Priority Application No. 100 48 757.2, filed Sep. 29, 2000.
FIELD OF THE INVENTION
[0002] The invention relates to a container for liquids, flowable formulations, pastes, powders, and the like, that includes a container body with a massage device comprising at least one rotatable device held within the body, and also to the use of the container.
BACKGROUND OF THE INVENTION
[0003] Containers, such as bottles and jars, serve as storage for liquids in the cosmetic and dermatological sector. The bottles here have in particular been manufactured from flexible plastic, and slight pressure on the body of the bottle is therefore sufficient to expel liquid present in the bottle from the aperture. By way of example, mention may be made here of the known plastics bottles for shower preparations, liquid soaps, and shampoos, this list not being intended to be complete. Preference is given to bottles which can be closed using a screw-fit lid. The bottles or containers are often produced by extrusion blow molding.
[0004] U.S. Pat. No. 3,892,829 discloses a process and a device for producing flat bottles from an extruded tube, which is preblown in an intermediate mold before being passed to a final blowing mold, the mold cavity of which has the profile of the flat bottle to be produced.
[0005] DE 37 02 844 A1 discloses a process which follows this principle, and an extrusion blow molding machine which operates accordingly. Here, a plastics tube is freely extruded and passed to an intermediate mold, where it is blown to give an intermediate molding with rotational symmetry. This intermediate molding, whose cross section at every point along its axis is therefore circular, has by this stage approximately the length (height) of the flat bottle to be produced, and its main sections (base, body, neck) have a circumference which approximates to a greater or lesser extent to the corresponding circumferences of the flat bottle. The latter is finally molded by passing the intermediate molding into the type of final blowing mold known by way of example from DE 27 20 448 C2. This is a proven method for producing flat bottles with substantially uniform wall thickness with minimal waste and therefore minimal pinch-off weld.
[0006] EP 0 688 658 A1 provides (mechanical) support from below to the intermediate molding, at least during transfer from the intermediate mold to the final blowing mold. At least during transfer from the intermediate mold to the final blowing mold, an additional, movable mold section is used to buttress the intermediate molding. This mold section may advantageously have been adapted to the base profile of the intermediate molding. The mold section generally has to be able to move vertically in order not to hinder the closing of the final blowing mold.
[0007] Typically, when dispensing a lotion or other healthcare or cosmetic product from the prior art containers discussed above, a user typically squeezes the product out of the container and then massages the product, by hand, into the desired area. For example, when dispensing lotion onto their left arm, a user would first squeeze a small amount of lotion into the palm of their right hand and then use their right hand to massage the lotion into the skin on their right arm.
[0008] One problem associated with this prior art method of applying a product to skin is that it requires the user to manage both the product's container and any applicator (e.g., a towel, or simply the user's free hand) to be used in applying the product to the user's skin. Accordingly, there is a need for an apparatus and method that allows a user to dispense and apply a product without having to simultaneously manage both a container and an applicator.
SUMMARY OF THE INVENTION
[0009] The present invention provides an apparatus and method that allows a user to dispense and apply a product without having to simultaneously manage both a container and an applicator.
[0010] More particularly, a container according to one embodiment of the invention comprises a container body defining: (A) a seating for receiving at least a portion of a rotatable device; (B) a product storage portion that is configured for receiving a product to be stored within the container; and (C) a neck type extension for dispensing the product from the container. The container also includes a rotatable device that is disposed at least partially within the seating so that a first portion of the rotatable device is within the seating, and so that a second portion of the rotatable device extends outside of the seating. The rotatable device is mounted to rotate relative to the container body.
[0011] In one embodiment of the invention, the container comprises a plurality of rotatable devices. In yet another embodiment of the invention, one or more of the rotatable devices is mounted to rotate about at least one axis of rotation. In a further embodiment of the invention, the exterior surface of at least one of the rotatable devices defines a symmetrical arrangement of depressions.
[0012] In a further embodiment of the invention, at least one of the rotatable devices is spherical. In another embodiment of the invention, at least one of the rotatable devices comprises a roller.
[0013] In one embodiment of the invention, the container body is configured to receive the rotatable device into the seating and to hold the rotatable device in place in a “snap fit” manner.
[0014] A container according to a further embodiment of the invention comprises a container body defining both a seating for receiving at least a portion of a rotatable device, and a product storage portion that is configured for receiving a product to be stored within the container. A rotatable device is disposed at least partially within the seating so that a first portion of the rotatable device is within the seating, and so that a second portion of the rotatable device extends outside of the seating. In one embodiment of the invention, the rotatable device is mounted to rotate relative to the container body about an axis of rotation.
[0015] A method of dispensing and applying a product according to one embodiment of the invention comprises the steps of: (1) providing a container that is filled at least partially with the product and that comprises at least one rotatable device that is disposed adjacent an exterior surface of the container, the container comprising a neck type extension for dispensing the product from the container; (2) dispensing a portion of the product from the outlet onto a user's skin; and (3) using the at least one rotatable device to distribute the product relative to the user's skin.
[0016] A method of dispensing and applying a product according to another embodiment of the invention comprises the steps of: (1) providing a container that is filled at least partially with the product and that comprises at least one rotatable device that is disposed adjacent an exterior surface of the container, the rotatable device being configured to rotate about an axis of rotation; (2) dispensing a portion of the product from the container onto a user's skin; and (3) using the at least one rotatable device to distribute the product relative to the user's skin. In one embodiment of the invention, the step of using the at least one rotatable device to distribute the product comprises causing the at least one rotatable device to rotate about the axis of rotation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0018] [0018]FIG. 1 shows the front view of a particularly advantageously designed container in bottle form with a number of devices which together form the massage equipment.
[0019] [0019]FIG. 2 shows the side view of the particularly advantageously designed container in bottle form with a number of devices.
[0020] [0020]FIG. 3 shows a plan view of the particularly advantageously designed container in bottle form with a number of devices.
[0021] [0021]FIG. 4 depicts a container according to one embodiment of the invention.
[0022] [0022]FIG. 5 depicts a container according to another embodiment of the invention.
[0023] [0023]FIG. 6 depicts a container according to yet another embodiment of the invention.
[0024] [0024]FIG. 7 depicts a container according to a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0026] Surprisingly, this object has been achieved by way of a container as described in independent claim 1. The various other claims provide further advantageous embodiments of this container. A method of using this container is also claimed.
[0027] The invention therefore provides a container for liquids, flowable formulations, pastes, powders, and the like, including a container body with a massage device comprising at least one rotatable device held within the body, and held within the body in such a way that at least part of the surface of the device protrudes from the body.
[0028] In a first advantageous embodiment, the device is held in a mounting which is formed from a seating which has been adapted to the shape of the rotatable device in such a way that the rotatable device has been fitted within the seating in such a way that part thereof protrudes from the seating. In another preferred embodiment, the device has also been mounted on at least one axis of rotation.
[0029] Another preferred container has two or more devices present, in particular arranged in a geometric pattern. The patterns may be composed of a regular arrangement of the devices on the container, and by way of example, therefore, the separations between the individual devices may be regular. The nature of the pattern to be selected may depend on the nature of the application sector for the container, and also on its contents. In a first embodiment of this device, it comprises a rotatable body, in particular of a geometric body with rotational symmetry.
[0030] The device may be composed of metal, glass, ceramics, porcelain, or of a suitable plastic. It is very advantageous for the material used to comprise polypropylene. Materials with excellent suitability are generally thermoplastics, elastomers, or combinations of plastics from these groups. Their properties can be varied widely by adding plasticizers, fillers, stabilizers, and other additives, and also by fiber-reinforcement. Examples which may be mentioned of thermoplastics and elastomers are: all of the plastics composed of linear polymer molecules or of polymer molecules cross linked in a thermally labile manner, examples being polyolefins, vinyl polymers, polyamides, polyesters, polyacetals, polycarbonates, and also some polyurethanes and ionomers; TPES (styrene-oligoblock copolymers), TPEO (thermoplastic polyolefins), TPEU (thermoplastic polyurethanes), TPEE (corresponding copolyesters), TPEA (corresponding copolyamides), and natural and synthetic rubbers.
[0031] Preference is given to devices which have a structured surface. In another very advantageous embodiment, the structuring forms depressions in the surface, in particular depressions in a symmetrical arrangement. In another variant, the device has structuring by virtue of elevations located on the surface.
[0032] The depressions in the surface preferably have the form of seatinges, grooves, notches, channels, or the like. However, any depression may be utilized here without restriction to increase functionality, and examples include depressions in the form of ornamentation, designs, or characters, or the like.
[0033] For the purposes of the invention, the following two device variants are very advantageous. First, the arrangement and dimensioning of the depressions may be such that the depressions are separate from one another, for example in the case of the above mentioned seatinges if these have no contact with one another (“closed-pore”). Second, there may be connection between the depressions so that there is a “channel system” located in the macroscopic surface of the sphere (“open-pore; seen in another way, this is equivalent to the abovementioned elevations on the surface of the sphere if the “floor” of the channels is taken as the macroscopic surface of the sphere). In a further embodiment of the device, this is a sphere, an ellipsoid, or a roller, either unstructured with macroscopically smooth surfaces or likewise with the structures mentioned. Examples of other shapes with good suitability are cones, hyperboloids, paraboloids of revolution, and also sections or portions or frusta of these geometric bodies, and also irregular geometric bodies.
[0034] The mounting is preferably comprises a socket whose shape substantially envelops the shape of the device and whose internal diameter is slightly greater than the external diameter of the device (in the case of elliptical bodies, the two semiaxes being correspondingly somewhat larger than those of the device). This socket is further described below, taking a spherical device (sphere). For devices of other shapes, the shape is to be adapted to the shape of the device, and the description applies analogously.
[0035] The socket in the body of the bottle narrows slightly toward the outside in the shape of a ring so that the diameter of the remaining aperture is somewhat smaller than the diameter of the sphere. The sphere may then be inserted into the socket using slight pressure, and therefore has a “snap fit” into the socket and does not spontaneously fall out again from the socket. Part of its surface therefore protrudes from the device, and the sphere is freely rotatable in all directions, so that when the devices forming a massage device in the bottle are passed across the skin with a rolling movement, a massage effect arises.
[0036] In one variant of this socket, there is no complete ring present, but instead at least two, preferably at least three, ring sections are present to hold the sphere. The shape of these is therefore such that the sphere does not fall out after it has been snap-fitted.
[0037] In the case of a roller-shaped device, the mounting comprises two opposite walls, each terminating in a narrowing toward the other wall. In one preferred embodiment, the two side walls here are sections of a tube whose diameter is somewhat greater than the diameter of the roller. Two plane-parallel walls may close the front and rear of this tube section. Given appropriate selection of the dimensions of the surface-structured sphere, of the ellipsoid, or of the roller, the structured systems can be inserted into the known mounting systems.
[0038] In the usual embodiments of the device, this has been fitted within the mounting so as to be capable of free rotation in all spatial directions, and this is particularly applicable to the application bodies with rotational symmetry. In another advantageous embodiment, the device has also been mounted on at least one axis of rotation. This gives the mounting additional stability and moreover prevents the device from falling out of the container. This also allows the direction of rotation of the body to be prescribed, opening up additional possibilities for designing the surface geometry. This structure may either permit the axis to rotate in its axis mounting or else permit the device to rotate on the axis.
[0039] The container of the invention can be used to store liquid or flowable substances, or else readily distributable solid substances, or else mixtures of two or more components, while at the same time the massage equipment makes it easier for the substances dispensed to be massaged into the skin. The container has excellent suitability for emulsions, suspensions, dispersions, solutions (of gaseous, of liquid, or of solid substances), colloids, and the like, very preferably for applying cosmetic or dermatological compositions to the skin, in particular gels, emulsions, Pickering emulsions, hydrodispersions, or lipodispersions. The flowable formulations are preferably emulsions, suspensions, colloids, dispersions, gels, or solutions.
[0040] Technically, gels are: readily deformable disperse systems comprising at least two components and having a degree of dimensional stability, generally composed of a—mostly solid—colloidally dispersed substance composed of long-chain molecular groups (e.g. gelatin, silica, polysaccharides) as structure-former, and of a liquid dispersion medium (e.g. water). The colloidally dispersed substance is often termed thickener or gelling agent. It forms a three-dimensional network in the dispersion medium, and there may be some degree of bonding here between individual colloidal particles by way of electrostatic interaction. The dispersion medium which surrounds the network has electrostatic affinity to the gelling agent, so that a predominantly polar (in particular: hydrophilic) gelling agent preferably gels a polar dispersion medium (in particular: water), and in contrast a predominantly non-polar gelling agent preferably gels non-polar dispersion media.
[0041] Strong electrostatic interactions, for example those arising when there are hydrogen bonds between gelling agent and dispersion medium, or else between molecules of dispersion medium themselves, can also lead to a high degree of crosslinking of the dispersion medium. Hydrogels may be composed of almost 100% of water (with from about 0.2 to 1.0% of a gelling agent, for example) while having a very firm consistency. The water content here is present in the form of structural units similar to those in ice.
[0042] Lipogels and oleogels (composed of waxes, fats, or fixed oils) are familiar in cosmetics and pharmaceuticals, as are carbogels (composed of paraffin or petrolatum). In the industry a distinction is made between oleogels, which are practically water-free, and hydrogels, which are practically fat-free. Gels are mostly transparent. Gels in cosmetics and pharmaceuticals very generally have a semisolid consistency, which is often flowable.
[0043] Surfactant gels are other familiar preparations of the prior art. These are systems which comprise water with a high concentration of emulsifiers, typically more than about 25% by weight, based on the entire composition. If oil components are solubilized into these surfactant gels the result is microemulsion gels, also termed “ringing gels”. Cosmetically more elegant microemulsion gels can be obtained by adding non-ionic emulsifiers, for example alkyl polyglycosides.
[0044] Emulsions are metastable two- or multiphase systems in which each of the phases present is a liquid. The most commonly encountered emulsions are OW and W/O emulsions. Multiple emulsions are less commonly found, these being those in which droplets of another dispersed phase are in turn present within the droplets of the dispersed (or discontinuous) phase, examples being W/O/W emulsions and O/W/O emulsions. Simple emulsions have finely dispersed droplets of the second phase (water droplets in W/O emulsions or lipid vesicles in O/W emulsions) surrounded by an emulsifier envelope within the first phase. The droplet diameters in the usual emulsions are in the range from about 1 μm to about 50 μm. Without addition of colorant additives, these “macroemulsions” have a milky white color and are opaque. Finer “macroemulsions” with droplet diameters in the range from about 10 −1 μm to about 1 um have a bluish-white color and are non-transparent, again without any colorant additives. Micellar and molecular solutions with particle diameters smaller than about 10-2 μm have a clear and transparent appearance.
[0045] In contrast, the droplet diameter in transparent or translucent microemulsions is in the range from about 10 −2 μm to about 10 −1 μm. These microemulsions mostly have low viscosity. The viscosity of many O/W-type microemulsions is comparable with that of water.
[0046] Emulsions are by far the most important type of product in the skin-care sector, or in the sector of cosmetic and/or dermatological preparations. Emulsions are disperse two- or multiphase systems, and cosmetic emulsions are composed of at least one fatty phase (fats and mineral oils, fatty esters, fatty alcohols, etc.) and of at least one aqueous phase (water, glycerine, glycols, etc.), these being distributed within one another in the form of very fine droplets with the aid of emulsifiers. If the two liquids are water and oil, and if there are oil droplets finely distributed in water, the material is an oil-in-water emulsion (O/W emulsion, an example being milk). The underlying character of an O/W emulsion is determined by the water. In the case of a water-in-oil emulsion (W/O emulsion, an example being butter), the reverse principle applies, the underlying character here being determined by the oil.
[0047] The oil phase is advantageously selected from the group of the esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids and saturated and/or unsaturated, branched and/or unbranched alcohols, from the group of the esters of aromatic carboxylic acids and saturated and/or unsaturated, branched and/or unbranched alcohols, from the group of the branched or unbranched hydrocarbons and hydrocarbon waxes, silicone oils, dialkyl ethers, the group of the saturated or unsaturated, branched or unbrancbed alcohols, or else the triglycerides of the fatty acids. For the purposes of the present invention, it is also advantageous to use any desired blend of these oil components and wax components. Where appropriate, advantageous use may also be made of waxes, such as cetyl palmitate, as sole lipid component of the oil phase.
[0048] The oil phase may advantageously have some content of cyclic or linear silicone oils, such as cyclomethicone (octamethylcyclotetrasiloxane), or be composed entirely of those oils, but it is preferable to use some additional content of other oil-phase components besides the silicone oil or the silicone oils. The emulsions described here and below can therefore be manufactured in the form of silicone emulsions, with partial or sole use of silicone oils. The same applies to the other oil-containing preparations.
[0049] The skilled worker is aware of a wide variety of possibilities for formulating stable O/W preparations for cosmetic or dermatological use, e.g. in the form of creams and ointments which are spreadable in the range from room temperature to skin temperature, or in the form of lotions and milks which are more flowable in this range of temperature and can be stored particularly advantageously using the container of the invention.
[0050] The stability of emulsions depends, inter alia, on their viscosity, in particular on the viscosity of the external phase. An emulsion becomes unstable if the finely dispersed particles accumulate again to give relatively large aggregates, and the droplets coalesce when they contact one another. This process is termed coalescence. The more viscous the external phase of the emulsion, the slower the coalescence process.
[0051] O/W emulsions are therefore generally stabilized by thickeners which increase the viscosity of the aqueous phase. Examples of materials suitable for this purpose are polyacrylates (carbomer) and other organic thickeners. One disadvantage of this method of improving stability is the sensitivity of these formulations toward electrolytes. This method moreover naturally produces formulations (such as creams or ointments) mainly of relatively high viscosity.
[0052] Emulsions with “liquid” (=flowable) consistency are used in cosmetics, for example as beauty lotion, cleansing lotion, facial lotion, or hand lotion. Their viscosity is generally from about 2 000 mPa·s to about 10 000 mPa·s. The stability of flowable emulsions requires particular attention, since the particles have considerably more freedom of motion, promoting more rapid coalescence.
[0053] Conventional emulsifiers can be subdivided into ionic (anionic, cationic, and amphoteric) and non-ionic on the basis of the hydrophilic moiety in their molecule. Probably the best known example of an anionic emulsifier is soap, this being the term usually used for the water-soluble sodium salts or potassium salts of the higher saturated or unsaturated fatty acids.
[0054] Important cationic emulsifiers are the quaternary ammonium compounds. The hydrophilic moiety in the molecule of non-ionic emulsifiers is often composed of glycerine, polyglycerine, sorbitans, or carbohydrates, or polyoxyethylene glycols, mostly linked to the lipophilic moiety in the molecule by way of ester bonds and ether bonds. The lipophilic moiety is usually composed of fatty alcohols, fatty acids, or isofatty acids. The lipophilic and hydrophilic properties of emulsifiers can be modified within wide limits by varying the structure and the size of the polar and of the non-polar moiety in the molecule.
[0055] A decisive factor for the stability of an emulsion is the correct selection of the emulsifiers. The characteristics of all of the substances present in the system have to be considered here. For example, in skin-care emulsions polar oil components and, for example, UV filters cause instability. Alongside the emulsifiers, use is therefore made of other stabilizers which increase the viscosity of the emulsion and/or act as a protective colloid.
[0056] There are no risks involved per se with the use of conventional emulsifiers in cosmetic or dermatological preparations. However, in particular cases emulsifiers can bring about allergic reactions or reactions due to hypersensitivity of the user, as indeed can any chemical substance. There have therefore been many attempts to reduce the amount of conventional emulsifiers to a minimum, or ideally eliminate these entirely.
[0057] One way of reducing the amount of emulsifier needed is to utilize the fact that very finely dispersed particles of solid have an added stabilizing action. The solid substance here becomes concentrated in the form of a layer at the oil/water phase boundary, thereby inhibiting coalescence of the disperse phases. It is the surface properties of the solid particles rather than the chemical properties which are of substantial importance here.
[0058] A relatively new technical development stabilizes cosmetic or dermatological preparations solely via very finely dispersed solid particles. These “emulsifier-free” emulsions are named for their inventor Pickering emulsions. According to May-Alert ( Pharmazie in unserer Zeit , volume 15 1986, No. 1, 1-7), an example of a method for solids-stabilization in a cosmetic or dermatological preparation is to use emulsifier mixtures which comprise both anionic and cationic surfactants. Since combining anionic and cationic surfactants always leads to precipitation of insoluble compounds with no electrical charge, controlled precipitation of these neutral surfactants at the oil/water interface can achieve additional Pickering-emulsion-type solids-stabilization.
[0059] WO 98/42301 A1 moreover describes emulsifier-free finely dispersed systems of water-in-oil type which are stabilized by addition of micronized inorganic pigments, these being selected from the group of the metal oxides, in particular titanium dioxide.
[0060] Emulsifier-free preparations based on what are known as hydrodispersions have been available to the consumer for some time. Hydrodispersions are dispersions of a liquid, semisolid, or solid internal (discontinuous) lipid phase in an external aqueous (continuous) phase.
[0061] In contrast to O-W emulsions, which nevertheless have a similar arrangement of phases, hydrodispersions are substantially free from emulsifiers. Like emulsions, hydro-dispersions are metastable systems with a tendency to convert into a condition with two coherent discrete phases. In emulsions, the selection of a suitable emulsifier inhibits phase separation.
[0062] In the case of hydrodispersions of a liquid lipid phase in an external aqueous phase, the stability of this system can, for example, be ensured by constructing, within the aqueous phase, a gel structure in which the lipid droplets have been stably suspended. By reverse analogy, W/O lipodispersions are finely dispersed emulsifier-free preparations of water-in-oil type. The invention also provides the use of a container in combination with cosmetic or dermatological preparations in the form of gels, emulsions, microemulsions, suspensions, dispersions, colloids, powders, and/or pastes.
[0063] Combination of the container of the invention with liquid cosmetic cleansing compositions which, by virtue of the specific container, can be used for cleansing with a massaging effect, is particularly advantageous. Liquid cosmetic cleansing compositions are known per se. The invention therefore provides the combination of these compositions with a packaging which permits the application of the cleansing composition with a massaging effect.
[0064] Liquid cosmetic cleansing compositions include all of the formulations with anionic, cationic, non-ionic, or amphoteric, or zwitterionic, surfactants. Skin-care substances may also be present in these formulations. Skin-care substances which may be used are refatting agents, conditioners, peeling agents, or active ingredients.
[0065] A particular advantage of this packaging is that the massager is easy to clean, since the specific construction permits unhindered passage of water through the passages. There is therefore no need for a high concentration of preservative in the cleansing composition. Another result is that microbiological safety of the product is ensured.
[0066] The specific construction of the massagers permits pure pressure massage, thus preventing irritation of the skin due to excessive rubbing on the surface of the skin. This method provides a very gentle means of using the cleansing compositions. During massage there is less irritation of the skin due to the use of a cleansing composition.
[0067] Five examples below are examples of cosmetic cleansing compositions for which the container of the invention can be used with excellent results.
EXAMPLES OF COSMETIC CLEANSING COMPOSITIONS
Example 1
[0068] [0068] % by weight Sodium laureth sulfate 9.00 Cocamidopropyl betaine 4.00 Decyl glucoside 1.00 Glycol distearate 2.00 Sodium cocoyl glutamate 0.30 Fragrance 0.80 Prunus ducis 0.20 Water ad 100.00
Example 2
[0069] [0069] % by weight Sodium laureth sulfate 9.00 Cocamidopropyl betaine 4.00 Decyl glucoside 1.00 Sodium cocoyl glutamate 0.30 Fragrance 1.00 Vitis vinifera 1.00 Aloe barbensis 1.00 Polyquaternium-10 0.30 Water ad 100.00
Example 3
[0070] [0070] % by weight Sodium laureth sulfate 12.00 Cocamidopropyl betaine 3.00 Sodium lauroyl sarcosinate 2.00 PEG-4 rapeseedamide 5.00 PEG-9 cocoglycerides 2.00 Fragrance 1.00 Hydroxypropyl guar 0.30 Hydroxypropyltrimonium chloride Water ad 100.00
Example 4
[0071] [0071] % by weight MIPA-laureth sulfate (+) laureth-4 41.00 cocamide DEA Soybean oil 40.00 Castor oil 14.00 Polxamer 10 1 4.00 Fragrance 2.00 Panthenol 1.00 Water ad 100.00
Example 5
[0072] [0072] % by weight Sodium laureth sulfate 10.00 Polyethylene 5.00 Sodium cocamphoacetate 4.00 Magnesium aluminum silicate 3.00 Sodium cocoyl glutamate 1.00 Fragrance 0.80 Water ad 100.00
[0073] Besides the advantages described above, the containers of the invention have an additional advantage for the user in the body-care sector, due to the massage effect brought about by the modified surface. During application of cosmetic or dermatological preparations, a simultaneous positive effect can be achieved, for example for skin firming or to counter cellulitis.
[0074] Turning now to the Figures, FIG. 1 illustrates the front view of a particularly advantageously designed container 10 in bottle form. The bottle 10 , produced by extrusion blow molding, is substantially rectangular in form, but the edges of the bottle 10 have been rounded. On the body of the bottle 10 there is a neck-type extension 12 , serving for dispensing of the contents. A lid 11 has been placed on the bottle 10 and at the same time closes the extension 12.
[0075] In one of the wider side walls of the bottle 10 there are a number of devices 20 which together form massage equipment. The devices 20 here have the form of spheres, and have been mounted rotatably in sockets in the wall.
[0076] The devices 20 form a regular pattern composed of a total of nine spheres. The pattern or the number of spheres in the pattern is freely selectable, depending on the application or contents of the bottle 10 . The same also applies to the size of the devices located in the container.
[0077] The user of the contents of the bottle 10 can use slight pressure on the bottle 10 to remove some of the contents and, for example, apply the same to the skin. The user can then use the massage equipment to massage the applied contents conveniently into the skin, without having to pick up or search for any additional apparatus.
[0078] [0078]FIGS. 2 and 3 show the side view and, respectively, the plan view of the bottle.
[0079] FIGS. 4 - 7 illustrate by way of example four different embodiments of the device, in each case here in the form of a sphere. Each figure illustrates the level surface 1 of the sphere, which can be regarded as the macroscopic surface of the sphere, and also illustrates the depressions 2 within this level surface.
[0080] In FIGS. 4 - 6 , these depressions 2 are separate from one another, and specifically have the shape of circular seatinges (FIGS. 4 and 5, different arrangements of the depressions 2 ), or square depressions (FIG. 6). FIG. 6 also illustrates the weld line 3 produced by injection molding in a two-part mold or during build-up of the sphere from two sphere halves.
[0081] [0081]FIG. 7 shows a spherical device with a system composed of connected channel-type type depressions 2 in the surface 1 (“open-pore system”). Seen in another way, the (in this example triangular) regions 1 represent elevations on the sphere formed by the “flat channel surfaces” 2 . | A container for storing a product, such as a liquid, flowable formulation, paste, or powder. The container comprises a container body that includes an integrated massage device. The massage device comprises at least one rotatable device that is partially disposed within a seating in the exterior surface of the container body. This rotatable device is mounted so that at least a portion of the rotatable device protrudes from the container body, and so that the rotatable device may rotate (e.g., about an axis of rotation) relative to the container body. The rotatable devices may be used to massage a product into a a user's skin after the product has been dispensed from the container onto the user's skin. | 1 |
PRIORITY CLAIM
[0001] This application claims priority from Provisional Application Ser. No. 61/351,361 filed Jun. 4, 2010.
FIELD AND BACKGROUND OF INVENTION
[0002] The invention is generally related to subsea well bores and more particularly to a subsea well containment and intervention apparatus.
[0003] Containment of a leak and intervention of an offshore subsea well poses significant risks.
[0004] The main tool for intervention is an ROV (remotely operated vehicle) and this tool may be well suited for observation and carrying out small tasks. However, heavy tools requiring high loads are required for any subsea well intervention.
[0005] One has to keep in mind the significant pressures encountered in an oil well. Pressures of 10,000+ psi are common place. Managing a simple task may become impossible due to the high pressures encountered.
[0006] In addition, the integrity of the well and its attachments are usually in question when intervention is required. The well components must be handled delicately for fear that further damage can be caused.
[0007] ROV's do not have the necessary power needed to handle large size tools and strength required to manage the intricate maneuvers. Limited capability of the ROV's puts a serious restriction on the range of operations possible.
[0008] ROV's are limited in their endurance and flexibility. They will have to return to the surface for maintenance, and replenishment of tools or consumables. Return to the surface is a slow process. When time is of the essence in any leak containment or intervention operation, the functionality of the ROV is questioned.
SUMMARY OF INVENTION
[0009] The present invention addresses the problems in the known art. The invention provides a rigid frame that includes a set of pilings for securely affixing the apparatus to the seafloor. Buoyancy modules included in the frame make the weight of the invention more manageable when in the water. Lifting eyes are provided on the frame for installation and removal. A series of tools are attached to the frame to eliminate the need for frequent trips to the surface to replace and replenish.
[0010] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. For a better understanding of the present invention, and the operating advantages attained by its use, reference is made to the accompanying drawings and descriptive matter, forming a part of this disclosure, in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the accompanying drawings, forming a part of this specification, and in which reference numerals shown in the drawings designate like or corresponding parts throughout the same:
[0012] FIG. 1 is a general isometric view of the basic components of the invention.
[0013] FIG. 2 illustrates the steel beams and tools used with the invention.
[0014] FIG. 3 illustrates the positioning of the invention over a well head.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The subsea well containment and intervention apparatus 10 is generally comprised of a frame 12 , buoyancy modules 14 , piles 16 , a series of tools, and means for controlling the tools.
[0016] As seen in FIG. 1 , the frame 12 is preferably formed from a plurality of steel beams 18 attached together. It is preferred they form essentially a cross or X shape. The steel beams 18 are preferably sized to handle a minimum of 10,000 tons of force both upwards and downwards. The size and length of the steel beams 18 are selected to suit the most common offshore sites.
[0017] The beams 18 are attached together so as to define an open central well 20 which can be placed over the well head 22 . The open central well 20 allows the use of tools stowed on the apparatus 10 for working on the subsea well.
[0018] A plurality of lifting eyes 24 are rigidly attached to the frame 12 to provide attachment points for lifting and lowering the apparatus 10 to the seafloor.
[0019] A plurality of pilings 16 , also referred to as piles (one or more at each end of the frame 12 ) are provided and are rigidly attached to the steel beams 18 . Piles 16 are preferably suction piles. At least one evacuation pump 26 is provided on each pile 16 , which is closed at the upper end. The diameter and length of the piles 16 are selected to suit the most common offshore sites and soil conditions. The piles 16 are used to establish the apparatus 10 in place around the well head 22 .
[0020] As known in the offshore industry, suction piles are open at the lower end and closed at the upper end and eliminate the need for a pile driving device by placing the lower open end of the pile on the seafloor and using an evacuation pump to remove air and water from the interior of the pile. The negative pressure created inside the pile causes the pile to be pushed into the soil by the external water pressure on the pile which is greater than the internal pressure.
[0021] It is preferable that the evacuation pumps 26 be of the positive displacement type and it is estimated that they should be able to create at least 2,500 psi differential pressure or more using either electrical or hydraulic power.
[0022] The evacuation pumps 26 are connected to a pump control center 28 that is preferably located on one of the steel beams 18 . An umbilical connector 30 mounted on the same steel beam as the pump control center 28 is used to bring aboard a control, electrical, and hydraulic umbilical line 32 .
[0023] Buoyancy modules 14 serve to reduce the effective submerged weight of the apparatus 10 and make handling from the surface more manageable. While any suitable type of buoyancy module may be used, syntactic foam buoyancy modules are preferred.
[0024] As indicated above, a series of tools may be provided on the apparatus 10 . FIG. 2 illustrates some examples of possible tools that can be used such as a wellhead cleaning tool 34 , a flow control tool 36 , a pressure plug ram 38 , or a pipe connector 40 . The tools are normally kept in their stowed position and deployed as required for use once the apparatus 10 is installed on the seafloor 42 . Using the top and bottom of the frame 12 , as many as eight tools can be installed on the apparatus 10 , thus minimizing or eliminating the need for repeated trips to the surface. Jacks 44 can be used for positioning the tools. Umbilical line 32 extends from a surface support vessel and is connected to umbilical connector 30 that serves as means for providing electrical and hydraulic power to and controlling the tools. Power and control lines not shown are provided on the frame 12 as needed for the tools.
[0025] A wellhead cleaning tool 34 can be used to prepare a damaged well head for being capped or being connected to a flow control tool 36 such as that illustrated in FIG. 2 . Jack 44 is used to move the flow control tool 36 into fluid communication with the well head 22 such that the oil and/or natural gas from the well flows through a flow diverter riser 46 into pipe connector 40 and into a pipe or riser not shown for safely diverting oil and/or natural gas from a damaged well.
[0026] FIGS. 2 and 3 illustrate a pressure plug ram 38 mounted on a skid plate 48 via extension jacks 50 . The skid plate 48 is movably mounted on the frame 12 and moved between positions by a jack 44 . As seen in FIG. 3 , the pressure plug ram 38 has been moved from a first retracted position to a second deployed position where it is aligned with the central well 20 and the well head 22 . The extension jacks 50 are used to force the pressure plug ram 38 into the well head 22 to block the flow of oil and/or natural gas from the well into the surrounding environment.
[0027] While only the pressure plug ram 38 is shown as being mounted on a skid plate 48 for movement during work on a well head, it should be understood that skid plates may be used for all of the tools to provide the greatest versatility for movement and working capability.
[0028] The control, electrical, and hydraulic umbilical line 32 provides a continuous supply of power to the tools.
[0029] The flow control tool 36 is connected to the flow diverter riser 46 that takes the flow away from the well head and through a riser to the surface.
[0030] One special tool is the pressure plug ram 38 . As the steel beams 18 are designed for 10,000 tons force, the pressure plug ram 38 is placed on either side and can exert the maximum force on top of the well head 22 to plug the well totally independent of the well and wellhead components 52 . As shown in FIG. 3 , the pressure plug ram 38 is brought directly over the well head 22 and using the extension jacks 50 the leaking well is sealed.
[0031] In operation, the apparatus 10 is lowered by a surface vessel using lifting eyes 24 and positioned above a subsea well head 22 . Once the piles 16 contact the seafloor 42 the evacuation pumps 26 are activated to drain water and air from the piles 16 . The pressure differential between the inside and outside of the piles causes the piles to be driven into the seafloor 42 and fix the apparatus 10 in place. Tools such as the well head cleaning tool 34 , the flow control tool 36 , or the pressure plug ram 38 are then used as needed to properly capture and direct the flow of oil and/or natural gas or to plug the well. When the work is completed and there is no longer a need for the apparatus 10 at the site, the evacuation pumps 26 can be used to pump water into the piles and create a pressure differential that pushes the piles out of the seafloor 42 and allow apparatus 10 to be lifted to the surface and recovered for reuse at another location.
[0032] The invention provides several advantages.
[0033] It provides a strong, rigid and stable platform in and around the subsea wellhead.
[0034] It provides a platform where a multitude of tools can be placed onboard prior to deployment and can be used independently.
[0035] It provides means of exerting a significant amount of force independent of the well and well head components.
[0036] It provides a steady stream of power to the tools.
[0037] The apparatus is removable and reusable.
[0038] While specific embodiments and/or details of the invention have been shown and described above to illustrate the application of the principles of the invention, it is understood that this invention may be embodied as more fully described in the claims, or as otherwise known by those skilled in the art (including any and all equivalents), without departing from such principles. | A subsea well containment and intervention apparatus. The invention provides a rigid frame that includes a set of pilings for securely affixing the apparatus to the seafloor. Buoyancy modules included in the frame make the weight of the invention more manageable when in the water. Lifting eyes are provided on the frame for installation and removal. A series of tools are attached to the frame to eliminate the need for frequent trips to the surface to replace and replenish. | 4 |
COPYRIGHT NOTICE
[0001] A portion of the disclosure of this patent contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to exercise equipment. In particular, the present invention relates to exercise equipment that improves the range of motion obtainable with appendage actuated exercise equipment.
[0004] 2. Description of Related Art
[0005] The use of exercise devices such as weight training and cardiovascular training machines include a repeated movement that moves over a designated path. For weight training there is a resistance provided by weights, bands, or the like to render the movement more difficult and intensify the exercise. With cardio type or shoulder rehabilitation type exercise, frequently handles are grasped and rotated in a circular fashion much like pedals on the bike either by hand or foot. The movement itself dictates the muscles or muscle groups involved in the exercise.
[0006] One great problem with exercise equipment in general is that handles, foot loops, or the like are usually fixed such that parallel back and forth or parallel circular motions are achieved. This is usually also done in a perpendicular to the user's chest fashion with arms spread apart shoulder width. These fixed handles limit the way the muscles are exercised and is not adequate to real life situations since in real life pushing, pulling, and rotation motions can end up in any of the 6 degrees of movements allowed by limbic rotation. For example, an individual may need to push an object with arms spread wide apart, thus using muscles differently than shoulder width apart on most machines. For all around training, current hand driven exercise machines are limited by design to at most those that raise and lower the handles and do not function to completely train and/or rehabilitate the individual. Using both hands on either side of a wheel to rotate the wheel limits the movements of the machine to exercising in a single plane and greatly limits the potential of the machine in both shoulder rehabilitation and upper body development.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention relates to devices which allow the user to set various ranges of motion other than just shoulder width.
[0008] Accordingly, in one embodiment of the invention there is an exercise machine adjustable for different ranges of motion for a user to perform an exercise while grasping a handle of the machine comprising:
a. one or two upright arms; b. an adjustment device attached to each of the one or two upright arms each device capable of
i. adjusting and locking vertically relative to the upright device; ii. adjusting and locking horizontally relative to the upright device; and iii. adjusting and locking rotationally around an axis that is perpendicular to the upright device; and
c. a handle and adjustable shaft attached to the adjustment device for grasping by the user and performing the exercise.
[0015] Another embodiment of the present invention is a method for rehabilitating a shoulder of an individual having a shoulder problem comprising exercising on a cardio spinning machine comprising:
a. one or two upright arms; b. an adjustment device attached to the one or two upright arms each device capable of
i. adjusting and locking vertically relative to the upright device; ii. adjusting and locking horizontally relative to the upright device; and iii. adjusting and locking rotationally around an axis that is perpendicular to the upright device; and
c. a handle and adjustable shaft attached to the adjustment device for grasping by the user and performing the cardio spinning exercise.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a front view of a machine of the present invention.
[0023] FIGS. 2 a - 2 c show a side view of the rotational function of the present invention.
[0024] FIG. 3 is a top view of the horizontal arms and a rotational embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0025] While this invention is susceptible to embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure of such embodiments is to be considered as an example of the principles and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings. This detailed description defines the meaning of the terms used herein and specifically describes embodiments in order for those skilled in the art to practice the invention.
DEFINITIONS
[0026] The terms “about” and “essentially” mean ±10 percent.
[0027] As used herein the term “comprising” is not intended to limit inventions to only claiming the present invention with such comprising language. Any invention using the term comprising could be separated into one or more claims using “consisting” or “consisting of” claim language and is so intended.
[0028] The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two or as more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0029] Reference throughout this document to “one embodiment”, “certain embodiments”, and “an embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without limitation.
[0030] The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
[0031] The drawings featured in the figures are for the purpose of illustrating certain convenient embodiments of the present invention, and are not to be considered as limitation thereto. Term “means” preceding a present participle of an operation indicates a desired function for which there is one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term “means” is not intended to be limiting.
[0032] As used herein the term “exercise machine” refers to an indoor type cycling device wherein the user grasps one or two handles and rotates them singly or together as one would pedal a bicycle with their feet (either opposing or non-opposing handles). The rotation (pedaling) can be done under resistance or no resistance and clockwise or counter clockwise. An exercise machine in another embodiment, can be a weight machine wherein one or two handles are grasped and weights or resistance applied to wheels and a repetition movement made to strengthen the muscle being exercised. In one embodiment, the handles are for grasping by the hands and in other embodiments are adapted to be used by one or two feet. The exercise is done periodically, and where to repair an injury or an upper body problem, periodically until there is acceptable improvement.
[0033] As used herein the phrase “different ranges of motion” refers to being able to fix the motion of the exercise machine in one of six degrees of freedom of movement for each hand or foot. While normal machines are fixed and operate shoulder width and perpendicular to the user, the present invention allows for adjustment (and locking in place) of any type of movement in order to strengthen the muscles all over and not limited to a single plane. As used herein “adjustable” means the user can set the six degrees of motion and lock them in place during use for each hand or foot. Range of motion extends to the ability to shorten and lengthen the shaft from the handle to the center of the wheel, changing the length of the shaft changes the degree of angular movement of the shoulder during the exercise.
[0034] As used herein a “user” refers to a person exercising on an exercise machine either hand cycling, foot cycling, or weight lifting using the one or two handles of the exercise machine.
[0035] As used herein the term “upright arms” refers to vertical support for the adjustment device of the present invention. In one embodiment, they are upright tubings (any cross section such as square or tubular) capable of supporting the weight of the adjustment device which will be mounted thereon. They can be steel or steel alloy but could also be a polymer, a carbon compound, or the like. One skilled in the art of building exercise machines could build and chose materials based on the description and example drawings herein. In one embodiment, the upright is generally perpendicular to the ground and high enough (tall enough) to mount the adjustment device at a level the user can grasp overhead or down to waste level properly/comfortably. The arms can, in one embodiment, be attached to a lower portion horizontal arm in which two arms meet in a center portion of the machine and approximately under the user's shoulders (e.g. underneath a seat in the device). In one embodiment, the arms are pivotally adjustable either with a pin, such as a spring loaded pin, and hole means of fixing with a pivot in the center or any other means for pivoting the arms radially. When pivoted, they can position the handles as close together or as far apart as desired. The horizontal arms can, in one embodiment, be rotated and backed in place about a total of 180 degrees, or in one embodiment the range of human movement. In one embodiment there is only one stand alone stationary upright and only one resistance wheel with the ability to raise and lower. The handle/handles on the wheel are rotated using only one hand. As long as the seat can move toward and away from the resistance wheel and lock into place and swivel left and right and lock in place, this results in the ability to exercise the shoulders and arms to the range of normal human movement but will also be limited to exercising in a single plane (without angular variation).
[0036] As used herein the term “handle” refers to a device for grasping by the user during an exercise on an exercise machine. One skilled in the art knows how to make handles and if the device is a hand cycling (cardio spinning) type exercise machine where the handles rotate or weight lifting/training type device, those skilled in the art can adapt handles based on the disclosure herein and standard exercise machine handles. The device can be for use by both hands/feet or just one hand or foot.
[0037] As used herein the term “adjustable shaft” refers to a device that functions as a adjustable radius of the wheel extending from the center of the wheel to the handle. While turning the wheel: as the radius increases the amount of shoulder angle (shoulder movement) increases, as the radius decreases the shoulder angle (shoulder movement) decreases.
[0038] In the present invention, each handle and adjustable shaft is attached to an adjustment device. As used herein the “adjustment device” is a device attached/mounted to the upright arms which allows the adjustment of the position and movement of the attached handles in 6 degrees of freedom including configurations and variations thereof. Therefore, when hand cycling or the like, instead of the normal shoulder width apart straight forward direction of movement, the user can set the handles in combinations and various degrees of movement to exercise and strengthen all the muscles of the upper body and not just those connected with a straight movement. The 6 degrees of movement (up, down, right, left, toward and away plus any angular combination) is made possible by having each adjustment device operated with only one hand (using two hands at the same time means using two separate adjustment devices).
[0039] The adjustment device consists of a device that first can adjust and lock vertically relative to the uprights, second it is capable of adjusting and locking horizontally relative to the upright device, and lastly adjusting and locking rotationally around an axis that is perpendicular to the upright device.
[0040] As used herein the “adjustment and locking means” of the present invention can be one of several different types for mounting and locking on or relative to the upright. For example, a series of holes with a pin, such as a spring loaded pin, can be utilized where a guide slides on the upright, or in other embodiments a guide rod is mounted and the adjustment is made by sliding along a bar, for example, horizontally. Rotating devices can adjust rotationally via rotation around a central axle.
[0041] In one embodiment shown in the drawings, the uprights are attached to a horizontal member on a lower portion of the uprights. In one further embodiment the horizontal end is attached to the bottom of the upright. The opposite end of the horizontal piece not attached to the upright is further capable of rotating around a central pivot point with two uprights. Each upright is attached to a pivot point and in one embodiment, the same pivot point.
[0042] Resistance for the machine can be of any established type currently in use for a hand driven wheel or foot cycling on an exercise machine, e.g. electric, magnetic, mechanical, etc. Such devices are well known. A device, such as a gas spring assembly or the like, is connected to a cable extending upward over the pulley attached on top of the vertical arm 3 , then extending downward and attaching to the top of the adjustment device 15 . The purpose of this is twofold 1) to provide a stabilizing lifting force so that the adjustment device can be safely raised and lowered and 2) by mounting it on the opposite side of the vertical arm and using a pulley one is able to substantially reduce the length size of the vertical arm.
[0043] In one embodiment of the present invention, the machine has a seat which is adjustable vertically, horizontally (toward and away from the stationary resistance wheel), and rotationally around a center pivot point of the chair.
[0044] The present device can be made from the traditional materials utilized to build exercise type devices. Therefore, structural steel for uprights or other frame components, plastic pieces, stainless steel, and the like all can be utilized.
[0045] The present device can be utilized especially for the exercise and treatment of a rotator cuff injury, shoulder problems or athletic training of the upper body. The present invention allows for more aggressive rehabilitation of the shoulder during a recovery phase or in a gym setting to build muscle and advance muscle tone and range of motion. Where a single arm is to be treated, only a single stationary upright support with attachments to raise and lower the adjustable device and a seat that swivels and locks into position would be all that is necessary (or the use of one of the handles of the two handle design shown).
[0046] In another embodiment the seat and or machine can be tilted back to push the user back into the seat more effectively during use. The present device then effectively shows greater precision control while exercising or while taking measurements (e.g. measure the progress of the rehabilitation).
[0047] Now referring to the drawings, FIG. 1 is a frontal view of an embodiment of the present invention with two handles, however, a single handle is also covered. Machine 1 comprises a pair of upright arms 2 which have a top end 3 and a bottom end 4 . The bottom end 4 is attached to distal end 5 of horizontal bar 6 . The proximal end 7 of horizontal bar 6 is attached to pivot point 8 . A system 10 joins each of the horizontal arms 6 in order to keep them aligned or adjusted. In this view a seat 11 embodiment is shown which is capable of up, down as well as tilting motions using the skill in the art for such mechanisms. Seat post 12 is shown in this view.
[0048] In this view only one adjustment device 15 is shown but in practice there would be one on each upright 2 adjusted in mirror image for use by both hands during exercise. For simplicity a cycling type machine for use in the treatment of a rotator cuff problem is shown but clearly other versions could be made from this disclosure and examples. In one embodiment, and using the same adjustable device on a single stationary upright support with the ability to raise and lower and with a seat that can swivel left and right and lock into position makes possible the 6 degrees of freedom found including combinations and variations for normal human movement, the same as on the two adjustable device machine.
[0049] Adjustment device 15 is divided into two parts A and B. A consists of a vertically adjusting bracket 16 which slides up and down upright 2 and held in place, i.e. locked, by any means such as holes in the upright and bracket through which a pin, such as a spring loaded pin, is placed. This bracket extends away from the upright 2 and is bent downward at both ends supporting two horizontal bars 18 . There are two small brackets on the main bracket 16 . The first bracket 14 is closest to the user which supports the placement of the vertical locking pin, the second small bracket is a connection point 36 on the top of main bracket 16 and toward the middle (balance point) for attachment to the cable and counterweight system. B consists of device 17 which rides horizontally along the two bars 18 (the two bars pass through device 17 ). Device 17 is attached to large bracket 19 which is bent downward at both ends to support axle 20 at both ends. Axle 20 can rotate at both connections with bracket 19 . Axle 20 is connected (no movement) to rotational device 21 and mounting box 25 on the front end (users end) and on the opposite end to mounting box 25 . A horizontal pin placement extending through bracket 19 using the pin hole provided 29 a on the front end and into a corresponding receiving hole 29 on the rotational device 21 will secure the rotation of the mounting box 25 around the axle 20 (other figures more clearly depict this aspect of the embodiment).
[0050] The handle 22 is used by the person exercising and in this embodiment is turned in a circular means for a cycling type exercise. It is connected to an adjustable shaft 23 and into a through adjustment/locking device 24 which will allow the shaft to change lengths and be locked into place with a pin type connection. It is mounted to mounting box 25 which provides resistance by an internal resistance device (within the skill of the art).
[0051] FIGS. 2 a , 2 b and 2 c depict the rotationally adjusting and locking device 21 from a side view so that its operation can more easily be seen. In FIG. 2 a vertical bracket 16 can be seen attached to upright 2 . Holes 27 are aligned on both the bracket 16 and upright 2 and locking pin 28 inserted to hold bracket in place. Rotational device 21 has multiple holes 29 which match to a hole 29 a in the horizontal bracket 19 and by use of a pin, such as a spring loaded pin, can be held in various positions as shown in FIGS. 2 a , 2 b and 2 c . Accordingly, handle 22 is placed in different positions based on the position of the rotational device 21 . Note that in this view, the rotational device axle 20 can be seen in which the device 25 can rotate clockwise or counter clockwise around 20 and be pinned in place, the device B 25 also moves horizontally (forward or backward) along support tubes 18 and pinned in place using a pin, such as a spring loaded pin, extending through bracket A 14 and into the receiving holes on bracket B 19 .
[0052] FIG. 3 is a top view showing the horizontal arms 6 each attached to a bar/pivot point 8 which allows the L shaped upright/horizontal bar combination to rotate according to arrows 30 and locked into place with a pin. Foot rest 31 can also be seen and the seat 11 has been removed for clarity but seat post 12 from a top view is shown. The top of the adjustment device is also shown showing the bracket A 14 for the pin placement into receiving holes B 26 to lock the horizontal movement. Bracket 36 is also shown for the cable attachment on the opposite side of the gas spring assembly.
[0053] The counterweight consists of a small connection bracket 9 toward the bottom of the upright 2 . A gas spring assembly 33 or the like with connector 32 is attached to bracket 9 . The movable end of the gas spring assembly extends upward where it connects with cable 34 . The cable extends upward over the pulley 35 and down to the adjustment device 15 . The attachment for the cable on the adjustment device can be found on bracket 16 toward a balance point and labeled bracket 36 .
[0054] Those skilled in the art to which the present invention pertains may make modifications resulting in other embodiments employing principles of the present invention without departing from its spirit or characteristics, particularly upon considering the foregoing teachings. Accordingly, the described embodiments are to be considered in all respects only as illustrative, and not restrictive, and the scope of the present invention is, therefore, indicated by the appended claims rather than by the foregoing description or drawings. Consequently, while the present invention has been described with reference to particular embodiments, modifications of structure, sequence, materials and the like apparent to those skilled in the art still fall within the scope of the invention as claimed by the applicant. | The present invention relates to an exercise machine for setting exercise in six degrees of motion. In particular, it exercises the shoulder more thoroughly and quickly than previously available. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention refers to an air bag collision safety device (air bag) for the occupants of a vehicle with an air bag being inflatable by means of a compressed gas source. Said compressed gas source can be a gas pressure cartridge, a gas producer cartridge or the like.
2. Description of Prior Art
An air bag of this kind is already known for instance from the German patent publications 36 44 554, 32 35 176 or 21 52 902.
In the solutions mentioned above, the air bag is inflated in case of a collision. Then it remains in this inflated state. If the gas contained in the air bag cannot be discharged, the immersion of the body in the air bag due to an accident is relatively hard.
A further problem consists in the fact to, on the one hand, inflate the air bag as quick as possible and, on the other hand, to not overstretch and destroy it thereby as a result of the quick inflation. For this purpose it has already been known to fire two propellant charges with a time delay, i.e. to inflate the air bag in a distance of time of e.g. 15 millisec. at first partially and then completely. The use of two compressed gas sources which must be opened in an exactly defined distance of time, requires an enormous expenditure.
SUMMARY OF THE INVENTION
It is an object of the present invention to render possible a soft immersion of the body into the air bag.
It is a further object of the invention to simplify an air bag with a still quick and reliable inflation.
This problem is solved according to the invention by an outlet valve being arranged between the air bag interior and the ambiance, said outlet valve opening when a predetermined pressure difference between the air bag interior and the ambiance is exceeded. The pressure difference required for the opening of the outlet valve is determined such that it is exceeded when the body immerses in the air bag. Through the outlet valve, a predeterminable amount of gas can escape, thereby rendering possible a soft immersion of the body in the air bag.
A further advantage obtainable with the invention is the fact that the air bag also shows a reliable effect in case of several subsequent collisions. It has already been known to provide a gas passage in the air bag, which permits that the air bag is completely inflated once but which then immediately allows the gas to escape from the air bag so that the air bag collapses and is no longer available for a further collision. According to the solution of the invention, during the first immersion of the body in the air bag the outlet valve is opened. As soon as the first immersion is terminated, the outlet valve is closed, and the gas in the air bag at this point of time remains therein so that it is available for a possible subsequent collision for the protection of the body. Also in this subsequent collision, the outlet valve opens during the immersion of the body so that also during the second and possible further collisions a soft immersion of the body in the air bag is rendered possible. With respect thereto, in the preknown gas passage the gas only remained in the air bag for about 40 to 50 millisec.. After expiration of this period of time, the air bag was ineffective. The period of time of 40 to 50 millisec., however, is not enough to cover several subsequent collisions. According to the solution of the invention, only that amount of gas escapes the air bag which is displaced by the respective immersion in the air bag in order to enable a soft immersion.
A further advantage to be achieved by the invention is the fact that also at high outside temperatures a destruction of the air bag is prevented. At relatively high outside temperatures, more gas is supplied to the air bag. This results in the risk that the air bag may be destroyed or torn. By the outlet valve provided according to the invention, the destruction of the air bag is avoided. The gas additionally supplied to the air bag due to the increased outside temperatures can be discharged therefrom through the outlet valve.
By the solution according to the invention it is rendered possible that no longer two compressed gas sources must be fired in the defined distance of time from each other, but that the air bag can also be inflated quickly and reliably by a single compressed gas source; however, there can still be used two compressed gas sources, which are fired at a distance of time. The outlet valve produces the effect that after a certain period of time the pressure in the air bag can be reduced. Said period of time can be predetermined. It is for instance possible to open the outlet valve after 10 to 15 millisec. (the smaller the air bag volume, the shorter the given period of time should be chosen). By the relief effected by means of the outlet valve, a destruction of the air bag is avoided. Nonetheless, the air bag is quickly and completely inflated.
Advantageous embodiments of the invention are described in the subclaims.
The given pressure difference preferably is 1 bar. At an ambient pressure of approximately 1 bar, this corresponds to a pressure of 2 bar in the air bag. When the given difference pressure is too low, there is the risk that during the immersion too much gas escapes so that for the subsequent collisions there is no longer a sufficient amount of gas. When the given pressure difference is chosen too large, the damping effect during immersion of the body in the air bag may be too low. Consequently, when determining the pressure difference for the outlet valve, a compromise must be found between the pressure loss or gas loss on the one hand and the dampening effect during immersion on the other hand.
It is advantageous when at first the outlet valve is completely closed and only activated after actuation of the compressed gas source, preferably after a predetermined period of time after actuation of the compressed gas source. When the outlet valve is at first completely closed, first of all after actuation of the compressed gas source the air bag can be completely inflated undisturbed. During this time the outlet valve is still not activated, i.e. it acts like a closed wall. The result thereof is that the given difference pressure is infinitely large. However, it can also be sufficient, if the given difference pressure is very large.
Only after actuation of the compressed gas source, the outlet valve is activated. When activated, the valve can operate as an outlet valve with a given pressure difference. Said activation is preferably carried out after a predetermined period of time following the actuation of the compressed gas source. Said period of time is chosen such that on the one hand there is sufficient time for a complete and undisturbed inflation of the air bag and, on the other hand, for an activation of the outlet valve as early as possible in order to enable a soft immersion of the body as soon as possible.
The outlet valve is preferably activated 30 millisec. after the actuation of the compressed gas source. Generally, 30 millisec. are sufficient for completely inflating the air bag.
According to a further advantageous development, the outlet valve is activated 10 to 15 millisec. after the actuation of the compressed gas source. After this period of time, the air bag has not yet been completely inflated. If only a single compressed gas source is used, and if the air bag is to be filled thereby quick enough, within a very short time a very high pressure is built up in the air bag which can result in an overstretching and in a destruction of the air bag material. If, however, the outlet valve is opened after 10 to 15 millisec., there is a pressure relief which prevents a destruction of the air bag, but it is nevertheless possible that the air bag is completely inflated by only one compressed gas source quickly enough without destruction.
According to an advantageous further development, two compressed gas sources are provided, the second compressed gas source being activated at a predetermined period of time of preferably 15 millisec. after the first compressed gas source. By the timely delayed actuation of two compressed gas sources, an especially quick and reliable inflation of the air bag is rendered possible without endangering the air bag or the air bag material, as is for instance described in the German laid-open print 31 50 297; however, the expenditure for the realization thereof is larger.
The outlet valve can be activated through a pyrotechnical triggering mechanism.
The outlet valve is preferably provided with a casing in which a valve rocker carrying a valve plate is guided for longitudinal movement thereof.
It is advantageous to provide the outlet valve with a closing plate at its side facing the air bag interior, said closing plate being preferably removable and/or destructible by a pin which is preferably drivable by a propellant. At first the closing plate is exclusively acting which effects a complete sealing of the outlet valve with respect to the air bag interior. After actuation of the compressed gas source the closing plate is removed or destroyed so that from this point of time on the outlet valve is activated. The pin removing or destroying the closing plate can be drivable by an electrically actuatable propellant. The compressed gas source is preferably constituted by a casing with an annulus. The annulus is preferably welded in an annular form on both sides. A center insert can be welded to the casing. It is advantageous to connect, preferably weld a closing plate (bursting disk) to the insert.
The casing can be disk-shaped. When the cross-section of the annulus, being preferably elliptic or like an ellipse, is smaller in the radial direction than in the axial direction, in case of a failure of the disk-like casing the occupant of the vehicle is protected. The disk-shaped casing is then destroyed in a radial direction so that parts being blown off do not endanger occupants of the vehicle sitting in axial direction in front of the casing.
Embodiments of the invention will now be described in the following with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a sectional view of a steering wheel with an air bag.
FIG. 2 shows an enlarged view of the gas distributor represented in FIG. 1.
FIG. 3 shows a sectional view taken along the line III--III in FIG. 2.
FIG. 4 shows a sectional view taken along line IV--IV in FIG. 2.
FIG. 5 shows an enlarged view of the outlet valve represented in FIG. 1.
FIG. 6 shows a sectional view through the aperture plate of the outlet valve according to FIG. 5.
FIG. 7 shows a sectional view of a disk-shaped casing receiving an annularly-shaped compressed gas source.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The vehicle air bag shown in FIG. 1 has gas pressure cylinders 1, 2 which are connected with the gas distributor 32 via the passages 31. From the other end of the gas distributor 32 passages 33 lead to the distributor nozzles 34. In the steering wheel 35 the folded air bag 3 is arranged below the tearing-open pad 12. For a co-driver air bag, the air bag is arranged behind a tearing-open pad in the instrument panel covering at the height at which otherwise the glove compartment is usually to be found. Additional lateral air bags can be provided in the doors.
If in case of an accident danger is indicated for the occupants of the vehicle, for instance by deformation of the car body, the compressed gas sources 1, 2 are fired subsequently with a time delay of 15 millisec.. From the compressed gas sources 1, 2, the compressed gas is supplied via the passages 31 and the gas distributor 32 as well as through the pressure lines 33 and the nozzles 34 to the air bag which is inflated thereby.
In FIG. 2 a gas distributor 32 is shown in an enlarged view. The gas distributor 32 consists of a first distributor disk 41 fixedly arranged at the vehicle and a second distributor disk 42 fixedly arranged at the steering wheel which between them confine a distributor interior 43. There are provided two gas passages 31 and four gas passages 33 as can be seen from FIG. 3 and 4. The compressed gas sources 1, 2 are fixedly arranged at the vehicle outside of the steering wheel 35. The first distributor disk 41 is connected with the steering wheel covering. The gas distributor 32 surrounds the steering column 17 annularly. The partial pressure passages 31 from the compressed gas sources 1, 2 to the first distributor disk 41 partially extend in the steering wheel covering 19. The lower distributor interior 43 belonging to the first distributor disk 41 is of an annular shape (see FIG. 3), the upper distributor interior space 43 belonging to the second distributor disk 42 consists of four annularly shaped partial spaces (see FIG. 4) which lead to one pressure passage 33, respectively. The distributor interior 43 is sealed by sealings 44. The mountings for permitting the relative movement of the first distributor disk 41 and the second distributor disk 42 are designated by the reference numeral 45.
Between the air bag interior 51 and the ambience 52 there is arranged an outlet valve 53 which is shown in FIG. 5 in an enlarged view. The outlet valve 53 is stationary and sealingly connected with a plate 54. The plate 54 is arranged fixedly at the steering wheel.
As shown in FIG. 5, the outlet valve 53 has a substantially cylindrical casing 55 in which a plate 56 with apertures 57 is mounted spring-biased and for a longitudinal movement thereof. The apertures 57 are arranged in the aperture plate 56 along an arc of a circle (see FIG. 6). In the casing 55 a valve rocker 59 carrying a valve plate 58 is guided for a longitudinal movement thereof. The outlet valve 53 has a closing plate 60 at its side facing the air bag interior 51, said closing plate 60 being closely and sealingly connected with the casing 55. At first, the closing plate 60 completely seals the air bag interior 51; the outlet valve 53 is not yet activated and therefore ineffective.
30 millisec. after firing of the first compressed gas source 1 and thus 15 millisec after firing the second compressed gas source 2, the closing plate 60 is destroyed. This is carried out by the pin 61 which is propelled upwards by the propellant 62 so that it bursts through and destroys the closing plate 60. Thereby the outlet valve 53 is activated. The propellant 62 can be electrically fired through wires 63.
After the removal of the closing plate 60 and thus after the activation of the outlet valve 53, the pressure in the air bag interior 51 acts on the upper side of the valve plate 58 via the apertures 57. Upon the lower side of the valve plate 58, the ambient pressure is acting. The difference pressure required for the opening of the outlet valve 53 is given by the force of the spring 64. Said spring 64 is supported below at a heel of the casing 55 and above at the aperture plate 56. The aperture plate 56 is fixedly connected with the valve rocker 59. At the upper outer annular surface of the valve plate 58 there is the washer 65 sealing the valve plate 58 with respect to the casing 55. When the difference pressure is large enough, the spring 64 is compressed so that the valve plate 58 is lifted off the casing 55. Then gas can escape out of the air bag interior 51 through the apertures 57 between the casing and the valve plate 58. By the gas outlet valve 53 there is rendered possible a gas displacement in the air bag, if a person is hurled against the air bag. By the escape of gas due to the displacement resulting from the body weight the air bag material can relax and a relatively soft immersion in the air bag is possible. The gas outlet valve is preferably actuated by computer control via a pyrotechnical firing system. It is closed when the gas is supplied to the air bag and is only opened after expiration of 28 to 30 millisec. to relax the material when the body immerses in the air bag. A repeated immersion of the body in the air bag due to an accident is possible without any risk; the support forces are reduced.
FIG. 7 shows a cross-section through a disk-shaped casing 71 which is substantially rotationally symmetrical around the axis 72. In the disk-shaped casing there is an annulus 73 which has the form of a torus. The apertures 74 which are conical in the cross-section and circular in the top plan view are completely welded and then grinded at the surfaces of the casing. Prior to the welding the torus-shaped annulus 73 can be produced through the apertures 74. Then said apertures 74 are completely welded and sealed thereby. A radial bore 75 leads to the interior 76 in which there also is compressed gas. In the casing 71 there is a center insert 77 which is welded with the casing 71 through a weld seam 78 being annularly shaped when seen from above. In a center heel of the insert 77 there is a closing plate 79 being welded 80 with the bottom surface of the heel in the insert 77.
From this description it follows that the inner space constituting the compressed gas source and comprising an annulus 73 and an interior space 76 is completely sealed by weldings. Therefore, special sealings are unnecessary. The space occluding the compressed gas is formed by two parts, namely by the casing 71 and the insert 77. The casing 71 and the insert 77 are welded with each other (weld seam 78). Also the apertures are welded: The apertures 74 of the casing 71 are welded, and also the closing plate 79 which covers the opening 81 of the insert 77 is welded to said insert 77 (reference numeral 80). Special sealings are unnecessary.
The casing 71 has a disk shape. Its height h is substantially lower than its diameter d. The cross-section of the annulus 73 is substantially elliptical. The extension of the annulus cross-section is smaller in radial direction x than in the axial direction y. If the pressure in the annulus 73 becomes too large, the casing 71 will fail in the radial direction x and not in the axial direction y. Since the occupant of the vehicle is seated in axial direction of the casing 71, he or she cannot be hit by broken pieces blown off in radial direction.
In the bottom of the housing 71 a bore 82 can be provided which conically extends towards the interior 76. In said bore 82 a locking pin 83 having the same form can be inserted When filling the compressed gas space 73, 76, the pin 83 is substantially hold in the position as shown in FIG. 7. After filling, the pin 83 is retracted, i.e. removed to the outside (in the representation of FIG. 7 downwards). Said movement is supported by the pressure existing within said interior space 76 (for this purpose the locking pin is conically extended; consequently, the end surface 84 is larger than the remaining cross-sectional surface of the locking pin 83). The locking pin 83 can be welded after the complete filling of the compressed gas space 73, 76, as indicated by the reference numeral 85.
A firing housing 86 is arranged in the insert 77. Said firing housing 86 is screw-connected through a thread 87 with the insert 77. In the firing housing 86 there is a hollow space 88 filled with a propellant (not shown in the drawing). The propellant can be fired through electrical connection wires (also not shown in the drawing). Then it propels a pin not shown in the drawing according to FIG. 7 through the bore 89 towards the closing plate (bursting disk) and therethrough. The closing plate 79 is destroyed and causes the compressed gas to be blown into the air bag (not shown in the drawing according to FIG. 7) via the annular path 90.
The embodiment shown in FIG. 7 permits an especially small and space-saving realization of a compressed gas container for an air bag. This is obtained by the fact that the space for the compressed gas is designed as an annulus and is annularly welded at the end surfaces of the disk-shaped casing. In a practical example, 33 normal liters of helium are filled into the volume of a total of 51 cma. The helium has a pressure of 700 bar at a temperature of 20° in the casing or in the compressed gas space. When heating the casing up to 80° C., the pressure is increased to 900 bar. Concerning safety regulations, the casing is designed for a maximum pressure of 1350 to 1400 bar. | An air bag collision safety device (air bag) for the occupants of a vehicle has an air bag (3) being inflatable by means of a compressed gas source (1, 2). In order to render possible a soft immersion of the body in the air bag (3), between the air bag interior (51) and the ambiance (52) an outlet valve (53) is arranged which is opened when a predetermined pressure difference between the air bag interior (51) and the ambiance (52) is exceeded (FIG. 1). | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Continuation of U.S. patent application Ser. No. 12/054,742, filed Mar. 25, 2008 (now abandoned), which is a Divisional of U.S. patent application Ser. No. 11/055,126, filed Feb. 9, 2005 (now U.S. Pat. No. 7,368,646, issued May 6, 2008). The entirety of all the above-listed applications are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to stringed musical instruments and in particular stringed musical instruments which include components made from glass materials. Specifically, a stringed musical instrument is disclosed where both ends of the strings touch glass.
BACKGROUND OF THE INVENTION
A variety of stringed instruments are well known for producing musical notes. In these musical instruments, a string is held between two points. The string is caused to vibrate. Vibration of the string causes the production of a musical sound.
A common stringed musical instrument is the guitar. Other stringed instruments are orchestral instruments and include the viola, violin, cello, and base. Many stringed instruments include a finger board, which is typically a long strip of wood against which strings are pressed during play of the instrument. On guitars, the finger board is fitted with small frets against which the strings are pressed so as to produce different musical notes when the strings are plucked on strummed. In violins and cellos, however, the finger board does not include frets. Thus, the musician presses the string against the finger board at exactly the right location so that, when the string is caused to vibrate, the string will produce a note at the desired frequency.
In the guitar and in the orchestral instruments, the strings produce notes by being plucked or strummed. Furthermore, in the orchestral instruments, those instruments produce sound by rubbing a bow against the strings. This causes those strings to vibrate.
A further well known stringed instrument is the piano. In the piano, strings are held taunt between two locations. To produce musical notes, keys are depressed which actuate hammers, which, in turn, strike the strings. By striking the strings with the hammers, the strings produce musical notes.
An interesting guitar is known thanks to the work of musician Ned Evett. In the Evett guitar, the finger board is made of glass. Furthermore, the finger board does not include frets. Thus, for the guitar to produce the correct notes, the guitar strings are pressed by fingers against the glass finger board at exactly the right locations.
SUMMARY OF THE INVENTION
A stringed musical instrument includes a string which, when vibrated, produces sound. Both ends of the vibrating portion of the string touch glass.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a peg head and a portion of a stringed instrument neck in accordance with an exemplary embodiment of the present invention.
FIG. 2 is a side view of a tuning peg, in accordance with a further exemplary embodiment of the present invention.
FIG. 3 is a cross-sectional view of cross-section 3 - 3 of FIG. 1 .
FIG. 4 is a side view of a musical instrument neck.
FIG. 5 is a cross-sectional view of section 5 - 5 of FIG. 1 .
FIG. 6 is a top view of a portion of a body of a musical instrument in accordance with an exemplary embodiment of the present invention.
FIG. 7A is a partial side view of the musical instrument body shown in FIG. 6 .
FIG. 7B illustrates a string in accordance with an exemplary embodiment of the present invention.
FIG. 8 is a top view of a musical instrument body in accordance with a further exemplary embodiment of the present invention. This further exemplary embodiment includes pickup coils.
FIG. 9 is a cross-sectional view of section 9 - 9 of FIG. 8 .
FIG. 10 is a top view of an orchestral stringed instrument in accordance with an exemplary embodiment of the present invention.
FIG. 11 is an interior view of a portion of a hammer actuated musical instrument.
DETAILED DESCRIPTION OF THE INVENTION
Detailed views of several exemplary embodiments of the present invention are illustrated by FIGS. 1-11 .
In order to simplify this explanation, exemplary embodiments of the present invention will be described with reference to a guitar. Subsequently, a brief explanation will be made which relates to the present invention when used with orchestral stringed instruments.
The methodology for making stringed musical instruments, such as guitars, is well known in the art, and the specifics of how such stringed musical instruments is made will not be described here. For a general description of the manufacture of guitars, the publication Koch, Martin, Building Electric Guitars, 2001 (ISBN 3-901314-07-5) is incorporated by reference for its teachings regarding the manufacturer of a guitar. The aforementioned publication provides information on how a guitar is built. The following description refers to modifications to the prior art process of manufacturing musical instruments.
FIG. 1 is a top view which illustrates an exemplary embodiment of the present invention. In FIG. 1 , a portion of guitar 10 is shown. Guitar 10 includes peg head 15 . A plurality of tuning pegs 56 are coupled to peg head 15 . Each peg 56 is also coupled to respective knob 54 . By turning knob 54 , tuning peg 56 also rotates.
In an exemplary embodiment of the present invention, peg 56 includes peg shaft 50 and shaft cover 52 secured thereon. Shaft cover 52 may include glass materials. The use of shaft cover 52 is optional. This is shown in FIG. 2 .
Coupled to each tuning peg 56 is respective string 20 . String 20 may engage page 56 through a hole formed thereon. Thus, by rotating knob 54 , the tension on respective string 20 can be increased and decreased.
Some portions of the interface between knob 54 and tuning peg 50 are not shown in FIG. 1 . This interface, however, is understood to one of ordinary skill in the art.
Moving from tuning peg 56 , each string 20 is in contact with bridge 22 . In an exemplary embodiment of the present invention, bridge 22 is a glass component.
Suitable glass components that can be used to manufacture bridge 22 are known in the art. An exemplary glass component is made of Pyrex and is manufactured by Corning Glass Company of Corning, N.Y. As another example, bridge 22 can be formed from a glass resin composite. Such a composite, for example, is described in U.S. Pat. No. 6,657,113 which is incorporated by reference for its teachings on molded frets. It is understood that other methodology for molding components that include glass are known to one of ordinary skill in the art.
After stretching across bridge 22 , each string 20 proceeds along a board unit which is represented in FIG. 1 as neck 30 . As string 20 proceeds along neck 30 , string 20 stretches across frets 34 . When playing the musical instrument, fingers, for example, are used to press strings 20 against neck 30 so that one or more strings 20 touch one or more frets 34 .
In an exemplary embodiment of the present invention, fret 34 also includes glass materials.
FIG. 3 is a cross-sectional view of neck 30 taken along section line 3 - 3 of FIG. 1 . In FIG. 3 , cross-sections of strings 20 are shown suspended over neck 30 . Because strings 20 are suspended over neck 30 , top air gap 32 may be defined. Below top gap 32 , glass tile 36 may be found to form a finger board. Glass tile 36 includes extension members 42 . Extension members 42 may engage tile holder 33 using, for example, a compression or a friction fitting. Tile holder 33 may be made of a variety of materials including, but not limited to, hardened rubber. Tile holder 33 may be coupled to neck base 31 . Neck base 31 can also be made of a variety of materials including, but not limited to, wood. Bottom air gap 44 is defined by the space between tile 36 and tile holder 33 .
FIG. 3 illustrates neck 30 according to one exemplary embodiment of the present invention. In an alternative embodiment of the present invention, neck 30 is made of another material such as, for example, wood. Thus, the exemplary embodiment illustrated in FIG. 3 is not intended as a limitation on the possible materials or configuration which may be used in manufacturing neck 30 .
FIG. 4 is a side view of neck 30 . As shown, neck 30 includes frets 34 . Thus, in one exemplary embodiment of the present invention, a specifically shaped orifice can be formed in the neck and each fret can be slid into the orifice. Alternatively, the frets can be situated in the neck using other methods that are known to one of ordinary skill in the art.
FIG. 5 illustrates a cross-sectional side view of neck 30 according to a further exemplary embodiment of the present invention. The cross-sectional view shown in FIG. 5 is taken along section line 5 - 5 of FIG. 1 .
In FIG. 5 , neck base 31 is again shown. Above neck base 31 may be optionally situated tile holder 33 . Glass tiles 36 and frets 34 are included. Extending from glass tiles 36 and frets 34 are extension members 42 . Again, extension members 42 may engage tile holders 33 using a force fitting or a friction fitting. Again, the embodiment shown in FIG. 5 is merely exemplary.
FIG. 6 illustrates body 26 of guitar 10 in accordance with the exemplary embodiment of the present invention. Strings 20 may stretch across optional opening 85 until they touch saddle fret 25 . Thus, saddle fret 25 touches strings 20 . Saddle fret 25 may include glass materials as has been previously described. After extending across saddle fret 25 , strings 20 may terminate at saddle 24 . Typically, as shown in FIG. 7A , there are openings formed in saddle 24 and a bulging section of each string 20 holds each string 20 in place relative to saddle 24 . Saddle 24 may also include glass materials.
An exemplary string is illustrated in FIG. 7B . The bulging section referred to above is formed by wrapping string 20 around circular member 27 (1 or multiple times) and then winding the trailing end of string 20 about itself. In an exemplary embodiment of the present invention, circular member 27 includes glass materials.
A further exemplary embodiment of the present invention is shown with reference to FIG. 8 . In the exemplary embodiment shown in FIG. 8 , pickup coils 60 are included. Pickup coils are also shown in FIG. 9 , which is a cross-sectional view of FIG. 8 taken along section line 9 - 9 . Coils 60 are situated above magnets 68 . Each magnet 68 is situated above pickup coil base 60 . The use of pickup coils is known to one of ordinary skill in the art.
As shown in FIGS. 8 and 9 , optional raised glass sections 62 are included. Optional raised glass sections 62 may be situated on opposite sides of pickup coil 60 and extend orthogonally from body 26 . In addition to optional raised glass sections 62 , further raised glass sections 64 may also be included. Further raised glass sections may also be situated on opposite sides of pickup coil 60 . Strings 20 thus may extend directly over further raised glass section 64 . Furthermore, in accordance with a further exemplary embodiment of the present invention, raised glass sections 62 may extend from body 26 higher (and optionally above the height of strings 20 ) then do further raised glass sections 64 .
As shown in FIG. 9 , glass including material may be used for other portions of body 26 . Thus, as shown in FIG. 9 , pickup coil 60 may be covered by encasement 67 (which may also include glass materials). Pick guard 65 may also include glass materials and may be situated between pickup coil 60 and an edge of body 26 . Other glass including materials may be used so that some or all of body 26 is covered with glass.
The above description as related to a guitar. The present invention, however, is equally applicable to other types of stringed instruments. FIG. 10 illustrates an orchestral stringed instrument (e.g. viola, violin, cello, base) in accordance with a further exemplary embodiment of the present invention. Orchestral instrument 80 differs from many guitars in that orchestral instrument 80 does not include frets. Also, orchestral instrument 80 includes bridge 82 . In an exemplary embodiment of the present invention, bridge 82 includes glass materials. Bridges for orchestral instruments are known to one of ordinary skill in the art.
FIG. 11 illustrates a further stringed instrument such as a piano. Thus, piano interior 70 is shown. Piano interior 70 includes hammer 72 which is actuated by operation of a key (not shown). Hammer 72 strikes string 20 . String 20 , at each end, is wrapped around tuning peg 56 . In accordance with a further exemplary embodiment of the present invention, tuning peg 56 includes a glass cover so that string 20 is in contact with glass material as it is wrapped around tuning pegs 56 . String 20 is held taunt by tension member 74 . In a further exemplary embodiment of the present invention, tension member 74 includes glass materials.
Strings in musical instruments are well known in the art and are typically made of nylon or metal (e.g. steel). Alternatively, in a further exemplary embodiment of the present invention, the strings may include glass materials, i.e. glass fibers.
While various musical instruments have been described, it is understood that many details of those instruments have not been explained, as those materials are known to one of ordinary skill in the art. Furthermore, it is understood that glass materials can be used in a variety of locations for the musical instruments that have been described.
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalence of the claims and without departing from the invention. | A stringed musical instrument includes a string which, when vibrated, produces sound. Both ends of the vibrating portion of the string touch glass. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for continuously dehydrating fabrics in rope form.
It is well-known that in order to perform the continuous dehydration of fabrics, wringing rolls are prevailingly used, which are commonly denominated "mangles" or "paddlers", and are arranged as pairs through which the fabrics, by being squeezed between the rolls, undergoing a wringing which causes the expulsion (as a function of applied pressure values) of large portion of the liquid which soddens the fabrics.
Other, less diffused systems, provide for the fabrics to slide above one or more pipe(s) equipped with holes or slots, through which a suction is drawn in order to remove most liquid contained in the fabric.
Both of these systems can be advantageously used in order to treat fabrics in open-width form, but they yield very poor results when they are used in order to dehydrate fabrics in rope form, in that the shape of the fabric in rope form is not very suitable for an efficacious expulsion of the liquid either by simple wringing or by suction.
Therefore, in order to dehydrate fabrics in rope form batchwise systems are often used, such as, e.g., basket centrifuges into which a batch of fabric is charged and then, when the centrifugation is ended, is discharged from the centrifuge. One will realize that these batchwise systems, although more achieving satisfactory results as regards the amount of liquid extracted from the fabric per unit weight, are however more time consuming and require more burdensome means in order to charge and discharge the fabrics to/from the centrifuges, and therefore are not very advantageous from an economical viewpoint.
SUMMARY OF THE INVENTION
The main purpose of the present invention is of providing a process and apparatus by means of which fabrics in rope form can be continuously dehydrated with decidedly better results than as obtainable by means of the continuous systems used to date, and, on the contrary, with results comparable to those presently obtainable in the dehydration of fabrics in open-width form.
Furthermore, with the present invention is advantageous from an economic viewpoint, thanks to the use of simple means in the realization of the apparatus and low costs and high efficiencies.
In order to achieve the above purposes, according to the present invention a process is provided for continuously dehydrating fabrics in rope form of the type in which the fabric is continuously advanced between at least two pairs of pressing rolls installed along a fabric advancement axis, which is characterized in that along the stretch between said two pairs of rolls, the fabric is submitted to a false twist.
Thanks to the twisting of the fabric besides the wringing of the same fabric by the rolls, a torsional wringing of the same fabric is accomplished along a certain stretch of its running path, with the result that the expulsion of a larger amount of liquid from the fabric is accomplished. By suitably varying the speed of revolution of the twisting organ relatively to the speed of linear advancement of the same fabric, the number of twists per unit length of fabric, and the tension of the fabric can be varied, with the result that a wringing action is obtained which is the better, the larger the number of twists, and the consequent necessary tension of the fabric.
Inasmuch as the fabric is submitted to a false twisting as it advances, downstream of the twisting organ the fabric resumes its initial, substantially linear shape owing to the effect of the untwisting which takes place downstream of the twisting organ.
Advantageously, the twisted fabric can be submitted to a centrifugation, with the degree of dehydration being consequently further improved.
In order to practice the process according to the present invention, an apparatus is proposed which comprises at least two pairs of pressing rolls installed along a fabric advancement axis, with at least the downstream pair of pressing rolls being suitable for dragging the fabric with a continuous motion, which apparatus is characterized in that between the two pairs of pressing rolls at least one twisting organ is provided, which is suitable for causing the fabric to rotate around the advancement axis, so as to give the fabric a false twist.
According to a further aspect of the present invention, the twisting organ can be combined with a centrifugation unit, suitable for centrifuging the twisted fabric. Such a unit can be constituted by a revolving structure which defines for the fabric a running path comprising one or more stretches parallel to the twisting axis and spaced apart from it. In that way, the fabric undergoes the action of centrifugation along its running path, and in particular along said parallel stretches. The revolution of the whole centrifugation unit makes it possible for the fabric to be automatically maintained in its twisted condition until it leaves the unit by again running along its advancement axis.
The apparatus is particularly simple from the structural viewpoint and in particular in its form of practical embodiment equipped with the centrifugation unit it makes it possible to obtain a very high dehydration rate, comparable to that which can be obtained by means of the presently available padders, or the like, used on fabric in open-width form.
Further details and advantages of the present invention will become more apparent from the following disclosure of the invention, and of preferred forms of practical embodiments thereof, as illustrated for exemplary purposes in the hereto attached drawings, to a period (.).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows in schematic form a first embodiment of an apparatus according to the present invention;
FIG. 2 shows another embodiment of an apparatus of the invention equipped with the centrifugation unit;
FIG. 3 illustrates another embodiment of the invention equipped with the centrifugation unit;
FIG. 4 and 5 schematically show the path of the fabric in two further embodiments of an apparatus according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a fabric 1 in rope form is caused to run through a first pair of pressing rolls 2, not necessarily driving rolls, made as splined rolls in a per se known way and provided with an elastic coating, in order to press the fabric 1 running between them.
At a certain distance downstream of the rolls 2 a twisting organ 3 is installed, which is substantially constituted by a revolving structure 4, supported by bearings 5 coaxially with the axis of advancement of the fabric 1 in rope form and rotatably carrying a pair of pressing twisting rolls 6 having their revolution axis perpendicular to the axis of advancement of the fabric 1 and spaced apart from each other substantially in the same way as of the rolls 2. The rolls 6, which can be of the same type as of the rolls 2, can be mounted idling, motor-driven, or sightly braked. The rotary structure 4 can be driven to revolve around the axis of advancement of the fabric 1 by means of a motor 7 through a belt transmission 8, 9, 10. The structure 4 is provided with an axial through opening 11 for the fabric 1.
Downstream the twisting organ 3, at a certain distance from it, which can advantageously be on the order of the distance between the twisting organ 3 and the first pair of rolls 2, a second pair of pressing rolls 12 are installed, which can be the same type as of the rolls 2 and are driven to rotate by a motor in at a revolution speed related to the revolution speed of the twisting organ 3. The rotation of the rolls 12 causes the fabric 1 to continuously advance between the pairs of rolls 2 and 12 and through the twisting organ 3 and the revolution of the twisting organ 3 around the axis of advancement of the fabric 1 causes the fabric 1 to rotate around said axis, causing a twisting of the fabric 1 to take place between the rolls 2 and the twisting organ 3, the effect of which twisting is of wringing said fabric 1 which undergoes hence an efficacious continuous dehydration.
Downstream the twisting organ 3 the running fabric 1 undergoes a twisting contrary to the twisting it underwent upstream the same organ, with this untwisting compensating for the twists supplied to the fabric in rope form along the upstream stretch, and returning it to its original, untwisted condition, but with a content of liquid which is substantially smaller than the original liquid content. Thus, the fabric undergoes a false twisting along the stretch comprised between the roll pairs 2 and 12.
The revolution speed of the dragging rolls 12 is correlated with the revolution speed of the rolls 2 and this correlation is a function of the tension and elasticity of the fabric 1. The inlet roll pair 2 can be either driven to revolve at a smaller speed than of the outlet rolls 12 or, preferably, is submitted to a braking action, with the effect being that of causing a tension to arise in the fabric which is twisted by the twisting organ 3, while the fabric is being pulled by the rolls 12.
It should be observed that the length of the stretch between the inlet rolls 2 and the twisting rolls 6 is immaterial for the purposes of the twisting/untwisting equilibrium, and is meaningful as regards the time the fabric 1 remains under twisted conditions. For example, if such a length is assumed to be 1meter and if the fabric is caused to advance at the advancing speed of 30 meters/minute (i.e., of 0.5 meters/second), the hold time of the fabric in the twisted state will be 1/0.5=2 seconds.
By properly adjusting the ratio of the advancement speed of the fabric 1 to the number of revolutions of the twisting organ 3 around the twisting axis, the number of twists can be reached, which are suitable for submitting the same fabric to an efficacious wringing for dehydration purposes. The efficiency of wringing is limited by the value of the tension the fabric can withstand and which has to be applied to the fabric 1 along the stretch between the roll pairs 2 and 6. This tension, which depends on the nature of the fabric, is essential in order to counteract the effect of shortening of the fabric 1 due to the twist formed therein. In fact, in the absence of such a tension, entanglement of the fabric would occur.
Tests indicate that the number of applicable twists is first of all a function of the weight of the fabric 1 per linear meter, as well as of the nature and composition of the fabric 1. In general, the maximum applicable number of twists per meter increases with decreasing weight per linear meter of the fabric 1.
According to the invention, the twisted fabric 1 can be submitted to a step of centrifugation, which causes a further efficacious dehydration of the fabric. For that purpose, some forms of practical embodiment of the apparatus according to the present invention are shown in FIGS. 2-5 for exemplifying purposes, in which the twisting organ is combined with a fabric centrifuging unit. For equal or equivalent elements, the same reference numerals are used.
On considering the example shown in FIG. 2, a centrifugation unit 13 is rotatably supported between two supports 14 and 15 and is essentially constituted by guide means for guiding the fabric 1, e.g., in the form of a tube 16 having a generally bent "S"-shape, with two stretches 17 substantially parallel to the revolution axis and spaced apart from it, and with an inlet stretch 18, a connection stretch 19 and an outlet stretch 20 generally running in radial direction. The fabric enters the tube 16 and leaves it, respectively through axial openings 21 and 22 provided through support flanges 23 and 24 at the ends of the tube 16. The revolution of the centrifugation unit 13 is obtained, e.g., by means of a motor 25 through a belt transmission 26. Along the stretches 17 openings 27 are provided on the external side of the tube in order to allow the expelled liquid to escape.
Inside the interior of the tube 16 fabric guide rollers 28 can be installed, which are suitable for guiding the fabric 1 along the bends, and for reducing friction. The speed of advancement of the fabric 1 is determined by the pair of dragging, outlet rolls 12, corresponding to the outlet rolls 12 of FIG. 1. The inlet rolls 2 are arranged and operate in the same as shown in the example of FIG. 1.
As one can see from FIG. 2 of the drawing, the revolution of the unit 13 around the axis of advancement of the fabric 1 automatically causes the twisting of the fabric, owing to the change in direction of the advancing fabric, and to the moving away thereof from its advancement axis after the same fabric entering the centrifugation unit 13, with said fabric being consequently obliged to rotate around the axis of the centrifugation unit 13. Only when the fabric 1 leaves the unit 13, and returns back to advance along its feeding axis--coincident with the axis of revolution of the centrifugation unit--the reversal of the twisting direction takes place, causing the fabric to be totally untwisted. The same effect would take place in case one single stretch 17 is used.
The time during which the fabric is submitted to the torsional wringing depends on the length of the path inside the tube 16 and on the advancement speed of the fabric.
The time during which the fabric is submitted to centrifugation essentially depends, on the contrary, on the length of the peripheral stretches 17 of the centrifugation path, besides the advancement speed of the fabric.
Therefore, in relation with the limits imposed by the maximum acceptable number of twists, the fabric advancement speed and the revolution speed of the centrifugation unit can be selected as a function of optimum characteristics of dehydration or as a function of the installation of the dehydration apparatus in a continuous treatment line.
The value of the centrifugal force the fabric is subjected to will obviously depend on the radius of the peripheral stretches 17, and on the square of the revolution speed of the centrifugation unit 13.
In FIG. 3 a further form of practical embodiment is shown of the apparatus according to the present invention, which, with its overall dimensions substantially being the same as of FIG. 2, is provided with longer peripheral centrifugation stretches 17 and therefore, with the speed of advancement of the fabric, and the revolution speed of the centrifugation unit being the same, makes it possible to increase the centrifugation time, and hence increase the dehydration effect.
In order to prevent fabric crossing points between the radial stretches and the axial stretches of the fabric path, an odd number of peripheral parallel stretches 17 should be preferably accomplished, such as, e.g., as shown in FIGS 4 and 5, with such stretches being distributed on a cylindrical surface coaxial with the axis of the centrifugation unit, so that the peripheral stretches 17 may lay, together with the relevant radial stretches 18, 20 on planes convergent towards the axis of the centrifugation unit. It will be easily understood that, with the overall dimensions in the diametrical direction and the revolution speed being the same, the larger the number of the centrifugation stretches 17 the greater the dehydrating effect.
Advantageously, the motor means which drive the rolls 12 and possibly the rolls 2, as well as the motor means which drive the centrifugation unit 13 are adjustable, so as to adapt the apparatus from time to time to the optimum conditions as a function of the treated fabric.
Optimum results were obtained, e.g., with values of speed of advancement of the fabric on the order of 60 meters/minute and values of revolution speed of the centrifugation unit on the order of 600-700 rpm. The dehydration of fabric could be increased up to a percentage of about 80 parts by weight of residual liquid per each 100 parts by weight of dry fabric.
In order to make it possible the initial end of the fabric 1 to be slid into the centrifugation unit 13 up to reach the outlet of same centrifugation unit, along portions of the tube 16 or the set of channels which define the path of the fabric, openings will be provided.
Instead of the fabric guide rolls 27 an anti-friction coating can be provided inside the interior of the tube 16 or of the various channels, which is suitable for reducing the fabric sliding friction.
Of course, an apparatus could be provided which comprises a plurality of twisting organs 3, e.g., two twisting organs arranged between relevant pairs of pressing rolls, and generating opposite-direction twists.
As it results evident from the above disclosure, a process and apparatus according to the present invention make possible, with limited means and costs, an efficacious dehydrating action carried out in a continuous manner on fabrics in rope form within very short times, such that on fabrics in rope form a dehydration is obtained, which is of the same order as of the dehydration obtainable to date on fabrics treated in open-width form only. | The dehydration process substantially consists in causing the fabric in rope form to continuously advance between at least two pairs of pressing rolls, with it being simultaneously submitted to a false twisting. The false twist causes a wringing of the fabric with the consequent partial evacuation of the liquid the fabric is sodden with. In order to improve the dehydration, a centrifugation of the twisted fabric is provided. The apparatus substantially comprises a twisting organ capable of giving a false twist to the running fabric. The twisting organ can be constituted by a revolving structure capable of causing the fabric to run along a path outside its advancement axis, with the fabric thereby simultaneously undergoing a twist and a centrifugation. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image heating apparatus suitable for use as a heat-fixing apparatus mounted on an image forming apparatus, such as a copier or printer. In particular, it relates to an image heating apparatus having heating means which contacts an outer peripheral surface of a “roller contacting a toner image”.
[0003] 2. Related Background Art
[0004] Of image heat-fixing apparatus to be mounted on image forming apparatus, those of a heat roller type and a film heating type are in practical use.
[0005] Typically, the heat roller type involves pressing a fixing roller (heat roller) containing a heat source, such as a halogen lamp, against a pressure roller to form a nip portion that feeds a recording material. The heat source in the fixing roller is controlled based on the temperature detected by a temperature detecting element provided on an outer peripheral surface of the fixing roller. The heat-fixing apparatus of the film heating type comprise a film-like rotatable member (referred to as a film, hereinafter), a heater which contacts the inner surface of the film and comprises a heat-generating resistor on a substrate of ceramic or the like, and a pressure roller pressed against the heater with the film interposed therebetween, in which a recording material is fed between the film and the pressure roller to heat the toner image thereon. Such fixing apparatus have a temperature detecting element for detecting the temperature of the heater, and the heat generation by the heater is controlled based on the temperature detected by the temperature detecting element.
[0006] As described above, typically, in such apparatus, the turn-on of the heater is controlled to apply an adequate quantity of heat to the recording material.
[0007] In the case of the heat roller type, the temperature of the surface of the heat roller is typically controlled by measuring the temperature of the surface with temperature measuring means, such as a thermistor, which is brought into contact with the surface.
[0008] In the case of the film heating type, the temperature of the heater is controlled by detecting the temperature with a thermistor abutting against the heater.
[0009] However, the fixing apparatus of the heat roller type have a problem that the thermistor abutting against the fixing roller causes a scratch on the surface of the roller or a soil or the like on the thermistor impairs the image. To avoid the problem, the thermistor may be disposed out of the sheet-feeding area of the fixing roller. However, the temperature of the sheet-feeding area of the fixing roller is difficult to control because it cannot be directly detected. A temperature detecting element which does not contact the fixing roller may be used. However, the tradeoff is a higher cost. Besides, the fixing apparatus of the heat roller type have a basic problem that they have a high thermal capacity and require a long time to be activated to an operable state. On the other hand, in the fixing apparatus of the film heating type, since the thermistor is disposed in contact with the heater, it does not cause a scratch on the film surface. In addition, the fixing apparatus of the film heating type have a low thermal capacity, and, thus, require a shorter time to be activated to an operable state. However, if the film has no resilient layer, it is difficult to ensure a sufficient nip width and to heat the toner in a wrap-around manner. Therefore, they are not suitable for fixing a full-color toner image, although they are suitable for fixing a monochrome toner image. Besides, if the film has a resilient layer, there arises a problem that, because of the heat insulation by the resilient layer, the heater reaches its target temperature and stops generating heat before a sufficient quantity of heat is transferred to the film surface, so that the nip portion is not heated to a temperature suitable for fixing.
[0010] Thus, there has been devised a method of heating the fixing roller from the outside thereof (externally heating type) (eg. Japanese Patent Application Laid-Open No. H10-133505). According to this method, since heat can be supplied to the roller from the outside thereof, the temperature of the roller is highly responsive to the turn-on of the heater, and, thus, the activation time can be shortened.
[0011] However, if the temperature detecting means abuts against the roller surface, this method also has a problem of a scratch, soil or the like as in the heat roller type. In addition, the temperature of the fixing apparatus is difficult to control, and a disadvantage, such as hot offset of a toner image or fixability reduction, may occur.
[0012] Thus, there is a need for an image heating apparatus that has a short activation time and an adequate fixability for a full-color toner image and is insusceptible to scratch on the surface of a rotatable member contacting a toner image.
SUMMARY OF THE INVENTION
[0013] The present invention has been made in view of the problems described above, and an object thereof is to provide an image heating apparatus that is insusceptible to scratch on the surface of a rotatable member contacting a toner image and has a short activation time.
[0014] Another object of the present invention is to provide that is insusceptible to scratch on the surface of a rotatable member contacting a toner image and ensures an adequate fixability for a full-color toner image.
[0015] Another object of the present invention is to provide that has a short activation time and an adequate fixability for a full-color toner image and is insusceptible to scratch on the surface of a rotatable member contacting a toner image.
[0016] Another object of the present invention is to provide an image heating apparatus that is insusceptible to hot offset and fixability reduction.
[0017] Another object of the present invention is to provide an image heating apparatus for heating an image formed on a recording material, comprising:
[0018] first rotatable member;
[0019] said first rotatable member contacting second rotatable member, wherein the recording material bearing the image passes through a nip portion formed at a position between said first rotatable member and said second rotatable member;
[0020] heating means for heating said first rotatable member, said heating means including a third rotatable member that is flexible and a temperature detecting element, wherein the third rotatable member contacts an outer peripheral surface of said first rotatable member with the third member, wherein the temperature detecting elements is provided in an area of an inside surface said third rotatable member, wherein said first rotatable member and said third rotatable member contacts in the area; and
[0021] control means for controlling said heating means based on detecting the temperature of said temperature detecting elements.
[0022] Other objects of the present invention will be apparent by reading the following detailed description with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a cross sectional view of a fixing apparatus according to an embodiment 1 of the invention;
[0024] [0024]FIG. 2 is a schematic diagram showing an image forming apparatus on which an image heating apparatus according to the invention is mounted;
[0025] [0025]FIG. 3 shows a change of the temperature of a surface of a fixing roller measured at a point 0 in FIG. 1 in the case where a sheet of paper is fed after the fixing apparatus is warmed up and then energization to a heater is stopped;
[0026] [0026]FIG. 4 shows a change of the temperature of a surface of a fixing roller measured at the point 0 in FIG. 1 in the embodiment 1;
[0027] [0027]FIG. 5 is a cross sectional view of a fixing apparatus according to a Comparative Example 1;
[0028] [0028]FIG. 6 is a cross sectional view of a fixing apparatus according to a Comparative Example 2;
[0029] [0029]FIGS. 7A and 7B show changes of the surface temperature of the fixing roller measured at the point O in the Comparative Examples 1 and 2;
[0030] [0030]FIG. 8 is a cross sectional view of a fixing apparatus according to an embodiment 2;
[0031] [0031]FIG. 9 is a cross sectional view of a fixing apparatus according to an embodiment 3; and
[0032] [0032]FIG. 10 shows a process of an operation of the image forming apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] <Embodiment 1> (See FIGS. 1 to 6 , 7 A and 7 B)
[0034] (1) Example of Image Forming Apparatus
[0035] [0035]FIG. 2 is a schematic diagram showing an example of an image forming apparatus. The image forming apparatus according to this example is an electrophotographic full-color printer, and is a center-reference device in which the feeding reference for a recording material is the middle along the width of the recording material.
[0036] Reference numeral 11 denotes an electrophotographic photosensitive drum (image carrier) made of an organic photoconductor, which is rotated at a predetermined process speed (peripheral speed) of 120 mm/s in a direction as indicated by an arrow.
[0037] During rotation, the photosensitive drum 11 is uniformly electrified with predetermined polarity and potential by an electrifier 12 , such as an electrification roller.
[0038] The electrified photosensitive surface is scanned with a laser beam L emitted from a laser optical unit (laser scanner) 13 . This causes an electrostatic latent image associated with image information to be formed on the photosensitive drum. The laser optical unit 13 is to emit a laser beam L modulated (turned on/off) based on the image information from a computer or the like (not shown), thereby achieving scan-exposure of the photosensitive drum surface to the laser beam L. By the scan-exposure, there is formed an electrostatic latent image corresponding to the target image information on the scan-exposed surface of the photosensitive drum 11 . Reference numeral 13 a denotes a mirror that reflects the laser beam emitted from the laser optical unit 13 toward an exposure-target area of the photosensitive drum 11 .
[0039] In the case of forming a full-color image, scan-exposure and latent image formation are first performed on a first color component image of a target full-color image, for example, an yellow component image, and an yellow developer 14 Y of a four-color image forming apparatus 14 develops the resulting latent image to form an yellow toner image. The yellow toner image is transferred to a surface of an intermediate transfer drum 16 at a primary transfer portion T 1 , which is a portion where the photosensitive drum 11 and the intermediate transfer drum 16 are in contact with each other (or close to each other). Once the toner image is transferred to the intermediate transfer drum 16 , a cleaner 17 cleans residues, such as remaining toner, off the surface of the photosensitive drum 11 .
[0040] The process cycle including the electrification, scan-exposure, development, primary transfer and cleaning described above is sequentially performed on the remaining color component images of the target full-color image, that is, a second color component image (for example, a magenta component image, which is developed by a magenta developer 14 M), a third color component image (for example, a cyan component image, which is developed by a cyan developer 14 C), and a fourth color component image (for example, a black component image, which is developed by a black developer 14 BK). Thus, the yellow toner image, the magenta toner image, the cyan toner image and the black toner image are transferred onto the surface of the intermediate transfer drum 16 in a superimposition manner, thereby forming a composite color image corresponding to the target full-color image.
[0041] The intermediate transfer drum 16 comprises a metallic drum, a resilient layer of a moderate resistance and an outer layer of a high resistance. It is rotated in a direction indicated by an arrow at substantially the same speed as the photosensitive drum 11 in a state where it is in contact with or close to the photosensitive drum 11 . A bias potential is applied to the metallic drum to provide a potential difference between the photosensitive drum 11 and the intermediate transfer drum 16 , which causes the toner image on the photosensitive drum 11 to be transferred to the intermediate transfer drum 16 .
[0042] At a secondary transfer portion T 2 , which is constituted by a contact nip portion between the intermediate transfer drum 16 and a transfer roller 15 , the composite color toner image formed on the intermediate transfer drum 16 is transferred to the surface of a recording material P fed, at a predetermined timing, from a sheet feeder unit (not shown) to the secondary transfer portion T 2 . The transfer roller 15 supplies charge of the polarity opposite to that of toner to the recording material P form the back thereof, thereby causing the composite color toner image on the intermediate transfer drum 16 to be sequentially transferred to the recording material P.
[0043] The recording material P having passed through the secondary transfer portion T 2 is separated from the surface of the intermediate transfer drum 16 and introduced into a fixing apparatus 10 , where the unfixed toner image is subject to a heat fixing process. Then, the recording material P with the color image is ejected onto an output tray (not shown).
[0044] The fixing apparatus 10 is an image heating apparatus according to the present invention and will be described in detail later in the section (2).
[0045] Once the color toner image is transferred to the recording material P, a cleaner 18 cleans residues, such as remaining toner and paper dust, off the intermediate transfer drum 16 . The cleaner 18 is spaced apart from the intermediate transfer drum 16 in a normal state, and is in contact with the intermediate transfer drum 16 during the secondary transfer of the color toner image from the intermediate transfer drum 16 to the recording material P.
[0046] Besides, the transfer roller 15 is also spaced apart from the intermediate transfer drum 16 until the fourth color (BK) image is formed, and is in contact with the intermediate transfer drum 16 during the secondary transfer of the color toner image from the intermediate transfer drum 16 to the recording material P.
[0047] In the monochrome image formation, in contrast to the full-color-image formation, only the black developer 14 BK is activated, and switching among the developers does not occur. An image for the following page can be successively formed on the intermediate transfer drum 16 , and a series of image forming operations is conducted with the transfer roller 15 and the cleaner 18 kept abutting against the intermediate transfer drum 16 . Therefore, a monochrome image can be formed at a speed about four times higher than that for a full-color image. In this example, the recording speed is 4 pages per minute for full-color image (A4 size) and is 16 pages per minute for monochrome image.
[0048] Image formation can be successively conducted by repeating the operation described above. FIG. 10 shows a process of the operation of the image forming apparatus.
[0049] 1) Multi-Pre-Rotation Step
[0050] This is a period for stating (activating) the image forming apparatus (warm-up period). The main power switch of the image forming apparatus is turned on to activate a main motor thereof, thereby preparing a desired processing unit.
[0051] 2) Stand-By Step
[0052] After the predetermined starting period, the main motor is stopped, and the image forming apparatus is kept in a stand-by (waiting) state until a print job starting signal is input.
[0053] 3) Prerotation Step
[0054] This is a period in which the main motor is restarted in response to input of the print job starting signal, and a pre-print-job operation of a desired processing unit is performed.
[0055] In a more practical order, the image forming apparatus receives the print job starting signal, develops an image using a formatter (the development time varies depending on the amount of image data and the processing speed of the formatter), and then, the multi-pre-rotation step is started.
[0056] Here, if the print job starting signal is input during the multi-pre-rotation step, the stand-by step is omitted, and the prerotation step is entered directly after the multi-pre-rotation step is completed.
[0057] 4) Print Job Execution Step
[0058] Once the predetermined prerotation step is completed, the image forming process described above is performed, and the recording material with the image formed thereon is output.
[0059] In the case of successive print jobs, the image forming process described above is repeated, and a predetermined number of recording materials with the respective images formed thereon are output.
[0060] 5) Paper Interval Step
[0061] This is a step for providing an interval between the trailing edge of a recording material P and the leading edge of the following recording material P in the case of successive print jobs. This step corresponds to a period in which no sheet is fed in the transfer portion and the fixing apparatus.
[0062] 6) Post-Rotation Step
[0063] This is a period in which the main motor is continuously kept moving to perform a post-print-job operation of a desired processing unit after the recording material with the image formed thereon is output (after the print job is finished) in the case of a one-sheet print job, or after the last recording material with the image formed thereon is output (after the print jobs are finished) in the case of successive print jobs.
[0064] 7) Stand-By Step
[0065] After the predetermined post-rotation step is completed, the main motor is stopped, and the image forming apparatus is kept in a stand-by state until the next print job starting signal is input.
[0066] (2) Fixing Apparatus 10
[0067] [0067]FIG. 1 is a partially cut away schematic view of the fixing apparatus 10 . The fixing apparatus 10 mainly comprises a fixing roller (first rotatable member) 1 and a pressure roller (second rotatable member) 3 , which constitute a rotatable member pair, and a surface heating unit (heating means) 2 for the fixing roller 1 .
[0068] The fixing roller 1 is a resilient roller having an outer diameter of 20 mm which comprises a cored bar 1 a , a silicone rubber layer 1 b having a thickness of 3 mm coating the outer peripheral surface of the cored bar and a PFA resin layer 1 c having a thickness of 50 μm coating the outer peripheral surface of the silicone rubber layer.
[0069] Similarly, the pressure roller 3 is a resilient roller having an outer diameter of 20 mm which comprises a cored bar 3 a , a silicone rubber layer 3 b having a thickness of 3 mm coating the outer peripheral surface of the cored bar and a PFA resin layer 3 c having a thickness of 50 μm coating the outer peripheral surface of the silicone rubber layer. The pressure roller 3 is pressed against the fixing roller 1 under a predetermined pressure (100N) to form a fixing nip N 1 .
[0070] The surface heating unit 2 comprises a ceramic heater 2 b as heating means, a heater holder 2 c supporting the ceramic heater 2 b , and an endless-belt (cylindrical) heating film (third rotatable member) 2 a rotatably fitted on the outer peripheral surface of the heater holder 2 c . A pressure stay 2 d presses the heater holder 2 c onto the fixing roller 1 against the resilience of the resilient layer 3 b of the fixing roller 1 to press the heater 2 b against the fixing roller 1 with the heating film 2 a interposed therebetween, thereby forming a heating nip N 2 .
[0071] The heater holder 2 c has a film guiding surface shaped so as to provide an extended film contact portion C 1 for the heating film 2 a to contact the fixing roller surface in an area upstream of the heater 2 b (heating nip N 2 ) in the direction of the rotation of the fixing roller.
[0072] That is, the heating film 2 a is guided by the heater holder 2 c so as to contact the fixing roller 1 at the heating nip N 2 and the contact portion C 1 upstream of the heating nip.
[0073] According to this embodiment, in the extended film contact portion C 1 of the surface heating unit 2 , a thermistor 5 as temperature detecting means is provided in such a manner that it is constantly pressed by a spring or the like against the surface of the heating film 2 a opposite to that in contact with the fixing roller 1 , that is, the inner surface (back surface) of the film.
[0074] The heating film 2 a comprises a polyimide (PI) resin layer having a thickness of 40 μm coated with a PFA resin layer having a thickness of 10 μm and has a perimeter of 56.5 mm. The ceramic heater 2 b comprises an alumina substrate having a width of 8 mm and a thickness of 1 mm, a resistor printed thereon and a protective glass layer formed thereon and has an output power of 700 W.
[0075] The fixing roller 1 is rotated by driver means M in a clockwise direction as indicated by the arrow in FIG. 1. As the fixing roller 1 rotates, the pressure roller 3 , which follows the fixing roller 1 , rotates in a direction indicated by the arrow by friction arising in the fixing nip N 1 . In addition, the heating film 2 a of the surface heating unit 2 , which follows the fixing roller 1 , slides along the outer peripheral surface of the heater holder 2 c in a counterclockwise direction indicated by the arrow by friction arising in the heating nip N 2 and the extended film contact portion C 1 with the inner surface thereof kept in contact with the surface of the heater 2 b and the thermistor 5 .
[0076] In addition, when a power supply circuit 101 energizes the heat-generating resistor layer, the temperature of the ceramic heater 2 b of the surface heating unit 2 rises rapidly. The heat generation by the heater 2 b causes the surface of the rotating fixing roller 1 to be heated via the heating film 2 a in the heating nip portion N 2 .
[0077] The thermistor 5 detects the surface temperature of the fixing roller 1 via the heating film 2 a . Based on the temperature detected by the thermistor 5 , a control circuit 100 adjust the power supplied from the power supply circuit 101 to the ceramic heater 2 b , thereby controlling the surface temperature of the fixing roller 1 to be kept at a predetermined fixing temperature.
[0078] Following the fixing roller 1 rotated, the pressure roller 3 and the heating film 2 a of the surface heating unit 2 rotate. In addition, the ceramic heater 2 b of the surface heating unit 2 is energized to heat the surface of the fixing roller 1 , and the surface temperature of the fixing roller 1 is controlled at a predetermined fixing temperature. In this state, a recording material P carrying an unfixed toner image t, which is to be heated, is introduced into the fixing nip portion N 1 between the fixing roller 1 and the pressure roller 3 . The recording material P is brought into intimate contact with the outer peripheral surface of the fixing roller 1 and passes through the fixing nip portion N as the fixing roller 1 rotates. During the process of passing through the fixing nip portion, the toner image t is heated via heat conduction from the fixing roller 1 and fixed. The recording material P having passed through the fixing nip portion N 1 is separated from the outer peripheral surface of the fixing roller 1 at the recording material outlet of the fixing nip portion N 1 and ejected.
[0079] (3) Temperature Control
[0080] In this embodiment, the surface heating unit 2 supplies heat to the fixing roller 1 from the outer surface (outer peripheral surface) thereof, and the heat supplied to the fixing roller 1 is used to heat the recording material P. To follow the change of the temperature of the fixing roller surface, the power supply condition of the ceramic heater 2 is controlled by PID (PID is to determine the next condition by a proportional, integral or derivative processing based on the temporal change of the past temperature). Thus, the heater according to this embodiment can change the amount of generated heat in a stepwise manner.
[0081] Now, a change of the surface temperature of the fixing roller 1 due to paper feeding is examined. Experimentally, after the surface temperature of the fixing roller 1 is kept at a certain temperature (200° C.), power supply to the ceramic heater 2 b is stopped, and one recording material P is inserted into the fixing nip N 1 . Then, the surface temperature of the fixing roller 1 measured at a point O at the recording material outlet side (ejection side) of the fixing nip N 1 varies as shown in FIG. 3. In the case of this fixing apparatus, the fixing roller rotates about four times while one recording material passes through the fixing nip. As shown in FIG. 3, the temperature detected at the point O decreases stepwise when the recording material passes through the fixing nip. This is because the recording material deprives the surface of the fixing roller 1 of heat as the rotation continues. In addition, the temperature detected at the point O returns to its original level after the trailing edge of the recording material have passed through the fixing nip. This is cause by heat accumulated in the fixing roller or pressure roller before feeding of the recording material. In this way, if energization of the heater is stopped before paper feeding, the surface temperature of the fixing roller at the point O, that is, immediately after the fixing roller has passed through the fixing nip decreases stepwise and then rises as shown in FIG. 3. Therefore, to achieve uniform fixing from the leading edge to the trailing edge of the recording material, an amount of heat equal to the amount of heat of which the recording material has deprived the fixing roller has to be supplied from the ceramic heater 2 b to the fixing roller 1 to maintain a uniform heat supply capability to the recording material.
[0082] During the first rotation of the fixing roller 1 after the recording material is fed, heat accumulated during heating before feeding of the recording material (in the paper interval step and the prerotation step) builds up not only in the surface but also in the depth of the roller and vicinity of the surface thereof, and thus, the heat supply capability is high. During the second rotation, the heat supply capability decreases. This is probably because heat supply from the vicinity of the surface of the roller is insufficient. Then, as the rotation continues, heat is further supplied from the depth of the roller to the vicinity of the surface thereof, and thus, the heat supply capability tends to get better.
[0083] Thus, first, an arrangement is considered in which the thermistor is disposed close to the point O, and energization of the heater is controlled so as to keep the temperature detected by the thermistor at a preset value.
[0084] As described above, if the recording material is fed after energization to the heater is stopped, the temperature of the fixing roller in the vicinity of the point O decreases stepwise. Even if the heater is energized also during paper feeding to compensate for the temperature reduction, the surface temperature of the fixing roller changes as is shown in FIG. 3 (although it is slightly higher than that in FIG. 3), because the point O is located next to the fixing nip, and the fixing roller surface has just been deprived of heat by the recording material when it reaches the point O. Therefore, even if the thermistor is disposed in the vicinity of the point O, and the heater is controlled to generate heat during paper feeding, the temperature detected by the thermistor decreases gradually. Besides, the heater generates more heat when the thermistor detects a lower temperature. As a result, an excessive amount of heat is supplied to the recording material. In addition, while heat supplied by the heater is accumulated not only in the surface of the fixing roller but also inside of the fixing roller, heat accumulation building inside of the fixing roller cannot be measured in the vicinity of the point O. As a result, an excessive amount of heat is supplied to the recording material, and a hot offset of toner occurs.
[0085] On the other hand, according to this embodiment, the thermistor is disposed inside the heating film (third rotatable member) of the surface heating unit and in an area where the fixing roller (first rotatable member) and the heating film are in contact with each other. That is, the thermistor 5 detects the surface temperature of the fixing roller 1 via the heating film 2 a , so that there is a temperature gradient between them due to a thermal resistance. Thus, the excessive heat generation by the heater can be avoided, and the hot offset can be prevented. In addition, since the thermistor is not direct contact with the fixing roller, the fixing roller surface can be prevented from suffering a scratch. Furthermore, in this embodiment, a higher target temperature is set for the paper feeding period to address the problems described above. Specifically, the target temperature is 180° C. for the period in which no sheet of paper is fed (paper interval period) and 200° C. for the paper feeding period.
[0086] Thus, the ceramic heater 2 b is energized and controlled so as to keep the surface temperature of the fixing roller at the ejection side substantially uniform (160° C.) as shown in FIG. 4.
[0087] In this embodiment, in the case of full-color image formation, which involves more toner and accordingly requires more heat for fixing, the paper interval (distance between the trailing edge of a recording material and the leading edge of the following recording material) can be about five times longer than the length of the recording material. Thus, the heat supply capability can be advantageously increased by maintaining the rotation and heating of the fixing roller in the fixing apparatus 10 to ensure a sufficient heat accumulation in the fixing roller 1 .
(4) COMPARATIVE EXAMPLES
[0088] [0088]FIGS. 5 and 6 are partially cut away side views showing examples of arrangement of the temperature detecting means according to Comparative Examples. FIG. 5 shows an arrangement in which the thermistor 5 is disposed immediately following the fixing nip and at the middle along the axis of the fixing roller (Comparative Example 1). FIG. 6 shows an arrangement in which the thermistor 5 abuts against the ceramic heater 2 b (Comparative Example 2).
[0089] Changes of the temperature of the fixing roller measured at the point O in the Comparative Examples 1 and 2 are shown in FIGS. 7A and 7B, respectively.
[0090] In the Comparative Example 1, while the temperature during the second rotation is controlled to be equal to that during the first rotation, the temperature rises during the third and later rotations, and a hot offset occurs in the latter half of the recording material. This is because the thermistor disposed as shown in FIG. 5 detects the temperature of only the surface of the fixing roller having just been deprived of heat by the recording material, and thus, the heat accumulation in the depth of the fixing roller 1 is not reflected to the temperature control, as described above. In addition, since the thermistor is in direct contact with the fixing roller, a scratch is made on the surface of the fixing roller.
[0091] On the other hand, in the Comparative Example 2, while the temperature during the second rotation is controlled to be equal to that during the first rotation, the temperature decreases during the third and later rotations, and a poor fixing occurs in the later half of the recording material. This is probably because, since the thermistor 5 detects the temperature increase in the ceramic heater 2 , it is insensitive to the temperature reduction in the surface of the fixing roller 1 and fails to raise the power.
[0092] In contrast to these Comparative Examples, according to this embodiment, the thermistor 5 detects the surface temperature of the fixing roller 1 , and the heat generation condition of the ceramic heater 2 is fed back via the film. Thus, the recovery of the heat supply capability for the second and later rotations can be compensated for, and thus, an excessive rise or reduction of the temperature of the fixing roller 1 does not occur.
[0093] In addition, in the Comparative Example 1, there arise problems that the thermistor 5 makes a scratch on the surface of the fixing roller 1 , and soil, such as toner residues or paper dust, is accumulated at the area where the thermistor 5 and the fixing roller 1 are in contact with each other, resulting in a poor quality or impairment of the image on the recording material. To the contrary, in this embodiment, since the thermistor 5 abuts against the inner surface of the heating film 2 a , such problems don't occur.
[0094] In short, according to the present invention, since the surface heating method is adopted, there can be provided a fixing apparatus and an image forming apparatus which have an advantageously shortened activation time (about 15 seconds), avoids a hot offset and poor fixing unlike the Comparative Examples as shown in Table 1, and does not suffer an image impairment.
TABLE 1 Soil Hot offset Fixability Comparative x x ∘ Example 1 Comparative ∘ ∘ x Example 2 This ∘ ∘ ∘ embodiment
[0095] <Embodiment 2> (See FIG. 8)
[0096] [0096]FIG. 8 is a partially cut away schematic diagram showing the fixing apparatus 10 according to an embodiment 2.
[0097] The apparatus according to this embodiment is the same as the apparatus shown in FIGS. 1 to 6 , 7 A and 7 B except for the position of the thermistor 5 as shown in FIG. 1.
[0098] That is, in the apparatus according to this embodiment, the heater holder 2 c has a film guiding surface shaped so as to provide an extended film contact portion C 2 for the heating film 2 a to contact the fixing roller surface in an area downstream of the heater 2 b (heating nip N 2 ) in the direction of the rotation of the fixing roller. The heating film 2 a is guided by the heater holder 2 c so as to contact the fixing roller 1 at the heating nip N 2 and the contact portion C 2 downstream of the heating nip. And, in the extended film contact portion C 2 of the surface heating unit 2 , the thermistor 5 as temperature detecting means is provided in such a manner that it is constantly pressed by a spring or the like against the surface of the heating film 2 a opposite to that in contact with the fixing roller 1 , that is, the inner surface (back surface) of the film.
[0099] Since the thermistor 5 detects, via the heating film 2 a , the temperature of the fixing roller having passed through the heating nip N 2 , the result of heating is reflected to the control of the apparatus, and thus, stable control can be achieved.
[0100] In addition, advantageously, the surface temperature of the fixing roller 1 is monitored and controlled at the point upstream of the fixing nip N 1 in the direction of the rotation of the fixing roller, and thus, the temperature of the fixing roller can be controlled by compensating for the variation of the heat supply condition in the heating nip N 2 resulting form variations of the ceramic heater 2 b or power supply voltage.
[0101] In this embodiment, if a metallic film, such as stainless, nickel or copper film, is used as the heating film 2 a instead of the polyimide (PI) resin film, a negative-feedback control with a higher responsibility can be achieved, and a more uniform fixability can be attained.
[0102] <Embodiment 3> (See FIG. 9)
[0103] [0103]FIG. 9 is a partially cut away schematic diagram showing the fixing apparatus 10 according to an embodiment 3.
[0104] The apparatus according to this embodiment is the same as the apparatus shown in FIGS. 1 to 6 , 7 A and 7 B, except for the configuration of the surface heating unit 2 ′ as shown in FIG. 9.
[0105] The surface heating unit 2 ′ comprises a heating roller 2 f , a halogen heater 2 e contained in the heating roller 2 f , a heating film 2 a rotatably fitted onto the outer peripheral surface of the heating roller 2 f , and a tension roller 2 g for exerting a tension to the heating film 2 a.
[0106] The heating roller 2 f is a hollow cylinder made of aluminum having a thickness of 1 mm and a diameter of 30 mm. The halogen heater 2 e has an output power of 700 W. The heating roller 2 f abuts against the fixing roller 1 with the heating film 2 a interposed therebetween to form the heating nip N 2 . The heating film 2 a , the heating roller 2 f and the tension roller 2 g rotate by following the fixing roller 1 .
[0107] The heating film 2 a comprises a PI resin layer having a thickness of 50 μm coated with a fluororesin layer having a thickness of 10 μm and has a perimeter of 120 mm.
[0108] The tension roller 2 g is a roller made of stainless having a thickness of 1 mm and a diameter of 15 mm. It exerts a tension of 20 N to the heating film 2 a and makes the heating film 2 a move along the surface of the fixing roller 1 to form an extended film contact portion C 1 where the heating film 2 a contact the fixing roller surface upstream of the heating roller 2 f (heating nip N 2 ) in the direction of the rotation of the fixing roller. The thermistor 5 is in contact with the inner surface of the film at the extended film contact portion C 1 .
[0109] This embodiment has an advantage that, since the heating roller 2 f having a relatively high thermal capacity is used as the heat source, the temperature is less likely to vary due to turn-on/off of the halogen heater 2 e and a uniform fixability can be achieved, although the activation time is slightly longer (about 30 seconds).
[0110] In addition, since the heating roller 2 f is a rotatable member, and the film can rotate at a low torque by following the heating roller, there is an advantage that the film can run stably.
[0111] <Others>
[0112] a) As for the rotatable pressure member 3 in the embodiments 1 to 3, instead of the pressure roller, a pressure film unit consisting of an endless belt and a pressure member disclosed in Japanese Patent Application Laid-Open No. 2001-228731 may be used for reducing the thermal capacity.
[0113] b) The fixing roller 1 serving as the heating rotatable member may be hollow, and a halogen heater or the like may be contained in the hollow as auxiliary heating means.
[0114] c) The heating rotatable member 1 is not limited to the roller configuration and may be a rotatable belt member.
[0115] d) The heating apparatus according to the present invention is not used exclusively as the image heat-fixing apparatus of the embodiments. It may be widely used as means or apparatus for heating a material, such as an image heating apparatus that heats a recording material carrying an image to reform the surface characteristics, such as luster, image heating apparatus for temporary fixing, an heating and drying apparatus for a material to be heated, and a heating lamination apparatus.
[0116] While various embodiments and examples of the present invention have been described above, it will be understood by one skilled in the art that the spirit and scope of the present invention is not limited to the specific description herein and the appended drawings, and the present invention includes various modifications and alterations as set forth in the claims. | The image heating apparatus for heating an image formed on a recording material, comprising: first rotatable member; said first rotatable member contacting second rotatable member, wherein the recording material bearing the image passes through a nip portion formed at a position between said first rotatable member and said second rotatable member; heating means for heating said first rotatable member, said heating means including a third rotatable member that is flexible and a temperature detecting element, wherein the third rotatable member contacts an outer peripheral surface of said first rotatable member with the third member, wherein the temperature detecting elements is provided in an area of an inside surface said third rotatable member, wherein said first rotatable member and said third rotatable member contacts in the area; and control means for controlling said heating means based on detecting the temperature of said temperature detecting elements.
Thus, the activation time can be shortened, and a scratch can be prevented from being made on the surface of the rotatable member contacting the toner image. | 6 |
REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 62/044,472, filed Sep. 2, 2014.
FIELD OF THE INVENTION
The present invention relates to a method and system of separating calcium carbonate eggshell from the inner lining of organic protein-based membrane in eggshell by-product, in an efficient manner, for the purpose of producing a high purity calcium carbonate product.
BACKGROUND
The egg processing industry discards over 600,000 tons of eggshells per year, after breaking the egg and removing the egg white and yolk. Eggshells are generally thought of as a waste product, however if the inorganic and organic components are separated, commercial materials can be obtained and utilized in a variety of applications. Large amounts of eggshell waste or by-product are generated annually and the majority ends up in landfills. Therefore the process of isolating the valuable products is of interest to keep the eggshell by-product out of landfill and to turn a low value material into a high value one.
There are two major components in eggshells: the membrane and the shell. The membrane consists mainly of organic material, including collagen and amino acids. These materials can be separated from the shell and used in the medical and cosmetic industries, among others. The inorganic component of eggshell consists of calcium carbonate with small amounts of magnesium carbonate and calcium phosphate. The majority of this portion is calcium carbonate (CaCO 3 ), which has a variety of applications. Many of these applications require the calcium carbonate product to be of a high purity, particularly where the calcium carbonate is to be used for human consumption.
There is variation across the egg processing industry of the process for discarding the shell. Some egg ‘breaking’ companies will dump and discard the remaining shell by-product immediately after the removal of the liquid egg. This eggshell by-product will still have remnants of wet material. Other breaking companies will first run the by-product through a centrifuge-type apparatus, for the purpose of removing the bulk of the remaining liquid egg, which will aid in reducing cost to discard the by-product.
Approaches to separating shells from membranes known in the prior art have limitations when considering the purity of the final calcium carbonate product, cost effectiveness of the approach, and scalability of the approach. Several prior art approaches are focussed on the purity and processing of the membrane by-product rather than the calcium carbonate by-product.
A number of approaches have been proposed where the separation is purely mechanical in nature, which inherently results in a relatively impure final calcium carbonate product with organic impurities. For example, U.S. Pat. No. 6,176,376 and U.S. Pat. No. 7,007,806 of MacNeil uses agitation in a liquid to create separation of the membrane and eggshell by relying on the differences in bulk density between the membrane and eggshell portions. The eggshell settles to the bottom of the tank while the membranes remain suspended in liquid. U.S. Pat. No. 6,649,203 of Thoroski describes an approach with centrifuging, washing, centrifuging, drying, and milling stages followed by a pneumatic membrane removal. In the pneumatic removal step, the membrane and eggshell fall through a suction flow which diverts the relatively light membrane but not the eggshell.
An approach that combines mechanical and chemical approaches may be seen in U.S. Publication No. 2006/0159816 and U.S. Pat. No. 7,954,733 of Vlad. This approach uses cavitation in a fluid tank (a mechanical step) to separate membrane from eggshell. Optionally, the membranes may be dried. Acetic acid may then be used to extract certain polypeptides from the membrane. However, this approach, and specifically the chemical extraction, is focused upon separation and treatment of the membrane materials, not the shells which are the source of calcium carbonate. In respect of the shells, they are again separated through a mechanical separation process only, and will have relatively high levels of organic impurities.
U.S. Pat. No. 7,597,280 of Floh describes a system wherein a slurry of finely ground shell and membrane is introduced into a separation tank with an upward flow and a number of overlapping vanes. The membrane is borne upwards and withdrawn by the vanes; the shell falls to the bottom of the tank and is removed. The membrane is dewatered (using protein dewatering) and dried. Again, the focus of this approach is on the production of the membrane as a product. In respect of the shells, they are separated through a mechanical separation process only, and will have relatively high levels of organic impurities. This approach is also quite costly.
SUMMARY
There is a need for a method of separating the membrane and calcium carbonate portions of eggshell by-products that produces calcium carbonate of a sufficiently high purity to meet USP and other quality standards and be used for human consumption in the food, pharmaceutical, nutraceutical and similar markets, but is also cost-effective, able to handle wide variations in the composition of the incoming eggshell by-product, can be scaled up as desired to accommodate an industrial volume of discharged eggshell by-product, and can be sold in commodity/bulk/ingredient form for inclusion in end-user/client products.
The method and apparatus disclosed herein for the separation and generation of high purity calcium carbonate from eggshell by-product can be broadly divided into mechanical and chemical stages that work together to break down the by-product into very pure forms of calcium carbonate via economically viable industrially-scalable methods.
In the mechanical stage, the by-product is first agitated (for example, through a mill apparatus) to create an initial mechanical separation of the membrane and shell in the by-product material in preparation for the sieving step. The second mechanical step is separation through sieving the by-product material to remove and recover relatively large pieces of membrane material. There are advantages to performing this step via a staged sieving process.
The sieved material will still have an undesirable (and in some markets, an unacceptable) amount of membrane attached to the calcium carbonate. The chemical phases involve digesting the material remaining from the sieve though digestion using base chemicals. These steps may be designed to work with a number of different bases, and with variations in the concentration of each base solution, the residence time involved in each digestion phase, the temperature of each base solution, and other variables associated with the processing of the material, number of digestion steps, and the processing parameters. The inventors have investigated these possibilities and have found that a process with a sodium hydroxide digestion followed by a sodium hypochlorite digestion (followed by a water wash) results in a calcium carbonate product of greater than 98% purity that will satisfy USP requirements for use for human consumption, as well as a number of end-use markets.
After the calcium carbonate is washed in water to remove remaining surface sodium hypochlorite and related salts, the purified calcium carbonate is typically dried. The purified calcium carbonate may then be milled or refined to any necessary particle size or subjected to other further processing as desired in the various marketplaces.
In accordance with the present invention, there is provided a method for the separation of calcium eggshell from an eggshell by-product comprising the steps of:
a. Agitating the eggshell by-product; b. Sieving the eggshell by-product; c. Subjecting the eggshell by-product to a functional digestion with a first base solution; d. Subjecting the eggshell by-product to a refining digestion with a second base solution; and e. Running the eggshell by-product through a washing stage using water.
In another aspect, the method further comprises the step:
f. Drying the eggshell by-product.
In another aspect of the present invention, the first base solution is one or more bases selected from the set of sodium hydroxide, ammonium hydroxide, potassium hydroxide, or an organic base, mixed with water. In another aspect of the present invention, the first base solution is primarily sodium hydroxide mixed with water. In another aspect of the present invention, the second base solution is primarily sodium hypochlorite mixed with water. In another aspect, the step of subjecting the eggshell by-product to a functional digestion with a first base solution comprises digestion with between 15-45% solids loading, a temperature between 30 to 90 degrees Celsius, and 0.5 to 5% NaOH in H 2 O, with fluidization and a residence time between 15 min to 60 min. In another aspect, the step of subjecting the eggshell by-product to a functional digestion with a first base solution comprises digestion with 15% solids loading by volume, a temperature of 60 degrees Celsius, a 2.5% sodium hydroxide (NaOH) solution mixed in water (by weight), with fluidization, and a residence time of 30 minutes. In another aspect, the step of subjecting the eggshell by-product to a refining digestion with a second base solution comprises a solids loading between 15-45% solids by volume, ambient temperature, 6%-12% sodium hypochlorite (NaClO) mixed in water (by weight) with trace elements (less than 1%) of sodium hydroxide (alkaline solution), with fluidization and a residence time of between 10 and 40 minutes. In another aspect, the step of subjecting the eggshell by-product to a refining digestion with a second base solution comprises a 30% solids loading (by volume), with an 8% NaClO solution (mixed in water by weight), at ambient temperature, with fluidization, with a residence time of between 10 to 15 minutes.
In accordance with the present invention, there is provided a method for the separation of calcium eggshell from an eggshell by-product comprising the steps of: a) agitating the eggshell by-product using a ball mill for between 5 and 40 minutes; b) sieving the eggshell by-product with a sieve with a mesh size between ⅛ of an inch and ¼ of an inch; c) subjecting the eggshell by-product to a functional digestion with a NaOH solution comprising digestion with between 15-45% solids loading, a temperature between 30 to 90 degrees Celsius, and 0.5 to 5% NaOH in H 2 O, with fluidization, and a residence time between 15 min to 60 min; d) subjecting the eggshell by-product to a refining digestion with a NaClO solution comprising digestion with a solids loading between 15-45% solids by volume, ambient temperature, 6%-10% sodium hypochlorite (NaClO) mixed in water (by weight) with trace elements (less than 1%) of sodium hydroxide (alkaline solution), with fluidization, and a residence time of between 10 and 40 minutes; and e) running the eggshell by-product through a washing stage using water.
In accord with the present invention, there is provided a system for the separation of calcium eggshell from an eggshell by-product comprising: an agitator, a sieving device, a functional digester using a first base solution, a refining digester using a second base solution, and a water rinse; wherein said apparatus is configured so that the eggshell by-product passes into the agitator, from the agitator to the sieving device, from the sieving device to the functional digester, from the functional digester to the refining digester, and from the functional digester to the water rinse.
In an aspect of the present invention, the first base solution is one or more bases selected from the set of sodium hydroxide, ammonium hydroxide, potassium hydroxide, or an organic base, mixed with water. In another aspect, the first base solution is primarily sodium hydroxide mixed with water. In another aspect, the second base solution is primarily sodium hypochlorite mixed with water. In another aspect, the functional digester is configured for digestion with between 15-45% solids loading, a temperature between 30 to 90 degrees Celsius, and 0.5 to 5% NaOH in H 2 O, with fluidization and a residence time between 15 minutes to 60 minutes. In another aspect, the functional digester is configured for digestion with 15% solids loading by volume, a temperature of 60 degrees Celsius, a 2.5% sodium hydroxide (NaOH) solution mixed in water (by weight), with fluidization, and a residence time of 30 minutes. In another aspect, the refining digester is configured for digestion with a solids loading between 15-45% solids by volume, ambient temperature, 6%-12% sodium hypochlorite (NaClO) mixed in water (by weight) with trace elements (less than 1%) of sodium hydroxide (alkaline solution), with fluidization and a residence time of between 10 and 40 minutes. In another aspect, the refining digester is configured for digestion with a 30% solids loading (by volume), with an 8% NaClO solution (mixed in water by weight), at ambient temperature, with fluidization, for a residence time of between 10 and 15 minutes.
In accord with the present invention, there is provided calcium carbonate obtained from eggshell by-product with a purity of greater than 98%. In accord with the present invention, there is provided calcium carbonate obtained from eggshell by-product with a purity of greater than 99%. In accord with the present invention, there is provided calcium carbonate obtained from eggshell by-product with a purity of greater than 99.5%.
In accord with the present invention, there is provided a product prepared by the inventive process, where the product comprises calcium carbonate and less than 2% impurities (excluding water). In accord with the present invention, there is provided a product prepared by the inventive process, where the product comprises calcium carbonate and less than 1% impurities (excluding water).
In accord with the present invention, there is provided a method for the separation of calcium eggshell from an eggshell by-product comprising the steps of: a) Subjecting the eggshell by-product to a functional digestion with a first base solution; b) subjecting the eggshell by-product to a refining digestion with a second base solution; and c) running the eggshell by-product through a washing stage using water. In another aspect, there is further provided the step of d) drying the eggshell by-product.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustrating the steps of the process for separating eggshell from membrane.
FIG. 2 is an elevation view of one embodiment of a system to implement the process;
FIG. 3 is an aerial view of the embodiment illustrated in FIG. 2 .
DETAILED DESCRIPTION
The process that is the subject of this patent works with a wide variety of liquid egg discharged by-product products. It can process both shell material that has or has not passed through a centrifuge, and material that has small amounts of liquid egg remaining. The method will also operate when there is little to no liquid egg remaining in the by-product feedstock.
Turning to FIG. 1 , the first stage of this process begins with newly discarded eggshell by-product 10 , which is waste to egg ‘breaking’ companies, containing shell and organic membrane. As a general matter, the shell may or may not be ground, and the organic membrane may or may not have been subject to some sort of separation process at the supplier (i.e. before it enters the present system). The present method can process by-product with wide variations without the need to recalibrate or vary the process.
In step 12 , the by-product 10 is agitated to loosen the membrane from the shell aiding the effectiveness of the subsequent sieving step(s) via this initial mechanical separation of membrane and shell.
This agitation may be accomplished by numerous types of equipment. The agitation may be accomplished by milling the incoming by-product. In a preferred embodiment, the mill is a ball mill that produces material with a diameter of no greater than 5 mm. Testing shows that with such a ball mill, sufficient separation can be achieved by between 5 and 60 minutes of milling. In a preferred embodiment, the separation is achieved by milling for 20 minutes.
Although the primary goal of stage 12 is agitation and the resulting separation of the membrane and shell, some size reduction of the shell will take place as a by-product of this stage. This reduction can assist in the efficient sieving in the next step 14 .
In step 14 , the discharged material from step 12 is sieved to separate larger pieces of organic membrane from smaller pieces of membrane and shell. Generally, as more organic membrane is removed at this stage, the subsequent digestion stage can become more efficient, proficient and cost-effective.
Generally, the sieving is best done through one or more screens or sieves. Flowing water may be added to aid in the screening/sieving of preliminarily separated membrane material and shell.
In a preferred embodiment, the sieving will use one or more mesh screens with each having a mesh size of ⅛ of an inch to ¼ of an inch, with flowing water. In another preferred embodiment, the sieves are tiered with decreasing mesh sizes, culminating in a sieve with a mesh size of ⅛ of an inch to ¼ of an inch.
The discharge of membrane and shell that has successfully passed through the sieving step will then pass on to the chemical phase of the process, step 18 . The membrane material that is removed by the sieving and is discharged from this process, indicated by 15 in FIG. 1 , will account for approximately 3%-7% of the by-product 10 , by weight. This membrane material 15 can be dried, preserved and further processed into a value-added saleable product.
Steps 12 and 14 comprise the mechanical portion of the process, indicated by 16 on FIG. 1 .
In step 18 , the sieved material is put through a digestion process comprised of at least two digestion steps using base solutions to remove remaining organic membrane and other impurities from the calcium carbonate (or shell). Many variations of which bases to employ, how many digestion steps to use, and the processing conditions are possible. The processing conditions include the solids content (as a percent of volume), the temperature of the base solution, the concentration of the base solution, the residence time, and the presence of agitation or fluidization.
A preferred embodiment has a functional digestion step 20 , intended to remove the bulk of organic membrane (left after the sieving step 14 ) from the shells, and a refining digestion step 22 , which is intended to remove the remaining traces of organic membrane as well as any other (non-membrane) organic impurities. The functional digestion step 20 could be performed with sodium hydroxide, ammonium hydroxide, potassium hydroxide, or an organic base. The functional digestion step could also be performed with a combination of bases. In a preferred embodiment, the functional digestion step 20 uses sodium hydroxide and the refining digestion step 22 uses sodium hypochlorite.
In a preferred embodiment of step 20 , after being screened through the screener/sifter in step 14 , the remaining sieved pieces of shell and membrane will be conveyed via mechanical and/or pneumatic conveyance to a steel tank fitted with an agitation apparatus containing a solution between 0.5 and 5% sodium hydroxide (NaOH) mixed in water, by weight. In a preferred embodiment, the solution is 2.5% sodium hydroxide (NaOH) mixed in water, by weight. The sodium hydroxide solution should be slightly warmer than ambient room temperature, and testing shows that the process works well at between 30 and 90 degrees Celsius. In a preferred embodiment, the temperature of the NaOH solution is 60 degrees Celsius.
The amount of solids loading (solids to liquid ratio) in step 20 will vary depending on desired operation time and volume required, but tests have shown that it should remain within a basic range of 15%-60% solids loading by volume. The desirable and effective residence time in the solution will also depend on application needs, and the temperature of the solution.
Tests have shown that an NaOH digestion step with between 15-45% solids loading, a temperature between 30 to 90 degrees Celsius, and 0.5 to 5% NaOH in H 2 O and a residence time between 15 min to 60 min will work. In a particularly preferred embodiment, tests have shown that at 15% solids loading by volume and a temperature of 60 degrees Celsius and a 2.5% sodium hydroxide (NaOH) solution mixed in water (by weight), a residence time of 30 minutes will be effective for this stage of separation.
All remaining eggshell material at the end of functional digestion step 20 will be discharged and conveyed to the refining digestion step 22 .
In a preferred embodiment of refining digestion step 22 , the remaining shell product will be conveyed via mechanical and/or pneumatic conveyance to a steel tank fitted with an agitation apparatus containing a base solution. In a preferred embodiment, the solution is a sodium hypochlorite solution. The sodium hypochlorite solution will work to remove any remaining membrane via digestion, as well as any other (non-membrane) organic impurities. Residence time and solids loading by weight can vary, however tests have shown that a high level of purity can be achieved with a solids loading between 15-45% solids by volume, ambient temperature, 6%-12% sodium hypochlorite (NaClO) mixed in water (by weight) with trace elements (less than 1%) of sodium hydroxide (alkaline solution) and an residence time of between 10 and 40 minutes.
In a particularly preferred embodiment (based on tests), step 22 has a 30% solids loading (by volume), with an 8% NaClO solution (mixed in water by weight), at ambient temperature, with fluidization/agitation, for a residence time of 10-15 minutes.
It is also possible for the solution in the refining digestion step to contain a mixture of bases, including mixtures of sodium hypochlorite with sodium hydroxide, ammonium hydroxide, potassium hydroxide, or an organic base.
The sodium hydroxide and sodium hypochlorite digestion stages 20 and 22 discussed above, working in tandem as a functional digestion followed by a refining digestion, act to achieve a high level of calcium carbonate purity via the digestion of organic membrane and purification of the shell. However, these stages 20 and 22 may be used independently of one another, and can each achieve a high level of purity in isolation, albeit lower than the purity achieved by the two steps together.
A re-circulation and/or drainage system may be built-in to the system used in steps 20 and 22 (or more broadly step 18 ) to accommodate the drainage and refilling of the digestion solutions upon the liquid becoming saturated and/or diluted from excessive batch use.
After digestion in step 18 , the remaining shell material will be conveyed via mechanical and/or pneumatic conveyance to a water rinsing stage 24 where it will pass through a water bath or spray to remove any remaining surface sodium hypochlorite or related salts (sodium chloride) (and surface NaOH, if any) from the shell.
At this stage, a high purity calcium carbonate has been achieved, albeit in the presence of water (for many purposes, the water will need to be removed as seen in the next stage).
From the water-rinsing phase, the material will typically be passed through a drying device in step 26 to remove any excess moisture. Equipment that could be used in this stage includes a range of different drying technologies. In a preferred embodiment, a rotary dryer is used. In a preferred embodiment, the dryer operates within a temperature range of 50 Degrees to 350 Degrees. It is important to not perform the drying stage in such a way as to calcine the calcium carbonate; generally, the temperature should be kept below 800 degrees Celsius.
The method described herein can produce a calcium carbonate product 28 in flake form with a purity between 99% and 100% calcium carbonate. The shell product can be packaged as is into various forms of sanitary packaging, or further passed through a mill capable of fine grinding to wide-ranging particle size distributions, followed by finished goods packaging, depending upon the target market(s) and/or application(s).
An analysis of a representative final product from this process is given in Table 1. In some specific experimental runs, this method has resulted in calcium carbonate purity (measured using thermographic metric analysis) of 100%, with all impurities being below detectable limits.
In principle, the functional and refining digestion stages 20 and 22 can be used without the initial agitation and/or sieving steps to achieve a high purity calcium carbonate product. However, this approach would be more costly than an approach that incorporates the agitation and sieving steps, since the agitation and sieving steps will remove membrane that otherwise would need to be removed through more aggressive and costly digestion.
TABLE 1
Chemical Composition Breakdown - Calcium Carbonate
Test Method
Compound Symbol
Compound Name
Results
Thermographic Metric Analysis (TGA)
CaCO3
Calcium Carbonate
98.3%
MgCO3
Magnesium Carbonate
0.23%
Infrared Spectroscopy
TOC
Total Organic Carbon
0.0052%
XRF & ICP
LOI @1000 C.
Loss on Ignition (Weight)
43.99%
X-Ray Fluorescence
CaO
Calcium Oxide
54.4%
Inductively Coupled Plasma
MgO
Magnesium Oxide
0.49%
SiO2
Silicon Dioxide (Silica)
0.33%
Al203
Aluminum Oxide
<0.1%
Fe2O3
Iron Oxide
<0.01%
Na2O
Sodium Oxide
0.01%
K2O
Potassium Oxide
<0.01%
TiO2
Titanium Dioxide
<0.01%
MnO
Manganese
<0.001%
SrO
Strontium Oxide (Strontia)
0.019%
P2O5
Phosphorous Pentoxide
0.31%
S
Sulfur
0.021%
Instrumental Neutron Activation Analysis
Cl
Chlorine
NMT 0.01%
AMS
Fe
Iron
<0.001%
Accelerator Mass Spectrometry
As
Arsenic
1.9 ppm
Ba
Barium
10.7 ppm
Cd
Cadmium
0.02 ppm
Cr
Chromium
<1 ppm
Pb
Lead
0.07 ppm
F
Fluorine
Not Detected
Cold Vapor
Hg
Mercury
Not Detected
Hunter Brightness
L Scale
94.3
a Scale
0.02
b Scale
3.73
Optionally, after the sieving stage but before the digestion stage, further membrane may be removed from the feedstock by burning. There are several devices known to persons skilled in the art that could be used for this step, including flash dryers. However, this step is disfavored, since such burning is necessarily an expensive process, and tends to produce a calcium carbonate product that is greyish in colour and thus unacceptable in many markets. It is also unnecessary, since a high purity calcium carbonate product can be achieved using the method described above without this step. If this step was to be used, care needs to be taken to avoid calcining the calcium carbonate, which occurs at temperatures approaching 800 degrees Celsius, and also occurs at a slower rate at lower temperatures.
FIGS. 2 and 3 illustrate a system implementation of the invention. Turning to FIG. 2 , the newly discarded eggshell by-product, containing inorganic shell and organic membrane, is introduced into an agitator 50 . Numerous types of equipment known to those skilled in the art may be used as an agitator 50 . One type of equipment that may be used is a milling machine. In a preferred embodiment, the agitator 50 is a ball mill that produces material with a diameter of no greater than 5 mm. Testing shows that with such a ball mill, sufficient separation can be achieved after between 5 and 60 minutes. In a preferred embodiment, the separation is achieved by agitating for 20 minutes.
The discharged material from agitator 50 is passed to a sieving device 52 . Optionally (and not illustrated), the discharged material may rest in a holding tank before being passed to a sieving device 52 . In a preferred embodiment, the sieving device has a single sieve with a mesh size of ⅛ of an inch to ¼ of an inch, optionally with flowing water to assist in moving the material. In another preferred embodiment, the sieving will use a multi-layer mesh screen with multiple sieves each having a mesh size of ⅛ of an inch to ¼ of an inch, optionally with flowing water to assist in moving the material. In another preferred embodiment, the sieves are tiered with decreasing mesh sizes, culminating in a sieve with a mesh size of ⅛ of an inch to ¼ of an inch, optionally with flowing water.
The organic membrane material that is removed by sieving device 52 is discharged into device 54 . Device 54 may be any desirable device for the further processing, holding, or disposal of the organic membrane material that is removed by sieving device 52 .
The shell and remaining organic membrane that has passed through sieving machine 52 is passed to a functional digester 56 which uses a base mixed with water. Optionally (and not illustrated), the discharged material may rest in a holding tank before being passed to the functional digester 56 . In a preferred embodiment, the shell and remaining organic membrane that has passed through sieving machine 52 are conveyed via mechanical and/or pneumatic conveyance to functional digester 56 . In a preferred embodiment, functional digester 56 is a steel tank fitted with an agitation apparatus containing a solution of sodium hydroxide (NaOH) mixed in water. In other embodiments, the solution may be ammonium hydroxide mixed in water, potassium hydroxide mixed in water, an organic base mixed in water, or a mixture of these possible bases (sodium hydroxide, ammonium hydroxide, potassium hydroxide, an organic base) mixed in water.
In a preferred embodiment, the functional digester 56 is implemented with a solids loading of between 15-45% (by volume), a temperature between 30 to 90 degrees Celsius, a 0.5 to 5.0% NaOH mixed in water solution (by weight) and a residence time between 15 minutes to 60 minutes. In a particularly preferred embodiment, the functional digester 56 is implemented at 15% solids loading by volume and a temperature of 60 degrees Celsius and a 2.5% sodium hydroxide (NaOH) solution mixed in water (by weight) and a residence time of 30 minutes.
All shell and remaining membrane material after processing through functional digester 56 is then conveyed to refining digester 58 which uses a second base (not the same as the base used in the functional digester) mixed with water. Optionally (and not illustrated), the discharged material may rest in a holding tank before being passed to the refining digester 58 . In a preferred embodiment, the shell and remaining organic membrane that has passed through functional digester 56 is conveyed via mechanical and/or pneumatic conveyance to refining digester 58 . In a preferred embodiment, refining digester 58 is a steel tank fitted with an agitation apparatus containing a solution of sodium hypochlorite (NaClO) mixed in water.
In a preferred solution, the refining digester 58 is configured so the incoming material has a residence time of between 10 and 40 minutes, solids loading between 15-45% solids by volume, ambient temperature, and a 6%-12% sodium hypochlorite (NaClO) mixed in water (by weight) with trace elements (less than 1%) of sodium hydroxide (alkaline solution).
In a particularly preferred embodiment, refining digester 58 is configured to operate at a 30% solids loading (by volume), with an 8% NaClO solution (mixed in water by weight), at ambient temperature, with fluidization, for a residence time of 10-15 minutes.
In another embodiment, the solution used in refining digester 58 is sodium hypochlorite plus one or more additional bases mixed with water. The additional bases may include sodium hydroxide, ammonia hydroxide, potassium hydroxide, or organic bases.
A re-circulation and/or drainage system (not illustrated) may be built-in to digesters 56 and 58 to accommodate the drainage and refilling of the digestion solutions upon the liquid becoming saturated and/or diluted from excessive use.
After digestion in the refining digester 58 , the remaining shell material will be conveyed to a water rinse 60 . Optionally (and not illustrated), the shell material may rest in a holding tank before being passed to the water rinse 60 . The water rinse may be any water bath or spray known in the art that will remove any remaining surface sodium hypochlorite or related salts (sodium chloride) (and surface NaOH, if any) from the shell. In a preferred embodiment, the shells pass via mechanical and/or pneumatic conveyance through water rinse 60 .
At this stage, a high purity calcium carbonate has been achieved, albeit in the presence of water (for many purposes, the water will need to be removed as seen in the next stage).
From water rinse 60 , the shell material is passed through a drying device 62 to remove any excess moisture. Optionally (and not illustrated), the shell material may rest in a holding tank before being passed to the drying device 62 . Many types of drying equipment are known to a person skilled in the art and could be used as drying device 62 . In a preferred embodiment, drying device 62 is a rotary dryer. In a preferred embodiment, the drying device 62 operates within a temperature range between 50 degrees to 350 degrees Celsius. It is important to not perform the drying stage at a temperature that would calcine the calcium carbonate; generally, the temperature should be kept well below 800 degrees Celsius.
The system and apparatus described above can produce a calcium carbonate product in flake form with a purity between 98% and 100% calcium carbonate.
The calcium carbonate can then be subject to further processing as desired for the end-market. The calcium carbonate product can be packaged as is into various forms of sanitary packaging, or further passed through a mill capable of super-fine grinding to a smaller/finer particle sizes, followed by finished goods packaging, depending upon the target market and/or application.
Although the foregoing description and accompanying drawings relate to specific preferred embodiments of the present invention as presently contemplated by the inventor, it will be understood that various changes, modifications and adaptations may be made without departing from the spirit of the invention. | A method and system is provided to separate calcium carbonate inorganic eggshell from the inner lining of organic protein-based membrane in eggshell by-product. The method involves three phases: mechanical agitation/separation, functional chemical digestion and refining chemical digestion. In the mechanical stage, agitation and sieving are used to remove large pieces, and the majority of, membrane material. In the functional chemical digestion stage, the by-product is processed through at least one basic solution to remove additional organic membrane and impurities. In the refining chemical digestion stage, the remaining organic membrane and impurities are removed. The purified calcium carbonate is then rinsed and dried, in preparation for further refinement and processing to finished goods specifications. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Sporting Goods; Hunting Accessories
2. Description of the Prior Art
Occasionally, a descriptive term in this application may be shortened so as to recite only a part rather than the entirety thereof as a matter of convenience or to avoid needless redundancy. In instances in which that is done, applicant intends that the same meaning be afforded each manner of expression. Thus, the term segment connecting hook might be used in one instance but in another, if meaning is otherwise clear from context, expression might be shortened to connecting hook or merely hook. Any of those forms is intended to convey the same meaning.
The term emplace or any of its forms when used in this application means the joining of two objects or parts so as to unite them in a reasonably easily removable way, such as the slipping of a loop over the end of a simple bow limb (100) or over a tine (15) of a segment connecting hook (12), discussed ante. The word emplace is also consistent in meaning with the word "detachable" as occasionally used in common parlance but not in this application, since it is derived from the root word attach. The term attach or fasten or any of their forms when so used means that the juncture is of a more or less permanent nature, such as might be accomplished by nails, screws. welds or adhesives. Employment of the words connect or join or any of their forms is intended to include the meaning of both in a more general way.
The archer's bow, at least in its most primitive configuration, is an ancient device. It has been employed in warfare, game hunting and for sport.
The efficacy of an archer's bow is attributable in part to the tensioned resiliency of the bow limb (100), due in part to its curvature but also in part to bowstring length, strength and even in some instances, inherent flexibility.
In general, the bow in its most elemental construction consists of a bow limb (100) and a bowstring, one end of which is connected to the limb's respective ends (102). Over the ages, refinements have been devised which improved its range, power, accuracy, portability and overall efficiency. Numerous kinds of systems and mechanisms have been devised in the past. Applicant is aware of none, however, which permit easy and convenient emplacement and removal of bowstring segments--that is, which are substitutive in character.
More recently, the archer's bow has been embellished with fairly complex gadgetry. Modern improvements such as that featured in the Cruise patent, ante, provide a wheel and pulley mechanism (103) with the line anchored within it at certain attachment points or strung over and through it unanchored. The wheel and pulley mechanism (103) may be configured so as to provide what is widely recognized in the prior art as a cam or center offset effect operation. A bow employing such a system (103) is occasionally referred to as a compound one, as distinguished from a simple or elementary one. As explained ante, the term bow limb covers in this application the load supporting structure of both the simple and complex bow.
There is a great need in archery for insertion, withdrawal or substitution of segments into an existing bowstring. A segment might be inserted into the bow system in order to increase the length of the line or bowstring by emplacing it where there was none before; or by substituting it for an existing shorter one. It would be conversely possible to shorten the line. Emplacement might also be made to substitute a segment for another which has been weakened by use; or to add elasticity, on the one hand, or rigidity, on the other, to the existing line. The need to be met in archery is that of enhancement of control over the features of strength, flexible resiliency and accuracy attending operation of the bow. It is the bow limb (100) and line--that is, the bowstring--which receive the benefits of the forces at work in its use.
The bowstring becomes impaired by wear and tear through repeated use. It tends to stretch over time and thereby affect the bow's power and accuracy. It may also break if sufficiently weakened. There are also occasions when it would be suitable to substitute a bowstring of one configuration, including length, for another.
Attempts to date to deal with those needs have almost exclusively been directed along avenues other than bowstring substitution--that is, construction in separate parts. Many of the devices of the prior art do involve separate parts constructed for bow assembly, but all too often, accuracy and power, not to mention operator safety, have become impaired because of the flailing or undue oscillation of some of the parts upon release of the bowstring.
In one embodiment of U.S. Pat. No. 5,031,599 issued to Cruise, a bowstring receiving hook is swaged into the end of a leader attached to the bow limb. The term swage and its forms generally entails winding a string or wire around a hook and hammering the hook over a properly shaped anvil to cause it to embed the string or wire in more or less permanent fashion. The end of the bowstring itself is left unswaged to permit emplacement upon the hook.
Forms of connection other than swaging may be employed, such as that shown in U.S. Pat. No. 5,381,589 issued to Bailey, one involving a combination of hitch type string fastening. However, while that device may present dependable fastening means, it would be cumbersome for use in archery.
That embodiment of the Cruise device, therefore, permits emplacement of a properly looped bowstring upon the bow. Thus, one bowstring could be substituted for another in that embodiment. The Cruise device was created primarily to address needs other than bowstring substitution. However, efficient and convenient bowstring substitution does present an important need and experience indicates that the emplacement of the bowstring in the Cruise embodiment may not be dependable under all circumstances. The high degree of tension produced during the bowstring's stretch during operation or oscillation upon its release could cause the bow limb attaching segment to weaken or break. A means of bowstring emplacement which distributes the tension over a greater portion or upon additional attachment sites of the bow limb attachment segment is needed.
It would also be desirable in use of the bow if the archer were permited to shift operation, without bowstring disassembly and assembly from one bowstring configuration to another. That need may be met in an embodiment which permits two lengths of bowstring to be simultaneously emplaced side-by-side so that the archer might make spur-of-the-moment selection between them when shifting from one operation to another. Applicant has observed that such dual emplacement need not impair the bow's operation. To the contrary, his invention permits efficient and accurate bow use while providing the convenience of alternative bowstring selection to address varied circumstances.
Another need in archery is that of improved sighting means. Various means have been devised. U.S. Pat. No. 5,086,567 issued to Tutsch features a desirable system of multiple aiming points. Many devices employ a simpler embodiment, however, commonly referred to as a peep sight--that is, a tiny ring embedded into the bowstring at what is eye level during operation. By peering through the ring, the archer is provided a visual guide for distance and lateral angle of aim. The strands of a bowstring may be separated to permit insertion of the sight. However, such partial undoing of the strands weakens the bowstring.
Dual bowstring configuration is referred to when words are used permitting employment of one or more of the encircling ring assemblies (1) or one or more of the midsegment assemblies (3) in side-by-side fashion. If dual bowstring emplacement were employed by the operator, emplacement of the sighting ring between the two side-by-side bowstring segments would be permitted as an option, thereby addressing the need for ring emplacement without bowstring strand separation. A single segment (50) with a peep sight embedded into it might also be substituted for another bowstring segment. A short peep sight featured segment might be inserted as one of a number of end to end segments within the span (104) between each of the bow's tethering points (101). A sight based upon the Tutsch structure, supra, could also be so inserted.
The invention hereof has been presented in terms of application to an archery bow. Numerous applications of it can be devised in connection with load binding systems in industrial, agricultural and generally commercial pursuits. Thus, a segment might be inserted into or substituted for another segment in a load securing line employed for transportation or storage.
SUMMARY OF THE INVENTION
The invention comprises an archery bow limb (100) assembly which permits quick, efficient insertion of one or more segments (2, 5, 8) or assemblies thereof (1, 3, 31) into it or substitution of one given configuration of them for another of different configuration.
On the one hand, an archery bow may be configured to comprise an encircling ring assembly (1) comprised of one or more encircling line segments (2), such as in a compound bow, where a line might be run continuously as a closed loop, that is--without attachment--through wheel and pulley mechanisms (103) at each bow limb end (102). The archer may operably insert an encircling line segment (2) or substitute one segment (2) for another (2).
On the other hand, the archery bow may be configured with an anchoring assembly (31) comprised of a pair of anchoring segments (8) which attach either to the ends (102) of the limbs (100) of a simple bow or to tethering points (101) within the wheel and pulley mechanism (103) of a compound bow. The bow may additionally be configured with substitutive midsegments (5) and segment connecting hooks (12) with loop engagement tines (15) disposed upon the hook ends (13) to engage hook loops (7, 11) of either of the ends of any segments.
The archer may operably substitute a midsegment (5) or midsegment assembly (3) of given configuration for another of either which is differently configured (3, 5). If more than one differently configured midsegment assemblies (3) are employed, the operator may make a spur-of-the-moment switch between them without disassembly and assembly. Within limits of practicality any number of midsegments (5) may be inserted end to end as a midsegment assembly (3). Moreover, certain types of sighting mechanisms including a peep sight constructed within a midsegment might be inserted into the assembly (3).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the entire assembly in its relationship to a bow limb (1);
FIG. 2 is a perspective view of a segment connecting hook (12), showing the spacial relationship of its tines (15);
FIG. 3 is an overhead, or plan, view of a segment connecting hook (12);
FIG. 4 illustrates the manner of connection between the bow limb anchoring string segment's hook loops (11) and one of the segment connecting hooks (12) as well as between the midstring segment's hook loop (7) and the hook (12);
FIG. 5 represents what is, in view of structural symmetry, both a front and a side view of a segment connecting hook (12);
FIG. 6 depicts a compound bow comprising a wheel and pulley mechanism (103) and an encircling ring assembly (1);
FIG. 7 represents a compound bow comprising a wheel and pulley mechanism with an anchoring assembly (31) as opposed to the encircling ring type (1).
FIG. 8 is an overhead view of an embodiment of a segment connecting hook (12) configured with three tines (15) at each end;
FIG. 9 is such a view of a hook (12) configured with four tines (15) at each end;
FIGS. 10 and 11 show perspective views of the three and four tined (15) embodiments, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The term bow limb (100) when employed herein includes both the ends of a simple bow, and the wheel and pulley mechanism (103) of a compound bow, both of which are discussed in greater detail herein. Embodiments of both may comprise tethering points (101) to which anchoring segments attach. However, an embodiment of the compound bow may instead employ an encircling ring assembly (1), also addressed herein and, thus, be devoid of tethering points (101).
In this application, the term segment, if unmodified by adjective, has reference to all of a midsegment (5), an anchoring segment (8), an encircling line segment (2) and an arrow impelling segment (105). If by context or explicit reference, a particular type of segment is addressed, that meaning is also within the scope of the word segment. The term line is used herein in a generic sense to include braided hemp, rope, string, leather thong, wire, sheathed cable, chain or the like--any elongated cord-like material that might be employed in any part serving as a bowstring of an archer's bow or as part of a wheel and pulley mechanism (103) of a compound bow, discussed ante.
This substitutive archery bowstring segment depending assembly may, as indicated, be configured either as an encircling ring assembly (1) or an anchoring assembly (31). A simple bow is comprised of a pair of anchoring segments (8) and segment connecting hooks (12). It may additionally be comprised of a midsegment assembly (3) comprised in turn of one or more midsegments (5). In the type of compound bow comprising an encircling ring assembly (1), that assembly (1) is comprised of two primary parts which are: One or more encircling line segments (2) and one or more segment connecting hooks (12). An anchoring assembly (31), when present in a compound bow in lieu of an encircling ring assembly (1), is comprised of a pair of anchoring segments (8), segment connecting hooks (12) and might additionally be comprised of one or more encircling line segments (2).
In a simple bow, the part of the line running from one bow limb end (102) to the other is by definition the tethering point-to-tethering point span (104), which is also the system's arrow impelling segment of the line (105). In a compound bow, a first tethering point (101) may be an attachment point within a first pulley wheel of a wheel and pulley mechanism (103) at a first bow end (102) and line may run from there to a second pulley wheel at the second bow limb end (102), then return to the first pulley wheel, cross back again to the second one where it may find its second tethering point (101), such as shown in FIG. 7. However, what is referred to as the arrow impelling segment (105) is only that part of the tethering point-to-tethering point span (104) which runs from one bow limb end (102) to the other (102).
As a matter of definition, it is occasionally stated herein that a bow limb (100) may comprise either the type associated with a simple bow or the type associated with a complex bow. Thus, the wheel and pulley mechanism (103) of a complex bow may be characterized as being part of the bow limb (100). In other instances, whee thought necessary for sake of clarification, it is stated herein that a wheel and pulley mechanism may be mounted upon a bow limb (100). It is intended that the same meaning be accorded either form of expression.
An anchoring assembly (31) might often be employed. The midsegment assembly (3) thereof (31) is comprised of at least one midsegment (5). It (5) should be constructed of material suitable for bowstrings. Whether the number of midsegments (5) is one or more than one connected end to end, the structure comprises a midsegment assembly (3). The midsegment assembly (3) has two ends (4), one at each extremity thereof. Similarly, each midsegment (5) has two ends (6). As many midsegments (5) as considered practicable may be joined to one another end (6) to end (6) as part of the midsegment assembly (3). One or more hook loops (7) are formed at each of the midsegment's ends (6). The loops (7) may be fastened by knotting, strand splicing, enwrapment by rigid band or by numerous closely wound finer line, encirclement by a strong length of wire, stapling, heat fusion, an adhesive or any other means extant. Each loop (7) must be large enough to accommodate the connecting hook's loop engagement tines (15) described ante, but should yet be small enough to avoid interference with the bow's operation such as might otherwise occur because of entanglement or other reasons.
The anchoring segments (8) may also be constructed of the same commercially available material employed for the midsegment (5, 50). However, the anchoring segments (8) may instead consist of any of the materials included in the definition of line herein. Whereas in the bow's arrow impelling segment (105), the construction material should be suitable to the tensions present when it is drawn back from the limb (100) and the oscillations which occur upon release by the operator, it is preferred that the portion of the anchoring segments (8) which does not serve as an arrow impelling segment (105) be of very strong material for which the concerns of elasticity and resiliency of the arrow impelling segment (105) are not crucial. The anchoring segments (8), of course, both have two ends (9, 14). One of them is the bow limb tethered end (9) and the other, which is designated as an untethered end (10) before connection of the parts, becomes the midsegment assembly connecting end (14) after making such connection. At each end of the bow limb (100), the bow limb tethered end (9) is connected to a tethering point (101). As discussed, supra, the span between tethering points (104) in a simple bow comprises the line's arrow impelling segment (105). When the parts are so connected, the span (104) is said herein to be closed. One or more hook loops (11), the same as was done supra in the case of the midsegment (5), are formed at the midsegment connecting end (14) of each anchoring segment (8).
The segment connecting hooks (12) have two ends (13). The hooks (12) may be oriented in either direction so that either end (13) may perform the function the other (13) would otherwise do. One of the hook's ends (1 3) is that which connects to the midsegment (5, 50). The hook's other end (13) is that which connects to the anchoring segment (8).
Preferably, the connecting hook (12) should be small enough not to significantly affect the bow's operation. Thus, if the hook (12) were constructed of metal, its weight would affect the forces at work in movement of the line's arrow impelling segment (105). If the arrow impelling segment (105) carried too much weight, it might oscillate more vigorously and, perhaps, less smoothly. It is generally recognized as a matter of physics that an increase in weight to an oscillating object increases the period of oscillation. The most important motion of the arrow impelling segment (105) one should be concerned with is that which occurs immediately upon its release--that is, as the archer's fingers are loosened from it when shooting an arrow. That motion experienced by the arrow impelling segment (105) is its being impelled forward toward the bow limb (100). Oscillation occurs after the arrow impelling segment (105) has reached a point proximate the bow limb. If oscillation is too vigorous, a part of the bowstring assembly might become loosened and flail about or worse, might break. Thus, the hooks (12) should preferably be very small, yet large enough to receive and retain the loops (7, 11) of the respective segments (5, 8).
The connecting hooks (12) each have loop engagement tines (15), at least one of which is disposed at each end (13) of the hook (12). Preferably, the tines (15), like those of a dining fork, are curved and extend in that curve in a direction toward the hook's opposite end (13). The tines (15) need not be as elongated as those of a dining fork, however. Moreover, a straight tine (15), as distinguished from a curved one (15), will operate satisfactorily. However, curvature in the tine (15) will serve to better trap the loop (7, 11) emplaced upon it (15).
In a preferred embodiment, when there are two tines (15) disposed upon at least one of the hook's ends (13), the two (15) are oriented to point in the same direction but are oppositely and radially disposed one another. The same is true if there are two tines (15) at the opposite end of the hook (12). However, each pair of tines (15) on the hook (12) in this preferred embodiment is radially disposed so that it (15) is offset from direct alignment with the opposite pair (15) by 90 degrees. Thus, the segment connecting hook has the shape depicted in FIG. 2. If there were three or more tines (15) at each end, they should be spaced evenly in the radial sense but, again, those at one end (13), as shown in FIGS. 8-11, should be offset from those at the other end (13). This tine (15) orientation offset embodiment is preferred because it more evenly balances the stresses imparted to the system when in use. It should be apparent that if there were only one loop (11) at the anchoring segment's midsegment connecting end (14), so that connection were made with only one tine (15) of the connecting hook's end (13), there would be an imbalance in connection symmetry and the assembly might be too unstable during midsegment (5) release by the operator. However, that offset orientation is not indispensable to satisfactory bow operation. Applicant has, therefore, indicated only that it is preferred.
Upon on-site application, one of the loops (7) of each midsegment (5), whether there are one or more of such segments (5), is emplaced upon one of the tines (15) of one of the connecting hook's ends (13). Each loop (11) of the anchoring segment (8), whether there are one or more than one of such loops (11), is emplaced upon one of the tines (15) of the connecting hook's other end (13). Preferably, the anchoring segment (8, 50) is comprised of two such loops (11) and the connecting hook's end with which the anchoring segment connects (13) is comprised of two tines (15), thereby providing balanced symmetry in connection between that segment (8) and the hook (12) as shown in the embodiment of FIG. 4. | Substitutive archery bowstring assembly, certain segments of which may be removed and substituted for by one or more of different configuration, including length; and, as a separate consideration, the segment connecting hook employed in joining the members of the assembly. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND
[0003] U.S. Pat. No. 8,074,742 issued to Scott et al. discloses a reaming tool for use during emplacement of tubular strings such as casing or liner in wellbores drilled through subsurface formations.
[0004] A rotary power section described in the above referenced patent may include a turbine section operated by flow of drilling or other fluid through an interior of the wellbore tubular being emplaced so that a reaming head can rotate without rotation of the wellbore tubular. It has been observed that fluid pressure used to operate the rotary power section may place large axial loading on bearings included in the power section to support such loading. It is desirable to have a reaming tool power section for use in emplacement of wellbore tubular that has more balanced axial loading resulting from fluid pressure.
SUMMARY
[0005] An apparatus for cutting a wellbore according to one aspect includes the apparatus a motor having a stator and a rotor. The rotor has an output shaft connected to a cutting structure so as to drive the cutting structure. The stator and rotor are spaced radially outwardly of the axis of rotation of the rotor such that at least one of the stator and the rotor is formed with an access bore that extends through the motor to a position adjacent the cutting structure. A further object can pass therethrough, without obstruction from the stator and rotor. The further object comprises a further cutting structure of the apparatus. A flow diverter is disposed in the motor proximate a connection between the motor and the wellbore tubular, the flow diverter having a first fluid outlet in fluid communication with a power section of the motor, the flow diverter having a second fluid outlet in fluid communication with the access bore. The flow diverter is coupled to the stator such that axial loading created by fluid pressure is substantially transferred to the stator.
[0006] Other aspects and advantages will be apparent from the description and claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a sectional side view of an example reaming tool including an annular rotary power section
[0008] FIG. 2 is another sectional side view of the reaming tool of FIG. 1 .
[0009] FIG. 3 is a more detailed part sectional, part cut away side view of the reaming tool of FIG. 1 showing a further cutting structure in two consecutive positions, with part of the apparatus in phantom;
[0010] FIG. 4 is a more detailed part sectional, part cut away side view of the reaming tool of FIG. 2 showing a further cutting structure in three consecutive positions.
[0011] FIG. 5 shows a flow diverter inside the reaming tool to provide fluid flow to both the rotary power section (turbine) and to an interior of the reaming tool and reaming head.
DETAILED DESCRIPTION
[0012] Most of the details of operating a fluid powered reaming tool for use with inserting a casing or liner into a wellbore drilled through subsurface formations are set forth in U.S. Pat. No. 8,074,742 issued to Scott et al. and incorporated herein by reference. Relevant portions of the foregoing patent will be set forth below to explain operation of a pressure balanced rotary power unit for a reaming tool used with inserting casing or liner into a wellbore.
[0013] FIG. 1 shows a lower part of a wellbore 1 formed by a prior drilling operation. The wellbore 1 is being lined or already has been lined with a “string” of wellbore tubulars in the form of a casing 3 (or a liner) having a lowermost end 4 . An annular space 6 is defined between the outer surface of the casing 3 and the wall of the wellbore 1 . The annular space 6 may be filled with cement once drilling and reaming operations are complete.
[0014] A reaming tool 5 comprises a cutting structure which, in this example, may be a reamer shoe 7 connected to an output shaft 9 . Rotation of the output shaft 9 rotates the reamer shoe 7 . In this example the reamer show 7 can be sacrificed by drilling or reaming after the casing 3 (or liner) is moved to its intended depth in the wellbore 1 .
[0015] The output shaft 9 comprises a rotor of a motor generally indicated at 11 . The rotor 11 in this example may be radially inward of a radially outward stator 13 fixedly connected to the lowermost end 4 of the casing 3 .
[0016] The stator 13 may be concentric with and extends around the periphery of the output shaft 9 and may thus be of hollow tubular form when viewed from the side or in transverse cross section. The stator 13 is therefore radially spaced from the rotational axis 10 of the output shaft 9 such that it does not, when viewed in cross section from the side, extend across the output shaft 9 . The output shaft 9 may be formed with an access bore 15 that extends along the length of the motor 11 from the reamer shoe 7 to the opposite, distal longitudinal end of the output shaft 9 , that is, the longitudinal end adjacent the lowermost end 4 of the casing 3 . The access bore 15 in this example may be co-axial with the axis of rotation 10 of the output shaft 9 . The access bore 15 may also extend in a direction aligned with but not co-axial with, the axis of rotation 10 .
[0017] The access bore 15 may have an internal diameter selected to receive and enable free passage therethrough of a further object and may arranged such that the further object can be located directly adjacent the reamer shoe 7 . The further object could comprise any desired device which may include, for example, a sensing device to transmit a signal indicative of physical parameters relevant to the cutting process. In the example, the further object may comprise a further cutting structure comprising a drill bit 17 connected to a drill pipe, pipe string or coiled tubing, shown generally at 19 .
[0018] In using the apparatus 5 , the casing 3 is moved through the wellbore 1 , which has already been drilled to a selected depth in the subsurface. The motor 11 may be activated to drive the output shaft 9 to rotate the reamer shoe 7 by pumping fluid through an interior of the casing 3 or liner. Rotating the reamer shoe 7 aids movement (“running”) of the casing 3 into the wellbore 1 to the selected depth.
[0019] Once the casing 3 has reached the selected depth, the motor 11 may be deactivated. The drill bit 17 and drill string 19 may then run be into the casing 3 . When the drill bit 17 reaches the lowermost end 4 of the casing 3 , the drill bit 17 may be moved into the access bore 15 of the output shaft 9 so as to effectively pass through the interior of the motor 11 , i.e., the functional parts of the motor are radially outward of the output shaft 9 and drill bit 17 and do not obstruct passage of the drill bit 17 toward the reamer shoe 7 . The motor workings do not therefore require drilling out or removal to allow the drill bit 17 access to the reamer shoe 7 .
[0020] When the drill bit 17 reaches the reamer shoe 7 , rotation of the drill bit 17 allows the drill bit 17 to cut through the sacrificial reamer shoe 7 so as to project beyond the reamer shoe 7 so as to move into contact with material to be drilled through to form a subsequent section of wellbore.
[0021] Referring to FIG. 2 another example reaming tool 21 is shown with like features being given like references to the reaming tool 5 described above. In the present example a modified output shaft 22 is concentric with and is radially outward of the motor stator. In the present example the motor stator may comprise a radially inward tubular stator 23 fixed to the lowermost end 4 of the casing 3 or liner. The tubular stator 23 may be formed with an access bore 25 that extends from the reamer shoe 7 to the lowermost end 4 of the casing 3 , in the present example co-axially with the axis of rotation 10 of the modified output shaft 22 . A further object, which in this example again comprises the drill bit 17 and drill pipe 19 , may be run into the access bore 25 in the tubular stator 23 .
[0022] Referring to FIG. 3 a flared portion 14 of the radially outward stator 13 may be rotationally locked to an interior surface of the lowermost end 4 of the casing 3 . Such locking can be achieved using any suitable locking means.
[0023] The radially inward output shaft rotor 9 may be rotatably mounted on the stator 13 using a suitable combination of rotational bearings 27 . Additionally a plurality of axial thrust bearings 29 may provided to limit axial movement between the rotor 9 and the stator 13 while still allowing relative rotation of these components. The thrust bearings 29 can be arranged to allow limited axial movement if desirable.
[0024] Any desired type, number and position of bearings may be used as required to deal with the loads generated. The motor rotor 9 and stator 13 can comprise any desired structure and components to generate power to rotationally drive the rotor 9 . In this example, the rotor 9 and stator 13 together comprise a turbine arrangement wherein the rotor 9 comprises turbine blades 30 arranged to deflect fluid pumped between the rotor 9 and stator 13 so as to convert some of the energy of the fluid into rotation of the rotor 9 and hence the reamer shoe 7 .
[0025] The stator 13 comprises a fluid inlet 31 between the stator 13 and the internal rotor 9 , at the lowermost end 4 of the casing 3 , the fluid inlet 31 being radially outwardly spaced from the axis 10 .
[0026] A flow diverter 32 (shown in phantom) is provided adjacent the fluid inlet 31 and serves to divert fluid pumped down the casing 3 radially outwardly so as to flow into the fluid inlet 31 .
[0027] The fluid flow path is indicated by arrows ‘A’. Having been diverted by the flow diverter, the fluid enters the inlet 31 adjacent the lowermost casing end 4 . The fluid is pumped in a direction generally parallel to the axis of rotation 10 of the rotor 9 in the void defined between the concentric rotor 9 and stator 13 , and subsequently exits the void and the turbine arrangement radially inwardly through the outlet 33 into the access bore 15 . The fluid then travels along the access bore 15 and subsequently generally radially outwardly and/or downwardly through jetting apertures (not shown) formed in the reamer shoe 7 . The fluid thus functions as a lubricant for the reamer shoe 7 before being forced up the annular space 6 between the casing 3 and the wellbore 1 .
[0028] Referring additionally to FIG. 4 , a flared portion 34 of the radially inward stator 23 of the second described reaming tool (in FIG. 2 ) 21 may be locked to the interior surface of the lowermost end 4 of the casing 3 . This can again be achieved using any suitable locking means.
[0029] The bearings, turbine arrangement and fluid flow path are otherwise similar to those described above with reference to FIG. 3 . In each example, the bearings could be lubricated by the fluid used to drive the turbine arrangement. In each example, the rotor of the motor could be integral with the output shaft or that these could comprise separate components connected together. Likewise it is possible that the output shaft may be integral with the cutting structure or that these could comprise separate components connected together, e.g., by threaded couplings of types known in the art.
[0030] As explained in the Background section herein, the axial thrust bearings (e.g., 29 in FIG. 3 ) are subject to loading resulting from pressure drop in the motor. Referring to FIG. 5 , a portion of an example motor in a reaming tool is shown having balanced fluid pressure that may relieve some of the pressure-induced axial loading. The reaming tool motor section shown in FIG. 5 may be configured with an external stator 13 and internal output shaft (rotor) 9 as in FIG. 1 . It should be understood that the motor arrangement of FIG. 2 may be used to the same effect. In FIG. 5 , the flow diverter 32 may be configured to have a first fluid outlet 35 that directs part of the fluid flow from within the casing 3 or liner into the motor 11 . A second fluid outlet 34 directs another part of the fluid flow from within the casing into the interior of the output shaft 9 (i.e., the access bore), and thence to the reamer shoe ( 7 in FIG. 1 ). If a motor such as shown in FIGS. 2 and 4 is used, the second fluid outlet will direct the other part of the fluid flow into the interior of the stator ( 23 in FIG. 4 ), i.e., the access bore, and thence to the reamer shoe 7 through a suitable bearing and flow crossover arrangement (not shown).
[0031] In the drilling or reaming of a wellbore with a motor which uses fluid flow as a power source there is a pressure drop through the motor. This pressure drop acts against the top most end of the rotary power output shaft in the manner of acting against a piston.
[0032] The cross sectional area of the equivalent piston is generally considered to be a function of the inside diameter of the body of the tool. This cross sectional area multiplied by the pressure drop through the motor is translated into an axial load through the motor which acts against any bearing system in the motor for carrying axial load. The pressure drop caused axial loading may be substantial.
[0033] The motor section shown in FIG. 5 seeks to reduce the hydraulically caused axial loading by manipulation of the effective piston area under hydraulic pressure. As the fluid passes through the motor 11 assembled to the output shaft 9 and reaches the axial end of the motor 11 there will be an associated pressure drop. The lowered pressure is also present at the cross section of the upper part of the output shaft 9 . By way of explanation, there are essentially two piston areas. There is a primary piston area created by parts ‘B’ & ‘A’, this piston area is connected by threads T to the body 13 . The primary piston area carries the majority of hydraulically induced pressure loading by carrying this load through into the body 13 and not into the axial bearings. A secondary or minor piston area is created by the cross section of the rotor blade area. There are circumferentially positioned axial bypass ports in part A, which allows the drilling fluid to enter into the motor 11 . The motor 11 has a smaller effective piston area than parts B & A combined. In this way axial load reduction may be reduced up 80% of that of an uncompensated system.
[0034] It can be understood that as the annular motor has a relatively small cross section as contrasted with the output shaft there will be a resultant reduction in hydraulic load imparted to the axial thrust bearings while still maintaining a desired relatively high pressure without detriment to produced power and hole cleaning efficiency when the drilling fluid is ported to the wellbore annulus ( 6 in FIG. 1 ). This reduction in axial loading which is imparted to the axial bearing of the power output shaft facilitates a reduction in the number of bearing sets required to carry the axial loading efficiently.
[0035] 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. | An apparatus for cutting a wellbore includes a motor having a stator and a rotor. The rotor has an output shaft connected to a cutting structure. The stator and rotor are spaced radially outwardly of the axis of rotation of the rotor such that at least one of the stator and the rotor had an access bore extending through the motor to adjacent the cutting structure. A further object can pass therethrough, without obstruction. The further object comprises a further cutting. A flow diverter is disposed in the motor proximate a connection between the motor and a wellbore tubular, and has a first fluid outlet in fluid communication with a power section of the motor, and a second fluid outlet in fluid communication with the access bore. The flow diverter is coupled to the stator such that axial loading created by fluid pressure is substantially transferred to the stator. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Section 365(c) continuation of International Application No. PCT/EP2005/006289 filed 11 Jun. 2005, which in turn claims the priority of DE Application 10 2004 030 938.8 filed Jun. 26, 2004, each of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to five or four novel genes and their gene products from Bacillus licheniformis and sufficiently similar genes and proteins which are involved in vivo in the formation, the modification and/or the degradation of polyamino acids, and can be used for this purpose, and, based thereon, improved biotechnological production methods by microorganisms which are characterized by an inactivation or activation of these genes.
BACKGROUND OF THE INVENTION
[0003] The present invention is in the area of biotechnology, in particular the preparation of viable products by fermentation of microorganisms able to form the viable products of interest. This includes for example the preparation of low molecular weight compounds, for instance of dietary supplements or pharmaceutically relevant compounds, or of proteins for which, because of their diversity, there is in turn a large area of industrial uses. In the first case, the metabolic properties of the relevant microorganisms are utilized and/or modified to prepare the viable products; in the second case, cells which express the genes of the proteins of interest are employed. Thus in both cases, genetically modified organisms (GMO) are mostly involved.
[0004] There is an extensive prior art on the fermentation of microorganisms, especially also on the industrial scale; it extends from the optimization of the relevant strains in relation to the formation rate and the nutrient utilization via the technical design of the fermenters and up to the isolation of the valuable products from the relevant cells themselves and/or the fermentation medium. Both genetic and microbiological, and process engineering and biochemical approaches are applied thereto. The aim of the present invention is to improve this process in relation to a common property of the microorganisms employed, which impairs the actual fermentation step, specifically at the level of the genetic properties of the strains employed.
[0005] For industrial biotechnological production, the relevant microorganisms are cultured in fermenters which are configured appropriate for their metabolic properties. During the culturing, they metabolize the substrate offered and, besides the actual product, normally form a large number of other substances in which there is ordinarily no interest and/or which—as explained hereinafter—may lead to difficulties in the fermentation or the working up.
[0006] Fermentations are normally very complicated processes in which a large number of different parameters must be adjusted and monitored. Thus, for example, aerobic processes are very often involved, meaning that the microorganisms employed must be supplied adequately with oxygen throughout the fermentation (control of the aeration rate). Further examples of such parameters are the reactor geometry, the continuously changing composition of the nutrient medium, the pH or the CO 2 formation rate. A particularly important parameter both in terms of the economics and in relation to the process management per se is the necessary energy input, for example via agitation systems which ensure that the reactor content is mixed as thoroughly as possible. In addition, besides the substrate distribution, also an adequate supply of oxygen to the organisms is ensured.
[0007] After completion of the fermentation it is normally necessary, besides the removal of the producer organisms, for the valuable product of interest to be purified and/or concentrated from the so-called fermenter slurry. The working up process can include for example various chromatographic and/or filtration steps. Thus, besides the content of valuable products, also decisive for the success of the overall working up process are the biophysical properties of the fermenter slurry, especially its viscosity immediately after completion of the fermentation.
[0008] The properties thereof are also influenced by the metabolic activities of the chosen microorganisms, it also being possible for unwanted effects to occur. These include for example a frequent increase in the viscosity of the nutrient medium during the fermentation. This impairs the mixing and thus the transport of matter and the oxygen supply inside the reactor. Additional difficulties mostly arise during the subsequent working up because increased viscosities considerably impair for example the efficiency of filtration processes.
[0009] It is known in particular that species of the genus Bacillus produce slime which consists essentially of poly-gamma-glutamate (PGA) and/or -aspartate, meaning polyamino acids linked via the relevant gamma peptide bonds. In scientific studies on Bacillus subtilis it is mainly the three genes ywsC, ywtA and ywtB and the gene products derived therefrom which are connected with the production of poly-gamma-glutamate; the gene product of ywtD is involved in the degradation. The general designation “ywt” for genes is in this connection synonymous with the abbreviations “cap” and “pgs” which are in common use for the same functions. This is explained below.
[0010] The publication “Physiological and biochemical characteristics of poly gamma-glutamate synthetase complex of Bacillus subtilis ” (2001) by M. Ashiuchi et al., in Eur. J. Biochem ., volume 268, pages 5321-5328, describes the PgsBCA (poly-gamma-glutamate synthetase complex BCA) enzyme complex, which consists of the three subunits PgsB, PgsC and PgsA, from B. subtilis . This complex is, according to this, an atypical amide ligase which converts both the D and the L enantiomer of glutamate into the corresponding polymer. According to this publication, a gene disruption experiment described therein is to be regarded as proof that this complex is the only one catalyzing this reaction in B. subtilis.
[0011] Y. Urushibata et al. demonstrate in the publication “Characterization of the Bacillus subtilis ywsC gene, involved in gamma-polyglutamic acid production” (2002), in J. Bacteriol ., volume 184, pages 337-343, inter alia via deletion mutations in the three genes ywsC, ywtA and ywtB, that the three gene products responsible in B. subtilis for the formation of PGA are encoded by these three genes. They form in this sequence and together with the subsequent gene ywtc a coherent operon in this microorganism.
[0012] The fact that a further gene relevant for the metabolism of PGA is located in the genome of B. subtilis downstream from ywtC in its own operon is shown by T. Suzuki and Y. Tahara in the publication “Characterization of the Bacillus subtilis ywtD gene, whose product is involved in gamma-polyglutamic acid degradation” (2003), J. Bacteriol ., volume 185, pages 2379-2382. This gene codes for a DL-endopeptidase which is able to hydrolyze PGA and thus can be referred to as gamma-DL-glutamyl hydrolase.
[0013] An up-to-date survey of these enzymes is additionally provided by the article “Biochemistry and molecular genetics of poly-gamma-glutamate synthesis” by M. Ashiuchi and H. Misono in Appl. Microbiol. Biotechnol ., volume 59, pages 9-14 of 2002. The genes homologous to pgsB, pgsc and pgsA and coding for the PGA synthase complex in B. anthracis are referred to therein as capB, capC and capA. The gene located downstream is referred to according to this article as dep (for “D-PGA depolymerase”) in B. anthracis and as pgdS (for “PGA depolymerase”) in B. subtilis.
[0014] In the current state of the art, these enzymic activities are already in positive use mainly for preparing poly-gamma-glutamate as raw material, for example for use in cosmetics, although their exact DNA sequences and amino acid sequences have not to date been known—especially from B. licheniformis . Thus, for example, the application JP 08308590 A discloses the preparation of PGA by fermentation of the PGA-producing strains itself, namely of Bacillus species such as B. subtilis and B. licheniformis ; the isolation of this raw material from the culture medium is also described therein. B. subtilis var . chunkookjang represents, according to the application WO 02/055671 A1, a microorganism which is particularly suitable therefor.
[0015] Thus, in some fermentations there is an interest in GLA as the valuable product to be produced by the fermentation.
[0016] However, the interest in all other fermentations is to prepare other valuable products; in this connection, the formation of polyamino acids means, for the reasons stated above, a negative side effect. A typical procedure for mastering the increased viscosity of the fermentation medium attributable to the formation thereof is to increase the agitator speed. However, this has an effect on the energy input. In addition, the fermented microorganisms are exposed thereby to increasing shear forces representing a considerable stress factor for them. In the end, very high viscosities cannot be overcome even thereby, so that premature termination of the fermentation may be necessary, although production could otherwise be continued.
[0017] Slime formation, as a negative side effect of numerous fermentation processes, may thus have negative effects on the overall result of fermentation for diverse reasons. Conventional methods for successfully continuing fermentations in progress despite an increasing viscosity of the nutrient medium can be designated only as inadequate, especially because they do not represent a causal control.
SUMMARY OF THE INVENTION
[0018] The more pressing problem was thus to suppress as far as possible an unwanted formation of slime, especially a slime attributable to poly-gamma-amino acids such as poly-gamma-glutamate, during the fermentation of microorganisms. It was intended in particular to find a solution representing a causal control. A further aspect of this problem is the provision of the relevant genes for a positive utilization of the GLA-synthesizing gene products and for the degradation and/or modification thereof.
[0019] Each of the following proteins involved in the formation or degradation of polyamino acids represents in each case a partial solution of in principle equal value for this problem:
YwsC (CapB, PgsB) which is encoded by a nucleotide sequence ywsC which shows at least 80% identity to the nucleotide sequence indicated in SEQ ID NO. 1; YwsC′ (as truncated variant of YwsC) which is encoded by a nucleotide sequence ywsC′ which shows at least 83% identity to the nucleotide sequence indicated in SEQ ID NO. 3; YwtA (CapC, PgsC) which is encoded by a nucleotide sequence ywtA which shows at least 82% identity to the nucleotide sequence indicated in SEQ ID NO. 5; YwtB (CapA, PgdA) which is encoded by a nucleotide sequence ywtB which shows at least 72% identity to the nucleotide sequence indicated in SEQ ID NO. 7; and YwtD (Dep, PgdS) which is encoded by a nucleotide sequence ywtD which shows at least 67% identity to the nucleotide sequence indicated in SEQ ID NO. 9.
[0025] As is evident for example from the mentioned publication by Urushibata et al., the four or three genes involved in GLA formation are present in B. subtilis in succession on the same operon. ywtD is located there directly downstream. It is to be expected that this organization of these components acting together in vivo in a complex, and of the downstream component acting on the polyamino acid formed thereby will also be found in many further microorganisms, in particular of the genus Bacillus . Thus, besides the common biochemical function, there also exists at the genetic level an aspect producing unity of the invention.
[0026] Further partial solutions are represented by the relevant nucleic acids ywsC, ywsC′, ywtA, ywtB and ywtD and, based thereon, the use of relevant nucleic acids for reducing the formation of slime attributable to polyamino acids during the fermentation of the microorganism, and corresponding methods for fermentation of microorganisms. In the reduction according to the invention of the formation of slime at the genetic level, at least one of the genes ywsC, ywsC′, ywtA or ywtB is functionally inactivated and/or the activity of ywtD is enhanced. In addition, there is the positive use of these genes or of the derived gene products for the preparation, modification or degradation of poly-gamma-glutamate.
[0027] This invention which is applicable in principle to all fermentable microorganisms, especially to those of the genus Bacillus , leads to the microorganisms employed for the fermentative production of valuable products other than polyamino acids, in particular of pharmaceutically relevant low molecular weight compounds or of proteins, being prevented at the genetic level from forming polyamino acids, especially GLA, or immediately degrading them again. On the one hand, this has an advantageous effect on the viscosity of the culture medium and additionally on the mixability, the oxygen input and the energy to be expended, and on the other hand the working up of the product of interest is considerably facilitated. In addition, most of the raw materials employed, for instance the N source, is not converted into a product of no interest, so that overall a higher fermentation yield is to be expected.
[0028] According to a further aspect of this invention, said genes are now available for a positive use of the GLA-synthesizing gene products or for their degradation and/or modification, specifically by the derived proteins YwsC, YwsC′, YwtA, YwtB and/or YwtD being produced biotechnologically and being introduced in the cells producing them or independently thereof as catalysts into appropriate reaction mixtures.
BRIEF DESCRIPTION OF THE FIGURES
[0029] FIG. 1 : Alignment of the gene ywsC (SEQ ID NO. 1) from B. licheniformis DSM 13 (B. l. ywsc) with the homologous gene ywsC from B. subtilis (B.s. ywsc).
[0030] FIG. 2 : Alignment of the gene ywsC′ (SEQ ID NO. 3) from B. licheniformis DSM 13 (B.l. ywsC′) with the homologous gene ywsC from B. subtilis (B.s. ywsC).
[0031] FIG. 3 : Alignment of the gene ywtA (SEQ ID NO. 5) from B. licheniformis DSM 13 (B.l. ywta) with the homologous gene ywtA from B. subtilis (B.s. ywtA).
[0032] FIG. 4 : Alignment of the gene ywtB (SEQ ID NO. 7) from B. licheniformis DSM 13 (B.l. ywtB) with the homologous gene ywtB from B. subtilis (B.s. ywtB).
[0033] FIG. 5 : Alignment of the gene ywtD (SEQ ID NO. 9) from B. licheniformis DSM 13 (B.l. ywtD) with the homologous gene ywtD from B. subtilis (B.s. ywtD).
[0034] FIG. 6 : Alignment of the protein YwsC (SEQ ID NO. 2) from B. licheniformis DSM 13 (B.l. YwsC) with the homologous protein YwsC from B. subtilis (B.s. YwsC).
[0035] FIG. 7 : Alignment of the protein YwsC′ (SEQ ID NO. 4) from B. licheniformis DSM 13 (B.l. YwsC′) with the homologous protein YwsC from B. subtilis (B.s. YwsC).
[0036] FIG. 8 : Alignment of the protein YwtA (SEQ ID NO. 6) from B. licheniformis DSM 13 (B.l. YwtA) with the homologous protein YwtA from B. subtilis (B.s. YwtA).
[0037] FIG. 9 : Alignment of the protein YwtB (SEQ ID NO. 8) from B. licheniformis DSM 13 (B.l. YwtB) with the homologous protein YwtB from B. subtilis (B.s. YwtB).
[0038] FIG. 10 : Alignment of the protein YwtD (SEQ ID NO. 10) from B. licheniformis DSM 13 (B.l. YwtD) with the homologous protein YwtD from B. subtilis (B.s. YwtD).
DETAILED DESCRIPTION OF THE INVENTION
[0039] The first partial solution represents a protein YwsC (CapB, PgsB) which is involved in the formation of polyamino acids and which is encoded by a nucleotide sequence ywsC which shows at least 80% identity to the nucleotide sequence indicated in SEQ ID NO. 1.
[0040] This specific enzyme was obtained by analysis of the genome of B. licheniformis DSM 13 (see Example 1). This protein is made reproducibly available through the nucleotide and amino acid sequences indicated in SEQ ID NO. 1 and 2 of the present application (see Example 1).
[0041] This takes the form, in agreement with the literature information mentioned in the introduction, of a subunit of the poly-gamma-glutamate synthetase complex. The protein known in the state of the art and most similar thereto has been found to be the homolog YwsC from B. subtilis which is noted in the GenBank database (National Center for Biotechnology Information NCBI, National Institutes of Health, Bethesda, MD, USA) under the accession number AB046355.1 and has a homology of 75.4% identity at the nucleic acid level, while the agreement is 86.1% identity at the amino acid level (see Example 2). These significant agreements suggest not only the same biochemical function, but also the presence within the claimed range of a large number of related proteins having the same function which is likewise included in the protection conferred by the present application.
[0042] The following embodiments are to be allocated to this first partial solution:
Any corresponding protein YwsC which is encoded by a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 1. This is because the conclusion to be drawn from an increase in agreement of the sequence is that there is an increase in agreement in the function and mutual replaceability at the genetic level. Any protein YwsC (CapB, PgsB) involved in the formation of polyamino acids and having an amino acid sequence which shows at least 91% identity, with increasing preference at least 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the amino acid sequence indicated in SEQ ID NO. 2.
[0045] In connection with the present application, an expression of the form “at least X %” means “X % to 100%, including the extreme values X and 100 and all integral and non-integral percentages between them”.
[0046] The specific protein obtained from B. licheniformis DSM13 is most preferred in each case, because this is specifically described in the present application and is made available 100% reproducibly.
[0047] The second partial solution represents a protein YwsC′ (as truncated variant of YwsC) which is involved in the formation of polyamino acids and is encoded by a nucleotide sequence ywsC′, which shows at least 83% identity to the nucleotide sequence indicated in SEQ ID NO. 3.
[0048] This specific enzyme was obtained by analysis of the genome of B. licheniformis DSM 13 (see Example 1). This protein is made reproducibly available through the nucleotide and amino acid sequences indicated in SEQ ID NO. 3 and 4 in the present application (see Example 1).
[0049] As additionally explained in Example 1, the comparison, shown in FIG. 6 , of the sequences between YwsC from B. licheniformis and B. subtilis suggests that the first 16 amino acids of YwsC from B. licheniformis are immaterial for its function as subunit C of the poly-gamma-glutamate synthetase complex. The present invention is thus also implemented with this truncated variant.
[0050] Mentioned in connection with the present application of “five or four genes” means that ywsC and ywsC′ are treated according to the invention as two genes and the derived proteins are treated as two proteins. On the other hand, it is probably to be assumed that both these “genes” are not in each case present in vivo in the relevant organisms, but in each case only one thereof, so that only one corresponding gene product YwsC or YwsC′ is also likely to be present. Thus, the first and the second partial solution represent to a certain extent two aspects of the same subject matter. Separation into two partial solutions does, however, appear justified because of the differences at the amino acid level.
[0051] The protein known in the state of the art and most similar thereto has again been found to be the homolog YwsC from B. subtilis which is noted in the GenBank database under the accession number AB046355.1 and has a homology of 78.5% identity at the nucleic acid level; the agreement at the amino acid level is 89.6% identity (see Example 2).
[0052] In accordance with the statements above, the following embodiments are to be allocated to this second partial solution:
Any corresponding protein YwsC′ which is encoded by a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 3. Any protein YwsC′ (as truncated variant of YwsC) which is involved in the formation of polyamino acids and has an amino acid sequence which shows at least 94% identity, with increasing preference at least 95%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the amino acid sequence indicated in SEQ ID NO. 4.
[0055] The specific protein obtained from B. licheniformis DSM13 is most preferred in each case because this is specifically described in the present application and is made available 100% reproducibility.
[0056] The third partial solution represents a protein YwtA (CapC, PgsC) which is involved in the formation of polyamino acids and which is encoded by a nucleotide sequence ywtA which shows at least 82% identity to the nucleotide sequence indicated in SEQ ID NO. 5.
[0057] This specific enzyme was obtained by analysis of the genome of B. licheniformis DSM13 (see Example 1). This protein is made reproducibly available through the nucleotide and amino acid sequences indicated in SEQ ID NO. 5 and 6 in the present application (see Example 1).
[0058] This takes the form, in agreement with the literature information mentioned in the introduction, of a further subunit of the poly-gamma-glutamate synthetase complex. The protein known in the state of the art and most similar thereto has been found to be the homolog YwsA from B. subtilis which is noted in the GenBank database under the accession number AB046355.1 and has a homology of 77.8% identity at the nucleic acid level, while the agreement is 89.9% identity at the amino acid level (see Example 2). These significant agreements suggest not only the same biochemical function, but also the presence within the claimed range of a large number of related proteins having the same function which is likewise included in the protection conferred by the present application.
[0059] The following embodiments are to be allocated to this third partial solution:
Any corresponding protein YwtA which is encoded by a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 5. Any protein YwtA (CapC, PgsC) involved in the formation of polyamino acids and having an amino acid sequence which shows at least 94% identity, with increasing preference at least 95%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the amino acid sequence indicated in SEQ ID NO. 6.
[0062] The specific protein obtained from B. licheniformis DSM13 is most preferred in each case, because this is specifically described in the present application and is made available 100% reproducibly.
[0063] The fourth partial solution represents a protein YwtB (CapA, PgsA) which is involved in the formation of polyamino acids and is encoded by a nucleotide sequence ywtB, which shows at least 72% identity to the nucleotide sequence indicated in SEQ ID NO. 7.
[0064] This specific enzyme was obtained by analysis of the genome of B. licheniformis DSM 13 (see Example 1). This protein is made reproducibly available through the nucleotide and amino acid sequences indicated in SEQ ID NO. 7 and 8 in the present application (see Example 1).
[0065] This takes the form, in agreement with the literature information mentioned in the introduction, of the third subunit of the poly-gamma-glutamate synthetase complex. The protein known in the state of the art and most similar thereto has been found to be the homolog YwsA from B. subtilis which is noted in the GenBank database under the accession number AB046355.1 and has a homology of 67.1% identity at the nucleic acid level, while the agreement is 65.8% identity at the amino acid level (see Example 2). These significant agreements suggest not only the same biochemical functional but also the presence within the claimed range of a large number of related proteins having the same function which is likewise included in the protection conferred by the present application.
[0066] The following embodiments are to be allocated to this fourth partial solution:
Any corresponding protein YwtB which is encoded by a nucleotide sequence which shows with increasing preference at least 75%, 80%, 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 7. Any protein YwtB (CapA, PgsA) involved in the formation of polyamino acids and having an amino acid sequence which shows at least 70% identity, with increasing preference at least 75%, 80%, 90%, 95%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the amino acid sequence indicated in SEQ ID NO. 8.
[0069] The specific protein obtained from B. licheniformis DSM13 is most preferred in each case, because this is specifically described in the present application and is made available 100% reproducibly.
[0070] The fifth partial solution represents a protein YwtD (Dep, PgdS) which is involved in the degradation of polyamino acids and is encoded by a nucleotide sequence ywtD, which shows at least 67% identity to the nucleotide sequence indicated in SEQ ID NO. 9.
[0071] This specific enzyme was obtained by analysis of the genome of B. licheniformis DSM 13 (see Example 1). This protein is made reproducibly available through the nucleotide and amino acid sequences indicated in SEQ ID NO. 9 and 10 in the present application (see Example 1).
[0072] This takes the form, in agreement with the literature information mentioned in the introduction, of the gamma-DL-glutamyl hydrolase, D-PGA depolymerase or PGA depolymerase. The protein known in the state of the art and most similar thereto was found to be the homolog YwtD from B. subtilis which is noted in the GenBank database under the accession number AB080748 and has a homology of 62.3% identity at the nucleic acid level; the agreement at the amino acid level is 57.3% identity (see Example 2). These significant agreements suggest not only the same biochemical function, but also the presence within the claimed range of a large number of related proteins having the same function which is likewise included in the protection conferred by the present application.
[0073] The following embodiments are to be allocated to this fifth partial solution:
Any corresponding protein YwtD which is encoded by a nucleotide sequence which shows with increasing preference at least 70%, 75%, 80%, 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 9. Any protein YwtD (Dep, PgdS) involved in the degradation of polyamino acids and having an amino acid sequence which shows at least 62% identity, with increasing preference at least 65%, 70%, 75%, 80%, 90%, 95%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the amino acid sequence indicated in SEQ ID NO. 10.
[0076] The specific protein obtained from B. licheniformis DSM13 is most preferred in each case, because this is specifically described in the present application and is made available 100% reproducibly.
[0077] Preference is given in each case among these in each case to a previously described protein of the invention which is involved in the formation or degradation of polyamino acids and which is naturally produced by a microorganism, preferably by a bacterium, particularly preferably by a Gram-positive bacterium, preferably among these by one of the genus Bacillus , particularly preferably among these by one of the species B. licheniformis and very particularly preferably among these by B. licheniformis DSM13.
[0078] This is because, in accordance with the problem, there was interest in improving the fermentation of microorganisms, for which bacteria from among these particularly Gram-positive ones, are frequently used, especially those which, like Bacillus , are able to secrete produced valuable products and proteins. In addition, there is a wealth of clinical experience concerning this. In addition, it was possible to detect, as mentioned, the proteins indicated in the sequence listing for B. licheniformis , specifically B. licheniformis DSM13. It is to be expected that an increasing degree of relationship of the relevant organisms will be associated with an increasing extent of agreement of the nucleotide and amino acid sequences and thus their exchangeability.
[0079] In accordance with that stated hitherto, the following in each case relevant nucleic acids are to be allocated as further expressions of the present invention to the stated partial solutions:
Nucleic acid ywsC (capB, pgsB) which codes for a gene product involved in the formation of polyamino acids and has a nucleotide sequence which shows at least 80% identity to the nucleotide sequence indicated in SEQ ID NO. 1; a corresponding nucleic acid ywsC having a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 1; nucleic acid ywsC′ (as truncated variant of ywsC) which codes for a gene product involved in the formation of polyamino acids and has a nucleotide sequence which shows at least 83% identity to the nucleotide sequence indicated in SEQ ID NO. 3; a corresponding nucleic acid ywsC′ having a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 3; nucleic acid ywta (capC, pgsC) which codes for a gene product involved in the formation of polyamino acids and has a nucleotide sequence which shows at least 82% identity to the nucleotide sequence indicated in SEQ ID NO. 5; a corresponding nucleic acid ywtA having a nucleotide sequence which shows with increasing preference at least 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 5; nucleic acid ywtB (capA, pgsA), which codes for a gene product involved in the formation of polyamino acids and has a nucleotide sequence which shows at least 72% identity to the nucleotide sequence indicated in SEQ ID NO. 7; a corresponding nucleic acid ywtB having a nucleotide sequence which shows with increasing preference at least 75%, 80%, 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 7; nucleic acid ywtD (dep, pgds) which codes for a gene product involved in the degradation of polyamino acids and has a nucleotide sequence which shows at least 67% identity to the nucleotide sequence indicated in SEQ ID NO. 9; and a corresponding nucleic acid ywtD having a nucleotide sequence which shows with increasing preference at least 70%, 75%, 80%, 85%, 90%, 92%, 94%, 96%, 97%, 98%, 99% and particularly preferably 100% identity to the nucleotide sequence indicated in SEQ ID NO. 9.
[0090] The nucleic acids provided herewith can be employed by methods of molecular biology known per se for inactivating or enhancing the activity of the relevant proteins. Thus, inactivations are possible for example via appropriate deletion vectors (see below); enhancement of the activity advantageously takes place by an overexpression which can be achieved with the aid of an expression vector (see below). Thus, the problem posed is implemented via these nucleic acids through inactivation of ywsC, ywsC′, ywtA and/or ywtB and/or by enhanced ywtD gene activity.
[0091] The corresponding genes falling within the homology ranges indicated in each case can be obtained from the organisms of interest for example with the aid of probes which can be prepared on the basis of sequences 1, 3, 5, 7, or 9. These complete genes may also serve as model for generating PCR primers via which the relevant genes can be rendered accessible from corresponding total DNA preparations; these genes in turn provide the proteins described previously. The success rate in this connection usually increases with the closeness of the relationship of the relevant strain to that which has served to construct the probe or the PCR primers, and thus in the present case to B. licheniformis.
[0092] Preference is given in each case among these in each case to a nucleic acid of the invention which is naturally present in a microorganism, preferably a bacterium, particularly preferably a Gram-positive bacterium, and among these preferably one of the genus Bacillus , particularly preferably among these one of the species B. licheniformis and very particularly preferably among these B. licheniformis DSM13.
[0093] This is because, as stated above, there is a particular interest in utilizing these genes for fermentations of such microorganisms. On the other hand, the present invention is also linked to the possibility of adjusting, via the genes and/or proteins described herein, the metabolism of the polyamino acids, especially gamma-glutamic acid, at least in parts when they are to be synthesized, modified and/or degraded. The success rate for this generally, especially in appropriate transgenic host cells, increases with the degree of agreement of the relevant genes with those of the natural cells.
[0094] It is additionally possible to isolate alternative embodiments of the genes and proteins easily from in principle all natural organisms.
[0095] A further embodiment of the present invention represents all nucleic acids which code for a protein of the invention described above.
[0096] Thus, differences exist, particularly between remotely related species, in the usage of synonymous codons coding for the respective amino acids, with which the protein biosynthesis apparatus also conforms, for instance via the available number of appropriate loaded tRNAs. Transfer of one of said genes into a less related species can be used particularly successfully for example for deletion mutation or for synthesis of the relevant protein if it is appropriately optimized in terms of the codons. It is possible thereby to introduce increasing percentage differences at the DNA level which, however, have no consequence at the amino acid level. For this reason, such nucleic acids also represent implementations of the present invention.
[0097] The invention further relates to vectors which comprise a previously designated nucleic acid region of the invention.
[0098] This is because in order to handle the nucleic acids relevant to the invention, and thus in particular to prepare for the production of proteins of the invention, they are suitably ligated into vectors. Such vectors and the relevant working methods are described in detail in the prior art. Vectors are commercially available in large number and range of variation, both for cloning and for expression. These include for example vectors derived from bacterial plasmids, from bacteriophages or from viruses, or predominantly synthetic vectors. They are also distinguished according to the nature of the cell types in which they are able to establish themselves, for example into vectors for Gram-negative, for Gram-positive bacteria, for yeasts or for higher eukaryotes. They form suitable starting points for example for molecular biological and biochemical investigations and for the expression of the relevant gene or associated protein. They are virtually indispensable—as is evident from the prior art relevant thereto - in particular for the preparation of constructs for deletion or enhancement of expression.
[0099] Vectors preferred among these are those comprising two or more of the nucleic acids of the invention described above.
[0100] This is because in addition on the one hand the relevant genes can at the same time be stored or can be expressed under the control of the same promoter. According to another application, a vector which simultaneously comprises two or more intact copies of the genes of the invention can serve to keep alive (rescue) a deletion mutant which is simultaneously deleted in a plurality of these genes. Targeted removal of this vector then results in this plurality of genes being simultaneously switched off.
[0101] In another embodiment, the vectors of the invention are cloning vectors.
[0102] This is because cloning vectors are, besides the storage, the biological amplification or the selection of the gene of interest, suitable for its molecular biological characterization. At the same time, they represent transportable and storable forms of the claimed nucleic acids and are also starting points for molecular biological techniques which are not linked to cells, such as, for example, PCR or in vitro mutagenesis methods.
[0103] The vectors of the invention are preferably expression vectors.
[0104] This is because such expression vectors are the basis for implementing the corresponding nucleic acids in biological production systems and thus producing the relevant proteins. Preferred embodiments of this subject matter of the invention are expression vectors which are by genetic elements necessary for expression, for example the natural promoter originally located in front of this gene, or a promoter from a different organism. These elements may be disposed for example in the form of a so-called expression cassette. An alternative possibility is for one or all regulatory elements also to be provided by the respective host cell. Expression vectors are particularly preferred in relation to further properties such as, for example, the optimum copy number matched to the chosen expression system, especially the host cell (see below).
[0105] The possibility of forming intact gene products on the basis of a vector existing as a replicon is particularly important for the rescue described above and the switching off of particular genes. Conversely, the provision of an expression vector is the best possibility for enhanced formation of a protein of the invention and thus an increase in the relevant activity.
[0106] Cells which, after genetic modification, comprise one of the nucleic acids of the invention designated above form a separate subject matter of the invention.
[0107] This is because these cells comprise the genetic information for synthesizing a protein of the invention. By these are meant in particular cells which have been provided with the nucleic acids of the invention by methods known per se, or which are derived from such cells. The host cells suitably selected for this purpose are those which can be cultured relatively simply and/or provide high product yields.
[0108] It is necessary in principle in countries where human embryonic stem cells may not be placed under patent protection for such human embryonic stem cells of the invention to be excluded from the protection conferred.
[0109] Cells of the invention make it possible for example to amplify the corresponding genes, but also for them to be mutagenized or transcribed and translated and eventually for the relevant proteins to be produced biotechnologically. This genetic information may be present either extrachromosomally as separate genetic element, meaning located in plasmids in the case of bacteria, or be integrated into a chromosome. The choice of a suitable system depends on questions such as, for example, the nature and duration of the storage of the gene or of the organism or the nature of the mutagenesis or selection.
[0110] These include, besides the cells which overexpress in particular YwtD, in particular those which comprise one of the genes ywsC, ywsC′, ywtA and ywtB via a vector in trans and can thus be used for corresponding deletions (see below).
[0111] This explains the preferred embodiment in which said nucleic acid is part of a vector, in particular of a previously described vector, in such a cell.
[0112] Host cells which are bacteria are preferred among these.
[0113] This is because bacteria are distinguished by short generation times and low demands on the culturing conditions. It is possible thereby to establish cost-effective methods. In addition, there is a wealth of experience in the techniques of fermentation of bacteria. Gram-negative or Gram-positive bacteria may be suitable for a specific production for a wide variety of reasons which are to be ascertained experimentally in the individual case, such as nutrient sources, product formation rate, time required etc.
[0114] A preferred embodiment involves a Gram-negative bacterium, in particular one of the genera Escherichia coli, Klebsiella, Pseudomonas or Xanthomonas , in particular strains of E. coli K12 , E. coli B or Klebsiella planticola , and very especially derivatives of the strain Escherichia coli BL21 (DE3), E. coli RV308 , E. coli DH5 α, E. coli JM109 , E. coli XL-1 or Klebsiella planticola (Rf).
[0115] This is because a large number of proteins are secreted into the periplasmic space with Gram-negative bacteria such as, for example, E. coli . This may be advantageous for specific applications. The application WO 01/81597 A1 discloses a method which achieves expulsion of the expressed proteins by Gram-negative bacteria too. The Gram-negative bacteria mentioned as preferred are usually available easily, meaning commercially or through public collections of strains, and can be optimized for specific preparation conditions in association with other components such as, for instance, vectors which are likewise available in large number.
[0116] An alternative, not less preferred embodiment involves a Gram-positive bacterium, in particular one of the genera Bacillus, Staphylococcus or Corynebacterium , very particularly of the species Bacillus lentus, B. licheniformis, B. amyloliquefaciens, B. subtilis, B. globigii or B. alcalophilus, Staphylococcus carnosus or Corynebacterium glutamicum , and among these in turn very particularly preferably a derivative of B. licheniformis DSM 13.
[0117] This is because Gram-positive bacteria have the fundamental difference from Gram-negative ones of immediately releasing secreted proteins into the nutrient medium which surrounds the cells and from which if desired the expressed proteins of the invention can be directly purified from the nutrient medium. In addition, they are related or identical to most of the organisms of origin of industrially important enzymes and mostly themselves produce comparable enzymes, so that they have a similar codon usage and their protein synthesis apparatus is naturally configured appropriately. Derivatives of B. licheniformis DSM 13 are very particularly preferred because they on the one hand are likewise widely used as biotechnological producer strains in the state of the art and because on the other hand the present application makes exactly the genes and proteins of the invention from B. licheniformis DSM 13 available, so that implementation of the present invention ought most likely to be successful in such strains.
[0118] A further embodiment of the present invention is formed by methods for preparing one or more of the gene products YwsC, YwsC′, YwtA, YwtB and YwtD described above.
[0119] This includes any method for preparing a protein of the invention described above, for example chemical synthetic methods. However, in relation thereto, all molecular biological, microbiological and biotechnological preparation methods which have been discussed above in individual aspects and are established in the state of the art are preferred. The aim thereof is primarily to obtain the proteins of the invention in order to make them available for appropriate applications, for example for the synthesis, modification or degradation of poly-gamma-glutamate.
[0120] Methods preferred in this connection are those taking place with use of a nucleic acid of the invention designated above, preferably taking place with use of a vector of the invention designated above and particularly preferably with use of a cell of the invention designated above.
[0121] This is because said nucleic acids, especially the nucleic acids indicated in the sequence listing under SEQ ID NO. 1, 3, 5, 7 and 9, makes the correspondingly preferred genetic information available in microbiologically utilizable form, i.e. for genetic production methods. It is increasingly preferred to provide on a vector which can be utilized particularly successfully by the host cell, or such cells themselves. The relevant production methods are known per se to the skilled worker.
[0122] Embodiments of the present invention may on the basis of the relevant nucleic acid sequences also be cell-free expression systems in which the protein biosynthesis is duplicated in vitro. All the elements already mentioned may also be combined to novel methods in order to prepare proteins of the invention. A large number of possible combinations of method steps is conceivable for each protein of the invention moreover, so that optimal methods need to be ascertained experimentally for each specific individual case.
[0123] Methods of the invention of such types are further preferred when the nucleotide sequence has been adapted in one or, preferably, more codons to the codon usage of the host strain.
[0124] This is because, in accordance with that stated above, transfer of one of said genes into a less related species can be used particularly successfully for synthesizing the relevant protein if it is appropriately optimized in relation to the codon usage.
[0125] A further expression of the present invention is the use of a nucleic acid ywsC of the invention described above, of a nucleic acid ywsC′ of the invention described above, of a nucleic acid ywtA of the invention described above, of a nucleic acid ywtB of the invention described above or of a corresponding nucleic acid which codes for one of the proteins of the invention described above or in each case parts thereof for the functional inactivation of the respectively relevant gene ywsC, ywsC′, ywtA or ywtB in a microorganism.
[0126] Functional inactivation means in the context of the present application any type of modification or mutation by which the function of the relevant protein as an enzyme involved in the formation of polyamino acids, or as subunit of such an enzyme, is suppressed. This includes the embodiment where a virtually complete but inactive protein is formed, where inactive parts of such a protein are present in the cell, up to the possibilities where the relevant gene is no longer translated or is even completely deleted. Thus, a specific “use” of these factors or genes in this embodiment consists of them no longer acting in their natural manner precisely in the relevant cell. This is achieved according to the subject matter of the invention at the genetic level by switching off the relevant gene.
[0127] An alternative embodiment for inactivating the genes ywsC, ywsC′, ywtA or ywtB is the use of a nucleic acid ywtD of the invention described above or of a corresponding nucleic acid which codes for one of the proteins of the invention described above for increasing the activity of the relevant gene ywtD in a microorganism.
[0128] This is because, as described in the introduction, the in vivo function of this enzyme is to degrade GLA. Enhancement of this activity thus leads to a reduction in the concentration of polyamino acids in the culture medium and has a positive effect according to the invention on the industrial fermentation of the relevant microorganisms. This enhancement of activity advantageously takes place at the genetic level. Methods for this are known per se. For example, mention may be made of the transfer of this gene to an expression vector: Such a vector can be introduced by transformation into the cells used for the fermentation and where appropriate be activated under certain conditions, so that the derived protein then acts in addition to the endogenously formed YwtD.
[0129] In preferred embodiments, both uses are those where the functional inactivation or increase in activity takes place during the fermentation of the microorganism, preferably with a reduction of the slime attributable to polyamino acids to 50%, particularly preferably to less than 20%, very particularly preferably to less than 5%, once again all intermediate integral or fractional percentages being understood in appropriately preferred gradation.
[0130] To determine these values, cells of an untreated strain and of a treated strain are fermented under conditions which are otherwise identical and suitably the viscosity of the respective medium is determined during the fermentation. Since the strains are otherwise identical, the differences in viscosity are attributable to the different contents of polyamino acids. Every reduction in viscosity is desired according to the invention. Comparable values as percentages are obtained by taking samples from both fermentations and determining the content of polyamino acid-containing slime by methods known per se. It is increasingly preferred for the value which can be determined in the sample of the invention to be at the transition into the stationary growth phase less than 50%, 40%, 30%, 20%, 10%, 5% and very especially less than 1% of the corresponding value for the comparative fermentation.
[0131] This is because the intention according to the problem was to improve the fermentation of the microorganisms employed for biotechnological production. Thus, it is worthwhile or, especially when a plurality of genes is affected, usually necessary to carry out the relevant molecular biological constructs on the laboratory scale and, where appropriate, on host cells which merely represent intermediate stages, for example construction of a deletion vector in E. coli . However, it is desired according to the invention for the inactivation of the genes ywsC, ywsC′, ywtA or ywtB to show the hoped-for effects especially during the fermentation. The increase in the activity of the ywtD gene can be controlled for example via inducible promoters which are for example of the relevant transgene. The activity of this gene can thus be switched on deliberately by adding an inducer at a time which appears suitable during the fermentation. As an alternative thereto, this gene can also be coupled to a promoter which responds to stress signals, for instance to an oxygen content which is too low, as also occurs when mixing is inadequate in a fermenter which is blocked by slime.
[0132] In further preferred embodiments, these uses of the invention are such that, with increasing preference, 2, 3 or 4 of the genes ywsC, ywsC′, ywtA and ywtB are inactivated, preferably in combination with an enhancement of the activity mediated by the ywtD gene.
[0133] It may be recalled at this point that in vivo in the relevant organisms it is probable that both the genes ywsC and ywsC′ may not be present simultaneously, but in each case only one thereof. In these cases it is possible for a maximum of 3 of said genes to be inactivated, so that this then represents the most preferred embodiment in this respect.
[0134] This embodiment serves as safeguard in the event that the molecular biological form of the inactivation chosen for inactivation of one of these genes is incomplete and the cell still has corresponding residual activities. This applies in particular to host cells other than B. subtilis for which, according to Ashiuchi et al. (see above), it has been demonstrated that these genes are present in only one copy in each case. It appears to be particularly worthwhile to combine the deletion approach with that of enhancement of the activity mediated by the ywtD, because two systems which act differently in principle are thereby combined together.
[0135] In one embodiment of the use for functional inactivation of one or more of the genes ywsC, ywsC′, ywtA and ywtB, a nucleic acid coding for an inactive protein and having a point mutation is employed.
[0136] Nucleic acids of this type can be generated by methods of point mutagenesis known per se. Such methods are described for example in relevant handbooks such as that of Fritsch, Sambrook and Maniatis “Molecular cloning: a laboratory manual”, Cold Spring Harbor Laboratory Press, New York, 1989. In addition, numerous commercial construction kits are now available therefor, for instance the QuickChange® kit from Stratagene, La Jolla, USA. The principle thereof is for oligonucleotides having single exchanges (mismatch primers) to be synthesized and hybridized with the gene in single-stranded form; subsequent DNA polymerization then affords corresponding point mutants. It is possible to use for this purpose the respective species-specific sequences of these genes. Owing to the high homologies, it is possible and particularly advantageous according to the invention to carry out this reaction on the basis of the sequences provided by SEQ ID NO. 1, 3, 5 and 7. These sequences can also serve to design appropriate mismatch primers for related species, especially on the basis of the conserved regions identifiable in the alignments of FIGS. 6 to 10 and 1 to 5 .
[0137] In one embodiment of this use, in each case a nucleic acid with a deletion mutation or insertion mutation is employed for the functional inactivation, preferably including the border sequences, in each case comprising at least 70 to 150 nucleic acid positions, of the region coding for the protein.
[0138] These methods are also familiar per se to the skilled worker. It is thus possible to prevent the formation of one or more of the factors YwsC, YwsC′, YwtA and YwtB by the host cell by cutting out part of the relevant gene on an appropriate transformation vector via restriction endonucleases, and subsequently transforming the vector into the host of interest, where the active gene is replaced by the inactive copy via the homologous recombination which is still possible until then. In the embodiment of insertion mutation it is possible merely to introduce the intact gene interruptingly or, instead of a gene portion, another gene, for example a selection marker. Phenotypical checking of the mutation event is possible thereby in a manner known per se.
[0139] In order to enable these recombination events which are necessary in each case between the defective gene introduced into the cell and the intact gene copy which is endogenously present for example on the chromosome, it is necessary according to the current state of knowledge that in each case there is agreement in at least 70 to 150 connected nucleic acid positions, in each case in the two border sequences to the non-agreeing part, with the part lying between being immaterial. Accordingly, preferred embodiments are those including only two flanking regions with at least one of these sizes.
[0140] In an alternative embodiment of this use, nucleic acids having a total of two nucleic acid segments which in each case comprise at least 70 to 150 nucleic acid positions, and thus flank at least partly, preferably completely, the region coding for the protein, are employed. The flanking regions can in this connection be ascertained starting from the known sequences by methods known per se, for example with the aid of outwardly directed PCR primers and a preparation of genomic DNA as template (anchored PCR). This is because it is not obligatory for the segments to be protein-encoding in order to make it possible to exchange the two gene copies by homologous recombination. According to the present invention it is possible to design the primers required for this on the basis of SEQ ID NO. 1, 3, 5 and 7 also for other species of Gram-positive bacteria and, among these, in particular for those of the genus Bacillus . As an alternative to this experimental approach it is possible to take such regions which are at least in part non-coding for many of these genes from related species, for example from B. subtilis database entries, for example the SubtiList database of the Institute Pasteur, Paris, France (http://genolist.pasteur.fr/SubtiList/genome.cgi).
[0141] A further preferred embodiment involves one of the described uses according to the invention in which an expression vector is employed for said enhancement of the activity mediated by the ywtD gene, preferably a vector which comprises this gene together with nucleic acid segments for regulating this gene.
[0142] As already stated above, the increased activity of this gene and thus of the derived protein can be deliberately regulated from outside thereby, or adapts automatically via the conditions prevailing in the fermentation medium to the need for a reduction in the polyamino acid concentration. It is particularly advantageous to use here for the nucleic acids of the invention described which code for ywtD, and very especially that according to SEQ ID NO. 9.
[0143] The present invention is also implemented in the form of genetically modified microorganisms, to which that stated above applies correspondingly.
[0144] These are very generally microorganisms in which at least one of the genes ywsC, ywsC′, ywtA or ywtB is functionally inactivated or ywtD has enhanced activity.
[0145] These are preferably microorganisms in which, with increasing preference, 2, 3 or 4 of the genes ywsC, ywsC′, ywtA or ywtB are inactivated, preferably in combination with an enhancement of the activity mediated by the ywtD gene.
[0146] These are preferably microorganisms in the form of bacteria.
[0147] The microorganisms among these which are preferred according to the statements hitherto are Gram-negative bacteria, especially those of the genera Escherichia coli, Klebsiella, Pseudomonas or Xanthomonas , especially strains of E. coli K12 , E. coli B or Klebsiella planticola , and very especially derivatives of the strains Escherichia coli BL21 (DE3), E. coli RV308 , E. coli DH5 α, E. coli JM109 , E. coli XL-1 or Klebsiella planticola (Rf).
[0148] Microorganisms which are not less preferred according to statements hitherto are Gram-positive bacteria, especially those of the genus Bacillus, Staphylococcus or Corynebacterium , very particularly of the species Bacillus lentus, B. licheniformis, B. amyloliquefaciens, B. subtilis, B. globigii or B. alcalophilus, Staphylococcus carnosus or Corynebacterium glutamicum and, among these, very especially B. licheniformis DSM 13.
[0149] According to the problem on which the present application is based, the intention was primarily to improve industrial fermentation methods. Accordingly, the invention is implemented especially in corresponding fermentation methods of the invention.
[0150] These are very generally methods for the fermentation of a microorganism of the invention described above.
[0151] According to statements hitherto, the methods characterized thereby are correspondingly preferred. These include in particular the embodiment of one or more of the genes ywsC, ywsC′, ywta or ywtB being functionally inactivated or the activity of ywtD being enhanced, in particular combinations of the two approaches. For this purpose, recourse is particularly preferably had to the nucleic acids of the invention described above, especially those indicated under SEQ ID NO. 1, 3, 5, 7, or 9. This applies correspondingly also to the species selected as suitable for the respective fermentation. According to the statements above, those among these which are increasingly preferred have an increasing extent of relationship to B. licheniformis DSM13, because the prospects of success on use of the stated nucleic acids increase thereby.
[0152] Among the fermentation methods of the invention, those for preparing a valuable product are preferred, especially for preparing a low molecular weight compound or a protein.
[0153] This is because this is the most important area of application of industrial fermentations.
[0154] These are preferably methods where the low molecular weight compound is a natural product, a dietary supplement or a pharmaceutically relevant compound.
[0155] In this way for example amino acids or vitamins which are used in particular as dietary supplements are produced. Pharmaceutically relevant compounds may be precursors or intermediates for medicaments or even the latter themselves. In all these cases, the term biotransformation is also used, according to which the metabolic properties of the microorganisms are utilized to replace, entirely or at least in individual steps, the otherwise elaborate chemical synthesis.
[0156] No less preferred are corresponding methods in which the protein produced in this way is an enzyme, in particular one from the group of α-amylases, proteases, cellulases, lipases, oxidoreductases, peroxidases, laccases, oxidases and hemicellulases.
[0157] Industrial enzymes prepared by such methods are used for example in the food industry. Thus, α-amylases are used for example to prevent bread becoming stale or to clarify fruit juices. Proteases are used for the lysis of proteins. All these enzymes have been described for use in detergent and cleaner compositions, a prominent place being occupied in particular by the Subtilisin proteases prepared naturally by Gram-positive bacteria. They are used in particular in the textile and leather industries for processing the natural raw materials. A further possibility is for all these enzymes in turn to be employed in the context of biotransformation as catalysts for chemical reactions.
[0158] Many of these enzymes are originally derived from Bacillus species and are therefore produced particularly successfully in Gram-positive organisms, especially those of the genus Bacillus , including in many cases also derivatives of B. licheniformis DSM13. Production methods based on these microbial systems in particular can be improved with the aid of the present invention, because the sequences indicated in particular in SEQ ID NO. 1, 3, 5, 7 and 9 are derived from precisely this organism.
[0159] Finally, the factors made available with the present application can also be employed positively, meaning in the sense of their natural function, meaning in connection with a targeted preparation, modification or degradation of poly-gamma-glutamate.
[0160] One embodiment is thus formed by microbial methods for the preparation, modification or degradation of poly-gamma-glutamate in which one of the nucleic acids ywsC, ywsC′, ywtA, ywtB and/or ywtD of the invention described above or a corresponding nucleic acid which codes a protein of the invention described above is employed transgenically, preferably to form the corresponding protein of the invention described above.
[0161] Preferred methods among these are those in which a microorganism from the genus Bacillus , in particular B. subtilis or B. licheniformis , is employed.
[0162] It is thus possible, as described for example in the applications JP 08308590 A or WO 02/055671 Al, to produce GLA microbially, specifically in B. subtilis and B. licheniformis . The DNA sequences made available with the present application can be utilized for example to increase the respective gene activities in appropriate cells, and thus to increase the yield.
[0163] As alternative thereto, cell-free methods for the preparation, modification or degradation of poly-gamma-glutamate are now also possible, involving a gene product YwsC, YwsC′, YwtA, YwtB and/or YwtD of the invention described above, which is involved in the formation of polyamino acids, preferably with use of a corresponding nucleic acid of the invention described above.
[0164] Thus, these factors can be reacted for example in a bioreactor. The design of such enzyme bioreactors is known from the prior art.
[0165] Corresponding methods of this type which are particularly preferred among these are those where 2, preferably 3, particularly preferably 4, different ones of said gene products or nucleic acids are employed.
[0166] This is because the factors YwsC, YwtA and YwtB in particular usually form, as described in the introduction, a coherent complex, so that it is necessary to speak of a joint activity. Simultaneous or subsequent activity of YwtD might serve for example to influence the biophysical properties of the formed polyamino acid and, for example, for adaptation for use in cosmetic preparations.
[0167] The following examples illustrate the present invention further.
EXAMPLES
[0168] All molecular biological working steps follow standard methods as indicated for example in the handbook by Fritsch, Sambrook and Maniatis “Molecular cloning: a laboratory manual”, Cold Spring Harbour Laboratory Press, New York, 1989, or comparable relevant works. Enzymes, construction kits and apparatuses were employed in accordance with the respective manufacturer's instructions.
Example 1
[0000] Identification of the Genes ywsC, ywsc, ywtA, ywtB and ywtD from B. licheniformis DSM 13
[0169] The genomic DNA was prepared by standard methods from the strain B. licheniformis DSM 13, which is available to anyone from the Deutsche Sammiung von Mikroorganismen und Zelikulturen GmbH, Mascheroder Weg 1 b, 38124 Braunschweig (http://www.dsmz.de), mechanically fractionated and fractionated by electrophoresis in a 0.8% agarose gel. For a shotgun cloning of the smaller fragments, the fragments 2 to 2.5 kb in size were eluted from the agarose gel, dephosphorylated and ligated as blunt-ended fragments into the Smal restriction cleavage site of the vector pTZ19R-Cm. This is a derivative which confers chloramphenicol resistance of the plasmid pTZ19R which is obtainable from Fermentas (St. Leon-Rot). A gene library of the smaller fragments was obtained thereby. As second shotgun cloning, the genomic fragments obtained by a partial restriction with the enzyme Saullial were ligated into the SuperCos 1 vector system (“Cosmid Vector Kit”) from Stratagene, La Jolla, USA, resulting in a gene library over the predominantly larger fragments.
[0170] The relevant recombinant plasmids were isolated and sequenced from the bacteria E. coli DH5α (D. Hannahan (1983): “Studies on transformation on Escherichia coli”; J Mol. Microbiol ., volume 166, pages 557-580) obtainable by transformation with the relevant gene libraries. The dye termination method (dye terminator chemistry) was employed in this case, carried out by the automatic sequencers MegaBACE 1000/4000 (Amersham Bioscience, Piscataway, USA) and ABI Prism 377 (Applied Biosystems, Foster City, USA).
[0171] In this way, inter alia the sequences SEQ ID NO. 1, 3, 5, 7 and 9 which are indicated in the sequence listing of the present application were obtained and stand in this sequence for the genes ywsC, ywsC′ (as truncated variant of ywsC), ywtA, ywtB and ywtD. The amino acid sequences derived therefrom are indicated in the corresponding sequence in SEQ ID NO. 2, 4, 6, 8 and 10, respectively. A truncated variant ywsC′ (or YwsC′) is indicated for the gene or protein ywsC (or YwsC) because the comparison, shown in FIG. 6 , of the amino acid sequences for the homologous protein in B. subtilis shows a polypeptide which is N-terminally shorter by 16 amino acids with otherwise quite high homology and therefore comparable activity.
[0000] Reproducibility
[0172] These genes and gene products can now be artificially synthesized by methods known per se, and without the need to reproduce the described sequencing, in a targeted manner on the basis of these sequences. It is possible, as further alternative thereto, to isolate the relevant genes from a Bacillus strain, in particular the strain B. licheniformis DSM 13 which is obtainable from the DSMZ, via PCR, it being possible to use the respective border sequences indicated in the sequence listing for synthesizing primers. If further strains are used, the genes homologous thereto in each case are obtained, and the success of the PCR should increase with the closeness of the relationship of the selected strains to B. licheniformis DSM 13, because this is likely to be associated with an increasing agreement of sequences also within the primer binding regions.
Example 2
[0000] Sequence homologies
[0173] After ascertaining the DNA and amino acid sequences as in Example 1, in each case the most similar homologs disclosed to date were ascertained by a search in the databases GenBank (National Center for Biotechnology Information NCBI, National Institutes of Health, Bethesda, Md., USA; http://www.ncbi.nlm.nih.gov) and Subtilist of the Institute Pasteur, Paris, France (http://genolist.pasteur.fr/Subtilist/genome.cgi).
[0174] The ascertained DNA and amino acid sequences were compared with one another via the alignments depicted in FIGS. 1 to 10 ; the computer program used for this was Vector NTI® Suite Version 7 which is obtainable from Informax Inc., Bethesda, USA. In this case, the standard parameters of this program were used, meaning for comparison of the DNA sequences: K-tuple size: 2; Number of best Diagonals: 4; Window size: 4; Gap penalty: 5; Gap opening penalty: 15 and Gap extension penalty: 6.66. The following standard parameters applied to the comparison of the amino acid sequences: K-tuple size: 1; Number of best Diagonals: 5; Window size: 5; Gap penalty: 3; Gap opening penalty: 10 and Gap extension penalty: 0.1. The results of these sequence comparisons are compiled in Table 1 below, the accession numbers indicated being those from the NCBI database.
TABLE 1 Genes and proteins of greatest similarity to the genes and proteins found in Example 1. Gene or protein Database entry of found in B. Most closely the most closely licheniformis / related gene related gene or Homology in SEQ ID NO. or protein protein % identity ywsC/1 ywsC from B. subtilis AB046355.1 75.4 ywsC′/3 ywsC from B. subtilis AB046355.1 78.5 ywtA/5 ywsA from B. subtilis AB046355.1 77.8 ywtB/7 ywsB from B. subtilis AB046355.1 67.1 ywtD/9 ywtD from B. subtilis AB080748 62.3 YwsC/2 YwsC from B. subtilis AB046355.1 86.1 YwsC′/4 YwsC from B. subtilis AB046355.1 89.6 YwtA/6 YwsA from B. subtilis AB046355.1 89.9 YwtB/8 YwsB from B. subtilis AB046355.1 65.8 YwtD/10 YwsD from B. subtilis AB046355.1 57.3
[0175] It is evident that the found genes and the gene products derived therefrom are novel genes and proteins with a distinct difference from the prior art disclosed hitherto.
Example 3
[0000] Functional Inactivation of one or more of the Genes ywsC, ywsc′, ywtA and ywtB in B. Licheniformis
[0176] Principle of the preparation of a deletion vector
[0177] Each of these genes can be functionally inactivated, for example, by means of a so-called deletion vector. This procedure is described per se for example by J. Vehmaanpera et al. (1991) in the publication “Genetic manipulation of Bacillus amyloliquefaciens”; J. Biotechnol ., volume 19, pages 221-240.
[0178] A suitable vector for this is pE194 which is characterized in the publication “Replication and incompatibility properties of plasmid pE194 in Bacillus subtilis ” by T.J. Gryczan et al. (1982), J. Bacteriol ., volume 152, pages 722-735. The advantage of this deletion vector is that it possesses a temperature-dependent origin of replication. pE194 is able to replicate in the transformed cell at 33° C., so that initial selection for successful transformation takes place at this temperature. Subsequently, the cells comprising the vector are incubated at 42° C. The deletion vector no longer replicates at this temperature, and a selection pressure is exerted on the integration of the plasmid via a previously selected homologous region into the chromosome. A second homologous recombination via a second homologous region then leads to excision of the vector together with the intact gene copy from the chromosome and thus to deletion of the gene which is located in the chromosome in vivo. Another possibility as second recombination would be the reverse reaction to integration, meaning recombination of the vector out of the chromosome, so that the chromosomal gene would remain intact. The gene deletion must therefore be detected by methods known per se, for instance in a Southern blot after restriction of the chromosomal DNA with suitable enzymes or with the aid of the PCR technique on the basis of the size of the amplified region.
[0179] It is thus necessary to select two homologous regions of the gene to be deleted, each of which should include 70 base pairs in each case, for example the 5′ region and the 3′ region of the selected gene. These are cloned into the vector in such a way that they flank a part coding for an inactive protein, or are in direct succession, omitting the region in between. The deletion vector is obtained thereby.
[0180] Deletion of the Genes ywsC, ywsC′, ywtA and ywtB Considered here
[0181] A deletion vector of the invention is constructed by PCR amplification of the 5′ and 3′ regions of one of these four or three genes. The sequences SEQ ID NO. 1, 3, 5 and 7 indicated in the sequence listing are available for designing suitable primers and originate from B. licheniformis , but ought also to be suitable, because of the homologies to be expected, for other species, especially of the genus Bacillus.
[0182] The two amplified regions suitably undergo intermediate cloning in direct succession on a vector useful for these operations, for example on the vector pUC18 which is suitable for cloning steps in E. coli.
[0183] The next step is a subcloning into the vector pE194 selected for deletion, and transformation thereof into B. subtilis DB104, for instance by the method of protoplast transformation according to Chang & Cohen (1979; “High Frequency Transformation of Bacillus subtilis Protoplasts by Plasmid DNA”; Molec. Gen. Genet. (1979), volume 168, pages 111-115). All working steps must be carried out at 33° C. in order to ensure replication of the vector.
[0184] In a next step, the vector which has undergone intermediate cloning is likewise transformed by the method of protoplast transformation into the desired host strain, in this case B. licheniformis . The transformants obtained in this way and identified as positive by conventional methods (selection via the resistance marker of the plasmid; check by plasmid preparation and PCR for the insert) are subsequently cultured at 42° C. under selection pressure for presence of the plasmid through addition of erythromycin. The deletion vector is unable to replicate at this temperature, and the only cells to survive are those in which the vector is integrated into the chromosome, and this integration most probably takes place in homologous or identical regions. Excision of the deletion vector can then be induced subsequently by culturing at 33° C. without erythromycin selection pressure, the chromosomally encoded gene being completely deleted from the chromosome. The success of the deletion is subsequently checked by Southern blotting after restriction of the chromosomal DNA with suitable enzymes or with the aid of the PCR technique.
[0185] Such transformants in which the relevant gene is deleted are additionally distinguished by a limitation or even complete inability to form GLA. | The invention relates to five or four novel genes and the gene products thereof from Bacillus licheniformis and sufficiently similar genes and proteins which are involved in vivo in the formation of polyamino acids. The gene in question is ywsC, ywsC′, ywtA, ywtB and ywtD or proteins coded thereby. The gene ywsC, ywsC′, ywtA and ywtB can be used to improve biotechnological production methods by microorganisms, wherein they are functionally inactivated; the gene ywtD which codes for a peptide decomposing poly-gamma glutamate can, inversely, contribute to the improvement of biotechnological production methods by increased expression. Said genes can be used positively, preferably to result in a modification or decomposition of poly-gamma glutamate. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation application of application Ser. No. 13/454,307, filed Apr. 24, 2012 (now U.S. Pat. No. 8,622,726, issued Jan. 7, 2014), which is a continuation of application Ser. No. 13/031,367, filed Feb. 21, 2011 (now U.S. Pat. No. 8,163,208, issued Apr. 24, 2012), which is a continuation of application Ser. No. 12/429,177, filed Apr. 23, 2009 (now U.S. Pat. No. 7,906,048, issued Mar. 15, 2011) and claims the benefit of U.S. Provisional Patent Application No. 61/125,214 filed on Apr. 23, 2008; the entire disclosures of which are hereby fully incorporated by reference as part of the present application.
FIELD OF THE INVENTION
The present invention relates generally to thermoplastic molding methods and apparatus, and more particularly pertains to methods and apparatus for injection molding thermoplastic.
BACKGROUND
Injection molding machines are expensive to purchase, require expensive factory space and substantial quantities of electrical power. Additionally, set-up and operation of injection molding machines is a highly subjective trade, wherein there are significant set-up charges each time a tool is set. Starts and stops of such machines can be very expensive and there are always technicians and/or operators directly involved in such activities. The general practice on start up of an injection molding machine is provide an initial machine configuration (e.g., screw rotation rate, operable screw barrel temperature, injection pressure, etc.), then a “purging” process is performed where an operator first confirms that the injection molding machine is not connected to a mold, and then commences to process plastic but discarding the resulting plastic melt until the operator judges that the output plastic looks hot enough and appears to be of a low enough viscosity to commence molding test parts. Subsequently, a plurality of test parts are produced for inspection and/or analysis to thereby determine whether the machine is configured appropriately to successfully produce parts having the intended characteristics (e.g., fully conforming to the intended part shape, density, elasticity, etc.). Accordingly, the machine settings are generally fixed for mass producing the part.
The above described injection molding practice has substantial problems in that various part affecting parameters can change during the part mass production. For example, the operator settings may not be adequate for keeping the injection machine in a state for maintaining part consistency. In particular, it may not be possible to adequately determine whether the plastic is sufficiently uniformly heated so that acceptable parts can be produced therefrom. Additionally, since patches of plastic raw material inherently vary in their composition, variation in part production may be necessary dependent upon variation in the plastic raw material. Furthermore, the various injection molding parameters (whether settable by an operator or not) are generally interrelated with respect to producing acceptable parts. For instance, (a) nozzle injection pressure and plastic flow rate are inversely related, (b) plastic flow rate and plastic temperature are generally directly related, and (c) changes in screw rotation may generally be directly related to plastic temperature, although such may depend on the degree to which plastic heating is performed by shearing of the plastic in the screw barrel. Accordingly, it is very difficult to effectively and consistently configure a conventional injection molding machine to produce acceptable quality parts, and for very small quantities of parts the overhead for configuring such a machine can unacceptably expensive.
Accordingly, it would be advantageous to have an injection molding system and method of operation that is substantially more cost effective to manufacture and operate. Additionally, it is desirable for such a system and method to be less dependent upon operator trial and error to configure such systems for consistently producing acceptable quality parts.
SUMMARY
A thermoplastic injection molding system and method of use is disclosed for molding parts from heated plastics and other organic resins, wherein the system includes an injection molding machine and a controller for controlling the machine such that when the controller is supplied with input from various machine sensors providing real time measurements related to the characteristics of the plastic or resin (collectively referred to a “plastic” hereinbelow) in the injection molding machine, the controller dynamically adjusts the injection molding process to achieve more consistent and reliable molded parts.
The injection molding machine disclosed herein includes a screw for transporting the solid unmolded plastic material (e.g., pellets) from a storage container or hopper to an injection zone or chamber for collecting melted plastic in preparation for injecting the melted plastic therein into mold. The screw is configured within a barrel or cylinder in a manner that substantially prevents the plastic being conveyed therein from being sheared, and in particular, prevents such shearing between the barrel and the screw. Accordingly, the rotation of the screw when conveying plastic requires substantially less torque than prior art injection molding machines having a screw that shears the plastic. In particular, the tolerances and configuration of the screw within the barrel are such that the gaps between the inside diameter of the barrel and the outside diameter of the screw are small enough so that the plastic pellets cannot be sheared therebetween. Moreover, the barrel (and plastic therein) is heated, insufficient heat is applied to allow the plastic to deform into such gaps and be sheared, and insufficient heat is applied to induce the plastic to adhere to the screw flutes or the inside of the barrel for substantially an entire length of the screw. Thus the present injection molding machine uses substantially less energy to rotate the screw. Furthermore, the screw can be easily removed from the barrel since both the screw and barrel are substantially free of adhered to plastic.
Due to the screw being primarily a conveyance mechanism for the plastic pellets, the screw can be designed for efficient and effective conveyance rather than for shearing. Moreover, a result of such a screw design in the present injection molding machine is that the pellets compact within the barrel as they travel toward and ultimately enter plastic melting zones of the present injection machine. Such compaction has a particular advantage of effectively providing a barrier for preventing melted plastic from leaking or flow backward in the injection molding machine. Accordingly, a valve for preventing such flow back is unnecessary. However, in the event that such compaction is diminished enough so that there is plastic melt flow back, there may be one or more thermocouples or other heat sensors for detecting an inappropriate increase in heat, and providing such information to the controller (e.g., a computer system specifically configured for controlling the production of parts by the present injection molding machine, and/or programmable logic controller), wherein one or more of the following may be initiated by the controller: an operator may be alerted, the screw rotation rate at least temporarily increased, shutting down the mold injection machine (e.g., in the event that there are insufficient plastic pellets in the hopper), activating a pellet jam breaking mechanism for jams in the hopper, and/or activating a mechanism for automatically feeding additional pellets to the hopper.
The hereinabove described screw and a corresponding extent of the barrel may be considered as a first zone of the injection molding machine, wherein there is a series linearly aligned injection molding machine zones for transforming the plastic into a melt acceptable to mold parts. At the end of this first zone (e.g., substantially where the plastic pellets compact), a second zone commences wherein one or more heat sources (controlled by the controller) are active for heating the plastic within this zone so that the plastic becomes flowable. In general, the increase in heat over that of the first zone may be only a few degrees above the heat applied in the first zone (e.g., an increase in temperature in a range of 25-250° F.). The heat sources may be one or more of a resistance, inductance or ultrasonic heat source. These heat sources are positioned and arranged so that the heat generated affects the plastic, within a relatively short portion of the screw, and substantially at the termination of the screw flutes, so that the plastic becomes flowable. More specifically, the plastic becomes sufficiently flowable (due to pressure of additional upstream plastic moving into this second zone) to flow downstream through heating channels of a third zone described hereinbelow. Since most plastics do not conduct heat well, the second zone (also known as the “transition zone” herein) may be configured so that there is an increase in heated surface area for contacting the plastic within this second zone. In one embodiment, such an increase in heated surface area may be at least partially due to a heated annular interior barrel wall that serves as an intermediary barrel portion for connecting the barrel interior of the first zone to the downstream third zone having a barrel interior of reduced cross sectional dimension. In particular, the portion of the barrel extent for the first zone may have a first diameter in a range of, e.g., 2 inches to 10 inches, and the interior dimension of the third zone may have a diameter in a range of, e.g., 40% to 60% less. Such a heated wall provides a substantial increase in surface area for transmitting heat to the adjacent plastic. Moreover, such a wall can be configured to be substantially perpendicular to the general helical path of the plastic to thereby induce a buildup of plastic (and corresponding pressure which may be in a range of 100-5000 psi (pounds per square inch)) adjacent to and in contact with this wall for facilitating heat transfer to the plastic. Additionally, the terminal end of the screw within the second zone may terminate in a substantially convex shape (e.g., a truncated conical surface which forces the plastic closer the heated wall). In one embodiment, this terminal end of the screw may also radiate heat via, e.g., one of the heat sources identified hereinabove.
It is worthwhile to note that since sufficient heat to induce adherence of the plastic to internal machine surfaces only commences in the second zone, and since this zone is of short length (relative to the screw length and the length of the machine) any plastic that adheres to the internal machine surfaces in this second zone (e.g., due to a machine shutdown or heat interruption) will not be so substantial that the screw cannot be readily extracted from the barrel. In particular, the linear extent of the total barrel residing in the second zone may be only 2% to 10% of the length of the screw, and there may be few (if any) screw portions (e.g., attenuated screw flutes) in this second zone where there could be a sufficient buildup of resolidified plastic that would substantially inhibit the screw from being extracted without damaging some portion of the machine or without disassembling the barrel screw combination from the remainder of the machine.
In the third zone following the second or transitional zone, the flowable plastic is forced by pressure buildup in the second zone, to flow through one or more (preferably a plurality of) channels of this zone, wherein such channels conduct the plastic through the length of this third zone, and into a fourth or injection zone described hereinbelow. The channels may be distributed circumferentially about an extension of the screw shaft, wherein in at least one embodiment this extension includes an injection plunger that reciprocates along the rotational axis of the screw for repeatedly injecting melted plastic into a mold. Each channel may extend parallelly to the shaft axis between a receiving opening for receiving plastic, and an exit opening from which the plastic exits. The third zone is also heated by one or more of the heat sources for continuing to elevate the temperature of the plastic provided therein. Moreover, since the channel(s) may substantially increase the heated barrel surface area in contact with the plastic, the plastic in the channel(s) liquefies, or substantially reduces its viscosity so that it may flow into the injection zone (when not prevented) at a rate in direct proportion to the number of screw rotations realized within the system. The temperature increase in the plastic due the heat imparted via the channel(s) may be in a range of 25-250° F. Note that the heat sources for this third zone may be external to the portion of the barrel for the third zone, embedded within the barrel, and/or provided by the extension to the screw shaft (such extension may have a length of, e.g., 1.5 inches to 12 inches depending on the size and plastic processing capacity of the present injection mold machine).
In at least some embodiments, the shaft extension extends (along the axial length of the barrel) substantially the entire length of the third zone. However, when the plunger is fully retracted into the screw shaft, the exit opening(s) of the channel(s) opens into the injection zone so that melted plastic can exit the channel(s) and into this injection zone. Thus, since the melted plastic is typically under pressure (e.g., a range of 100-1000 psi) in the channel(s), and there is a reduced pressure in the injection zone (e.g., ambient atmospheric pressure), plastic will flow out of the channels and into the injection zone whenever such a pressure differential exists. However, when the plunger extends into the injection zone for forcing plastic into a mold, such extension closes the channel exit opening(s) so that there is substantially no backwards flow of plastic from the injection zone into the channel(s) due to the plunger induced pressure increase in the injection zone. Accordingly, the plunger serves a dual purpose of both forcing melted plastic into the mold, and also iteratively opening and closing the channels to the injection zone. So, in particular, the present injection mold machine requires no separate valve for metering the plastic melt into the injection zone.
The fourth or injection zone (also identified as a “plastication zone”) includes an injection chamber for receiving plastic from the channels, and an injection tube through which plastic flows from the injection chamber to an injection nozzle which is attached to the mold for providing plastic therein. As with other plastic conveying portions of the present injection molding machine, the injection chamber and the injection tube are connected so that the melted plastic flows generally in a straight path along the axis of the barrel. Thus, this linear arrangement prevents plastic pressure drops which can occur where the pressurized liquid plastic is constrained to abruptly flow in substantially different directions (e.g., around a 90 degree corner).
The injection zone also includes one or more of the heat sources for providing additional heat to the plastic provided therein. As with the heat sources in the other zones, the heat sources for the injection zone are controlled by the controller (e.g., a computer system specifically configured for controlling the production of parts by the present injection molding machine, and/or programmable logic controller),
It is worthwhile to note that in one embodiment of the present injection mold machine, a vacuum controlled break valve is provided for control of gas (e.g., air) entering the injection zone. In particular, the vacuum break valve allows air to enter the injection chamber when the injection plunger lowers the pressure within the fourth zone (in particular, the injection chamber) due to the plunger retracting from the injection chamber and into the screw shaft extension. In at least one embodiment, the vacuum break valve is provided along a shaft of the plunger, wherein this plunger shaft reciprocates into and out of the screw shaft. Accordingly, when a lower pressure (e.g., lower than ambient atmospheric pressure) occurs in the injection chamber, the vacuum break valve opens to introduce air into the injection chamber as will be described further hereinbelow. During plunger retraction (toward and/or into the screw shaft), the vacuum break valve remains open until (or just before) the plunger retracts sufficiently so that the channels are open to the injection chamber, and then the valve closes hereby preventing the melted plastic entering the chamber from exiting via the valve.
It is additionally worthwhile to note that when plastic is urged under pressure into the injection chamber, the heated gas (e.g., air) therein readily escapes as a backflow product through, e.g., the channel(s). Such gas backflow is facilitated in the present injection molding machine since the screw does not tightly fit within the barrel, and thus, gas can escape into the barrel (via the channel(s)) as plastic enters the injection chamber. Empirical evidence indicates that when the present injection molding machine is operating for molding acceptable parts, the pressure in the channels is effective for rapidly filling of the injection chamber with melted plastic. Accordingly, it is believed that the melted plastic enters the injection chamber at sufficient velocity to fill this chamber with melted plastic beginning with the opposite end of the chamber from the chamber end that repeatedly provides the plastic via the channel(s). Accordingly, since the exit opening for providing plastic from the injection chamber to the injection tube is located in this opposite end of the injection chamber, when the high velocity plastic commences to fill the chamber, it does so from the chamber opposite end. Consequently, the gas within the injection chamber is displaced from this opposite chamber end thereby substantially preventing gas pockets from being trapped within the plastic proximate exit opening. Moreover, since it is believed that the melted plastic collects within the chamber from this opposite end first, the gas within the chamber is forced to travel backward toward the channel opening(s) as the melted plastic under pressure injects into the injection chamber. In some embodiments, such channel opening(s) may be shaped to facilitate the melted plastic filling the injection chamber from the opposite end to the chamber end having the channel opening(s). In particular, such channel opening(s) may be shaped to direct the melted plastic into particular portions of the injection chamber. For example, the channel opening(s) may be shaped so that when the channel(s) initially opens, melted plastic is directed generally toward the interior of the opposite end of the chamber, and as the channel opening(s) widens, the melted plastic may be generally directed to a portion of the axial centerline of the plunger reciprocation wherein this portion is progressively closer to the channel opening(s). Accordingly, the gas backflow may be generally along or adjacent to the chamber sides providing relatively direct backflow paths to the channel open(s).
Moreover, it is aspect of the present injection molding machine, that since such escaping gas is heated to substantially the temperature of the injection chamber, this gas may be reused to facilitate the heating of the plastic in the second and/or the third zones. Alternatively/additionally, such heated gas may also be recirculated back into the injection chamber via the vacuum break valve described above. Accordingly, the recycling/reuse of the heat within the escaping gas increases the efficiency of the present injection molding machine.
Further note that in one embodiment, there may be backflow vents separate from the above described channels, wherein such backflow vents do not conduct melted plastic into the injection chamber.
The injection tube of the fourth zone may be of reduced cross sectional area in comparison to the injection chamber, and additionally may be of sufficient length to contain at least one volume of plastic from the injection chamber, but generally less than two such volumes. Accordingly, since the injection tube has an increased surface area (relative to volume) in comparison to the injection chamber, and is also heated, the plastic therein is acceptably liquefied for mold injection. However, due to the relatively small volume of plastic therein, the energy consumption of the injection molding machine is reduced over similar prior art injection molding machines.
The fourth zone may also include a programmable nozzle valve at or proximate to the injection nozzle, wherein this valve opens to release melted plastic in a mold cavity when there is sufficient pressure within the injection nozzle.
It is an aspect of the present injection molding machine that the controller mentioned hereinabove receives various sensor readings indicative of plastic temperatures, plastic pressures, and plastic viscosity. In particular, the controller receives the following measurements from the injection molding machine:
(a) A pressure measurement from a screw pressure sensor at the end of the screw opposite the screw end terminating in the second zone. When the screw rotates to push the plastic pellets forward, there is a corresponding back pressure induced to push the screw in the opposite direction from the direction to pellets move. Such back pressure is related to the quantity of pellets being moved by the screw, and more importantly, the quantity of pellets being compacted in the second zone. Accordingly, unless a predetermined back pressure is sensed by the controller from the screw pressure sensor providing such pressure measurements, the activation of the plunger will not commence, or if already reciprocating, the plunger may cease to reciprocate until a threshold pressure is detected by the controller from the screw pressure sensor. (b) A temperature sensor in the first zone for monitoring the temperature of the plastic pellets and/or the barrel in this zone. Accordingly, the controller controls the one or more first zone heating devices so that the pellets are heated just below their softening or deforming temperature in the first zone. (c) A chamber pressure sensor for sensing pressure within the injection chamber. Unless there is at least a predetermined pressure within the injection chamber, the injection plunger will not be activated to send a plastic pressure wave into the injection tube and consequently cause melted plastic to be injected into a mold cavity. Accordingly, the present injection molding machine only forms parts when an appropriate pressure is registered by this pressure sensor. (d) A tube temperature sensor located in the injection tube, at or proximate to the nozzle. Unless the plastic and/or the injection tube is determined to be of a threshold temperature (e.g., specific to the plastic), the plunger will not be activated, and the nozzle valve will not be opened to allow plastic to be injected into a mold cavity. (e) A tube pressure sensor located in the injection tube, at or near the nozzle. Unless the plastic is determined to have a threshold pressure within the injection tube (such pressure obtained from the most recent injection(s) of plastic via the plunger), the nozzle valve will not be opened to allow plastic to be injected into a mold cavity. Accordingly, the plunger may be activated a plurality of times between openings of the nozzle valve or activated only with nozzle valve opening depending on the pressure requirements for the plastic within the injection tube. In some embodiments, the controller may use the tube pressure for determining a length of time the nozzle valve may be allowed to be open since the pressure on the melted plastic in combination known viscosity characteristics of the plastic at the tube temperature can be used to determine the amount of plastic that will be injected into a mold cavity.
It is a further aspect of the present injection molding system that it may achieve plastic and resin plastication through the conduction of electrically generated heat as opposed to pressure induced shear heat generation methods currently used by most injection molding machines. The conduction of electrically generated heat provides a process of plastication that is more accurate than shear generated heat. Additionally, since there is also a reduced pressure applied to the plastic (due to the lack or substantially reduced shearing), the injection molding machine may be used to mold parts from non-traditional materials (e.g., bio-based resins of any type, metal injection molding feedstock, and liquid silicone) that would degrade under shearing, and may be used to produce part with enhanced performance characteristics.
It is a further aspect of the present injection molding system and method of use that there may be continuous material plastication that preserves the plastic/resin quality with exact application of prescribed levels of heat to known volumes of plastic/resin. This method dramatically reduces the force and strength requirements for the subsequent injection process (via the plunger), thereby allowing a more accurate and responsive delivery of melted plastic/resin into an injection mold cavity.
It is a further aspect of the present injection molding system and method of use that integrated pressure and temperature sensors may be used by the controller to accurately quantify the output of the present injection molding machine, and in particular during the injection molding cycle for perfecting changes to the injection molding process in order to affect parts being produced. This is accomplished even when variations in the raw material are present. Moreover, such real time mold injection process changes are provided by an injection mold controller that is data-driven from measurements obtained from sensors provided in the injection molding machine. In particular, such a data-driven machine and method results in various components of the present injection molding machine having activations that are more asynchronous to one another than the lock step or a predetermined non-deviating sequence of steps prevalent in the prior art.
It is a further aspect of the present injection molding system and method that this system can initiated without an operator present (assuming the proper mold is connected to the injection molding machine, and this machine is appropriately clean). Moreover, the presently disclosed injection molding system and method can also operate unattended for molding parts. Thus, activation and operation of the present injection molding system may be performed automatically and remotely such as via a communications network (Internet) activation, wherein the present injection molding system and method remain unattended while producing the desired parts.
The above described aspects of the present injection mold system and method were combined at least in part due to the recognition of the longstanding unmet drawbacks in various prior art injection molding machines and methods. Moreover, even relatively recent supposedly improvements in plastic injection mold technology have substantial drawbacks. For example, the following recent references have been considered, and are incorporated herein by reference:
U.S. Patent Application Publication No. 2003/0021860 by Clock et. al. filed Jul. 24, 2001, wherein an injection molding apparatus is disclosed that includes: an extruder configured to receive and compound raw materials, a plunger disposed longitudinally within the extruder, and a mold positioned at the outlet end of the extruder and configured to receive the compounded raw materials. The extruder includes first and second screws intermeshed with each other along at least a portion of the length thereof. The plunger is typically positioned longitudinally within a bore defined within the first screw and is translatable within the bore. The method for using the apparatus includes adding at least one material to the extruding unit proximate a first end thereof, compounding the material, transporting the material to an outlet port proximate a second end of the extruding unit, and transferring the material from the outlet port to the mold via a reciprocating action of the plunger relative to the first screw. The Clock application discloses a check ring for preventing back flow of the liquid plastic out of an injection chamber. Such a check ring: can be unreliable, and introduce inaccuracies into the quantity of the plastic injected into a mold due to both the variability in the closing by the check ring as well as the restrictions to plastic flow therethrough. Note that such impedances to plastic flow are magnified in that such check rings are typically heat sinks; thus, causing the plastic to flow less readily. Moreover, it appears that the Clock's plunger (also a heat sink having sizable plastic contacting surface area) must rotate with the screw. Accordingly, since it is irregularly shaped (e.g., there are flutes therein), there is unnecessary drag on the motor rotating the screw. Additionally, since the check ring is not monitored during operation for determining if it is performing properly, there can be significant variability in parts produced, and for which machine configurations settable by the operator may have an unpredictable (if any) effect. U.S. Patent Application Publication No. 2002/0020943 by Leopold et. al. filed May 9, 2001, wherein a molding machine is disclosed for molding microparts containing between 0.001 to 3.5 cubic centimeters of plastic shot volume includes a plasticizing portion operatively connected to an injection portion and a mold portion. A valve member is provided to open and close the connection between the plasticizing portion and the injection portion. A linear motor member is associated with the injection portion to permit molding times of presumably 0.01 seconds at pressures up to about 100,000 psi during injection of the molten plastic into the mold portion. Leopold discloses using a valve for apparently allowing melted plastic to flow into a bore for injection into a mold. Moreover, Leopold also needs an additional valve at his injection nozzle. There are reliability problems with such valves since a temperature decrease of the plastic in or around such valves can cause these valves to malfunction due to an increase in the viscosity or solidification of the plastic. Moreover, such valves are particularly problematic if the plastic includes one or more filler materials that may be fibrous since such valves may fail to fully close and/or open due to fiber build up or compaction in or around the valves.
Other features and benefits of the presently disclosed injection molding machine and method of use are disclosed in the accompanying figures, and the description hereinbelow. In particular, various novel aspects of the presently disclosed injection molding machine and method not described above may be described hereinbelow. Accordingly, this Summary section is intended to present a general overview of the present injection molding machine and method of use, but may not identify every patentable aspect thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the machine showing the logical connections between the machine and the controller in one embodiment of the present disclosure;
FIG. 2 is side elevation view of the machine;
FIG. 3 is a cutaway side view of the machine showing the logical connections between the machine and the controller in one embodiment of the present disclosure;
FIG. 3A is a detailed cutaway side view of portions of the plunger 160 ;
FIG. 4 is a cutaway side elevation view of the machine;
FIG. 5 is a cross-sectional view of the machine at a point indicated as A-A in FIG. 3 , viewed from left to right with reference to FIG. 3 ;
FIG. 6 is a cross-sectional view of the machine at a point indicated as B-B in FIG. 3 , viewed from left to right with reference to FIG. 3 ;
FIG. 7 is a cross-sectional view of the machine at a point indicated as C-C in FIG. 3 , viewed from left to right with reference to FIG. 3 ;
FIG. 8 is a cross-sectional view of the machine at a point indicated as D-D in FIG. 3 , viewed from left to right with reference to FIG. 3 ;
FIG. 9 is a detailed partial cutaway side elevation view of the machine; and
FIG. 10 is a block diagram showing components of the system 12 , which includes machine 20 and controller 16 in one embodiment of the present disclosure.
FIG. 11 is a block diagram of the injection molding system 12 .
FIG. 12 is a flowchart of the processing performed by the controller 16 .
DETAILED DESCRIPTION OF THE INVENTION
In order to more fully appreciate the present invention, the following references are fully incorporated herein:
U.S. Pat. No. 7,122,146 by Akopyan, filed Apr. 18, 2005, wherein an injection molding machine utilizing microwave heating is disclosed. In particular, a microwave oven and a microwave absorbent plasticizing vessel therein, is utilized in an injection molding system to heat polymer granules to an injection temperature and injection of a resulting plastic melt into a cavity of an injection mold. The polymer granules may be preheated by conventional heating systems to a temperature at which the granules become microwave absorbent before heating to the injection temperature in the microwave oven. The injection molding machine also contains a hydraulic actuator for injection of the resulting plastic melt. The ceramic materials forming the plasticizing vessel are selected to provide equal heating rates of mold members and relatively uniform heating of polymer to desired injection temperature. U.S. Pat. No. 7,361,294 by Pierick et. al. filed Feb. 2, 2005, wherein an injection molding system and method is disclosed for making microcellular foamed materials are provided as well as microcellular articles. U.S. Patent Application Publication No. 2006/0197254 by Onishi filed May 2, 2006, wherein an induction-heating-type heating apparatus is attached to an area of the outer circumference of a heating cylinder adjacent to a cooling apparatus, whereby the temperature of the heating cylinder can be uniformly controlled to a proper value, and the temperature of the heating cylinder can be changed quickly. An injection apparatus is adapted to intermittently feed forward a resin within a heating cylinder by a screw in accordance with an injection molding cycle. The injection apparatus includes a cooling apparatus attached to a rear portion of the heating cylinder, and an induction heating apparatus attached to the heating cylinder to be located forward of the cooling apparatus and adjacent to the cooling apparatus. U.S. Patent Application Publication No. 2007/0104822 by Okabe filed Jun. 23, 2006, wherein a plasticizing apparatus is disclosed for use with a resin material wherein the apparatus is reduced in size and wherein a plastication state of a resin material is presumably stabilized without raising a heating temperature for a plasticizing barrel. On the inner surface of a plasticizing barrel for plasticizing the resin material, one or more lines of a heat transfer pieces shaped like a ridge is/are disposed in a protrusion condition in a spiral or a straight line, and on the outer surface of the barrel, one or more lines of a heat receiving piece is/are disclosed. U.S. Patent Application Publication No. 2009/0057938 by Zhang filed Aug. 28, 2007, wherein a method is provided for improving melt quality in an injection unit. A closed loop control system regulates operation of the injection unit in accordance with a reference value for at least one operating parameter. A sensor measures the present el value of a load upon the motor which drives an injection screw during operation of the injection unit. A processor compares the present value of the load to a reference value for the load. If the present value of the load deviates from the reference value of the load by more than a predetermined amount, then the processor may adjust the reference value of the at least one operating parameter. Operating parameters can include barrel temperature, back pressure and screw RPMs. U.S. Patent Application Publication No. 2009/0045538 by Davina et. al. filed Aug. 13, 2007, wherein a method of controlling a screw in a two-stage injection unit and a system for implementing the method is disclosed. The method is executable at a computing apparatus associated with the two-stage injection unit. The method comprises receiving an indication of an operational parameter associated with the screw of the two-stage injection unit; based on the indication of the operational parameter, determining a target speed (STARGET) for the screw, the target speed (STARGET) being sufficient to enable the screw to produce a required amount of material in a molten state; causing the screw to rotate at the target speed (STARGET), thereby causing the screw to operate in a substantially continuous manner.
The above-identified references each have their own corresponding drawbacks that make them at most partially useful in addressing injection molding machine related problems.
An embodiment of the presently disclosed injection molding system 12 is shown in FIG. 1 , wherein a controller 16 is shown together with the injection molding machine 20 that the controller 16 controls. The injection molding machine 20 will be first described hereinbelow, followed by a description of the controller 16 .
In reference to FIGS. 3 and 4 , a cross sectional view of an embodiment of the injection molding machine 20 is shown. The machine 20 includes a material hopper 24 for providing plastic material (e.g., plastic pellets) to the machine 20 , wherein the pellets, by gravity, enter a substantially vertical escapement 28 below the hopper 24 . The escapement 28 may be an opening in a throat block 32 which may be a metal block (e.g., cube or other shape) acceptable for providing support and stability to the material hopper 24 attached thereto as well as various components of the machine 20 . In particular, the throat block 32 includes generally horizontal barrel opening 36 therethrough which intersects with the escapement 28 . The barrel opening 36 is fitted with a barrel 40 that extends horizontally beyond the throat block 32 out one of the sides of throat block 32 . The throat block 32 also includes a plurality of water channels 42 for circulating coolant (e.g., water or other suitable coolant) therein since, as will become evident from the description hereinbelow, excessive heat from the plastication of the pellets may transfer into throat block 32 and heat the pellets in the escapement 28 or the hopper 24 excessively (e.g., wherein the pellets might be soft). The barrel 40 provides the structural support within which the pellets are transformed into a suitable liquid state for injection into a mold 46 . The barrel 40 includes a first stage 44 extending substantially through the throat block 32 and out of the throat block to the right in FIG. 3 . This first stage 44 is coincident in extent (along the axis 112 ) with the first zone described in the Summary section hereinabove, and accordingly such an extent may be also referred to as the first zone 44 . A cross section of the first stage 44 (in a direction traverse to the cross section shown in FIG. 3 ) is shown in FIG. 5 . However, a cylindrical shape may be preferred. The first stage 44 may have a cylindrical interior extending therethrough. The first stage 44 terminates outside the throat block 32 at an interior annular wall 48 which reduces the interior of the barrel 40 . From this annular wall 48 and extending further away from the throat block 32 is a second stage 52 of the barrel 40 , this second stage being coincident in extent (along the axis 112 ) with the second zone described in the Summary section hereinabove, and accordingly such an extent may be also referred to as the second zone 52 . This second stage 52 may have a generally cylindrical shaped interior which has center axis collinear with a center axis of the first stage 44 . However, instead of having a smooth cylindrical interior surface as the first stage has, the second stage 52 includes a plurality of channels 56 in its interior side wall 58 (a representative cross section of the second stage 52 is shown in FIG. 6 ), wherein these channels extend outwardly from the center axis and such channels may be distributed about the circumference of the second stage. Since the channels 56 extend through the horizontal length of the second stage 52 , the second stage terminates with channel openings at each end of the second stage. The end of the second stage distal from the first stage 44 is integral with a third stage 60 which has therein a cylindrical injection chamber 64 that may be of the same diameter as the second stage (excluding the channels 56 ), this third stage being coincident in extent (along the axis 112 ) with the third zone described in the Summary section hereinabove, and accordingly such an extent may be also referred to as the third zone 60 . The injection chamber 64 has a horizontal center axis that is collinear with the center axes of the first and second stages 44 and 52 . The injection chamber 64 extends away from the second stage 52 until a second diameter reducing annular interior wall 68 is reached, wherein a central opening 72 in the wall 68 ( FIG. 9 ) may have a center point on the center axis of the injection chamber 64 . From this second annular wall 68 , a fourth stage 76 of the barrel 40 commences which includes an injection tube 78 that extends from an opening 72 in the second wall 68 to a nozzle end 80 of the machine 20 , wherein the nozzle end is configured for attaching to the plastic injection mold 46 and injecting melted plastic therein as one skilled in the art will understand. Note that this fourth stage is coincident in extent (along the axis 112 ) with the fourth zone described in the Summary section hereinabove, and accordingly such an extent may be also referred to as the fourth zone 76 . In comparison to the diameter of the injection chamber 64 , the injection tube 78 includes a substantially reduced diameter cylindrical interior. Moreover, near or substantially at the nozzle end 80 , there is a nozzle valve 82 which opens and closes under the direction of the controller 16 . The nozzle valve 82 remains closed until a desired plastic consistency and pressure is detected within the injection tube 78 . Once such conditions occur in the injection tube 78 , and assuming the mold 46 is in a state wherein plastic can be accepted, the nozzle valve 82 is opened by the controller 16 for providing plastic to the mold cavity 83 .
The barrel 40 also includes an opening 84 for receiving plastic pellets from the escapement 28 . Such pellets enter the barrel 40 and are retained between the flights 88 of an auger screw 92 (also “screw” herein) provided within the barrel. The screw 92 is preferably concentric or coaxial with the barrel 40 . The screw 92 includes a shaft 96 from which one or more helical flights 88 project outwardly therefrom, and such flights 88 extend from generally below the escapement 28 through the first stage 44 of the barrel 40 . The shaft 96 also extends horizontally in the opposite direction from the escapement 28 , wherein a thickened shaft portion 100 adjacent to the throat block 32 is secured thereabout with a bearing 104 , which is provided within a mounting plate 108 , which is fixedly attached to the adjacent side of the throat block 32 . Accordingly, the bearing 104 supports and maintains alignment of the screw 92 within the barrel 40 so that the screw can rotate about a center axis 112 of the barrel, this center axis including the center axes for each of the first, second, third, and fourth stages of the barrel as described hereinabove. In particular, the screw 92 diameter within the barrel 40 is smaller than the interior diameter of the first stage by a tolerance of approximately 0.01 to 0.08 inches so that the screw can rotate freely within barrel when there is no plastic in the barrel to impede such free rotation. Note that the tolerance between the interior of the first stage 44 and the screw 92 may be dependent upon the intended size of the plastic pellets to be provided in the material hopper 24 since such tolerance is intended to be small enough so that such pellets cannot be caught and sheared between the interior surface of the first stage 44 and the portions (apexes) of the auger screw flights 88 that rotate closest to the first stage interior surface. Accordingly, the tolerance range above is believed appropriate for pellets that are approximately 0.125 inches in width, height and depth, pellets being a standard size for use in injection molding machines.
The shaft 96 also extends beyond the mounting plate 108 , wherein a pulley 116 is also secured thereabout. For rotating the screw 92 , a belt (not shown) is provided in the annular recess 120 of the pulley 116 and also provided about a pulley of a drive motor (also not shown) for rotating the pulley 116 and consequently the screw 92 .
The screw 92 has a central bore 124 therethrough, the center axis of the bore is coincident with the center axis 112 . Within the bore 124 there is an injection plunger 160 (having a plunger head 132 and a plunger shaft 136 ), and a plunger shank 140 . The plunger shank 140 extends from the screw 92 rearward beyond the pulley 116 . Prior to exiting the screw 92 , the plunger shank 140 and the interior surface of the bore 124 are intermeshed via mating gear teeth 142 or another mechanism for both supporting the shank 140 within the bore 124 , and for allowing the shank to shift along the center axis 112 under the urging of the motor (or pneumatic cylinder, hydraulic cylinder) 144 to which the shank end attaches via a bearing 148 . In another embodiment, instead of mating gear teeth 142 , a bearing that allows the shank 140 to move in the axial direction relative to the bore 124 and provide support for the shank 140 within the bore 124 may replace the mating gear teeth 142 . Accordingly, the bearing 148 allows the shank 140 to rotate with the rotation of the screw 92 by the pulley 116 . However, when activated (by the controller 16 , also shown in FIGS. 1 and 3 , and described hereinbelow) the motor 144 shifts the shank along the center axis 112 either for pushing the shank further into the screw, or for extending further rearward outside of the screw. In particular, the extent that the shank 140 may shift in either direction does not disengage the shank from the interior of the bore 124 at the shift mechanism 142 . Moreover, length of such a shift (in either direction) may be identical to the travel of the plunger head 132 in the injection chamber 64 as will be further described hereinbelow. The shank 140 attaches, at a second end thereof opposite to the shank end attached to the motor 144 , to a receptacle 152 . In one embodiment, the receptacle 152 may be threaded and the second end of the shank 140 may have corresponding threads (e.g., male-female junction). In particular, the receptacle 152 may threadably mate with the end of the shank 140 .
The sleeve 156 also projects beyond the fluted end of the screw 92 . The portion of the sleeve 156 that extends beyond the end of the screw 92 is within a fine tolerance of the interior surface of the second stage 52 of the barrel 40 . More precisely, the smallest interior diameter of the second stage interior side wall 58 may be within a tolerance of approximately 0.01 inches of the outer diameter of the sleeve 156 . Thus, the sleeve 156 forms a rotatable inner most side of each channel 56 in the second stage 52 . In the present embodiment, the exterior surface of the sleeve 156 forming the inner most channel sides may be highly polished or otherwise provided with a coating that substantially prevents melted or softened plastic from adhering thereto.
The sleeve 156 and the plunger head 132 are sealed together (such combination also referred to as plunger 160 ), and may be considered as an embodiment of the “shaft extension” referred in the Summary section hereinabove. An outside diameter of the sleeve 156 may be within a fine tolerance of the inside diameter of the injection chamber 64 , e.g., within a range of 0.005 to 0.001, so that this sleeve 156 and plunger head 132 combination can enter the injection chamber (via an urging by the motor 144 ) for injecting melted plastic from the injection chamber into the injection tube 78 , and also via an opposite urging by the motor 144 , the plunger 160 can retract out of the injection chamber 64 once the plunger 160 reaches its full extension into the injection chamber 64 .
The plunger head 132 includes a one way vacuum break valve 164 (e.g., a poppet style valve) for opening and providing a gas (e.g., air) or other fluid substance therethrough when a reduced atmospheric pressure occurs in the injection chamber 64 relative to a pressure on an opposite side of this valve, and remaining closed otherwise. When the valve 164 opens, the gas provided to the injection chamber 64 comes, in one embodiment, from within the bore 124 , and more particularly, from within a plunger vent 168 within the plunger shaft 136 ( FIG. 3A ). However, it is within the scope of the present disclosure that such gas may come from a backflow of gas (i.e., in an opposite direction from the flow of plastic toward the nozzle end 80 ) through the channels 56 . The vacuum break valve 164 may be configured for opening when there is a pressure differential between sides of the valve in a range of 2 to 1,000 psi. Accordingly, when the plunger 160 retracts back into the screw 92 , the vacuum break valve 164 opens so that the retraction of the plunger does not cause the melted plastic within the injection tube 78 to withdraw back into the injection chamber 64 .
The injection molding machine 20 also includes a plurality of heat sources (e.g., such heat sources may generate heat via electrical resistance, electrical inductance, microwave or ultrasonic energy) distributed about and in contact with (or proximate to) various portions of the barrel 40 . In particular, one or more such heat sources 172 may surround the barrel 40 in a later or terminal portion of the barrel first stage 44 near the commencement of the barrel second stage 52 , and continue to surround barrel 44 in substantially the second stage 52 . The heat sources 172 (under the control of the controller 16 ) preheat the plastic pellets to a point just below the softening point of the plastic.
The heat sources 172 (under the control of the controller 16 ) heat the plastic pellets therein to a temperature where they become at least soft and deformable for flowing into the channels 56 due to the pressure exerted on such deformable pellets from additional pellets moving into the second stage 52 .
The steps performed by the controller 16 for appropriately activating and deactivating the heat sources 172 are described hereinbelow in the section entitled “Controller Operation”. Note that in one embodiment, an additional heat source 176 (not shown in figures) may be placed on a different location of the barrel 44 and controlled by controller 16 . Note that in such an embodiment of the controller 16 the heat sources 172 and 176 are activated and deactivated in unison by the same processing in the controller 16 . That is, the controller may not distinguish between the heat sources 172 and 176 . In another embodiment, heat sources 172 and 176 may be activated, for example, in a serial or sequential manner.
An additional one or more heat sources 180 may surround the barrel 40 in substantially its third stage 60 and fourth stage 76 . The heat sources 180 (under the control of the controller 16 ) further heat the plastic in the injection chamber 64 and the injection tube 78 so that the temperature of the plastic is above a minimum threshold to be injected into the mold cavity 83 . The steps performed by the controller 16 for appropriately activating and deactivating the heat sources 180 are also described hereinbelow in the section entitled “Controller Operation”.
The injection molding machine 20 also includes a plurality of sensors for communicating measurements related to plastic processing to the controller 16 . In one embodiment of the injection molding machine 20 , there is a screw 92 pressure sensor (denoted “PT1” herein) attached, e.g., to the screw end between the pulley 116 and the motor 144 , wherein this sensor measures the forces on the screw, wherein such forces are substantially along the center axis 112 , and induced by the compaction of the plastic in first and second barrel stages 44 and 52 . Accordingly, such for forces are in the direction for pushing the screw 92 out of the end of the barrel 40 provided in the throat block 32 .
The injection molding machine 20 also includes a plurality of sensors for communicating measurements related to plastic processing to the controller 16 . In one embodiment of the injection molding machine 20 , there is a screw 92 pressure sensor or pressure transducer (denoted “PT1” herein) attached, e.g., to the screw 92 end between the pulley 116 and the motor 144 , wherein this sensor measures the pressure on the screw, wherein such pressure is substantially along the center axis 112 , and induced by the compaction of the plastic in first and second barrel stages 44 and 52 . Accordingly, such for pressure may be considered a force in a direction for pushing the screw 92 out of the end of the barrel 40 provided in the throat block 32 . A temperature sensor (denoted “TC1” herein) is attached to the barrel 40 (more particularly, the third stage thereof) for detecting temperatures in the injection chamber 64 . The sensor TC1 may be a thermocouple as one skilled in the art will understand. Also attached to the barrel third stage is a pressure sensor or pressure transducer (denoted “PT2” herein) for measuring the pressure within the injection chamber 64 . Downstream from the sensor PT2 is another pressure sensor or pressure transducer (denoted “PT3” herein), wherein this sensor measures the pressure within the injection tube 78 . Additionally, there is a temperature sensor (denoted “TC2” herein) is attached to the barrel 40 (more particularly, the fourth stage thereof) for detecting temperatures in the injection chamber 64 . The sensor TC2 may be a thermocouple as one skilled in the art will understand. Finally, there is a temperature sensor (e.g., a thermocouple) provided in the mold 46 for detecting temperatures therein. This last sensor identified as “TC3”. Each of the above identified sensors provides their corresponding readings to the controller 16 as will be described in further detail hereinbelow.
FIG. 11 shows a block diagram of the injection molding system 12 , wherein additional detail is provided of the internal components of the controller 16 . Referring to the controller 16 , it includes a main controller 204 that performs that high level control functionality for controlling the injection molding machine 20 . A flowchart of the processing performed by the main controller 204 is presented in FIG. 12 described hereinbelow. The main controller 204 activates a plurality of subcontrollers that may perform their tasks asynchronously from one another. In particular, subcontroller 304 is provided for controlling the heat source(s) 172 for heating the first and second zones 44 and 52 . A subcontroller 308 is provided for controlling the heat source(s) 180 for heating the third and fourth zones 60 and 76 . A subcontroller 312 is provided for controlling the screw 92 rotation during startup of the injection molding machine 20 , and more particularly, prior to injection molding machine entering a plastic processing state where processed plastic is flowing through the injection molding machine appropriately for making parts. A subcontroller 316 is provided for controlling the screw 92 rotation once plastic is flowing through the injection molding machine appropriately for making parts. A description of each of these subcontrollers is provided hereinbelow. However, prior to providing such descriptions, a description of the flowchart of FIG. 12 representing the processing performed by the main controller 204 is provided.
Referring to FIG. 12 , in step 404 , the controller 16 receives input for activating the injection molding system 12 . Such activation may be from an operator at the injection molding system 12 , or an operator that is remote from the location of the system 12 . Moreover, since the controller 16 can be remote from the injection molding machine 20 (e.g., in communication therewith via a communications network such as the Internet), the operator may reside at the controller site, or at the injection molding machine site. Alternatively/additionally, the operator may not reside at the site for either the controller 16 or the injection molding machine 20 , but instead may communicate with controller via a communications network. Moreover, the input received may be from another computational system such as an inventory management system that automatically requests additional parts to be produced by the injection molding system 12 .
Note that such input may include a type of material to be supplied to the injection molding machine 20 , an identification(s) of the part(s) to be molded, the quantity of parts to be produced.
In step 408 of FIG. 12 , the controller identifies from the input received the type of material to supply to the injection molding machine 20 . Such identification may be precisely identified in the input, or may be only generally identified (e.g., by a plastics chemical family, or by required part functionality such as elasticity, compression strength, biodegradable, acceptable for retention in a human body, non-toxic if ingested, etc. In one embodiment, such material may be automatically supplied to the hopper 24 for commencing to produce the parts desired, and the desired mold 46 may be automatically attached to the injection molding machine 20 , e.g., once the mold is located in an inventory of molds 46 . Subsequently, in step 412 , a database management system 410 ( FIG. 11 ) may be accessed for determining the injection molding machine 20 parameters to use in molding the desired parts.
In step 416 , the subcontroller 304 is activated for controlling the heat source(s) 172 for heating the second and third zones 44 and 52 . The input to the subcontroller 304 may include a desired start temperature range for readings from the temperature sensor TC1 as determined for plastic to be processed; the range of temperatures may be, e.g., +/−10 degrees F., and the range may be a set point range identified as the range [set_pt_low, set_pt_hi] wherein set_pt_low is a low set point for the readings from TC1, and set_pt_hi is a high set point for these readings. Pseudo-code representative of the processing performed by the subcontroller 304 is as follows:
Subcontroller 304 processing:
Activate asynchronously (the following processes):
Process 1:
At “X” frequency read input temperature measurement from TC1;
If the input temperature measurements are below “set_pt_low”, then
Make sure the heat sources 172 are activated for heating;
Else make sure the heat sources 172 are not heating;
Process 2:
Repeat every “Y” time interval:
If (Delta12_Not_Measured) then /* “Delta12_Not_Measured” is set to TRUE
after the plunger 160 retracts into the screw 92
*/
If (the plunger 160 is fully retracted into the screw 92)
then {
Pt1 ←Read PT1;
Pt2 ← Read PT2;
Delta12 ← Pt1 − Pt2;
Delta12_Not_Measured ← FALSE;
If (Delta12 >= its corresponding predetermined set point) then {
/* either plastic viscosity in screw 92 is high, and/or, plastic is
not flowing through channels 56 into the injection chamber 64
*/
Tc1 ← read TC1;
If (Tc1 <= set_pt_hi) then
Override Process 1, and make sure the heat sources 172 are
heating;
}
Until (subcontroller 304 is deactivated).
Referring to the subcontroller 304 pseudo-code hereinabove, process 1 and process 2 may be activated for being performed simultaneously. However, note that process 2 can override process 1 to force the heat source(s) 172 to heat zones 44 and 52 . It is believed that an important aspect of the controller 16 is the use of the pressure measurements from the sensors PT1 and PT2 to modulate the heat delivered to the first and second zones 44 and 52 . In particular, the computation of “Delta12” provides a quantitative index as to whether plastic viscosity in screw 92 is high, and/or the plastic is not flowing through channels 56 into the injection chamber 64 . For example, if the value Pt1 is high relative to the value of Pt2, then there is substantial pressure in the first and second zone 44 and 52 for pushing the screw 92 out the rear end of the injection molding machine 20 , and little (if any) plastic in the injection chamber 64 . Accordingly, this is indicative of the plastic in the second and third zones 52 and 60 not being hot enough to proper flow through the channel 56 and into the injection chamber 64 . Thus, in this case, any deactivation of the heat source(s) 172 is overridden by process 2 . Note that it may be important for the reading of PT1 and PT2 to be taken substantially simultaneously, and that the readings of PT2 be taken when the pressure in the injection chamber 68 is not being impacted by the movement of the plunger 160 into or out of the injection chamber. Accordingly, such reading are only taken when the controller 16 detects that the plunger is fully retracted from the injection chamber 64 . The use of the Boolean variable “Delta12_Not_Measured” assists in making sure the readings are taken at a proper time.
In step 420 , the subcontroller 308 is activated for controlling the heat source(s) 180 for heating the fourth zone 76 . As described in the pseudo-code following. Note that the input for this subcontroller is: a desired start temperature range for readings from the temperature sensor TC2 (for heat sources 180 ) for plastic to be processed, the range of temperatures (e.g., +/−10 degrees F.) creating a set point range, i.e., a range: [set_pt_low2, set_pt_hi2] for the readings from TC2.
Subcontroller 308 processing:
Activate asynchronously (the following processes):
Process 3:
At “X” frequency the subcontroller 308 reads input temperature measurements
from TC2;
If the input temperature measurements are below “set_pt_low2”, then
Make sure the heat sources 180 are activated for heating;
Else make sure the heat sources 180 are not heating.
Process 4:
Repeat every “Y” time interval:
If (Delta23_Not_Measured) then /* “Delta23_Not_Measured” is set to TRUE
after the plunger 160 retracts into the screw 92
*/
If (the plunger 160 is fully retracted into the screw 92)
then {
Pt2 ←Read PT2;
Pt3 ← Read PT3;
Delta23 ← Pt2 − Pt3;
Delta23_Not_Measured ← FALSE;
If (Delta23 >= its corresponding predetermined set point) then {
/* either plastic viscosity in injection chamber 64 is high,
and/or, plastic is not flowing through injection tube 78 */
Tc2 ← read TC2;
If (Tc2 <= set_pt_hi2) then
Override Process 3, and make sure the heat sources 180 are
heating;
}
Until (subcontroller 308 is deactivated).
Note that the variables “Delta23” and “Delta23_Not_Measured” have similar meanings as “Delta12” and “Delta12_Not_Measured” described hereinabove.
Subsequently, step 424 is performed, wherein the subcontroller 312 is activated for controlling the screw 92 rotation. Pseudo-code describing the actions performed by this subcontroller follow.
Subcontroller 312 processing:
Repeat at predetermined intervals:
If (the input temperature measurements are in the range [set_pt_low, set_pt_hi])
then
Make screw 92 is rotating Until (PT1 indicates back pressure exceeds
maximum pressure allowed) OR (PT2 indicates pressure from
plastic presence is above a predetermined set point);
If (PT1 indicates back pressure exceeds maximum pressure) then
Stop the screw 92 for an elapsed time “X”, and PT1 pressure
readings are monitored at “X” time intervals. When PT1 drops
below maximum pressure allowed, the screw 92 is rotated;
If (PT2 indicates pressure from plastic presence is above a predetermined
minimum set point) then
The screw 92 is stopped until pressure at PT2 falls below the
predetermined minimum set point for PT2, and PT2 pressure
readings are monitored pressure at “X” time intervals. When PT2
drops below the predetermined minimum set point for PT2, the
screw 92 is rotated;
Until (subcontroller 312 is deactivated).
Subsequently, in step 428 , the expression: (the most recent value of pt2 by subcontroller 304 is within its corresponding predetermined set point range) AND (the most recent value of Delta12 computed by subcontroller 304 is within a predetermined set point range) is repeatedly evaluated. When this expression evaluates to “TRUE”, the subcontroller 312 is deactivated and the subcontroller 316 , whose pseudo-code is hereinbelow, is activated.
Subcontroller 316 processing:
Repeat at predetermined intervals:
If ((the most recent value of Pt3 indicates a pressure below its
minimum corresponding predetermined low set point) OR (the
most recently computed value for Delta23 is outside of its
predetermined set point range) then
Make sure screw 92 is rotating;
If (the most recent value of Pt3 indicates pressure exceeds
maximum set point pressure) then
Stop the screw 92 for an elapsed time “X”, and PT1 pressure
readings are monitored at “X” time intervals. When PT1 drops
below maximum pressure allowed, commence rotating the screw
92;
If (the most recent value of Pt2 indicates pressure is above a
predetermined minimum set point) then
The screw 92 is stopped ”, and PT2 pressure readings are
monitored at “X” time intervals. When PT2 drops below the
predetermined minimum set point for PT2, commence rotating
the screw 92;
Until (subcontroller 316 is deactivated).
Subsequently, step 440 is performed.
When an appropriate profile is achieved by measurements of the heat source(s) 172 and heat source(s) 180 sequences via their corresponding sensors, we then have a volume of material where the viscosity as measured as resistance to flow, is optimized and known. When this condition is achieved we will have realized a low delta between PT1 and PT2 and furthermore a low delta between PT1 and PT3. This allows the use of the screw 92 to extrude plastic directly into the mold 46 when desired.
In any of the following modes of injection molding, operation of the last key component is PT4 pressure transducer in the injection mold.
The above disclosure lays the foundation for four different injection molding processes: Plastic Injection Molding Method (PIMM) 1 through 4 described hereinbelow.
(a) PIMM1—the Injection Plunger is advanced beyond the truncation of the Lobe Geometry to evacuate the Injection Zone. As the Injection Plunger advances the Nozzle valve is opened to allow flow of plastic into the injection mold causing the mold cavity to fill and plunger travel ceases upon satisfying predetermined pressure set point as indicated by PT4. (b) PIMM2—Screw Auger rotates continuously to extrude plastic and the Nozzle valve is opened to allow flow of plastic into the injection mold causing the mold cavity to fill to some predetermined percentage through plastic extrusion (low speed, low shear) when the Injection Plunger is then utilized to finish the injection process to the predetermined pressure set point as indicated by PT4 at which time plunger travel ceases. (c) PIMM3—Screw Auger rotates continuously to extrude plastic and the Nozzle valve is opened to allow flow of plastic into the injection mold causing the mold cavity to fill completely by extrusion (low speed, low shear) to the predetermined pressure set point as indicated by PT4 at which time extrusion ceases. (d) PIMM4—Screw Auger rotates continuously to extrude plastic and the Nozzle valve is opened to allow flow of plastic into the injection mold causing the mold cavity to begin filling when the Injection Plunger is then utilized to cycle repeatedly until realizing predetermined pressure set point as indicated by PT4 at which time plunger travel ceases.
The foregoing discussion of the injection molding system 12 has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention(s) disclosed herein any to the form disclosed. Consequently, variation and modification commiserate with the above teachings, within the skill and knowledge of the relevant art, are within the scope of the present invention. The embodiment described hereinabove is further intended to explain the best mode presently known of practicing the invention, and to enable others skilled in the art to utilize each invention herein, or in other embodiments thereof, and as may be provided with the various modifications required by their particular application or uses of the invention(s) herein. | A thermoplastic injection molding system and method of use is described for molding parts from heated plastics and other organic resins. The machine uses heat sources located along the barrel to heat the source material while an auger screw transports the source material in the barrel. This transport step does not shear the source material, nor does it use friction to produce the heat necessary to melt the source material. The material becomes substantially liquid or melted during the heating process, and the melted material is forced, by the auger screw, into a chamber whereupon a plunger, situated concentrically with the auger screw, injects the material from the chamber into a mold. Sensors located along the barrel and in the chamber ensure consistency between mold cycles. The controller dynamically adjusts the injection molding process to achieve more consistent and reliable molded parts. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a wear resistant aluminum alloy elongate body having superior shear-cutting property, manufacturing method thereof, and to a piston for a car air conditioner including the wear resistant aluminum alloy elongate body.
[0003] 2. Description of the Background Art
[0004] Cast aluminum alloy containing 7 to 13 mass % of silicon, 2.0 to 5.0 mass % of copper and 0.3 to 1.0 mass % of magnesium is light weight and has superior wear resistance and mechanical properties. Therefore, the alloy has been used for a member such as a piston for a car air conditioner, which requires such superior characteristics. In the alloy of this type, in order to attain both wear distance and mechanical properties, the amount of crystallized silicon grains is controlled.
[0005] Japanese Patent Laying-Open No. 64-17834, for example, proposes a representative high strength wear resistant aluminum alloy. The aluminum alloy disclosed in this laid-open application is manufactured by casting, such as continuous casting or semi-continuous casting of fixed molding method, at a high cooling rate. In the inner texture of the cast bar manufactured by this method, the size of the eutectic silicon grains is at most 8 μm, the grain size is uniform and the grains are distributed uniformly. To the aluminum alloy in this example, in order to reduce the size of the silicon grains, titanium and boron are added to be at most 0.25 mass % in total, and after casting, cooling is performed at a rate of at least 4° C./sec. As a result, surface hardness is controlled to be 67 to 75 according to F scale of Rockwell hardness. Further, an appropriate amount of alloy component is added to enhance toughness of aluminum alloy matrix. This is to solve the following problem. Namely, in a cast bar used with the cast texture intact, silicon grains are segregated at the grain boundary at the time of solidification, and at the time of shear-cutting, a crack changes its direction along the segregated silicon grains, making it difficult to obtain a smooth cut surface.
[0006] By such measures, the aluminum alloy disclosed in the aforementioned laid-open application comes to have flat shear surface when shear-cut, and becomes less susceptible to brittle damage, namely, the aluminum alloy has a so-called satisfactory shear-cutting property.
[0007] The method of manufacturing aluminum alloy disclosed in the aforementioned laid-open application, however, involves high cost of facilities to perform rapid cooling after casting, and production efficiency is not very high, as the manufacturing process is semi-continuous.
[0008] Therefore, the inventors have studied a manufacturing method that does not involve the above described rapid cooling step and that enhances production efficiency in continuous casting. As a result, it has been found that an alloy having superior shear-cutting property can be obtained by a continuous casting method with higher production efficiency that combines a continuous casting machine of movable molding method represented by a Properzi continuous casting machine with hot rolling, though the range of silicon grain distribution widens.
[0009] The continuously cast rolled member obtained by the method studied by the inventors consists of hot rolling texture, re-crystallized texture, or a mixed texture of hot rolling texture and re-crystallized texture. Therefore, at the time of shear-cutting, the member exhibits more satisfactory cross section than the conventional cast bar in which coarse silicon grains are segregated at the grain boundary of the matrix.
[0010] When the casting method is used, a perspiration zone, a ripple mark, an external damage or the like is generated on the surface of the ingot. when such defects are not removed, cutting crack results at the time of shear-cutting, forging crack results at the time of forging, and fatigue strength and the like degrade in the final product. Therefore, generally, surface cutting process is performed before shear-cutting.
[0011] The surface cutting of an elongate body includes a peeling process for scraping by a cutting tool, and a dice-skinning process for scraping by means of a fixed dice.
[0012] [0012]FIG. 6 represents the peeling process in which the surface of the workpiece 1 is scraped off by using a cutting tool 2 . FIG. 7 represents the dice-skinning process in which the surface of workpiece 1 is scraped off by a fixed dice. Generally, productivity of dice-skinning process is higher than that of peeling process. The dice-skinning process, however, is difficult in casting in accordance with the conventionally performed fixed molding method including the one disclosed in Japanese Patent Laying-Open No. 64-17834, because of the following restrictions, and hence the peeling process has been used.
[0013] Namely, the cast bar manufactured by continuous casting of fixed molding method has cast texture, and therefore, dice-skinning process is not possible. In the dice-skinning process, referring to FIG. 7, a dice consisting of a pair of centering dices 3 and a skinning dice 4 is used. The centering dice 3 performs, though to a small extent, cold working on the workpiece, for centering of workpiece 1 introduced to the skinning dice 4 . Here, the cast bar as the workpiece cannot withstand the cold working, and is fractured.
[0014] By contrast, a continuously molded rolled member has better processability as compared with the cast bar and withstands cold working, as hot rolling texture is formed by the hot rolling step. The aluminum alloy having compositions disclosed to date, however, suffers from the problems of fracture and surface peeling off (surface roughening), when the continuously cast rolled member is subjected to dice-skinning process.
SUMMARY OF THE INVENTION
[0015] Therefore, an object of the present invention is to provide a wear resistant aluminum alloy elongate body having superior shear-cutting property and both high fatigue strength and high wear resistance that can withstand dice scanning process, a manufacturing method thereof, and a piston for car air conditioner including the wear resistant aluminum alloy elongate body.
[0016] The wear resistant aluminum alloy elongate body in accordance with the present invention contains at least 7 mass % and at most 13 mass % of silicon (Si), at least 0.001 mass % and at most 0.3 mass % of iron (Fe), at least 2.0 mass % and at most 5.0 mass % of copper (Cu), at least 0.3 mass % and at most 1.0 mass % of magnesium (Mg), at least 0.001 mass % and at most 0.3 mass % of manganese (Mn), at least 0.001 mass % and at most 0.3 mass % of chromium (Cr), at least 0.003 mass % and at most 0.03 mass % of strontium (Sr), and at least 0.005 mass % and at most 0.05 mass % of titanium (Ti), and the remaining part of aluminum (Al) and an unavoidable impurity. The size of the silicon grains existing in the aluminum alloy elongate body is 10 μm or smaller in average and 30 μm or smaller as the maximum value, and the size of the silicon grains existing in a range of 1.5 mm deep from the surface is 6 μm or smaller as the maximum value. Further, crystal texture of aluminum alloy is one selected from the group consisting of hot rolled texture, re-crystallized texture, and a mixed texture of hot rolled texture and re-crystallized texture.
[0017] In the wear resistant aluminum alloy elongate body of the present invention, particularly in order to improve dice-skinning property, the content of iron should preferably be in the range of higher than 0.2 mass % and at most 0.3 mass %.
[0018] In the wear resistant aluminum alloy elongate body in accordance with the present invention, particularly in order to improve shear-cutting property, surface hardness of the aluminum alloy should preferably be in the range of at least 50 and at most 90 of Rockwell hardness F scale.
[0019] Further, in order to prevent crack biasing resulting from unevenness on the surface at the time of shear-cutting process, surface roughness of aluminum alloy should preferably be made at most 10 μm in terms of Rmax.
[0020] Preferably, the piston for car air conditioner in accordance with the present invention employs the wear resistant aluminum alloy elongate body including the above described structure.
[0021] The method of manufacturing the wear resistant aluminum alloy elongate body in accordance with the present invention includes the following steps.
[0022] (a) The step of obtaining a cast body, by continuous casting of aluminum alloy such that secondary arm spacing of dendrite is at most 40 μm.
[0023] (b) The step of obtaining a rolled body by hot rolling the cast body at a temperature range of at least 350° C. and at most 500° C. with reduction of processing being at least 40%.
[0024] (c) The step of heat-treating the rolled body in a temperature range of at least 300° C. and at most 480° C. for at least 2 hours and at most 50 hours.
[0025] When the aluminum alloy elongate body is manufactured through the above described manufacturing method, the dice-skinning process of the resulting rolled body is facilitated.
[0026] It is noted that in the aluminum alloy disclosed in Japanese Patent Laying-Open No. 64-17834, dendritic secondary grains surely exist as plumate crystal when viewed microscopically. The texture, however, mainly consist of columnar crystal when viewed macroscopically, and hence the texture is different from that of the aluminum alloy obtained in accordance with the present invention.
[0027] Further, in the method of manufacturing wear resistant aluminum alloy elongate body of the present invention, preferably, the dice-skinning process is performed on the surface of the rolled body, after the step of heat treatment.
[0028] When the dice-skinning process is to be performed, the surface hardness of the rolled body is preferably controlled to be within the range of at least 45 and at most 85 of Rockwell hardness F scale, before the step of performing the dice-skinning process. Further, in the step of dice-skinning process, the amount of skinning by the dice is, preferably, at most 1 mm.
[0029] The wear resistant aluminum alloy elongate body in accordance with the present invention is suitable for an application that requires high wear resistance, such as a piston for car air conditioner. Specifically, as the body is subjected to continuous casting and rolling, when a processed surface orthogonal to the flow (alignment) along the longitudinal direction generated in the texture of the resulting aluminum alloy is placed at a portion to be the sliding surface, for example, at a shoe receiving portion of a swash type compressor piston, wear resistance can remarkably be improved.
[0030] As described above, according to the present invention, a wear resistant aluminum alloy elongate body that has high fatigue strength and high wear resistance and in addition, has superior shear-cutting property and dice-skinning property can be obtained. Thus, a material suitable for a member that requires superior wear resistance such as a piston for car air conditioner, can be provided.
[0031] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] [0032]FIG. 1 is a perspective view showing a wear resistant aluminum alloy elongate body as an embodiment of the present invention.
[0033] [0033]FIG. 2 is a perspective view showing a piston for car air conditioner as another embodiment of the present invention.
[0034] [0034]FIG. 3 is a graph representing relation between grain diameter of largest silicon grains existing in the range of down to 1.5 mm deep from the surface and shear-cutting defective ratio.
[0035] [0035]FIG. 4 is a graph representing relation between surface hardness (Rockwell hardness F scale) and shear-cutting defective ratio.
[0036] [0036]FIG. 5 represents shear-cutting defective ratio after peeling process and dice-skinning process.
[0037] [0037]FIG. 6 is a schematic illustration representing the peeling process.
[0038] [0038]FIG. 7 is a schematic illustration representing the dice-skinning process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] A wear resistant aluminum alloy elongate body 10 such as shown in FIG. 1 will be described in detail, as an embodiment of the present invention.
[0040] Contents of various component elements of the aluminum alloy in accordance with the present invention are limited from the following reasons.
[0041] Addition of copper and magnesium determines strength. If the amount of these is too small, strength would be insufficient, and if the amount is too large, brittleness sets in. For an application that requires high wear resistance such as the piston 20 for car air conditioner shown in FIG. 2, considering wear resistance and dice-skinning property, it is necessary that the copper content is in the range of 2.0 mass % to 5.0 mass %, and magnesium content is in the range of 0.3 mass % to 1.0 mass %.
[0042] Amount of addition, grain diameter and grain diameter distribution of silicon have influence on wear resistance and fatigues strength. Control of the grain diameter and the grain diameter distribution much depends on the manufacturing method. According to Japanese Patent Laying-Open No. 64-17834, manufacturing method includes casting with relatively high cooling rate. In the present invention, distribution and variation of cooling rate are allowed, and therefore the size of the crystallized silicon grains tends to be larger. Different from the manufacturing method disclosed in Japanese Patent Laying-Open No. 64-17834, however, increase in size of the silicon grains is suppressed by adding strontium, and variation in silicon grain diameter is moderated by heat treatment, thereby the grain diameter and grain diameter distribution of silicon grains can be controlled. Though strontium is effective to make smaller the primary crystal silicon, the amount of addition thereof is set to the range of 0.003 mass % to 0.03 mass %. When the content of strontium exceeds 0.03 mass %, the effect of making smaller the silicon grains is saturated, while gas absorption increases significantly. When the content of strontium is smaller than 0.003 mass %, the effect of making smaller the silicon grains is not recognized.
[0043] In the aluminum alloy in accordance with the present invention, the upper limit of the amount of added silicon is limited to the eutectic composition. Therefore, expansion of eutectic point is recognized when solidified in non-equilibrium state, and therefore the upper limit of silicon content is set to 13 mass %. When silicon content is small, the aluminum alloy primary crystal (α phase) becomes coarse, and therefore, the lower limit of silicon content is set to 7 mass %.
[0044] Titanium is necessary to make smaller the α phase. When the content of titanium is smaller than 0.005 mass %, the effect of making smaller is marginal, and when titanium is added by more than 0.05 mass %, the effect is again marginal.
[0045] The iron content is from 0.001 mass % to 0.3 mass %, manganese content is from 0.001 mass % to 0.3 mass %, and chromium content is from 0.001 mass % to 0.3 mass %.
[0046] When iron content is too large, coarse crystals of other added elements in the alloy tend to form at the time of solidification of the aluminum alloy, possibly damaging mechanical characteristic of the alloy. Therefore, the iron content is set to be at most 0.3 mass %. Therefore, content of manganese and chromium that form coarse crystallized substances with iron are also set to be at most 0.3 mass %.
[0047] In order to improve both shear-cutting property and skinning property, the iron content should be larger than 0.2 mass % and at most 0.3 mass %.
[0048] Further, in the present invention, in order to prevent crack biasing phenomenon at the time of shear-cutting and to ensure dice-skinning property as will be described later, the size of silicon grains existing therein is controlled to be 10 μm or smaller in average, and 30 μm or smaller as the maximum value. Further, the size of silicon grains in the range of down to 1.5 mm deep from the surface is set to be 6 μm or smaller by the maximum value.
[0049] Unless the size of the silicon grains is not controlled in this manner, an aluminum alloy having both superior shear-cutting property and superior dice-skinning property cannot be obtained even when the range of aluminum alloy composition of the present invention is satisfied, if copper and magnesium contents are 3.0 mass % or more and 0.5 mass % or more, respectively. The reason and the relation with the texture of aluminum alloy of the present invention may be as follows.
[0050] When a large silicon grain exceeding 30 μm, for example, exists in the aluminum alloy, crack biasing becomes more likely at the time of shear-cutting. Further, in the initial stage of shear-cutting, that is, when a shear-cutting force is exerted on the surface, deformation of the material would be large unless there is generated an appropriate crack, increasing possibility of generation of a void around the large silicon grain. Further, the silicon grain would be fractured and the cracks would be biased. When the amount of deformation of the material increases in this manner, even a silicon grain smaller than 30 μm becomes the cause of crack biasing. Therefore, a phenomenon tends to occur in which crack biasing and deformation affect each other. Therefore, in order to generate an appropriate crack at the initial stage of shear-cutting, it is necessary that the silicon grain size existing in the range of 1.5 mm deep from the surface, to be, by the maximum value, at most 6 μm.
[0051] At this time, when the silicon grains have the eutectic composition in which the silicon grains are crystallized with high density at the crystal grain boundary of the matrix as seen after casting of the aluminum alloy disclosed in Japanese Patent Laying-Open No. 64-17834, a crack easily develops biased along the crystal grain boundary, that is, along the region of high density silicon grains. Thus, flatness of the cut surface is lost. Therefore, in order to perform shear-cutting without generating crack biasing at the time of shear-cutting, the aluminum alloy of the present invention is controlled to have any of hot rolled texture, re-crystallized texture or a mixed texture of hot rolled texture and re-crystallized texture, eliminating the cast texture.
[0052] The hardness of the material also has an influence on shear-cutting property. When the amount of deformation of the material increases before generation of a crack in the initial stage of shear-cutting, even a silicon grain smaller than 30 μm functions to bias the crack, as described above. Therefore, surface hardness should preferably be at least 50 in accordance with Rockwell hardness F scale. When the surface roughness becomes higher than 90 in accordance with Rockwell hardness F scale, generation of initial crack at the surface of the material becomes too sensitive to the surface roughness. Therefore, the range of the surface hardness is preferably 50 to 90 of Rockwell hardness F scale.
[0053] As the surface roughness of the material also has an influence on the shear-cutting property, preferably, it is at most 10 μm in terms of Rmax.
[0054] The present invention proposes the aluminum alloy elongate body having the above described characteristics further subjected to dice-skinning process, as the body having highest shear-cutting property. The dice-skinning process removes surface defects and does not generate any spiral kerf step that is unavoidable in the peeling process. Therefore, crack biasing along the step at the time of shear-cutting is avoided.
[0055] Fracture of the material generated at the time of dice-skinning process occurs when copper and magnesium added to improve mechanical strength are contained by a large amount, as work hardening capability of these components is high and aluminum alloy reaches the limit of processing. In order to prevent the fracture, generally, it is necessary to lower hardness by softening. When hardness lowers by the softening process, however, peeling off becomes more likely at the time of dice-skinning process. In order to overcome the mutually incompatible problems, in the present invention, the size of the silicon grains is controlled in the manner as described above.
[0056] More specifically, the inventors studied improvement of material fracture and suppressing of peeling at the time of dice-skinning process. As a result, it has been found that the size of silicon grains existing within the material is related to the material fracture. Specifically, when a silicon grain larger than 30 μm exists in the material, chevron crack easily occurs in the material. Therefore, the silicon grain size must be 30 μm or smaller, even by the maximum value, and preferably, the size should be 20 μm or smaller.
[0057] In order to suppress generation of peeling, it is effective to increase surface hardness of the material. Considering work-hardening at the time of dice-skinning, the surface hardness should preferably be increased to be within a range that prevents fracture during the dice-skinning process. In the appropriate hardness differs dependent on the copper and magnesium contents. Generally, in order to attain the surface hardness after dice-skinning process of 50 to 90 in Rockwell hardness F scale, that is the hardness suitable for shear-cutting, the surface hardness before the dice-skinning process should preferably be adjusted to be in the range of 45 to 85 in Rockwell hardness F scale.
[0058] Further, in order to make smooth the surface after skinning, the size of silicon grains existing at the surface to be removed should be 6 μm or smaller, by the maximum value. When the size of the silicon grain at the surface layer exceeds 6 μm, crack biasing becomes more likely at the time of shear-cutting, and in addition, a large scratch of silicon grain results at the time of dice-skinning process.
[0059] By such a control of silicon grain size, satisfactory skinning process becomes possible.
[0060] Even when the above described control of silicon grain size is performed based on a cast texture, material having such superior shear-cutting property and dice-skinning property as the present invention cannot be obtained. Namely, as the crystal texture of the aluminum alloy in accordance with the present invention has any of hot rolled texture, re-crystallized texture or a mixed texture of hot rolled texture and re-crystallized texture, an aluminum alloy having both superior shear-cutting property and superior dice-skinning property can be obtained.
[0061] The amount of skinning at the time of dice-skinning process is also an important condition in manufacturing. When the amount of skinning is excessive, resistance increases at the skinning dice, resulting in fracture of the material and increased material loss. Therefore, preferable amount is at most 1 mm. More preferably, in order to remove surface defects, the amount of skinning should be 0.01 mm to 1 mm.
[0062] In order to obtain the inner texture of aluminum alloy as described above, basically, it is preferred to manufacture the aluminum alloy elongate body by using continuous casting rolling method, that combines a caster of movable molding method and a hot roller. The reason is that when a method involving batch type casting and rolling is employed, a re-crystallized grain tends to be large, making cold working of the resulting material difficult.
[0063] It is noted that the cooling rate at the time of casting must be controlled such that secondary arm spacing of dendrite is at most 40 μm, so as to attain the silicon grain size controlled in the above described manner. When the secondary arm spacing of dendrite is set to be 40 μm or smaller, the size of iron-based compound precipitated after casting also becomes smaller. When an elongate body is manufactured by the continuous casting rolling method of the present invention using a composite having the basic composition of aluminum alloy of the present invention, the size of iron based compound tends to be coarse, unless the secondary arm spacing of dendrite is controlled in particular. When the secondary arm spacing of the dendrite is not controlled, iron content must be suppressed to be at most 0.2 mass %, in order to attain the shear-cutting property and the dice-skinning property of the present invention. In that case, contents of manganese and chromium that form compounds with iron at the time of casting must also be suppressed to be at most 0.25 mass %.
[0064] In the manufacturing method of the present invention, the secondary arm spacing of dendrite is controlled to be at most 40 μm. Accordingly, it becomes possible to increase iron content to 0.3 mass % and the contents of manganese and chromium to 0.3 mass %, respectively. Therefore, an alloy having both superior shear-cutting property and superior dice-skinning property can be obtained even when the iron content is in the range of larger than 0.2 mass % and not larger than 0.3 mass %.
[0065] When iron content exceeds 0.3 mass %, however, an iron based compound having the size larger than 20 μm generates, and, similar to a coarse silicon grain, it causes chevron crack at the time of dice-skinning.
[0066] Further, in the manufacturing method of the present invention, after casting, hot rolling is performed with the rolling temperature set in the range of 350° C. to 500° C. with the reduction of processing being at least 40%. The reduction of processing is necessary to convert the cast texture to hot rolled texture, re-crystallized texture or the mixed texture of hot rolling texture and re-crystallized texture. The rolling temperature is set in the above described range, because when the temperature is lower than 350° C., rolling becomes difficult because of work-hardening, and when the temperature exceeds 500° C., rolling becomes difficult because of intergranular cracking. The aluminum alloy after hot rolling may be wound in a coil, or cut by a prescribed length to form bar members. In order to make use of the advantage of dice-skinning process, winding in a coil is preferred.
[0067] The aluminum alloy in the shape of a coil or a bar is subjected to heat treatment in a temperature range of 300° C. to 480° C. for 2 to 50 hours, in order to adjust hardness, adjust silicon grain diameter and to control crystal grains. When the heat treatment temperature is lower than 300° C., the time for heat treatment would be too long. When the heat treatment temperature exceeds 480° C., small void results from material balance, when copper based compound crystallized in the non-equilibrium state makes a transition to equilibrium state at the time of solidification, and the amount of copper subjected to solid solution increases. The generated void would be a starting point of fracture at the time of dice-skinning, and copper of solid solution increases work hardening capability, making difficult the dice-skinning process.
[0068] Examples of the present invention will be described in the following.
[0069] Samples having three different inner textures were fabricated for each of the compositions of the present invention and compositions for comparison (unit: mass %) listed in Table 1. The characteristics of the three different inner textures are as shown in the left column of Table 2 in correspondence with the composition number. Samples having inner textures ( 1 ) and ( 2 ) were fabricated by Properzi continuous casting machine. The samples having inner texture ( 3 ) were fabricated by horizontal continuous casting machine.
[0070] Cross sectional area of the cast material fabricated by the Properzi continuous casting machine was 3500 mm 2 , and the casting temperature of molten metal to the casting machine was 650° C. to 690° C. The cast material fabricated by the Properzi continuous casting machine was subjected to hot rolling at a temperature of 420° C. within 5 minutes after completion of solidification, to provide an elongate body having the diameter of 30 mm. The elongate body was wound to a coil having the diameter of 1.7 m. The reduction of processing at this time was 80% in terms of reduction ratio. Samples fabricated by using the Properzi continuous casting machine having inner texture ( 1 ) were continuously cast to have secondary arm spacing of dendrite of at most 40 μm, and those having inner texture ( 2 ) were continuously cast to have secondary arm spacing of dendrite of at most 50 μm. For the samples having inner texture ( 1 ), in order to realize faster cooling rate, the number of cooling nozzles and the amount of cooling water of the Properzi casting machine were increased, and mold material was changed from steel alloy to copper alloy.
[0071] Samples having inner texture ( 3 ) were fabricated as cast bars having the diameter of 30 mm, in accordance with the method disclosed in Japanese Patent Laying-Open No. 64-17834, using a horizontal continuous casting machine.
[0072] Every sample was subjected to heat treatment at a temperature of 450° C. for 8 hours before conducting shear-cutting test.
[0073] Table 2 shows details of inner texture and results of comparison in silicon grain diameter, shear-cutting property, fatigue characteristic and wear resistance among the samples fabricated to have three different inner textures ( 1 ), ( 2 ) and ( 3 ) for each of the compositions of the present invention and compositions for comparison. In the column of inner texture of Table 2, the numeral represents, by the unit of μm, “average grain diameter of silicon (maximum grain diameter) maximum grain diameter at the surface”. In the column of inner texture of Table 2, “C” represents cast texture, “H” represents hot rolled texture and “R” represents re-crystallized texture.
[0074] The shear-cutting test was performed by cutting the samples by a shear cutter, unevenness of the shear surface was visually observed, and defective ratio among 5000 samples was counted for evaluation.
[0075] Fatigue test and wear resistance test were performed after T 6 processing (heat treatment at 480° C. for 5 hours, followed by quenching in water and aging treatment at 180° C. for 8 hours). In the fatigue test, a dumbbell test piece (a parallel portion having the diameter of 8 mm and GL of 10 mm) was fabricated from each bar material, completely reversed (R=−1) S-n curve was calculated, and fatigue property was evaluated by the stress value of 10 5 times. In the wear resistance test, a pin/disk type tester was used. To a disk formed of SUJ2 rotating at 600 rpm, a pin having the diameter of 28 mm fabricated from each bar material was pressed with the force of 50 kgf, and amount of reduced weight was measured as the wear amount after the lapse of 300 hours.
[0076] Evaluations of shear-cutting property, fatigue characteristic and wear resistance are given by ◯ (superior), Δ (good) and X (poor) among the samples having the same composition, in Table 2. When the characteristics were comparable, evaluations are given by the same signs.
TABLE 1 Composition No. Si Fe Cu Mg Mn Cr Sr Ti Composition 1 7 0.01 2.1 0.3 0.01 0.01 0.01 0.02 of 2 7 0.29 2.1 0.3 0.29 0.3 0.01 0.01 the 3 7 0.29 5 0.9 0.27 0.29 0.01 0.01 Invention 4 10 0.02 2 0.3 0.01 0.01 0.01 0.02 5 10 0.21 3 0.4 0.22 0.15 0.01 0.02 6 10 0.29 4.9 1 0.3 0.2 0.02 0.03 7 13 0.01 2 0.4 0.2 0.01 0.03 0.04 8 13 0.15 4.5 0.6 0.15 0.1 0.03 0.05 9 13 0.3 4.9 0.9 0.3 0.29 0.03 0.05 Comparative 10 7 0.32 4.9 0.3 0.28 0.28 0.03 0.05 Composition 11 7 0.29 4.8 0.8 0.32 0.32 0.03 0.05 12 8 0.28 4.9 0.7 0.33 0.24 0.04 0.06 13 7 0.24 5.2 0.9 0.1 0.1 0.03 0.05 14 7 0.24 4.8 1.3 0.1 0.1 0.03 0.05 15 7 0.3 1.8 0.9 0.2 0.15 0.02 0.04 16 12 0.31 4.8 1 0.23 0.22 0.03 0.03 17 13 0.23 5.3 0.8 0.22 0.01 0.02 0.02 18 13 0.24 2.2 1.4 0.01 0.02 0.03 0.01 19 12 0.23 1.9 0.8 0.2 0.23 0.03 0.01 20 15 0.2 2.1 0.32 0.02 0.1 0.03 0.04 21 10 0.22 3.5 0.8 0.15 0.12 0.02 0.08 22 11 0.2 3.6 0.7 0.12 0.001 0.1 0.004
[0077] [0077] TABLE 2 Shear-cutting Fatigue Property Characteristic Wear Resistance Inner Inner Inner Inner Inner Inner Inner Inner Inner Inner Inner Inner Com- Tex- Tex- Tex- Tex- Tex- Tex- Tex- Tex- Tex- Tex- Tex- Tex- position ture ture ture ture ture ture ture ture ture ture ture ture No. (1) (2) (3) (1) (2) (3) (1) (2) (3) (1) (2) (3) Composition 1 8(28)2 R 16(32)4 R 4(8)6 C ◯ Δ X ◯ ◯ Δ ◯ ◯ Δ of the 2 9(27)3 H 18(33)4 H 2(7)7 C ◯ X Δ ◯ X Δ ◯ X Δ Invention 3 5(25)1 R 19(37)4 R 1(6)5 C ◯ X Δ ◯ X Δ ◯ X Δ 4 4(24)4 R 16(32)3 R 0.8(5)5 C ◯ Δ X ◯ ◯ Δ ◯ ◯ Δ 5 7(26)2 R + H 19(29)7 R 0.9(7)6 C ◯ Δ X ◯ Δ X ◯ ◯ Δ 6 7(19)3 H 15(35)4 H 0.9(5)4 C ◯ X Δ ◯ X Δ ◯ X Δ 7 4(22)5 R 17(38)5 R 0.5(4)3 C ◯ Δ X ◯ ◯ Δ ◯ ◯ Δ 8 6(26)5 R 19(40)6 R 8(3)3 C ◯ Δ Δ ◯ ◯ Δ ◯ ◯ Δ 9 9(29)6 R + H 14(34)7 R + H 0.2(2)1 C ◯ X Δ ◯ X Δ ◯ X Δ Comparative 10 8(28)3 H 18(32)4 H 2(8)7 C Δ X ◯ Δ X ◯ Δ X ◯ Composition 11 8(29)4 R + H 18(31)5 R + H 1(7)5 C Δ X ◯ Δ X ◯ Δ X ◯ 12 8(27)3 R + H 19(33)5 R + H 2(6)6 C Δ X ◯ Δ X ◯ Δ X ◯ 13 7(28)4 R 19(36)5 R 1(5)5 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 14 6(25)5 R + H 20(39)8 R + H 0.9(5)5 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 15 7(26)4 H 18(34)7 H 0.8(6)4 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 16 6(28)3 H 17(33)4 H 0.7(4)4 C Δ X ◯ Δ X ◯ Δ X ◯ 17 9(27)6 H 16(34)8 H 0.9(4)3 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 18 8(25)7 R + H 18(37)9 H 1(6)5 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 19 7(27)4 H 19(39)6 H 0.7(5)4 C ◯ Δ ◯ ◯ Δ ◯ ◯ Δ ◯ 20 10(50)20 R 22(90)35 R 1.1(8)6 C Δ Δ ◯ Δ X ◯ Δ X ◯ 21 6(24)4 R 20(38)8 R 0.9(7)5 C Δ Δ ◯ Δ X ◯ Δ X ◯ 22 18(50)20 H 24(120)30 H 0.8(6)6 C Δ Δ ◯ Δ X ◯ Δ X ≡
[0078] As can be seen from Table 2, samples having the inner texture ( 1 ) of composition Nos. 1-9 of the present invention (samples of the present invention), that is, aluminum alloy elongate bodies in accordance with the present invention had superior shear-cutting property not observed in the prior art, and in addition, fatigue characteristic and wear resistance comparable to or higher than the prior art, because of the composition and the inner texture.
[0079] The influence of silicon grain diameter at the surface, which is another restriction on the inner texture of the aluminum alloy elongate body of the present invention, will be discussed in the following. The ingot fabricated by the Properzi casting machine has a chill layer formed near the surface that is in contact with the mold. In the chill layer, the silicon grains are crystallized in very fine dispersion, and hence an appropriate crack tends to occur at the time of shear-cutting. When the silicon grains in the chill layer are grown, density of the silicon grains decreases, making crack biasing more likely. In an elongate body having reduction of processing of 40% or higher, the chill layer is in the range of down to 1.5 mm deep from the surface. Therefore, control of silicon grains within this range is necessary.
[0080] [0080]FIG. 3 represents relation between the maximum silicon (Si) grain diameter existing in the range of down to 1.5 mm from the surface and the shear-cutting defective ratio, when samples having the above described inner textures ( 1 ), ( 2 ) and ( 3 ) of composition No. 5 of the present invention shown in Table 2 were fabricated, with the time of heat treatment at 450° C. changed variously.
[0081] In FIG. 3 and FIGS. 4 and 5 that will be referred to data, the defective ratio (%) is given by the following equation, where the number of defective samples having inner texture ( 3 ) without any further processing being a reference.
[0082] Defective ratio={(number of defects)/number of defects having inner texture ( 3 ) without any processing)}×100
[0083] The standard for determining successful/unsuccessful shear-cutting will be described in the following. Samples were cut by a shear cutter, unevenness of shear surface was visually observed, and number of defects among 30000 samples was counted. The defects counted were classified into external surface crack, that is, a crack generated at an external surface (peripheral surface) by cutting, and an end surface crack, that is, a crack generated at an end surface (cut surface) of the sample by cutting.
[0084] In a strontium-added alloy, smaller silicon grains grow faster because of a mechanism that is considered to be Ostwald ripening, and therefore, in a cast material using Properzi continuous casting machine, silicon grains in the chill layer region grow faster. Therefore, within the studied range of heat treatment, average grain diameter did not exceed 10 μm and maximum grain diameter did not exceed 30 μm among samples having inner texture ( 1 ), and average grain diameter did not exceed 20 μm and the maximum grain diameter did not exceed 40 μm among samples having inner texture ( 2 ). In samples having inner texture ( 3 ), minute silicon grains are dispersed deep inside, because of high cooling rate. Therefore, the maximum silicon grain diameter in the range down to 1.5 mm from the surface and the maximum silicon grain diameter of the entire sample were almost the same.
[0085] As is apparent from FIG. 3, when the maximum silicon grain diameter in the range of down to 1.5 mm from the surface exceeds 6 μm, defective ratio increases even when the average grain diameter is at most 10 μm and the maximum grain diameter is at most 30 μm in the entire sample, and the advantage over the prior art material is lost. Similar study was made on samples having Composition Nos. 2 and 8 of the present invention, and the results were similar.
[0086] That the shear-cutting property differs dependent on the hardness of aluminum alloy elongate body will be discussed in the following. FIG. 4 represents shear-cutting defective ratio of samples of the alloy elongate body having Composition No. 6 of the present invention shown in Table 2, which were subjected to heat treatment at 480° C. for 5 hours and cooled with various cooling conditions to have different hardnesses (HRB: Rockwell hardness, F scale). Similar to FIG. 3, FIG. 4 represents defective ratio of samples having inner texture ( 1 ) (present invention), and samples having inner textures ( 2 ) and ( 3 ). The samples of the present invention represent particularly satisfactory shear-cutting property with the hardness in the range of 50 to 90 in accordance with Rockwell hardness F scale. Similar study was conducted on samples having Composition Nos. 2 and 8 of the present invention shown in Table 2, and the results were similar.
[0087] The defects of shear-cutting test of the aluminum alloy elongate body having inner texture ( 1 ) of the present invention shown in Table 2 was inspected, and it was found that surface defect such as a small scratch plays a role. From inspection of the fracture surface, it was found that critical size of the scratch was larger than 10 μm in terms of surface roughness Rmax. In order to remove surface defects, surface cutting is desirable. Here, as the size of the scratch is larger than 10 μm in terms of surface roughness Rmax as mentioned above, it is necessary that the surface roughness is at most 10 μm in Rmax.
[0088] Samples having inner textures ( 1 ), ( 2 ) and ( 3 ) of Composition Nos. 3, 6 and 9 of the present invention shown in Table 2 were subjected to peeling process and dice-skinning process. As a result, it was found that the dice-skinning process was impossible on samples having inner textures ( 2 ) and ( 3 ). FIG. 5 represents shear-cutting defective ratio of respective samples. As can be seen from FIG. 5, shear-cutting defective ratio is low after the dice-skinning process among the samples of the present invention (samples having inner texture ( 1 )). Samples after the peeling process exhibited higher defective ratio as compared with the samples subjected to dice-skinning process. The reason is considered to be a step resulting from blade boundary on the surface, which is unavoidable in view of the nature of the processing. It is noted that the dice-skinning process enabled processing at the linear velocity of 60 m/min, while linear velocity upper limit of the peeling process was 10 m/min.
[0089] The ingots fabricated by the Properzi continuous casting machine were studied. As a result, it was found that in order to obtain the aluminum alloy elongate body having the inner texture ( 1 ) of the present invention shown in Table 2, continuous casting that ensures secondary arm spacing of dendrite in the cast body to be at most 40 μm was necessary. When casting is performed with low cooling rate not satisfying this condition, the satisfactory shear-cutting property described above cannot be attained. After casting, rolling temperature was varied, and it was found that the ingot could be processed only within the temperature range of 350 to 500° C. Further, the aluminum alloy elongate body in accordance with the present invention described above must have any of hot rolled texture, re-crystallized texture and the mixed texture of hot rolled texture and re-crystallized texture. This is apparent from the fact that most of the cut surfaces that result in defective cast bars in the shear-cutting test of Table 2 were cracked along the cast grain boundary. After casting, samples were picked up from respective rolling stands and studied, and as a result, it was found that the cast texture was almost eliminated when the reduction of processing attained 40%.
[0090] With the hardness adjusted in the above described manner, heat treatment for adjusting silicon grain diameter and for controlling crystal grains could be performed at a temperature range of 300 to 480° C. and the time range of 2 to 50 hours.
[0091] As for the dice-skinning process, samples of aluminum alloy elongate body having Composition Nos. 3, 6 and 9 of the present invention shown in Table 1 were subjected to heat treatment at 480° C. for 5 hours, and skinning process conditions were studied with the cooling condition changed variously. Cracks were generated when the hardness according to Rockwell hardness F scale was equal to or lower than 30, 34 or 40, respectively. As to the upper limit of hardness, chevron crack was not generated and skinning process was possible up to 98, 96 and 93, respectively, in accordance with Rockwell hardness F scale. When heat treatment step is added after the dice-skinning process, possibility of external damage increases, and therefore, considering work hardening at the time of dice-skinning, the hardness is adjusted as a precaution to be in the range of 45 to 85 in accordance with Rockwell hardness F scale, so that the hardness appropriate for shear-cutting after dice-skinning process, that is, the appropriate hardness range of 50 to 90 in accordance with Rockwell hardness F scale can be attained.
[0092] Here, the amount of dice-skinning must not remove the fine silicon particles in the chill layer region at the surface. When the chill layer is removed or when the grains in the chill layer region are grown, crack bias becomes more likely, making dice-skinning process difficult, as confirmed by the dice-skinning test performed on the samples having inner texture ( 1 ) (present invention) shown in FIG. 3. Therefore, the dice-skinning process should be performed within the range shallower than 1.5 mm from the surface. Considering mechanical load and material loss, favorable range is the depth of at most 1 mm. Similar study was conducted on Composition Nos. 1 to 9 of the present invention shown in Table 1, and shapes of shavings resulting from the dice-skinning process were compared. Shavings of Composition Nos. 2, 3, 5, 6 and 9 were fragmented into smaller shapes as compared with Composition Nos. 1, 4, 7 and 8. The dice-skinning property was particularly satisfactory when iron content was larger than 0.2 mass % and not larger than 0.3 mass %.
[0093] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | The wear resistant aluminum alloy elongate body contains 7-13 mass % of Si, 0.001-0.3 mass % of iron, 2.0-5.0 mass % of Cu, 0.3-1.0 mass % of Mg, 0.001-0.3 mass % of Mn, 0.001-0.3 mass % of Cr, 0.003-0.03 mass % of Sr, 0.005-0.05 mass % of Ti, and the remaining part of Al and unavoidable impurity. The size of Si grains existing in the elongate body is, by the average value, at most 10 μm and by the maximum value, at most 30 μm, and the size of the Si grains in the range of down to 1.5 mm deep from the surface is, by the maximum value, at most 6 μm. Further, crystal texture of Al alloy is one selected from the group consisting of hot rolled texture, re-crystallized texture and mixed texture of hot rolled texture and re-crystallized texture. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on, and claims benefit of, U.S. provisional patent application No. 61/437,153 filed Jan. 28, 2011, the entire content of which is hereby incorporated herein by reference.
MICROFICHE APPENDIX
[0002] Not Applicable.
TECHNICAL FIELD
[0003] The present disclosure relates to electronic transaction systems, and in particular to a system and methods for managing risks associated with electronic transactions within an un-trusted environment.
BACKGROUND
[0004] For the purpose of the present description, an “untrusted environment” shall be understood to mean any communications or networking environment in which it is possible for attackers to modify messages, delete messages or even add or replay messages. The public Internet is a common example of an untrusted environment, since it is not possible to prohibit attackers from modifying, deleting, adding or duplicating messages.
[0005] For the purposes of the present description, a “sensitive transaction” shall be understood to refer to any message exchange or communications session between two or more parties, in which it is desired that message content(s) should be reliably transferred between the parties, and be secure against unauthorized viewing and/or manipulation. Examples of “sensitive transactions” include, but are not limited to: financial transactions such as electronic funds transfers and eCommerce; remote sensing and telemetry data transfer messaging; and electronic voting schemes.
[0006] Internet-based electronic transaction systems are well known in the art. In order to mitigate risks associated with sensitive transactions in an un-trusted environment such as the Internet, such systems typically employ a secure server, which acts as an intermediary between parties to any electronic transaction. In some cases, the secure server merely serves to authenticate the parties. More commonly, the secure server both authenticates the parties and controls the actual funds transfer. As a result, the secure server is able to provide both parties with confidence that the transaction has been completed properly, and also enables the server to generate a detailed audit trail, by which the service provider can detect fraudulent or otherwise inappropriate use of the system by any party. A limitation of this arrangement is that the requirement for users to log into the central server in order to perform any transaction, is inconvenient, and thus so limits user acceptance of the system.
[0007] Various schemes have been proposed which are intended to enable electronic person-to-person financial transactions in a manner that is directly analogous to fiat cash transactions, in that the intervention of a central server to mediate the transfer of funds is not used. A central theme of such systems is the provision of security mechanisms that provide at least the same level of security and trustworthiness that is afforded by conventional central server-based systems, but without the inconvenience of requiring the parties to log into a central server. However, these systems suffer a limitation in that, because a user may log into a central server infrequently (or even never), there is no reliable mechanism by which a service provider can build an audit trail that would permit the detection of fraudulent or otherwise inappropriate activity.
SUMMARY
[0008] Accordingly, the present invention sets out to provide a practical way of overcoming the above limitations of the prior art.
[0009] Accordingly, an aspect of the present invention provides a method of detecting unauthorized activity in an electronic message transfer system comprising a plurality of devices, each device being configured to generate and receive cryptographically secured value transfer messages for exchanging amounts monetary value with other devices in the system. In each device, audit information is accumulated in a memory of the device. The device periodically forwards at least part of its accumulated audit information to a secure server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further features and advantages will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
[0011] FIG. 1 is a block diagram schematically illustrating a secure message exchange system in which methods in accordance with the present invention may be implemented;
[0012] FIG. 2 is a block diagram schematically illustrating a subscriber's communications device, usable in the system of FIG. 1 ; and
[0013] FIG. 3 is a block diagram of a diagram schematically illustrating an alternative subscriber's communications device, usable in the system of FIG. 1 .
[0014] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION
[0015] It is anticipated that users (subscribers) of an online service that enables sensitive transactions will be required to indicate their acceptance of a published set of terms and conditions, as a condition of their use of the system. Among other things, these terms and conditions will set out limitations in the proper use of the service, including, for example, that the user agrees to not use the service for illegal or unethical purposes.
[0016] Upon acceptance of the terms and conditions, the user may be provided with an electronic storage and transfer device generally of the type described in Applicant's co-pending international patent applications Nos. PCT/CA2010/000435 filed Mar. 30, 2010 and PCT/CA2010/001434 filed Sep. 17, 2010, both of which designate the United States of America, the disclosures of both of which are incorporated herein by reference.
[0017] Referring to FIG. 2 , as described in PCT/CA2010/001434, the storage and transfer device 4 comprises an input/output (I/O) interface 8 configured to enable the device 4 to send and receive messages through the communications medium 6 ; a controller 10 responsive to received messages to record transfers of content to the device 4 and to transfer content from the device 4 ; and a memory 12 storing a respective unique identifier 14 of the device 4 , a private (or secret) key 16 and a certificate 18 uniquely assigned to the device 4 , a log 20 of content transfers to and from the device 4 , and a current content (Cur.Val) 22 of the device 44 .
[0018] The secret key 16 and a certificate 18 , facilitate message encryption and digital signature functionality using, for example, well-known Public Key Infrastructure (PKI) techniques. For this purpose, the secret key 16 can be securely generated by the storage and transfer device 4 and the certificate 18 would typically be generated by a trusted Issuing Authority, such as, for example, Verisign™.
[0019] As described in PCT/CA2010/001434, in a “transfer-out process”, the device 4 , operates to generate a cryptographically secured content (asset value) transfer message containing the content to be transferred, a nonce for enabling detection and proper handling of duplicate messages, a digital signature generated using the secret key 16 , and the certificate 18 . With this information, a receiving device 4 can execute a “transfer-in” process in which the certificate can be used to verify the digital signature, and so detect any corruption of the message during transport through the network, detect (and discard) duplicate messages by the use of protected sequencing or equivalent identifying information in the message, and finally update its current content (Cur.Val) 22 with the content conveyed in the message. In addition, the processor 10 can record information about each transfer-in and transfer-out in the log 20 . Among other things, the log may be accessed by the user to obtain a record of transactions.
[0020] It is anticipated that the device 4 may be constructed in two variants. In a first variant, the device 4 is constructed as a physical device suitable for distribution to and use by an individual person. In a second variant, the device 4 is constructed as server configured to emulate a desired number of physical storage devices allocated to individual users. In this latter case, a user may access their device 4 by means of suitable application software stored on a communications device. In principle, the log can be used to construct an audit trail (at least in respect of the particular device) and so could be used to detect non-compliant use of the device 4 . However, in practice, it is possible for a user to use their device 4 to engage in person-to-person financial transactions without logging in to a central server that could access the log 20 to obtain the required transaction information. In this situation, it is possible that the service provider might never be able to ensure that the system is free from abuse.
[0021] The following three strategies may be employed for addressing this problem.
[0022] 1. Encoding utilization limits into the firmware of the processor 10 . Such utilization limits can take any of a variety of different forms, depending on the type of data stored in the memory 12 , either within the log 20 or in other data storage fields (not shown) provided in the memory 12 for that purpose. For example, utilization limits based on an accumulated amount of asset value transferred, or a total number of transactions can be readily defined. Other utilization limits may also be defined, as desired. In operation, when the utilization limit has been reached, the processor 10 may reject any further requests to transfer content in to, or out of the device 4 , until the user either logs in to a central server and resets their device 4 , or alternatively contacts the service provider to exchange their device 4 for a new one. In either scenario, the service provider is enabled to access the memory 12 of the device 4 , and thereby detect non-compliant use of the device 4 .
[0023] 2. Encoding transaction limits into the firmware of the processor 10 . A representative transaction limit may, for example, take the form of a maximum content amount (such as, for example, a monetary amount) that can be transferred in any given transfer message. If the transaction limit is exceeded, the processor 10 may issue a notification to the user requesting that they log onto a central server to obtain authorization for the transaction. Here again, once the user completes the log on procedure, the secure server can access and analyze all or part of the data stored in the memory 12 , and thereby detect non-compliant use of the device 4 .
[0024] 3. Configuring the firmware of the processor 10 to embed encrypted audit information in each content transfer message, for example within a predefined field of the message. The audit information may comprise data stored in the memory 12 (or be derived from such stored data), that can be analysed to detect unauthorized or otherwise non-compliant use of the device 4 . This audit information may, for example, include an accumulated amount of asset value transferred, or a total number of transactions, as well as any of a variety of possible fault codes that could be generated by the processor 10 during operation. Such fault codes could, for example, comprise a total number of transfer-in or transfer-out processes that were not successfully completed. Other audit information may be defined as desired and accumulated in the memory 12 for inclusion in content transfer messages. In order to ensure secure encryption of the audit information, a provider's secret key (PSK) 24 (see FIG. 3 ) that is known only to the service provider may be installed in the device 4 .
[0025] During each transfer-put process, the processor 10 can extract the audit information from the memory 12 , encrypt it using the PSK 24 , and attach the encrypted audit information to the content transfer message prior to applying the digital signature (based on the user's Secret key 16 ) and certificate 18 . With this arrangement, the digital signature encompasses the encrypted audit information, so that attempts to fraudulently manipulate the encrypted audit information can be detected (and result in failure of the transaction). Encryption of the audit information using a Provider's Secret Key (PSK) 24 separate from the user's secret key 16 ensures that the recipient of any content transfer messages (with the sole exception of the service provider itself) will be unable to access and read the audit information.
[0026] The embedding of encrypted audit information in each content transfer message enables the service provider to enter into specific service agreements with selected parties (such as, for example, on-line merchants) whereby each party agrees to forward a copy of some (or all) received content transfer messages to the service provider. Upon receipt of these copied messages, the service provider can decrypt and analyse the embedded audit information. It is anticipated that, by entering into appropriate agreements with on-line merchants (and other parties who may be expected to interact with a large number of individual users), the service provider will receive copies of a significant portion (although likely not all) of the asset transfer messages being exchanged between all users of the system. Consequently, the service provider can analyse the decrypted audit information to detect unauthorized activities, as well as derive statistically valid metrics regarding the status of the system as a whole.
[0027] The embodiment(s) of the invention described above is(are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims. | A method of detecting unauthorized activity in an electronic message transfer system comprising a plurality of devices, each device being configured to generate and receive cryptographically secured transfer messages for exchanging content with other devices in the system. In each device, audit information is accumulated in a memory of the device. The device periodically forwards at least part of its accumulated audit information to a secure server. | 6 |
GOVERNMENT INTEREST
The United States Government, as represented by the Department of Energy, has a paid-up license in the invention described and may manufacture and/or use this invention for governmental purposes in accordance with the terms of Contract No. DE-AC52-06NA25396.
FIELD OF THE INVENTION
This invention relates to a low temperature process for preparing actinide nitrides, for use as fuel in nuclear reactors.
BACKGROUND OF THE INVENTION
With the increasing demand for energy and the pressing issues associated with CO2 emissions, nuclear power is once again becoming an attractive alternative for electrical production. The generation-IV reactors which are under development will run at much higher temperatures and with a much greater burn-up of the fuel than the current generation of nuclear reactors. A consequence of this higher working temperature and greater burn-up is a need for new fuel formulations.
There are many materials that may fit the requirements of the generation-IV reactors. Oxides are relatively simple to produce and are the current materials of choice for conventional reactors. Unfortunately, oxide fuels have several inherent limitations, which include a relatively low fissile density that reduces the breeding ratio and poor thermal conductivity that restricts the linear heating rate. Of the alternatives, nitrides represent the best combination of properties with the potential to solve these problems.
Uranium nitride has many favorable fuel properties, such as a high fissile density, a high melting point similar to that of oxide fuel and high thermal conductivity similar to that of metal fuel. While uranium nitride (UN) has many of the properties that would make it an excellent reactor fuel, it has failed to make the leap to practical systems due to the difficulty in its synthesis. In particular, the inclusion of carbon from the currently favored carbothermic reduction routes to UN is a major issue in the production of nitride fuels. The carbothermic synthesis relies on the conversion of the uranium carbide to the nitride at high temperatures. The high temperatures required for the UN production have unfortunate side effects in that the low vapor-pressure actinides, particularly americium, become volatile leading to serious contamination issues.
GB 1,186,630 discloses a process for the production of uranium nitride, plutonium nitride, or mixtures thereof, by reaction of uranium or plutonium tetrafluorides or trifluorides by high-temperature ammonolysis into the corresponding higher nitride or mixture of higher nitrides, which is then dissociated in vacuo into the corresponding mononitride or mixture of mononitrides. Optionally, zirconium nitride can be included in the admixture.
U.S. Pat. No. 3,953,355 discloses a process for the preparation of actinide nitrides from massive actinide metal, massive being a single piece of metal having a mass of 0.1 kg or more. The process involves partially hydriding the massive metal and simultaneously dehydriding and nitriding the dehydrided portion. The process is repeated until all of the massive metal is converted to a nitride.
U.S. Pat. No. 5,128,112 discloses a process of preparing an actinide nitride, phosphide, sulfide or oxide, by admixing an actinide organometallic precursor with a suitable solvent and a protic Lewis base selected from ammonia, phosphine, hydrogen sulfide and water, and heating the mixture until the actinide compound is formed.
B. N. Wani et al. report in Fluorination of Oxides of Uranium and Thorium by Ammonium Hydrogen Fluoride. J. Fluorine Chem. 44 (1989) 177-185, that UO 2 , U 3 O 8 and ThO 2 were fluorinated by NH 4 HF 2 at room temperature to produce (NH 4 ) 4 UF 8 ·2H 2 O, (NH 4 ) 3 UO 2 F 5 ·H 2 O and (NH 4 ) 4 ThF 8 ·2H 2 O, respectively.
There remains a need to provide low temperature methods of preparing actinide nitrides for use as nuclear fuels.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a method of preparing an actinide nitride fuel for nuclear reactors comprising the steps of: a) providing at least one actinide oxide and optionally zirconium oxide; b) mixing the oxide or oxides with a source of hydrogen fluoride for a period of time and at a temperature sufficient to convert the oxide to a fluoride salt; c) heating the fluoride salt to remove water; d) further heating the fluoride salt in a nitrogen atmosphere for a period of time and at a temperature sufficient to convert the fluoride salt to nitride; and e) heating the nitride under vacuum and/or inert atmosphere for a period of time and at a temperature sufficient to convert the nitride to mononitride.
The present invention provides a process for producing actinide nitrides such as uranium nitride at temperatures of 1100° C. or less without carbon contamination. The method utilizes the simple conversion of oxides to fluorides and their subsequent conversion to nitrides. The process does not rely on any significant change in oxidation state of the uranium and hence does not employ carbothermic reduction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further illustrated by the following drawing in which:
FIG. 1 is a line graph of x-ray diffraction data for UN 2 .
DETAILED DESCRIPTION OF THE INVENTION
As used herein, unless otherwise expressly specified, all numbers such as those expressing values, ranges, amounts or percentages may be read as if prefaced by the word “about,” even if the term does not expressly appear. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. Plural encompasses singular and vice versa.
Actinide series elements are the fifteen chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89-103. Suitable actinides for use in nuclear fuels include, for example, thorium, uranium, plutonium, neptunium, americium and curium. Mixtures of two or more actinide oxides are preferred, such as mixtures of plutonium and uranium. Mixtures of three or more actinides can also be used, such as mixtures of plutonium, uranium and thorium. Especially preferred are mixtures of oxides of thorium, uranium, plutonium, neptunium, americium and curium; plutonium, neptunium, americium and curium; and uranium, plutonium, neptunium, americium and curium. In any of the above mixtures, the relative amount of each actinide may vary from 0.01-100% in the mixture.
Optionally, zirconium oxide can be added to the actinide oxide in amounts known in the art. Zirconium oxide is a well known stabilizer for nuclear fuels and is also used for cladding the fuel pellets. As used throughout the specification and claims, “oxide” or “oxides” refers to the at least one actinide oxide, which is optionally mixed with zirconium oxide. The process of the present invention thus produces at least one actinide mononitride, which is optionally mixed with zirconium mononitride.
The actinide oxide or oxides are mixed with a source of hydrogen fluoride for a period of time and at a temperature sufficient to convert the oxide to a fluoride salt, according to the following reaction (where “Act” denotes actinide):
ActO 2 +4NH 4 HF 2 →(NH 4 ) 4 ActF 8 ·2 H 2 O (1)
Suitable sources of hydrogen fluoride include, for example, ammonium bifluoride, ammonium fluoride and combinations of these. Preferably, the ammonium bifluoride and/or ammonium fluoride is enriched to at least 50% 15 N, with higher levels more preferred. The reaction of the oxide with hydrogen fluoride can be carried out at ambient temperature, at temperatures between 20°-30° C. As the temperature is increased to about 50° C. the salt is dried and water is driven off:
(NH 4 ) 4 ActF 8 ·2 H 2 O→(NH 4 ) 4 ActF 8 +2 H 2 O (2)
Following removal of water, fluoride salt is further heated in a nitrogen atmosphere for a period of time and at a temperature sufficient to convert the fluoride salt to nitride:
(NH 4 ) 4 ActF 8 +2NH 3 →ActN 2 +4NH 4 F+H 2 (3)
Preferably, the nitrogen atmosphere is ammonia. 100% ammonia is preferable for rate optimization, however ammonia as a percentage in any inert carrier gas will work. The temperature used in this step of the process is between 600°-1000° C., more preferably 750°-850° C., and the period of time sufficient to complete the reaction is between 15 minutes to 3 hours, more preferably 30 minutes to 2 hours.
After conversion to the nitride, the at least one actinide nitride (and optionally zirconium nitride) is heated under vacuum and/or inert atmosphere for a period of time and at a temperature sufficient to convert the actinide nitride to a mononitride:
ActN 2 →ActN+½N 2 +H 2 +2H 2 O (4)
This is accomplished at temperatures between 1000°-1300° C., more preferably at temperatures between 1050°-1200° C. Complete 100% conversion to the mononitride occurs within ten hours, usually within 3-5 hours.
EXAMPLE
UO 2 was reacted with NH 4 HF 2 to give (NH 4 ) 4 UF 8 on a 50 g scale with a 10% excess of NH 4 HF 2 . Analysis of the bright green material indicates that it was mainly (NH 4 ) 4 UF 8 with small amounts of α-(NH 4 ) 2 UF 6 and γ-(NH 4 ) 2 UF 6 .
By washing the green material with large amounts of water, the reaction was completed and (NH 4 ) 4 UF 8 ·2H 2 O was obtained as the exclusive product, with no impurities detected. The hydrate was dried at 50° C. to give (NH 4 ) 4 UF 8 in quantitative yield (100% yield).
When the (NH 4 ) 4 UF 8 was heated to 800° C. under NH 3 , a quantitative conversion from (NH 4 ) 4 UF 8 to a uranium nitride, which analyzed as UN 2 , occurred.
For the UN 2 , x-ray diffraction patterns (shown in FIG. 1 ) can be indexed as cubic, with a=5.305034(30) Å. The Rietveld Refinement (see Table 3, below) confirmed the product as UN 2 with a small impurity (0.7%) consisting of UO 2 . While UN 2 has been previously characterized, it is one of the rarer uranium nitrides with very few reports describing its preparation or properties.
The EXAFS spectrum also confirmed the known UN 2 structure and lattice parameters and are presented in Table 2.
An examination of the thermal stability of UN 2 using thermogravimetric analysis (TGA) indicated that a significant weight loss occurs at 1000° C. Heating the UN 2 to 1100° C. resulted in the complete conversion to UN within 2 hours. The materials obtained for the thermal decomposition of UN 2 was cubic UN. The EXAFS spectrum fits the x-ray data and confirms the presence of the simple UN.
TABLE 1
Experimental Powder X-ray Diffraction Pattern of Uranium Dinitride
calculated
experimental
hkl
d(A)
20
intensity
intensity
111
3.06379(2)
29.12313
100
100
002
2.65332
33.75363
37.2
44.68
022
1.87618
48.48097
38.2
40.16
311
1.60001
57.55807
34.2
27.57
222
1.53189
60.37619
7.8
6.92
004
1.32666
70.98974
4.7
4.75
331
1.21743
78.50319
11.1
10.22
042
1.1866
80.95721
8.4
8.59
TABLE 2
Comparison of XRD and EXAFS Spectroscopy
Results on Uranium Dinitride
EXAFS
XRD*
Bond
R ± 0.02 Å
C.N ± 20%
R ± 0.002 Å
C.N.
U-N1
2.28
7.5
2.299
8
U-U1
3.73
12
3.754
12
U-N2
4.38
24
4.402
24
TABLE 3 Rietveld Refinement, Experimental versus Calculated Fit R-Values Rexp: 0.83 Rwp: 9.19 Rp: 7.10 GOF: 11.07 Rexp′: 1.41 Rwp′: 15.58 Rp′: 16.25 DW: 0.45 Quantitative Analysis—Rietveld Phase 1: “LaB6 SRM 660a” 50.231(91)% Phase 2: “UN2 Fm-3m” 49.380(91)% Phase 3: “Uraninite C” 0.389(78)% Background Chebychev polynomial, 9884(14) Coefficient 0 1 −6544(24) 2 3848(21) 3 −1595(21) 4 710(17) 5 −179(16) Instrument Primary radius (mm) 240 Secondary radius (mm) 240 Receiving slit width (mm) 0.0809(99) Divergence angle (°) 1.000(16) Full Axial Convolution Filament Length (mm) 10 Sample Length (mm) 20(11) Receiving Slit Length (mm) 30(15) Primary Sollers (°) 2.3 Secondary Sollers (°) 2.3 Tube_Tails Source Width (mm) 0.092(55) Z1 (mm) −0.04(38) Z2 (mm) 0.345(31) Fraction 0.121(43) Corrections Zero Error 0.0516(20) Specimen displacement 0.0690(45) LP Factor 0 Structure 1 Phase name LaB6 SRM 660a R-Bragg 2.240 Spacegroup Pm-3m Scale 0.07313(20) Cell Mass 203.778 Cell Volume (A{circumflex over ( )}3) 71.83047 Wt %—Rietveld 50.231(91) Crystallie Size Cry Size Lorentzian (nm) 307.8(34) Crystal Linear Absorption Coeff. (1/cm) 1124.705 Crystal Density (g/cm{circumflex over ( )}3) 4.711 PVII peak type FWHM = a + b/Cos(Th) + c Tan(Th) a 0.0013(86) b 0.0009(91) c 0.0068(33) Exponent m = 0.6 + ma + mb/Cos(Th) + mc/Tan(Th) ma 20(570) mb 0(430) mc 5(79) Lattice parameters a(Å) 4.1569000 Site Np x y z Atom Occ Beq La1 1 0.00000 0.00000 0.00000 La 1 0.7038 B1 6 0.19587 0.50000 0.50000 B 1 0.65(13) Structure 2 Phase name UN2 Fm-3m R-Bragg, 6.256 Spacegroup Fm-3m Scale 0.006623(12) Cell Mass 1064.164 Cell Volume (Å{circumflex over ( )}3) 149.3016(26) Wt %—Rietveld 49.380(91) Crystallite Size Cry Size Lorentzian (nm) 207.1(16) Crystal Linear Absorption Coeff. (1/cm) 3267.166(56) Crystal Density (g/cm{circumflex over ( )}3) 11.83568(20) PVII peak type FWHM = a + b/Cos(Th) + c Tan(Th) a 0.0001(60) b 0.0001(66) c 0.0299(38) Exponent m = 0.6 + ma + mb/Cos(Th) + mc/Tan(Th) ma 0.0(17) mb 0.05(59) mc 1.70(96) Lattice parameters a (Å) 5.305034(30) Site Np x y z Atom Occ Beq U1 4 0.00000 0.00000 0.00000 U + 6 1 1 N1 8 0.25000 0.25000 0.25000 N 1 3.52(21) Structure 3 Phase name Uraninte C R-Bragg 2.184 Spacegroup Fm-3m Scale 0.0000472(95) Cell Mass 1080.105 Cell Volume (Å{circumflex over ( )}3) 162.38(24) Wt %—Rietveld 0.389(78) Crystallite Size Cry Size Lorentzian (nm) 0(3600000) Crystal Linear Absorption Coeff. (1/cm) 3010.5(45) Crystal Density (g/cm{circumflex over ( )}3) 11.045(16) PV_TCHZ peak type U 1.2(39) V 0.4(26) W −0.09(45) Z 0 X 0.0(12) Y 0 Lattice parameters a (Å) 5.4556(27) Site Np x y z Atom Occ Beq U1 4 0.00000 0.00000 0.00000 U + 4 1 1 O1 8 0.25000 0.25000 0.25000 O−2 1 1 Very weak unknown peaks at dhkl × 4.403 Å, 5.486 Å, 2.496 Å.
Very weak unknown peaks at dhkl=4.403 Å, 5.486 Å, 2.496 Å.
Whereas particular embodiments of this invention have been described above for purpose of illustration, it will be evident to those skilled in the art the numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims. | A method of preparing an actinide nitride fuel for nuclear reactors is provided. The method comprises the steps of a) providing at least one actinide oxide and optionally zirconium oxide; b) mixing the oxide with a source of hydrogen fluoride for a period of time and at a temperature sufficient to convert the oxide to a fluoride salt; c) heating the fluoride salt to remove water; d) heating the fluoride salt in a nitrogen atmosphere for a period of time and at a temperature sufficient to convert the fluorides to nitrides; and e) heating the nitrides under vacuum and/or inert atmosphere for a period of time sufficient to convert the nitrides to mononitrides. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2009/054127, filed Apr. 7, 2009 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 08009023.6 EP filed May 15, 2008. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a process for producing a bonding layer and to a layer system according to the claims.
BACKGROUND OF INVENTION
[0003] In thermal barrier coating systems, use is often made of a metallic bonding layer in order to improve the bond between the outer ceramic thermal barrier coating and the metallic substrate. Single-layer MCrAlX systems or even recently roughened two-layer MCrAlX systems are often used as bonding layers. In this case, the outer MCrAlX layer has a different structure, which contributes in particular to an improvement in resistance to oxidation and corrosion. Said second MCrAlX layer is applied separately, which represents an additional process step and also entails bonding problems. The desired phase of the outer layer cannot always be controlled precisely.
SUMMARY OF INVENTION
[0004] It is therefore an object of the invention to solve the above-mentioned problem.
[0005] The object is achieved by a process as claimed in the claims, in which only a single-layer system is applied but is converted into a two-layer system by a heat treatment, and by a layer system as claimed in the claims.
[0006] The dependent claims each list further advantageous measures which can be combined with one another, as desired, in order to obtain further advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 schematically shows the sequence of the process,
[0008] FIGS. 2 , 3 show exemplary uses of the layer system produced in this way,
[0009] FIG. 4 shows a gas turbine,
[0010] FIG. 5 shows a perspective view of a turbine blade or vane,
[0011] FIG. 6 shows a perspective view of a combustion chamber, and
[0012] FIG. 7 shows a list of superalloys.
[0013] The figures and the description represent only exemplary embodiments.
DETAILED DESCRIPTION OF INVENTION
[0014] FIG. 1 schematically shows the sequence of the process.
[0015] The layer system 1 has a substrate 4 and a metallic layer 7 made of an MCrAlX or MCrAl alloy (M=Ni and/or Co).
[0016] In particular in the case of the component 120 , 130 , 155 ( FIGS. 5 , 6 ) of a gas turbine 100 ( FIG. 4 ), the substrate 4 consists of a superalloy according to FIG. 7 .
[0017] An MCrAl or MCrAlX layer 7 applied by APS, LPPS, VPS, HVOF or other coating processes is present on the nickel- or cobalt-based superalloy.
[0018] X is preferably yttrium (X═Y) and M is preferably Ni and Co.
[0019] According to the invention, only one coating operation of the layer 7 takes place with only one powder type.
[0020] By virtue of a heat treatment (T) at 1000° C.-1200° C., preferably 1140° C.-1180° C., preferably in a vacuum, the chromium in the MCrAl or MCrAlX alloy evaporates, such that a different chemical composition (reduced chromium content) is present in the outermost layer region 8 ′.
[0021] The duration of the heat treatment is two to eight hours. It is preferable for a different phase to also form, and it is very preferable for a β-NiAl layer to form. The heat treatment is preferably carried out for an accordingly long time.
[0022] If appropriate, a second heat treatment which can be distinguished from the chromium evaporation is carried out, in order to carry out the phase transformations of Ni—Al, Ni—Al—Cr, Ni—Al—Co, Ni—Al—Cr—Co to β-NiAl.
[0023] The layer 7 ′ which is changed in this way thus consists of an outer layer region 8 ′ with a reduced chromium content, preferably of a β-NiAl phase, and an unchanged lower layer region 8 , which has the same composition as the originally applied layer 7 but is thinner (thickness of 8 ′ thickness of 7 ′ or thickness ( 8 + 8 ′)=thickness ( 7 ) or thickness ( 8 + 8 ′)=thickness ( 7 ′)).
[0024] This heat treatment has two advantages.
[0025] On the one hand, a homogeneous single-phase structure is formed on the surface. On the other hand, a homogeneous oxide layer with very small spinel fractions and very small fractions of nickel and/or chromium oxides is formed at high temperatures. The oxide layer thus formed is the starting point for a further homogeneous, thermally grown oxide layer 10 (TGO) ( FIGS. 2 , 3 ).
[0026] For use as the layer system 1 , oxidation can be brought about intentionally or the oxide layer 10 forms during the application of a ceramic outer thermal barrier coating 13 ( FIG. 3 ).
[0027] The layer 7 ′ may likewise be used as an overlay layer, i.e. it forms the outermost layer with the exception of the TGO layer 10 which forms thereon.
[0028] The layer region 8 ′ has therefore not been applied by a second coating operation or not by the change of the powder (from MCrAl to NiAl powder) during the coating operation, and therefore also bonds well to the underlying layer region 8 .
[0029] FIG. 4 shows, by way of example, a partial longitudinal section through a gas turbine 100 .
[0030] In the interior, the gas turbine 100 has a rotor 103 with a shaft which is mounted such that it can rotate about an axis of rotation 102 and is also referred to as the turbine rotor.
[0031] An intake housing 104 , a compressor 105 , a, for example, toroidal combustion chamber 110 , in particular an annular combustion chamber, with a plurality of coaxially arranged burners 107 , a turbine 108 and the exhaust-gas housing 109 follow one another along the rotor 103 .
[0032] The annular combustion chamber 110 is in communication with a, for example, annular hot-gas passage 111 , where, by way of example, four successive turbine stages 112 form the turbine 108 .
[0033] Each turbine stage 112 is formed, for example, from two blade or vane rings. As seen in the direction of flow of a working medium 113 , in the hot-gas passage 111 a row of guide vanes 115 is followed by a row 125 formed from rotor blades 120 .
[0034] The guide vanes 130 are secured to an inner housing 138 of a stator 143 , whereas the rotor blades 120 of a row 125 are fitted to the rotor 103 for example by means of a turbine disk 133 .
[0035] A generator (not shown) is coupled to the rotor 103 .
[0036] While the gas turbine 100 is operating, the compressor 105 sucks in air 135 through the intake housing 104 and compresses it. The compressed air provided at the turbine-side end of the compressor 105 is passed to the burners 107 , where it is mixed with a fuel. The mix is then burnt in the combustion chamber 110 , forming the working medium 113 . From there, the working medium 113 flows along the hot-gas passage 111 past the guide vanes 130 and the rotor blades 120 . The working medium 113 is expanded at the rotor blades 120 , transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the latter in turn drives the generator coupled to it.
[0037] While the gas turbine 100 is operating, the components which are exposed to the hot working medium 113 are subject to thermal stresses. The guide vanes 130 and rotor blades 120 of the first turbine stage 112 , as seen in the direction of flow of the working medium 113 , together with the heat shield elements which line the annular combustion chamber 110 , are subject to the highest thermal stresses.
[0038] To be able to withstand the temperatures which prevail there, they may be cooled by means of a coolant.
[0039] Substrates of the components may likewise have a directional structure, i.e. they are in single-crystal form (SX structure) or have only longitudinally oriented grains (DS structure).
[0040] By way of example, iron-based, nickel-based or cobalt-based superalloys are used as material for the components, in particular for the turbine blade or vane 120 , 130 and components of the combustion chamber 110 .
[0041] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents form part of the disclosure with regard to the chemical composition of the alloys.
[0042] The guide vane 130 has a guide vane root (not shown here), which faces the inner housing 138 of the turbine 108 , and a guide vane head which is at the opposite end from the guide vane root. The guide vane head faces the rotor 103 and is fixed to a securing ring 140 of the stator 143 .
[0043] FIG. 5 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0044] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0045] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 and a main blade or vane part 406 and a blade or vane tip 415 .
[0046] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0047] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0048] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0049] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0050] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0051] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents form part of the disclosure with regard to the chemical composition of the alloy.
[0052] The blade or vane 120 , 130 may in this case be produced by a casting process, by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0053] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0054] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0055] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0056] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures (directionally solidified structures).
[0057] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1.
[0058] The blades or vanes 120 , 130 may likewise have coatings protecting against corrosion or oxidation e.g. (MCrAlX; M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element, or hafnium (Hf)). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0059] The density is preferably 95% of the theoretical density.
[0060] A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).
[0061] The layer preferably has a composition Co-30Ni-28Cr-8Al-0.6Y-0.7Si or Co-28Ni-24Cr-10Al-0.6Y. In addition to these cobalt-based protective coatings, it is also preferable to use nickel-based protective layers, such as Ni-10Cr-12Al-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1.5Re.
[0062] It is also possible for a thermal barrier coating, which is preferably the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, to be present on the MCrAlX.
[0063] The thermal barrier coating covers the entire MCrAlX layer. Columnar grains are produced in the thermal barrier coating by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0064] Other coating processes are possible, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks. The thermal barrier coating is therefore preferably more porous than the MCrAlX layer.
[0065] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines).
[0066] FIG. 6 shows a combustion chamber 110 of the gas turbine 100 . The combustion chamber 110 is configured, for example, as what is known as an annular combustion chamber, in which a multiplicity of burners 107 , which generate flames 156 , arranged circumferentially around an axis of rotation 102 open out into a common combustion chamber space 154 . For this purpose, the combustion chamber 110 overall is of annular configuration positioned around the axis of rotation 102 .
[0067] To achieve a relatively high efficiency, the combustion chamber 110 is designed for a relatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To allow a relatively long service life even with these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided, on its side which faces the working medium M, with an inner lining formed from heat shield elements 155 .
[0068] Moreover, a cooling system may be provided for the heat shield elements 155 and/or their holding elements, on account of the high temperatures in the interior of the combustion chamber 110 . The heat shield elements 155 are then, for example, hollow and may also have cooling holes (not shown) opening out into the combustion chamber space 154 .
[0069] On the working medium side, each heat shield element 155 made from an alloy is equipped with a particularly heat-resistant protective layer (MCrAlX layer and/or ceramic coating) or is made from material that is able to withstand high temperatures (solid ceramic bricks).
[0070] These protective layers may be similar to the turbine blades or vanes, i.e. for example MCrAlX: M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element or hafnium (Hf). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0071] It is also possible for a, for example, ceramic thermal barrier coating to be present on the MCrAlX, consisting for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide.
[0072] Columnar grains are produced in the thermal barrier coating by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0073] Other coating processes are possible, e.g. atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks.
[0074] Refurbishment means that after they have been used, protective layers may have to be removed from turbine blades or vanes 120 , 130 or heat shield elements 155 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed. If appropriate, cracks in the turbine blade or vane 120 , 130 or in the heat shield element 155 are also repaired. This is followed by recoating of the turbine blades or vanes 120 , 130 or heat shield elements 155 , after which the turbine blades or vanes 120 , 130 or the heat shield elements 155 can be reused. | Bonding agent layers are often used in heat insulation layers in order to improve the bonding of an outer ceramic layer to a metal substrate. A process is provided wherein a MCrAlX or MCrAl alloy is applied to a substrate whereby an outer layer region within the layer is produced using a heat treatment. | 8 |
This is a division of application Ser. No. 454,936, filed Jan. 3, 1983, now U.S. Pat. No. 4,497,953 which is a division of application Ser. No. 268,921, filed June 1, 1981, now U.S. Pat. No. 4,390,695, issued June 28, 1983, which is a division of application Ser. No. 162,341, filed June 23, 1980, now U.S. Pat. No. 4,310,461, issued Jan. 12, 1982.
BACKGROUND OF THE INVENTION
The recent literature discloses a variety of mercaptoacyl amino acids which are useful for inhibiting the conversion of angiotensin I to angiotensin II in mammals, and are, therefore, useful in the treatment of hypertension.
U.S. Pat. No. 4,105,776, issued Aug. 8, 1979 discloses mercaptoacyl amino acids wherein the amino acid is, inter alia, proline, 4-hydroxyproline and 4-alkylproline.
U.S. Pat. No. 4,154,935, issued May 15, 1979 discloses mercaptoacyl amino acids wherein the amino acid is, inter alia, 4-halogen substituted proline, or 4,4-dihalogen substituted proline.
BRIEF DESCRIPTION OF THE INVENTION
Compounds having the formula ##STR1## and salts thereof, and the symmetrical dimer thereof, inhibit the action of angiotensin converting enzyme, and are, therefore, useful for the treatment of hypertension. In formula I, and throughout the specification, the symbols are as defined below.
R 1 and R 2 are the same or different and are hydrogen, alkyl, cycloalkyl, 1-adamantyl, aryl, arylalkyl, alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl, alkylsulfonyl, arylsulfonyl, or arylvinylcarbonyl (aryl-CH═CH--CO--), or together with the nitrogen atom to which they are attached R 1 and R 2 are 1-pyrrolidinyl, 1-piperidinyl, 1-homopiperidinyl, 4-morpholinyl, 4-alkyl-1-piperazinyl, 4-aryl-1-piperazinyl, 1-imidazolyl, 1-pyrrolidinyl-2,5-dione(succinimido), 3-alkyl-1-pyrrolidinyl-2,5-dione, 3-aryl-1-pyrrolidinyl-2,5-dione, 1-piperidinyl-2,6-dione, 3-alkyl-1-piperidinyl-2,6-dione, 3-aryl-1-piperidinyl-2,6-dione, 2H-isoindol-2-yl-1,3-dione (phthalimido), hexahydro-2H-isoindol-2-yl-1,3-dione (hexahydrophthalimido), 2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl(maleimido), 1,1,3-trioxo-1,2-benzisothiazol-2(3H)-yl(2-saccharinyl), or 1,3-dihydro-1,3-dioxo-2H-benz[de]isoquinolin-2-yl(1,8-naphthalenedicarboximido);
R 3 is hydrogen, alkyl, aryl, arylalkyl, or a hydrolyzable acyl protecting group such as alkanoyl or arylcarbonyl;
R 4 is hydrogen, alkyl, alkylthio, or trifluoromethyl;
R 5 is hydrogen, alkyl, or arylalkyl;
n is 0, 1 or 2; and
p is 1 or 2.
The term "aryl", as used throughout the specification either by itself or as part of a larger group, refers to phenyl, 1-naphthyl, 2-naphthyl or phenyl substituted with halogen, alkyl, alkoxy, alkylthio, hydroxy, alkanoyl, nitro, amino, dialkylamino, phenyl or trifluoromethyl groups. Phenyl and monosubstituted phenyl are the preferred aryl groups; phenyl is the most preferred group.
The term "cycloalkyl", as used throughout the specification either by itself or as part of a larger group, refers to cycloalkyl groups having 3 to 7 carbon atoms.
The term "alkyl", as used throughout the specification either by itself or as part of a larger group, refers to groups having 1 to 8 carbon atoms. Alkyl groups having 1 to 3 carbon atoms are preferred.
The term "alkoxy", as used throughout the specification either by itself or as part of a larger group, refers to groups having 1 to 8 carbon atoms. Alkoxy groups having 1 to 3 carbon atoms are preferred.
The term "halogen", as used throughout the specification either by itself or as part of a larger group, refers to fluorine, chlorine, bromine and iodine. The preferred halogen groups are fluorine and chlorine.
The term "alkanoyl", as used throughout the specification either by itself or as part of a larger group, refers to groups having up to 9 carbon atoms.
The asterisk in formula I indicates a center of asymmetry in the ring. In the instance wherein the ring is proline (p is 1) this asymmetric center is in the L-configuration. In the instance wherein the ring is pipecolic acid (p is 2) this asymmetric center is in the DL- or L-configuration.
The carbon atom to which the group NR 1 R 2 is attached is another asymmetric center. Depending on the definition of R 4 , the sulfur containing side-chain may also contain an asymmetric center. The product of formula I, therefore, exists in stereoisomeric forms and as racemic mixtures thereof. All are within the scope of this invention. The synthesis described below can utilize the racemate or one of the enantiomers as starting materials. When one of the starting materials is chiral and the other is racemic, the stereoisomers obtained in the final product can be separated by conventional chromatographic or fractional crystallization methods. Preferably, if there is an asymmetric center in the sulfur containing side-chain, it is in the D-configuration.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula I, and salts thereof, and the dimer thereof, are useful as hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II and, therefore, are useful in reducing or relieving angiotensin related hypertension. The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma, produces angiotensin I. Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causative agent in various forms of hypertension in various mammalian species, e.g., rats and dogs. The compounds of this invention intervene in the angiotensinogen→(renin)→angiotensin I→(ACE)→angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II. Thus by the administration of a composition containing one or a combination of the compounds of this invention, angiotensin dependent hypertension in the species of mammal (e.g., humans) suffering therefrom is alleviated. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to 100 mg. per kilogram of body weight per day, preferably about 1 to 15 mg. per kilogram of body weight per day is appropriate to reduce blood pressure. The substance is preferably administered orally, but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this invention can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effective amount which comprises a total daily dosage of about 30 to 600 mg., preferably about 30 to 300 mg. of a compound of this invention, and about 15 to 300 mg., preferably about 15 to 200 mg. of the diuretic, to a mammalian species in need thereof. Exemplary of the diuretics contemplated for use in combination with a compound of this invention are the thiazide diuretics, e.g., chlorthiazide, hydrochlorthiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methychlothiazide, trichlormethiazide, polythiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triamterene, amiloride and spironolactone and salts of such compounds.
The compounds of formula I can be formulated for use in the reduction of blood pressure in compositions such as tablets, capsules or elixirs for oral administration or in sterile solutions of suspensions for parenteral administration. About 10 to 500 mg. of a compound or mixture of compounds of formula I is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
The compounds of this invention can be prepared using 4-hydroxy-L-proline or 4-hydroxypipecolic acid as the starting material. In converting these 4-hydroxy compounds to the corresponding 4-amino, amido or imido compounds it is necessary to first protect the nitrogen atom and the carboxyl group. A protecting group such as carbobenzyloxy, tosyl, acetyl, benzoyl, etc., can first be attached to the nitrogen atom. For example, as described in the literature (see Journal of the American Chemical Society, 86, 4709 (1964)), 4-hydroxy-L-proline can be reacted with p-toluenesulfonyl chloride to yield 4-hydroxy-1-[(4-methylphenyl)sulfonyl]-L-proline. The carboxyl group of the 4-hydroxy-N-tosyl-L-proline or pipecolic acid can be protected by esterification, e.g., by reaction with a diazoalkane (see Journal of the American Chemical Society, 79, 191 (1957)).
The 4-hydroxy substituent of the resulting 4-hydroxy-N-tosyl-L-proline or pipecolic acid ester can be converted to a leaving group using art-recognized procedures. For example, reaction of the 4-hydroxy compound with p-toluenesulfonyl chloride following the procedure described in the Journal of the American Chemical Society, 79, 191 (1957) yields 4,N-ditosyl-L-proline, alkyl ester.
Displacement of the 4-protecting group with a compound having the formula
HNR.sub.1 'R.sub.2 ', II
or an alkali metal salt thereof, is accomplished with inversion of the stereoisomerism of the compound. Therefore, if 4-trans-hydroxyproline is used as the starting material the product will have the cis configuration, and if 4-cis-hydroxyproline is used as the starting material the product will have the trans configuration. The resulting compound will have the formula ##STR2## In formulas II and III, and throughout the specification, the symbols R 1 ' and R 2 ' have the same definitions as R 1 and R 2 respectively, except R 1 ' and R 2 ' cannot both be hydrogen; the symbols Y 1 and Y 2 are a protecting group and a protected carboxyl group respectively.
Prior to acylating an intermediate of formula III to obtain a product of formula I, the protecting group is removed from the nitrogen atom and can optionally be removed from the carboxyl group. Techniques for deprotection are well known in the art. If the carboxyl group has been esterified to protect it, the protecting group can be removed using conventional saponification techniques. If the nitrogen atom has been protected with a tosyl group, that group can be removed by treating the compound with a solution of hydrogen bromide. The deprotected amino acid has the formula ##STR3##
The compounds of formula I (R 1 and R 2 other than hydrogen) can be obtained by acylating an intermediate of formula IV with an acid having the formula ##STR4## wherein R 3 ' is alkyl, aryl, arylalkyl or a hydrolyzable acyl protecting group. The acylation reaction is run in the presence of a coupling agent such as dicyclohexylcarbodiimide, or the acid can be activated by formation of its mixed anhydride, symmetrical anhydride, acid halide (preferably acid chloride) or acid ester, or by use of Woodward reagent K, N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline or the like. For a review of these methods of acylation reference can be made to Methoden der Organischen Chemie (Houben-Weyl), Vol. XV, part II, page 1 et seq. (1974).
To prepare a compound of formula I wherein R 3 is hydrogen, a corresponding product of formula I wherein R 3 is a hydrolyzable acyl protecting group can be treated with base, such as potassium hydroxide or ammonia, in water or other suitable solvent.
The compounds of this invention wherein one, or both, of R 1 and R 2 are hydrogen can be obtained from the corresponding product of formula I wherein one, or both, of R 1 and R 2 are phenylmethyl. The phenylmethyl group can be removed by treatment with sodium and liquid ammonia.
An alternative synthesis for the preparation of the compounds of this invention, wherein at least one of R 1 and R 2 is alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl, alkylsulfonyl, arylsulfonyl or arylvinylcarbonyl also utilizes 4-hydroxy-L-proline or pipecolic acid as the starting material. The nitrogen atom is first protected, e.g., by reaction with benzyl chloroformate in the presence of an organic amine (e.g., triethylamine). The reaction can be run in an inert solvent and yields N-benzyloxycarbonyl-4-hydroxy-L-proline or pipecolic acid. Protection of the carboxyl group of the N-protected compound can be accomplished by reaction with a diazoalkane or by heating with benzyl chloride in the presence of an organic amine following the procedure described in the Canadian Journal of Biochemistry and Physiology, 37, 583 (1959). The resulting N-benzyloxycarbonyl-4-hydroxy-L-proline or pipecolic acid ester can be reacted with a compound having the formula
HNR.sub.1 "R.sub.2 " VI
in the presence of diethylazodicarboxylate and triphenylphosphine to yield N-benzyloxycarbonyl-4-(NR 1 "R 2 ")-L-proline or pipecolic acid ester, which can in turn be deprotected by catalytic hydrogenation using, for example a palladium catalyst. Acylation of 4-(NR 1 "R 2 ")-L-proline, or pipecolic acid (using the procedures described above for the acylation of an intermediate of formula III) yields the corresponding product of formula I. The symbols R 1 " and R 2 " are the same or different and are hydrogen, alkyl, cycloalkyl, 1-adamantyl, aryl, arylalkyl, alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl, alkylsulfonyl, arylsulfonyl or arylvinylcarbonyl, with the proviso that at least one of R 1 " and R 2 " are one of the acyl or substituted sulfonyl groups.
A preferred synthesis for the products of formula I wherein R 1 and R 2 each is hydrogen comprises first preparing the corresponding product of formula I wherein --NR 1 R 2 is phthalimido. Reaction of this product with hydrazine in an inert solvent yields the corresponding 4-amino product.
Still another procedure for preparing the compounds of this invention wherein R 1 is hydrogen and R 2 is alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl or arylvinylcarbonyl comprises first preparing 4-azido-1-tosyl-L-proline or pipecolic acid (see the Australian Journal of Chemistry, 20, 1493 (1967)). This compound can be reduced using catalytic hydrogenation to obtain 4-amino-1-tosyl-L-proline or pipecolic acid, alkyl ester. Acylation of this compound yields the corresponding 4-acylamino-1-tosyl-L-proline or pipecolic acid, alkyl ester which can be deprotected and then acylated with an acid of formula V following the procedure described above.
Still another procedure for preparing the compounds of this invention utilizes the 4-hydroxyprolines or 4-hydroxypipecolic acids having the formula ##STR5## wherein R 3 and R 5 are other than hydrogen, as starting materials. The compounds of formula VII are disclosed in U.S. Pat. No. 4,105,776. Reaction of a compound of formula VII wherein the 4-hydroxyl group is first converted to a leaving group such as tosylate, methanesulfonate or triflate (CF 3 --SO 2 ) with a compound of the formula
HNR.sub.1 R.sub.2, VIII
or a sodium or potassium salt thereof, gives the corresponding product of formula I.
Still another procedure for preparing the compounds of this invention wherein at least one of R 1 and R 2 is alkylcarbonyl, arylcarbonyl, arylalkylcarbonyl, alkylsulfonyl, arylsulfonyl or arylvinylcarbonyl comprises reacting a compound of formula VII with a compound of formula VI in the presence of triphenylphosphine and diethylazodicarboxylate.
The compounds of this invention form basic salts with various inorganic and organic bases which are also within the scope of the invention. Such salts include ammonium salts, alkali metal salts like sodium and potassium salts (which are preferred), alkaline earth metal salts like the calcium and magnesium salts, salts with organic bases, e.g., dicyclohexylamine salt, benzathine, N-methyl-D-glucamine, hydrabamine salts, salts with amino acids like arginine, lysine and the like. The non-toxic, physiologically acceptable salts are preferred, although other salts are also useful, e.g., in isolating or purifying the product.
The salts are formed in conventional manner by reacting the free acid form of the product with one or more equivalents of the appropriate base providing the desired cation in a solvent or medium in which the salt is insoluble, or in water and removing the water by freeze drying. By neutralizing the salt with an insoluble acid like a cation exchange resin in the hydrogen form (e.g., polystyrene sulfonic acid resin like Dowex 50) or with an aqueous acid and extraction with an organic solvent, e.g., ethyl acetate, dichloromethane or the like, the free acid form can be obtained, and, if desired, another salt formed.
The symmetrical dimer of a product of formula I, i.e., compound having the formula ##STR6## is also contemplated as an integral part of this invention. It is readily prepared from the corresponding product of formula I wherein R 3 is hydrogen by direct oxidation with iodine.
Compounds of formula I wherein p is 1 are preferred. Also preferred are compounds of formula I wherein n is 1 and R 4 is methyl.
The following examples are specific embodiments of this invention.
EXAMPLE 1
[1(S),4S]-4-(Benzoylamino)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline
(A) (R)-4-Hydroxy-1-[(4-methylphenyl)sulfonyl]-L-proline
A stirred solution of 52.45 g (0.40 mole) of trans-4-hydroxy-L-proline in 500 ml of sodium hydroxide is treated with 85.79 g (0.45 mole) of p-toluenesulfonyl chloride in 500 ml of ether at room temperature. Stirring is continued for 6 hours, the layers are separated and the aqueous phase is cooled to 5° C. in an ice-bath. The mixture is then acidified while cooling with 30 ml of concentrated hydrochloric acid to pH 2 and the precipitated white solid is collected, washed with 150 ml of cold water, and dried in vacuo yielding 106.2 g of material, melting point 139°-143° C. Crystallization from 300 ml of ethyl acetate yields 98.6 g of the title compound, melting point 142°-145° C.
(B) (R)-4-Hydroxy-1-[(4-methylphenyl)sulfonyl]-L-proline, methyl ester
The above N-tosyl-L-proline (24.25 g, 0.085 mole) is esterified with diazomethane in methanolether as described in The Journal of the American Chemical Society, 79, 191 (1957) yielding 25.3 g of product, melting point 101°-104° C.
(C) (R)-1-[(4-Methylphenyl)sulfonyl]-4-[[(4-methylphenyl)sulfonyl]oxy]-L-proline, methyl ester
A stirred solution of 23.95 g (0.08 mole) of the above trans-4-hydroxy-L-proline derivative in 50 ml of dry pyridine is treated dropwise at -5° C. to -8° C. with a solution of 17.16 g of p-toluenesulfonyl chloride (0.09 mole) in 20 ml of pyridine. The solution is stored in the cold room for 72 hours, added with stirring to 425 ml of ice-cold 2N hydrochloric acid, and the precipitated gum extracted with 200 ml of chloroform. The aqueous phase is extracted with additional chloroform (three 125 ml portions). The combined organic layers are dried (MgSO 4 ) and the solvent evaporated to give a viscous oil. The oil is dissolved in ethyl acetate (125 ml) and the product crystallized with cooling and rubbing to yield 26.8 g of trans-N,O-ditosylhydroxy-L-proline methyl ester, melting point 92°-94° C.
(D) (S)-1-[(4-Methylphenyl)sulfonyl]-4-azido-L-proline,methyl ester
A stirred solution of 22.68 g (0.05 moles) of the above trans-N,O-ditosylhydroxy-L-proline, methyl ester is dissolved in 150 ml of dimethylformamide, and 3.6 g (0.055 mole) of sodium azide in 17 ml of water is added. The reaction mixture is heated at 70° C. for 5 hours. It is cooled, and poured into a mixture of saturated brine (1000 ml) and water (200 ml), and extracted with ether (three 250 ml portions). The combined ether extracts are washed with saturated brine and dried (MgSO 4 ). Removal of the ether and crystallization of the residue from ether/light petroleum ether yields 12.4 g of the title cis-azide ester as needles, melting point 69°-70° C.
(E) (S)-4-Amino-1-[(4-methylphenyl)sulfonyl]-L-proline, methyl ester
A solution of 9.73 g of the above cis-azide ester (0.03 mole) is dissolved in 100 ml of methanol and 1.0 g of 10% palladium on charcoal is added to the mixture. The mixture is hydrogenated for 6 hours at 50 psi. (The reaction bottle is flushed twice with hydrogen to remove the nitrogen as it is formed). The mixture is then filtered through Celite and the methanol removed in vacuo yielding 8.94 g of the amino product as a viscous oil. [α] D 26 -50°(c=2,MeOH).
(F) (S)-4-(Benzoylamino)-1-[(4-methylphenyl)sulfonyl]-L-proline, methyl ester
A stirred solution of 8.95 g (0.03 mole) of the above cis-amino ester and 2.4 g (0.031 mole) of triethylamine in 100 ml of chloroform is cooled to 0° to 5° C. in an ice-bath and treated with 4.20 g (0.031 mole) of benzoyl chloride. The reaction is maintained under nitrogen and allowed to stir for about 16 hours at room temperature. The mixture is extracted with water (two 75 ml portions) followed by washing with 100 ml of a saturated salt solution. The chloroform solution is dried over anhydrous MgSO 4 and the chloroform removed in vacuo yielding a solid. Crystallization from 75% ethanol yields 10.46 g of the title compound, melting point 167°-169° C.
(G) (S)-4-Benzoylamino-1-[(4-methylphenyl)sulfonyl]-L-proline
The above ester (10.0 g, 0.0248 mole) is dissolved in 120 ml of methanol, treated dropwise at 0° C. with 37.5 ml (0.0372 mole) of 2N sodium hydroxide kept at 0° C. for 1 hour, and at room temperature for about 16 hours. After removing about 1/2 of the solvent on a rotary evaporator, the solution is cooled and acidified with 6N HCl to pH 2, and extracted with four 150 ml portions of ethyl acetate. The combined extracts are washed with 100 ml of a saturated salt solution dried (MgSO 4 ) and the solvent evaporated to give 7.18 g of the title compound, melting point 120°-125° C. (sintering at 118° C.).
(H) (S)-4-(Benzoylamino)-L-proline, hydrobromide (1:1)
The above N-tosyl acid (7.0 g, 0.017 mole) and phenol (3.2 g, 0.035 mole) are treated with 28 ml of hydrogen bromide in acetic acid (30-32%), stoppered loosely, and stirred for 18 hours. Ether (300 ml) is added with swirling to the mixture and when the crystalline product has settled, the etheral liquor is decanted and the material is washed with 300 ml of fresh ether by decantation. The product is heated on the steam bath with 80 ml of methyl ethyl ketone, cooled, filtered, washed with cold methyl ethyl ketone and with ether, and dried in vacuo, yielding 2.6 g of the title compound, melting point 184°-188° C., dec.
(I) (S),4S]-1-[3-(Acetylthio)-2-methyl-1-oxopropyl]-4-(benzoylamino)-L-proline
The above amino acid hydrobromide salt (2.6 g, 0.0078 mole) and 1.6 g of (0.0086 mole) of D-3-(acetylthio)-2-methylpropionyl chloride in 5 ml of ether are reacted in 50 ml of water in the presence of Na 2 CO 3 . Initially, 2.4 ml of 25% Na 2 CO 3 solution is required to obtain a pH of 8.0. Approximately 14 ml of 25% Na 2 CO 3 (w/v) is consumed to stabilize the pH of 8.0-8.2 during the acylation (time approx. 45 minutes). The mixture is allowed to warm to room temperature and stirred for 11/2 hours under argon. The mixture is worked up after an additional 1 hour by washing with 25 ml of ethyl acetate which is discarded, layered over with 25 ml of ethyl acetate, cooled, stirred, acidified carefully with 1:1 HCl to pH 2.0, saturated with salt and separated. The aqueous phase is extracted with three 25 ml portions of ethyl acetate, the combined organic layers are dried (MgSO 4 ) and the solvent removed in vacuo. The product is obtained as a syrupy oil, yield 2.30 g, which slowly begins to crystallize. The oil is treated in 30 ml of ethyl acetate with 1.5 g of dicyclohexylamine to give 2.18 g of the dicyclohexylamine salt of the title compound, melting point 160°-163° C., [α] 26 -51° C. (c=1; methanol). Acidification of the dicyclohexylamine salt (2.18 g) with 26 ml of 10% KHSO 4 and extraction with 40 ml of ethyl acetate (four times) yields 1.1 g of the title compound, melting point 82°-84° C., [α] D 26 -81° (c=1; CHCl 3 ).
(J) [1(S),4S]-4-(Benzoylamino)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline
Argon is passed through a cold solution of 1.5 ml of concentrated ammonium hydroxide in 8.0 ml of water for 0.25 hours which is then added while cooling and under a blanket of argon to 1.0 g (0.0026 mole) of the above S-acetyl compound. The mixture is swirled in an ice-bath until a solution is obtained. Stirring under argon is continued at room temperature for an additional 2 hours, then the solution is extracted with 15 ml of ethyl acetate (this and subsequent operations are carried out as much as possible under an argon atmosphere). The aqueous layer is cooled, stirred, layered over with 15 ml of ethyl acetate and acidified portionwise with approximately 4.2 ml of 6N HCl. The layers are separated, the aqueous phase extracted with three 15 ml portions of ethyl acetate, the combined ethyl acetate layers dried (MgSO 4 ) and the solvent evaporated to give 0.46 g of the title compound after drying in vacuo, melting point 150°-152° C., [α] D 26 -44° (c=1; EtOH).
EXAMPLE 2
[1(S),4S]-1-[3-(Acetylthio)-2-methyl-1-oxopropyl]-4-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-L-proline
(A) (S)-4-(1,3-Dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-[(phenylmethoxy)carbonyl]-L-proline, phenylmethyl ester
To a solution of 7.0 g of N-(benzyloxycarbonyl)-4-trans-hydroxy-L-proline, benzyl ester (described in Can. J. Biochem. & Phy., 37, 583 (1959)) 4.34 g of phthalimide, and 7.73 g of triphenylphosphine in 200 ml of dry (sieve) tetrahydrofuran is added 5.13 g of diethyl azodicarboxylate over 1 hour at room temperature. Thin layer chromatography (silica gel-ether) shows consumption of starting material is complete in less than two hours. The solvent is removed under vacuum and the residue diluted with 200 ml of ether. The resulting precipitate is filtered off and the filtrate is concentrated to about 40 ml. This material is flash chromatographed on silica gel with ether:pentane (1:1) to yield a total of 9.15 g of residue. The product is isolated in two fractions A (first portion eluted) and AA (second portion eluted). Both fractions are taken up in ether and allowed to stand. The resulting crystals are filtered off to yield the final product A 1 and AA 1 . A 1 melts at 89°-90° C. while AA 1 melts at 117°-119° C., but on standing for several days the melting point changes to 89°-90° C., [α] D 25 -47.8°(a=0.5%;CHCl 3 ). Both fractions are identical chromatographically and spectrally (NMR) and are combined for further use.
(B) [1(S),4S]-1-[3-(Acetylthio)-2-methyl-1-oxopropyl]-4-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-L-proline
A solution of 5.0 g of (S)-4-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-1-[(phenylmethoxy)carbonyl]-L-proline, phenylmethyl ester in 200 ml of ethyl acetate and 100 ml of ethanol is hydrogenated with 2.0 g of 10% palladium on charcoal at room temperature and 40 psi. After 2 days the mixture is filtered to yield a mixture of the amino acid product and catalyst as the filter cake.
The mixture of catalyst and amino acid is suspended in 75 ml of dry pyridine and treated with 3 g of (S)-3-(acetylthio)-2-methylpropionyl chloride at room temperature. After 1 hour another 2 g of acid chloride is added. The mixture is stirred for 2 hours and filtered. The filtrate is evaporated to dryness and the residue partitioned between 1N HCl and ethyl acetate. The ethyl acetate solution is washed with water and saturated NaCl, dried (Na 2 SO 4 ) and the solvents are removed under vacuum. The residue is chromotographed on silica gel with 7:1 toluene:acetic acid. The fraction with an R f of 0.1 (tlc) is collected and evaporated to dryness. The residue is taken up in ethyl acetate and filtered. The filtrate is again evaporated to dryness to yield 2.8 g of an oil. The oil is taken up in ether and allowed to stand for about 16 hours. The resulting crystals are filtered off and washed with ethyl acetate to yield the product, melting point 185°-188° C.; [α] D 25 -95.3° (c=1%;CHCl 3 ).
EXAMPLE 3
[1(S),4S]-4-Amino-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline
To 0.8 g of [1(S),4S]-1-[3-(acetylthio)-2-methyl-1-oxopropyl]-4-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-L-proline suspended in 20 ml of methanol is added 36 drops of anhydrous hydrazine. After 30 minutes the mixture is concentrated to 5 ml and placed on a column of DEAE Sephadex which is eluted with a 0.005M to 0.5 molar gradient of aqueous ammonium carbonate. The fractions giving a positive sulfhydryl test (nitroprusside solution) are combined and lyophilized to yield the partially purified product. Further purification is achieved by chromatography on silica gel and elution with butanol:acetic acid:water (4:1:1).
EXAMPLES 4-17
Following the procedure of Example 2, but substituting the compound listed in Column I for phthalimide, yields the compound listed in Column II.
______________________________________Columm I Column II______________________________________4 hexahydropthalimide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- (hexahydro-2H--isoindol-2- yl-1,3-dione)-L-proline5 1,8 naphthalenecar- [1(S),4S]--1-[3-(acetylthio)- boximide 2-methyl-1-oxopropyl]-4- (1,3-dihydro-1,3-dioxo-2H-- benz[de]isoquinolin-2-yl)- L-proline6 saccharin (1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4-(1,- 1,3-trioxo-1,2-benzisothia- zol-2(3H)--yl)-L-proline7 succinimide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- (1-pyrrolidinyl-2,5-dione- L-proline8 glutarimide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- (1-piperidinyl)-2,6-dione- L-proline9 maleimide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- (2,5-dihydro-2,5-dioxo-1H-- pyrrol-1-yl)-L-proline10 diacetamide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- diacetamido-L-proline11 dibenzamide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- dibenzamido-L-proline12 N--acetylbenzamide [1(S),4S]--1-3-(acetylthio)- 2-methyl-1-oxopropyl]-4- (N--acetylbenzamido)-L-proline13 diphenacetamide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- diphenacetamido-L-proline14 dicinnamoylamine [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- dicinnamoylamino-L-proline15 dimethylsulfonamide [ 1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- dimethylsulfonamido-L-proline16 dibenzenesulfonamide [1(S),4S]--1-[3-(acetylthio)- 2-methyl-1-oxopropyl]-4- dibenzenesulfonamido-L-pro- line17 N--(benzenesulfonyl)- [1(S),4S]--1-[3-(acetylthio)- acetamide 2-methyl-1-oxopropyl]-4- (N--(benzenesulfonyl)aceta- mido)-L-proline______________________________________
EXAMPLES 18-29
Following the procedure of Example 1, but substituting the compound listed in Column I for benzoyl chloride in part F, yields the compound listed in Column II.
______________________________________Column I Column II______________________________________18 4-fluorobenzoyl chloride [1(S),4S]--4-(4-fluoro- benzoylamino)-1-(3-mer- capto-2-methyl-1-oxopro- pyl)-L-proline19 2,6-dichlorobenzoyl [1(S),4S]--4-(2,6-dichlor- chloride obenzoylamino)-1-(3-mer- capto-2-methyl-1-oxopro- pyl)-L-proline20 2,4,6-trimethylbenzoyl [1(S),4S]--4-(2,4,6-tri- chloride methylbenzoylamino)-1- (3-mercapto-2-methyl-1- oxopropyl)-L-proline21 3,4 dimethoxybenzoyl [1(S),4S]--4-(3,4-dimeth- chloride oxybenzoylamino)-1-(3- mercapto-2-methyl-1-oxo- propyl)-L-proline22 4-ethylthobenzoyl [1(S),4S]--4-(4-ethylthio- chloride benzoylamino)-1-(3-mercap- to-2-methyl-1-oxopropyl)- L-proline23 2-hroxybenzoyl [1(S),4S]--4-(2-hydroxy- chloride benzoylamino)-1-(3-mer- capto-2-methyl-1-oxopro- pyl)-L-proline24 4-acetylbenzoyl [1(S),4S]--4-(4-acetylben- chloride zoylamino-1-(3-mercapto- 2-methyl-1-oxopropyl)-L- proline25 4-nitrobenzoyl [1(S),4S]--4-(4-nitroben- chloride zoylamino)-1-(3-mercapto- 2-methyl-1-oxopropyl)-L- proline26 3-fluoro-4-methoxy- [1(S),4S]--4-(3-fluoro-4- benzoyl chloride methoxybenzoylamino)-1-(3- mercapto-2-methyl-1-oxo- propyl)-L-proline27 4-dimethylaminobenzoyl [1(S),4S]--4-(4-dimethyl- chloride aminobenzoylamino)-1-(3- mercapto-2-methyl-1-oxo- propyl)-L-proline28 4-phenylbenzoyl [1(S),4S]--4-(4-phenylben- chloride zoylamino)-1-(3-mercapto- 2-methyl-1-oxopropyl)-L- proline29 3-trifluoromthylbenzoyl [1(S),4S]--4-(3-trifluoro- chloride methylbenzoylamino)-1- (3-mercapto-2-methyl-1- oxopropyl)-L-proline______________________________________
EXAMPLE 30
[1(S),4S]-1-(3-Mercapto-2-methyl-1-oxopropyl)-4-(1-piperidinyl)-L-proline, hydrochloride
(A) [4S]-1-[(Phenylmethoxy)carbonyl]-4-(1-piperidinyl)-L-proline, methyl ester
A mixture of 15.0 g of 1-[(phenylmethoxy)carbonyl]-trans-4-tosyloxy-L-proline, methyl ester (J.A.C.S., 79, 191 (1957)) and 75 ml of piperidine is stirred at room temperature for 24 hours. The excess piperidine is removed under reduced pressure and the residue is dissolved in 50 ml of chloroform. The latter solution is extracted twice with 10 ml portions of water, dried (MgSO 4 ), filtered and the solvent evaporated to give the title compound.
(B) [4S]-4-(1-Piperidinyl)-L-proline, methyl ester
A solution of 10.0 g of [4S]-1-[(phenylmethoxy)carbonyl]-4-(1-piperidinyl)-L-proline, methyl ester in 100 ml of methanol is treated with a suspension of 2 g of 5% palladium on charcoal in 10 ml of water and placed under 3 atmospheres of hydrogen. After an equivalent quantity of hydrogen is consumed, the suspension is filtered and the solvent evaporated to give the title compound.
(C) [1(S),4S]-1-[3-(Acetylthio)-2-methyl-1-oxopropyl]-4-(1-piperidinyl)-L-proline, methyl ester, hydrochloride.
A solution of 7.0 g of [4S]-4-(1-piperidinyl)-L-proline, methyl ester in 100 ml of chloroform is stirred and maintained at 20°-25° C. during the addition of an equivalent quantity of (S)-3-(acetylthio)-2-methylpropionyl chloride. After stirring for 4 hours at room temperature, the solvent is removed yielding the title compound.
(D) [1(S),4S]-1-(3-Mercapto-2-methyl-1-oxopropyl)-4-(1-piperidinyl)-L-proline, hydrochloride. A solution of 5.0 g of [1(S),4S]-1-[3-(acetylthio)-2-methyl-1-oxopropyl]-4-(1-piperidinyl)-L-proline, methyl ester, hydrochloride in 50 ml of dioxane is treated with 3.0 ml of a saturated solution of hydrogen chloride in methanol, and the resulting solution is allowed to stand for 12 hours at 0°-10° C. The solvent is evaporated to give the title compound.
EXAMPLES 31-44
Following the procedure of Example 30, but substituting the compound listed in Column I for piperidine, yields the compound listed in Column II.
______________________________________Column I Column II______________________________________31 pyrrolidine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (1-pyrrolidinyl)-L-proline, hydrochloride32 morpholine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (4-morpholinyl)-L-proline, hydrochloride33 4-methylpiperazine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- 4-methyl-1-piperazinyl)- L-proline, hydrochloride34 4-phenylpiperazine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (4-phenyl-1-piperazinyl)- L-proline, hydrochloride35 imidazole [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (1-imidazolyl)-L-proline, hydrochloride36 diethylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (diethylamino)-L-proline, hydrochloride37 cyclohexylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (cyclohexylamino)-L- proline, hydrochloride38 1-adamantylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (1-adamantylamino)-L- proline, hydrochloride39 N--methyl-1-adamantyl- [1(S),4S --1-(3-mercapto- amine 2-methyl-1-oxopropyl)-4- (N--methyl-1-adamantyl- amino)-L-proline, hydro- chloride40 t-butylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (t-butylamino)-L-proline, hydrochloride41 aniline [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (phenylamino)-L-proline, hydrochloride42 p-chloroaniline [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (4-chlorophenylamino)-L- proline, hydrochloride43 benzylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl-4- (benzylamino)-L-proline, hydrochloride44 phenethylamine [1(S),4S]--1-(3-mercapto- 2-methyl-1-oxopropyl)-4- (phenethylamino)-L-pro- line, hydrochloride______________________________________
EXAMPLES 45-48
Following the procedure of Example 1, but substituting the compound liste in Column I for D-3-(acetylthio)-2-methylpropionyl chloride, yields the compound listed in Column II.
______________________________________Column I Column II______________________________________45 3-(acetylthio)-2-(tri- (4S)--4-(benzoylamino)-1- fluoromethyl)propionyl (3-mercapto-2-trifluoro- chloride methyl-1-oxopropyl)-L-proline46 4-(acetylthio)butyryl (4S)--4-(benzoylamino)-1 chloride (4-mercapto-1-oxobutyl)- L-proline47 2-(acetylthio)acetyl (4S)--4-(benzoylamino)-1- chloride (3-mercapto-1-oxoethyl)- L-proline48 3-actylthio)-2- (4S)--4-(benzoylamino)-1- (methylthio)propionyl [3-mercapto-2-methylthio)- chloride 1-oxopropyl)-L-proline______________________________________
EXAMPLE 49
[1(S),4S]-4-(Benzoylamino)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline, sodium salt
A suspension of 5.0 g of [1(S),4S]-4-(benzoylamino)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline is suspended in 15 ml of water and treated with 1 equivalent of sodium bicarbonate. The solution is evaporated under reduced pressure to give the title compound.
EXAMPLE 50
[1(S),4S]-4-(1-Homopiperidinyl)-1-(3-mercapto-2-methyl-1-oxopropyl)-L-proline
Following the procedure of Example 30, but substituting homopiperidine for piperidine in part A, yields the title compound.
EXAMPLE 51
[1(S),4S]-(3-Mercapto-2-methyl-1-oxopropyl)-4-(1-naphthoylamino)-L-proline
Following the procedure of Example 1, but substituting 1-naphthoyl chloride for benzoyl chloride in part F, yields the title compound.
EXAMPLE 52
[1(S),4S]-(3-Mercapto-2-methyl-1-oxopropyl)-4-(2-naphthoylamino)-L-proline
Following the procedure of Example 1, but substituting 2-naphthoyl chloride for benzoyl chloride in part F, yields the title compound.
EXAMPLE 53
[1(S),1'(S), 4R, 4'R]-1,1'-[Dithiobis(2-methyl-1-oxopropane-3,1-diyl)bis]4-benzylamino-L-proline
A solution of the product from Example 1 is dissolved in ethanol, stirred and treated with a solution of one equivalent of iodine in ethanol. The pH of the solution is maintained at 6-7 by the addition of N-sodium hydroxide solution. The solvent is evaporated and the residue extracted with ethyl acetate. After drying over MgSO 4 , the solution is filtered and the solvent evaporated to give the title compound.
EXAMPLE 54
[1(S)]-4-(Benzoylamino)-1-(3-mercapto-2-methyl-1-oxopropyl)-DL-pipecolinic acid
Following the procedure of Example 1, but substituting DL-4-hydroxypipecolinic acid for trans-4-hydroxy-L-proline in part A, the title compound is obtained. | Imido, amido and amino derivatives of mercaptoacyl prolines and pipecolic acids are useful for the treatment of hypertension. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/710,389, filed Feb. 23, 2010, now allowed, which is a continuation of U.S. application Ser. No. 10/807,273, filed Mar. 24, 2004, now U.S. Pat. No. 7,692,749, which is a continuation of U.S. application Ser. No. 10/305,226, filed Nov. 25, 2002, now U.S. Pat. No. 6,914,655, which is a continuation of U.S. application Ser. No. 09/239,066, filed Jan. 25, 1999, now U.S. Pat. No. 6,498,634, which is a continuation of U.S. application Ser. No. 08/770,703, filed Dec. 19, 1996, now U.S. Pat. No. 5,892,562, which claims the benefit of a foreign priority application filed in Japan as Serial No. 7-349670 on Dec. 20, 1995, all of which are incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a liquid crystal electro-optic device having good electrical characteristics and angle of visibility characteristics with which a uniform display can be obtained over an entire screen.
[0003] As a method of widening the angle of visibility of a liquid crystal electro-optic device, a method wherein the direction of an electric field impressed on a liquid crystal is made substantially parallel to the surface of a substrate (hereinafter referred to as the super TFT method) is disclosed for example in Japanese Unexamined Patent Publication No. H.6-160878. In this case, an electric field is induced between a source electrode and a common electrode formed on one substrate, and the liquid crystal molecules are oriented in the direction of this electric field. Also, in Japanese Unexamined Patent Publication No. H.6-214244, the electric field impressed on the liquid crystal is made uniform by making the height of the electrodes the same as the cell thickness.
[0004] In this kind of liquid crystal electro-optic device, because switching is carried out with the long axes of the liquid crystal molecules kept parallel with the substrate, there is no change with angle of visibility in the optical characteristics of the liquid crystal. Consequently, there is less light leakage and contrast reduction and the like resulting from angle of visibility than with conventional TN and STN methods.
[0005] However, electrodes of the super TFT method conventionally used have been of a trapezoidal or rectangular structure, and the electric fields produced by these electrodes have been noncontinuous at vertices of the trapezoid or rectangle. Consequently, the electric field impressed on the liquid crystal has changed at certain points. That is, the electric field (electric flux density) has changed suddenly at the vertices of the trapezoid or rectangle. Consequently, switching of the liquid crystal by the electric field has not been carried out evenly in the cell, and a phenomenon of the time taken for the electric field to change from OFF to ON or from ON to OFF (these are respectively called the rise time and the fall time) varying within the cell has appeared.
[0006] This is a shortcoming which appears particularly markedly in the super TFT method, wherein a horizontal electric field is used to carry out liquid crystal driving.
[0007] The above-mentioned electric field noncontinuity will be explained with reference to FIG. 1 . Here, for simplicity, the state of lines of electric force around the electrodes when a voltage is impressed across a pair of parallel electrodes ( 101 , 102 ) each of a rectangular cross-section of height ‘a’ and width c formed with a spacing 2 b between the electrodes on an insulating substrate ( 103 ) will be described. (For lines of electric form formed by electric changes, please refer to works on electromagnetism, for example ‘Electromagnetism’, Kazukiyo Nagata, published by Asakura, or ‘Detailed Electromagnetic Practice’, Goto and Yamazaki, Kyoritsu publishing.) Here, a direction parallel with the substrate and perpendicular to (the height direction of) the electrodes will b e made an x-axis and a direction perpendicular to the surface of the substrate will be made a y-axis. An origin will be so defined that the electrode surfaces parallel with the substrate are at y=0.
[0008] (1) In the region y<0 (−b≦x≦b), i.e. the region between the electrodes:
[0009] Because electric charge can be regarded as being distributed evenly over the electrode surfaces ( 104 , 105 ), the lines of electric force ( 106 ) here are perpendicular to the electrodes (and parallel with the substrate).
[0010] (2) In the region y>0, i.e. the region above the electrodes:
[0011] Here, for the sake of simplicity, the state of the lines of electric force in the xy plane will be investigated.
[0012] Electric charge can be regarded as being distributed evenly over the electrode surfaces ( 107 , 108 ).
[0013] For any point in the region y>0, the distance from the origin will be written r and the angle made by r and the x-axis will be written θ. Also, expressing z as a point in a complex plane using x, y and r, θ, the following relationship holds:
[0000] z=x+iy=r exp( i θ)
[0000] Here, to simplify the analysis, a value w will be defined as follows:
[0000] w=Alogz
[0000] (A is a constant of proportionality). If the real and imaginary parts of w are written u and v, then:
[0000] w=u+iv=A log z
[0000] and
[0000] u+iv=A log{ r exp( i θ)}= A log r+iAθ
[0000] is obtained. Therefore,
[0000] u=Alogr, v=Aθ
[0014] Therefore, the set of curves expressed u=constant in the w plane are the set of curves r=constant in the xy plane, i.e. the set of concentric circles about the origin.
[0015] This result is illustrated in FIG. 1 , from which it can be seen that the electric field distributions of the electrode side surfaces and the electrode top surfaces are different.
[0016] Here, as an example, the electric field between electrodes whose cross-sections are rectangular was shown, but the situation is the same between electrodes whose cross-sections are trapezoidal also. This is because since electric fields are formed perpendicular to the electrode surfaces the electric field of the taper parts and the electric field of the parts parallel with the substrate are noncontinuous at the electrode vertices.
[0017] This kind of noncontinuity of the electric field at the electrode vertices is a problem which cannot be ignored when making very small pixels. This is because when as a result of the adoption of very small pixels the number of electrodes increases and the interelectrode distance becomes small the noncontinuous electric field distributes at a high density.
[0018] As another method of solving the above-mentioned problem, an invention wherein in order to impress an electric field on the liquid crystal evenly in the cell thickness direction the height of the electrodes is made the same as the thickness of the cell has been proposed, in Japanese Unexamined Patent Publication No. H.6-214244. However, in making extremely tall electrodes, the following technological difficulties arise.
[0019] Firstly, when the height of an electrode is made as great as the cell thickness, a large difference in the horizontal direction electrode thickness tends to arise between the top and the base of the electrode. In the super TFT method, wherein the liquid crystal is driven with a horizontal electric field, a difference in the electrode thickness constitutes a difference in the interelectrode distance. Consequently, because the electric field strength in the cell thickness direction varies within the same pixel, driving the liquid crystal becomes difficult.
[0020] Secondly, when the electrodes are extremely tall, the coverage of layers formed on top of the electrodes is poor and line breakage tends to occur.
[0021] Thirdly, in making very small pixels, with extremely tall electrodes it is difficult to make the horizontal direction film thickness thin and obtain a large taper angle.
[0022] Consequently, in making very small pixels, to solve the above-mentioned problems, an electrode structure which can be made by a simple method and which also does not produce a noncontinuous electric field has been being sought.
SUMMARY OF THE INVENTION
[0023] It is therefore an object of the invention to provide a liquid crystal electro-optic device which has an electrode structure such that noncontinuity of the electric field strength around each pixel electrode is minimized and the display characteristics of the device are thereby improved and which can be made by a simple method.
[0024] To achieve this object and other objects, the invention provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a curved sectional profile.
[0025] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a semi-circular or semi-elliptical sectional profile.
[0026] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a curved sectional profile.
[0027] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a semi-circular or semi-elliptical sectional profile.
[0028] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein a nonlinear device is connected to at least one of the electrodes and at least one of the electrodes has a curved sectional profile.
[0029] The invention also provides a liquid crystal device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein a nonlinear device is connected to at least one of the electrodes and a peripheral driving circuit for driving a liquid crystal material is formed on at least one of the substrates and at least one of the electrodes has a curved sectional profile.
[0030] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein a nonlinear device is connected to at least one of the electrodes and at least one of the electrodes has a semi-circular or semi-elliptical sectional profile.
[0031] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates including an electrode for liquid crystal driving and a common electrode having parts formed in parallel on the same substrate, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein a nonlinear device is connected to at least one of the electrodes and a periphal driving circuit for driving a liquid crystal material is formed on at least one of the substrates and at least one of the electrodes has a semi-circular or semi-elliptical sectional profile.
[0032] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a curved sectional profile and the tangential direction of a line of electric force around the surface of this electrode changes continuously over the entire surface of the electrode.
[0033] The invention also provides a liquid crystal electro-optic device comprising a pair of substrates of which at least one is transparent, electrodes formed on at least one of the substrates, a liquid crystal layer held between the substrates, and electric field impressing means for impressing an electric field on the liquid crystal layer by way of the electrodes, wherein at least one of the electrodes has a semi-circular or semi-elliptical sectional profile and the tangential direction of a line of electric force around the surface of this electrode changes continuously over the entire surface of the electrode.
[0034] An example of a construction using the invention disclosed in this specification is shown in FIG. 4 and FIG. 5 . FIG. 4 is a schematic plan view of a pixel part of an active matrix type liquid crystal electro-optic device wherein nematic liquid crystal is used and this liquid crystal material is driven with a horizontal electric field and a-Si TFTs are used as the driving devices, and FIG. 5 is a sectional view on the line A-A′ in FIG. 4 .
[0035] In the construction shown in FIG. 4 and FIG. 5 , 401 denotes first and second substrates, 402 a base SiO 2 film, 403 a gate electrode, 404 a common electrode, 405 a gate insulating film, 406 a-Si, 407 a source electrode, 408 a drain electrode, 409 a protective layer, 411 an orienting film, 412 a polarizing plate and 413 a liquid crystal layer.
[0036] The liquid crystal electro-optic device of this invention is one wherein a liquid crystal material is operated by controlling the strength of an electric field (a horizontal electric field) between a drain electrode and a common electrode formed on a TFT substrate.
[0037] For the above-mentioned first and second substrates, a transparent material having a certain degree of strength with respect to outside forces, for example an inorganic material such as glass or quartz, is used. For the substrate on which the TFTs are formed (hereinafter called the TFT substrate), non-alkali glass or quartz glass is used. When a lightweight liquid crystal electro-optic device is to be made, a film having little birefringence, for example PES (Poly Ethylene Sulfate) or the like also can be used.
[0038] As the method by which the liquid crystal material is driven, the multiplex method or the active matrix method may be used.
[0039] With the multiplex method, all that need be formed on the first substrate are electrodes for display and reference electrodes, but in the case of the active matrix method, in addition to these a nonlinear device, for example a thin film transistor (TFT) or a diode, is formed for each pixel as a switching device.
[0040] As the TFT, a transistor in which amorphous silicon or polysilicon (polycrystalline silicon) is used as an active layer can b e used. In the case of the active matrix method, as the construction of the driving device, a known construction such as the stagger type or the reverse stagger type can be used. In the case of a transistor wherein polysilicon is used, it is possible to form a peripheral driving circuit for driving the liquid crystal material on the substrate on which the TFTs are formed. The peripheral driving circuit can be formed in the same process as that by which the TFTs are made. This peripheral driving circuit is made up of complementary devices wherein n-channel and p-channel transistors are combined.
[0041] As the device electrodes, Cr, Al, ITO and Ta can be used. The sectional profiles of the electrodes are made smoothly sloping or curved by a method shown below. A sectional profile forming a smoothly sloping surface or a curved surface shown in this specification can be made by a dry process or a wet process. Examples of dry processes include:
[0042] (a) methods wherein anisotropic plasma etching and isotropic plasma etching are combined; and
[0043] (b) methods wherein plasma isotropic etching is carried out using a mask.
[0044] As a method of category (a) above, a mask is patterned on a n electrode and anisotropic plasma etching is carried out. The mask is then removed, and resist is coated onto parts not to be isotropically plasma etched. After that, isotropic plasma etching is carried out without a mask on parts to be given a curved sectional profile. In this way, projecting parts are shaved off and it is possible to make an electrode having a smoothly sloping curved sectional profile. After that, the resist is removed. As a method of category (b) above, it is possible to obtain a neat arcuate sectional profile by suitably setting a discharge gas voltage.
[0045] In a wet process, on the other hand, as the resist, one whose etching selection ratio is not much different from that of the electrode being etched is used. Also, a resist whose taper angle is somewhat small is used. When this is done, the mask and the electrode being etched are etched by wet etching at about the same rate. In this way, it is possible to make an electrode having a smoothly sloping curved sectional profile with rounded vertices.
[0046] The above-mentioned methods are just examples of methods for making electrodes having smoothly sloping curved sectional profiles, and the method by which an electrode having a smoothly sloping curved sectional profile of the invention is made is not limited to these methods.
[0047] If one of the electrode materials mentioned above is used, by forming an oxide film of the metal constituting the electrode material on the electrode surface by a method such as anodic oxidation after the curved sectional profile is formed as described above, it is possible to make this an interlayer insulating film. I n this way, it is possible to improve interelectrode insulation even in cases of constructions wherein adjacent electrodes or electrode patterns overlap.
[0048] Also, it is possible to use silicon oxide (SiO 2 ) or silicon nitride (SiN) as interlayer insulating films and TFT protecting layers.
[0049] For the opposing substrate, the same material as that used for the substrate on which the TFTs are formed can be used. Also, although it is not particularly necessary to form any electrodes on the opposing substrate, in some cases electrodes 414 may be formed on all or part of the opposing substrate as shown in FIG. 8A . As the electrode material in this case, besides the above-mentioned metals, a material having transparency, for example ITO or the like, can be used.
[0050] To improve contrast by blocking light from parts not contributing to display, a black matrix 415 is formed on the opposing substrate or the TFT substrate or both substrates using a metal such as Cr or a resin material in which a black pigment has been dispersed as shown in FIG. 8B . Also, in the case of color display, R (red), G (green), B (blue) or C (cyan), M (magenta), Y (yellow) color filters are formed in positions corresponding to respective pixels. As the arrangement of the colors of the color filters, a stripe arrangement or a delta arrangement or the like can be used.
[0051] After that, an orienting process is carried out on the substrate on which the driving devices are formed and on the opposing substrate. This orienting process is carried out so that the liquid crystal molecules are parallel with the substrate and oriented uniaxially. As the orienting process, rubbing treatment wherein the substrate surface or the surface of an organic resin film of nylon or polyimide or the like (orienting film) ( 411 ) formed on the substrate is rubbed in one direction is effective.
[0052] The rubbing direction differs according to the liquid crystal material ( 413 ) used, and on the TFT substrate side, in the case of a liquid crystal material whose dielectric constant anisotropy is positive, the rubbing direction is made a direction not parallel to the electric field, and preferably at 45° to the electric field. In the case of a material whose dielectric constant anisotropy is negative, the rubbing direction is made a direction not orthogonal to the electric field, and preferably 45° to the electric field. Rubbing of the opposing substrate side is carried out in a direction parallel or oppositely parallel to the rubbing direction of the TFT substrate.
[0053] The pair of substrates thus made are brought face-to-face with each other with a fixed spacing therebetween to form a liquid crystal cell. A sealing agent (not shown) as an adhesive is formed in a predetermined pattern on one of the substrates. As the sealing agent, a resin material hardened thermally or by ultraviolet rays is used. As this resin material, an epoxy or urethane acrylate material can be used. Spacers (not shown) for maintaining the spacing between the two substrates over the whole cell are distributed on the other substrate. After the sealing agent is hardened, the liquid crystal material is injected into the liquid crystal cell by vacuum injection or the like.
[0054] Examples of liquid crystal materials which can be used in this invention include nematic, cholesteric and smectic materials, but using a nematic material is particularly preferable. Also, from among nematic liquid crystals, one whose dielectric constant anisotropy is positive or one whose dielectric constant anisotropy is negative is suitably chosen according to the driving method. Also, to reduce the influence of birefringence, a liquid crystal material whose refractive index anisotropy is small is preferable.
[0055] In a liquid crystal electro-optic device of the invention, to carry out display utilizing the birefringence of the liquid crystal material, a pair of polarizing plates ( 412 ) are arranged with their optical axes intersecting orthogonally and the liquid crystal cell is sandwiched between this pair of polarizing plates. At this time, the orientation direction of the liquid crystal material is parallel with the optical axis of the analyzer, i.e. the polarizing plate nearer the light source.
[0056] In a liquid crystal electro-optic device made in this way, the orientation of the liquid crystal material is such that when there is no electric field the long axis of the liquid crystal material is uniaxially oriented in parallel with the substrate and in parallel with the rubbing direction. Then, when an electric field is impressed, the liquid crystal molecules in the vicinities of the orienting film surfaces, which are subject to a strong orientation restricting force, remain parallel with the rubbing direction while the optical axes of the liquid crystal molecules in the vicinity of the middle of the liquid crystal layer, which are only subject to a weak orientation restricting force, are changed by the electric field. When a liquid crystal material whose dielectric constant anisotropy is positive is used, the long axes of the liquid crystal molecules become oriented in parallel with the electric field direction, and when the dielectric constant anisotropy is negative the long axes of the liquid crystal molecules become oriented perpendicular to the electric field direction.
[0057] Consequently, with respect to light passing through the liquid crystal electro-optic device, because when there is no electric field the orientation of the liquid crystal material inside the cell is parallel with the optical axis of the analyzer, incident light cannot pass through the polarizer and the amount of light passing through at this time is zero. When an electric field is impressed, on the other hand, the orientation of the optical axis of the liquid crystal material changes and consequently incident light becomes elliptically polarized light and passes through the polarizer.
[0058] In the construction described above, two polarizing plates are used, but if a reflecting plate made of metal or the like is formed on one of the two substrates, it is possible to make the liquid crystal electro-optic device using only one polarizing plate, and a bright display can be realized. The metallic reflecting plate can also double as for example a pixel electrode.
[0059] When a liquid crystal electro-optic device is constructed according to this invention, compared to electrodes having rectangular or trapezoidal sectional profiles which have been used in conventional liquid crystal electro-optic devices, the electric field around the electrodes is continuous. This continuity of the electric field is clear from the state of lines of electric force around the electrodes when a voltage is impressed on the electrodes. The state of lines of electric force around electrodes will now be described in detail with reference to FIG. 2 .
[0060] First, for simplicity, a case wherein point charges q 1 , q 2 exist at points O 1 , O 2 will be considered.
[0061] Here, the straight line joining O 1 , O 2 will be taken as an x-axis and a direction perpendicular to the x-axis will be made a y-axis. An origin will be defined as the point half-way between the points O 1 , O 2 .
[0062] A line of electric force passing through any point P as shown in FIG. 2 will be considered. This is in the plane formed by the point P and the points O 1 , O 2 .
[0063] When this line of electric force is rotated about the O 1 , O 2 axis, a surface of rotation is obtained, and the electric flux passing through any cross-section of this surface of rotation should be constant.
[0064] The electric flux passing through a vertical section S passing through P will now be obtained.
[0065] If the angles made by the lines O 1 P and O 2 P and the O 1 O 2 axis are respectively written θ 1 , θ 2 , the electric flux φ 1 passing through S due to q 1 is:
[0000] φ 1 =q 1 ·2π(1−cos θ 1 )/4π
[0000] and the electric flux φ 2 passing through S due to q 2 is:
[0000] φ 2 =q 2 ·2π(1−cos θ 2 )/4π
[0000] and therefore the total electric flux φ passing through S is given by:
[0000] φ=½{( q 1 +q 2 )−( q 1 cos θ 1 +q 2 cos θ 2 )}
[0000] Therefore, on one line of electric force,
[0000] q 1 cos θ 1 +q 2 cos θ 2 =constant
[0000] If
[0000] q 1 =−q 2 ,
[0000] on the line of electric force there is the relationship:
[0000] cos θ 1 −cos θ 2 =constant
[0066] Lines of electric force ( 110 ) and equipotential surfaces ( 111 ) formed by this pair of point charges are shown in FIG. 3 .
[0067] The distribution of these lines of electric force is the same even if charges the same size as the above-mentioned point charges are distributed on a conducting surface of radius ‘a’. Also, in the region y≧0, it can be approximated to an electric field created by two semi-circular electrodes. Therefore, if the electrode sectional profiles are semi-circular, the distribution of the lines of electric force is continuous with respect to the cell thickness direction.
[0068] In the above description, an example wherein the entire sectional profile of the electrode has a circular curvature was shown, but the invention is not limited to this and the same effects can be obtained with an electrode having an elliptical curvature. Also, the sectional profile does not have to form a regular semi-circle, and the same effects can be obtained with a sectional profile forming an arc. The electrode edge section may have a curved surface of a circular arc shape or the like. An electrode having a sectional profile having a polygonal shape with gentle boundary changes may of course also be used.
[0069] Also, films formed on thin films such as electrodes having smoothly sloping curved sectioned profiles have good coverage, because of roundness of the thin films. Therefore, there is also the effect of preventing mixing in of impurities and line breakage caused by poor coverage.
[0070] The technique of this invention of making the sectional profile of an electrode curved or smoothly sloping can of course be applied not only to the above-mentioned a-Si type TFTs but also to poly-Si type TFTs.
[0071] In particular, when poly-Si is used for the active layer of a TFT, because the carrier mobility of the active layer is larger than when a-Si is used for the active layer and consequently the same characteristics as an a-Si transistor can be obtained with a smaller device region, devices can be made small and therefore a high percentage aperture can be realized. Also, in impressing a horizontal electric field, a higher response speed can be realized when poly-Si, having a large carrier mobility, is used for the TFT active layer. Furthermore, when poly-Si is used, it is possible to also form a peripheral driving circuit for driving the liquid crystal material on the substrate and this contributes to reduction of the number of steps required to manufacture the device, improvement of yield and reduction of the price of the device.
[0072] The invention has been discussed above with reference to a liquid crystal electro-optic device of a type wherein a horizontal electric field is impressed on a liquid crystal material; however, the invention is not limited to this and can also be used in a liquid crystal electro-optic device of a type wherein a vertical electric field is impressed on liquid crystal material, for example a conventional TN type or the like, whereby disturbances in the electric field at the ends can be reduced and it is possible to make an electro-optic device having good coverage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] FIG. 1 is a schematic view showing lines of electric force of when an electric field is impressed across electrodes in a conventional liquid crystal electro-optic device;
[0074] FIG. 2 is a simplified view of lines of electric force and equipotential surfaces formed by two point charges;
[0075] FIG. 3 is a view showing lines of electric force and equipotential surfaces around a pair of electrodes having a curved sectional profile;
[0076] FIG. 4 is a schematic plan view of a pixel region of a liquid crystal electro-optic device of a first preferred embodiment of the invention;
[0077] FIG. 5 is a schematic sectional view on the line A-A′ in FIG. 4 ;
[0078] FIG. 6 is a schematic plan view of a pixel region of a liquid crystal electro-optic device of a second preferred embodiment of the invention; and
[0079] FIGS. 7(A) to 7(E) are schematic sectional views on the line B-B′-B″ in FIG. 6 showing the device at different stages in the process of its manufacture. FIGS. 8A and 8B are schematic sectional views of the opposing substrate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0080] Preferred embodiments of the invention will now be described.
First Preferred Embodiment
[0081] A silicon oxide film of thickness 1000 to 3000 Å was formed as a base oxide film ( 402 ) on a Corning #7059 insulating substrate ( 401 ). As the method of forming this silicon oxide film, sputtering in an oxygen atmosphere or plasma CVD can be used. A film of Cr was then formed on this to a thickness of 1000 to 5000 Å and patterned. After that, isotropic plasma etching was carried out using resist as a mask. At this time, the discharge gas voltage was suitably set to give the electrodes curved surfaces. In this way, a gate electrode ( 403 ) and a common electrode ( 404 ) were formed.
[0082] A gate insulating film ( 405 ) consisting of silicon dioxide (SiO 2 ) was then formed so as to cover these electrodes. This film may alternatively consist of silicon nitride (SiN). An amorphous silicon film ( 406 ) was then formed on the gate insulating film above the gate electrode. Then, a source electrode ( 407 ) and a drain electrode ( 408 ) consisting of Al were formed so as to overlap with parts of the pattern of the amorphous silicon film. At this time, isotropic plasma etching was carried out using resist as a mask, and the discharge gas voltage was suitably set to give the electrodes curved surfaces. A silicon oxide insulating film ( 409 ) was then formed as a TFT protecting film. This insulating film may alternatively be an SiN film.
[0083] Also, on the opposing substrate or on the TFT substrate or o n both substrates, to improve contrast, a black matrix consisting of a metal such as Cr or a resin in which a black pigment is dispersed was formed to block light from parts not participating in display.
[0084] After that, an orienting film ( 411 ) consisting of polyimide was formed on the substrate on which the TFT was formed and on the opposing substrate. As the orienting film, polyimide was formed by a known spin coating or dipping method. The orienting film surfaces were then rubbed.
[0085] The rubbing direction differs according to the liquid crystal material used, and on the TFT substrate side, in the case of a liquid crystal material whose dielectric constant anisotropy is positive, the rubbing direction is made a direction not parallel to the electric field, and preferably at 45° to the electric field. In the case of a material whose dielectric constant anisotropy is negative, the rubbing direction is made a direction not orthogonal to the electric field, and preferably at 45° to the electric field. Rubbing of the opposing substrate side is carried out in a direction parallel or oppositely parallel to the rubbing direction of the TFT substrate.
[0086] The TFT substrate and the opposing substrate thus formed were brought face-to-face to form a liquid crystal panel. Spherical spacers of diameter 3 μm were interposed between the two substrates to obtain a uniform substrate spacing over the entire panel. The two substrates were then sealed with an epoxy adhesive to fix them together. The pattern of the sealing was made such that it surrounded the pixel region and a peripheral circuit region. After that, the pair of substrates were cut to a predetermined shape and a liquid crystal material was then injected between them.
[0087] Two polarizing plates ( 412 ) were then affixed to the outer sides of the substrates. The polarizing plates were so oriented that their optical axes intersected orthogonally and the optical axis of one of the polarizing plates was made parallel with the rubbing direction.
[0088] When the optical characteristics of this liquid crystal electro-optic device were measured, good display having less dispersion in rise characteristics than a liquid crystal display having conventional electrode shapes was obtained.
Second Preferred Embodiment
[0089] The liquid crystal electro-optic device of this preferred embodiment is a monolithic active matrix circuit wherein a peripheral driving circuit is also formed on the substrate. A process for making the device will be described using FIG. 6 and FIGS. 7(A) to 7 (E). FIG. 6 is a schematic plan view of a pixel of this preferred embodiment. FIGS. 7(A) to 7(E) are sectional views on the line B-B′-B″ in FIG. 6 , a process for manufacturing TFTs of a driving circuit being shown on the left side and a process for manufacturing a TFT of an active matrix circuit being shown on the right side. These processes are low temperature polysilicon processes.
[0090] First, a base silicon oxide film ( 402 ) was formed on a Corning #1737 first insulating substrate ( 601 ). This silicon oxide film may be formed by the same method as that shown in the first preferred embodiment.
[0091] After that, an amorphous silicon film was formed to 300 to 1500 Å, and preferably 500 to 1000 Å, by plasma CVD or LPCVD. Thermal annealing was then carried out at a temperature of over 500° C., and preferably 500 to 600° C., whereby the silicon film was crystallized or its crystallinity was raised. After this crystallization by thermal annealing, light (laser or the like) annealing may be carried out to further increase crystallinity. Also, as shown in Japanese Unexamined Patent Publications Nos. H.6-244103 and H.6-244104, at the time of crystallization by thermal annealing, an element such as nickel or the like which promotes the crystallization of silicon (a catalyst element) may be added.
[0092] The silicon film was then etched to form island-shaped active layers ( 602 ) (for a P-channel type TFT) and ( 603 ) (for an N-channel type TFT) of the TFTs of the driving circuit and an active layer ( 604 ) of the TFT of the matrix circuit (a pixel TFT). Also, a silicon oxide gate insulating film ( 605 ) of thickness 500 to 2000 Å was formed by sputtering in an oxygen atmosphere. As the method of forming the gate insulating film, plasma CVD may alternatively be used. When forming a silicon oxide film by plasma CVD, as the raw material gas, using nitrogen monoxide (N 2 O) or oxygen (O 2 ) and monosilane (SiH 4 ) was preferable.
[0093] After that, aluminum of thickness 2000 to 6000 Å was formed by sputtering over the entire surface of the substrate. Here, to prevent hillocks forming in a subsequent heating process, aluminum containing silicon or scandium or palladium or the like may be used. Then, gate electrodes ( 606 , 607 , 608 ) and a common electrode ( 609 ) were formed by isotropic plasma etching ( FIG. 7(A) ). At this time, the discharge gas voltage was suitably set to give the electrodes curved surfaces. After that, by ion doping, utilizing self-alignment with the gate electrodes ( 606 , 607 , 608 ) as masks, with phosphine (PH 3 ) as the doping gas, phosphorus was doped into all the island-shaped active layers. The dose amount was 1×10 12 to 5×10 13 atoms/cm 2 .
[0094] As a result, weak N-type regions ( 610 , 611 , 612 ) were formed. ( FIG. 7(B) ).
[0095] Next, a photoresist mask ( 613 ) covering the P-channel type active layer ( 602 ) and a photoresist mask ( 614 ) covering the active layer ( 604 ) of the pixel TFT as far as 3 μm from the ends of the gate electrode ( 608 ) in parallel with the gate electrode were formed.
[0096] Then, phosphorus was again injected by ion doping with phosphine as the doping gas. The dose amount was 1×10 14 to 5×10 15 atoms/cm 2 . As a result of this, strong N-type regions (source and drain) ( 615 , 616 ) were formed. The region ( 617 ) covered by the photoresist mask ( 614 ) on the pixel TFT remained weak N-type because no phosphorus was injected into it in this doping. ( FIG. 7(C) ).
[0097] Next, the N-channel type active layers ( 603 , 604 ) were covered with a photoresist mask ( 618 ), and boron was injected into the island-shaped region ( 602 ) by ion doping with diborane (B 2 H 6 ) as the doping gas. The dose amount was 5×10 14 to 8×10 15 atoms/cm 2 . In this doping, because the dose amount of boron is greater than the dose amount of phosphorus in FIG. 7(C) , the previously formed weak N-type region ( 610 ) inverts into a strong P-type region ( 619 ).
[0098] By the doping described above, strong N-type regions (source/drain) ( 615 , 616 ), a strong P-type region (source/drain) ( 619 ) and a weak N-type region (low concentration impurity region) ( 617 ) were formed. ( FIG. 7(D) )
[0099] After that, by carrying out thermal annealing at 450 to 850° C. for 0.5 to 3 hours, damage caused by the doping was repaired, the doped impurities were activated and the crystallinity of the silicon was restored. After that, a silicon oxide film was formed over the entire surface as an interlayer insulating film ( 620 ) to a thickness of 3000 to 6000 Å by plasma CVD. This may alternatively be a silicon nitride film or a multiple layer film comprising a silicon oxide film and a silicon nitride film. The interlayer insulating film ( 620 ) was etched by wet etching or dry etching to form contact holes above the source and drain regions.
[0100] Then, an aluminum film or a multiple layer film comprising titanium and aluminum of thickness 2000 to 6000 Å was formed by sputtering. This was then isotropically plasma etched using resist as a mask. At this time, the discharge gas voltage was suitably set to give the electrodes curved surfaces, and electrodes/interconnections ( 621 , 622 , 623 ) of the peripheral circuit and electrodes/interconnections ( 624 , 625 ) of the pixel TFT were formed.
[0101] Also, a silicon nitride film ( 626 ) of thickness 1000 to 3000 Å was formed as an interlayer film by plasma CVD. ( FIG. 7(E)
[0102] Thereafter, by the same method as in the first preferred embodiment, a liquid crystal cell was made. Here, the pattern of the seal was made such that it enclosed the pixel region and the peripheral driving circuit region. Also, after that, polarizing plates were affixed to the pair of substrates as in the first preferred embodiment to complete the liquid crystal electro-optic device.
[0103] When the optical characteristics of this liquid crystal electro-optic device were measured, good display having less dispersion in rise characteristics than a liquid crystal display having conventional electrode shapes was obtained.
[0104] With the construction of this preferred embodiment, because the driving circuit is made on the same substrate as the pixel TFT, there is the merit that the manufacturing cost is low.
[0105] As described above, with this invention it is possible to obtain with a simple manufacturing process a liquid crystal electro-optic device whose liquid crystal rise characteristics are better than those of a conventional horizontal electric field drive type liquid crystal electro-optic device. The invention also allows pixel size reduction. | In a horizontal electric field drive type liquid crystal electro-optic device, a gate electrode, a source electrode, a drain electrode, a semiconductor film and a common electrode are formed on a glass substrate and a liquid crystal material is driven by controlling the strength of an electric field substantially parallel to the glass substrate. The electrodes and the semiconductor film are made curved, for example semi-circular or semi-elliptical, in sectional profile. These curved sectional profiles can be formed by suitably selecting and combining various patterning and etching methods. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to a drill pipe for an oil or gas well and more particularly to a drill pipe having an internally coated conductive material for providing an electrical pathway for electronic data obtained down hole to be efficiently transmitted to the surface of an oil or gas well.
BACKGROUND OF THE INVENTION
[0002] Currently there exist tools in the oil and gas well industry that are specifically designed to obtain drilling and geological parameters downhole, near the drill bit. In some instances, the information obtained by these tools is stored in memory devices. In such cases, the stored information can be retrieved when the memory devices are returned to the surface of the well. This system, however, produces an undesirable lag time between the initial collection and storing of the downhole information and the retrieval of the downhole information at the surface of the well.
[0003] As an alternative, the downhole information can be transmitted to the surface of the well using pressure pulses in the drilling fluid. However, this method also produces an undesirable lag time caused by the time a pressure pulse takes to reach the surface. Accordingly, a need exists for a method and a system of transmitting data instantaneously and efficiently to the surface of a well.
SUMMARY OF THE INVENTION
[0004] In one embodiment, the present invention includes a drill pipe for an oil or gas well comprising a generally cylindrical hollow drill pipe having an inner diameter, an outer insulative coating is attached to the inner diameter of the drill pipe, a conductive coating is attached to the outer insulative coating, and an inner insulative coating is attached to the conductive coating, wherein the outer insulative coating, the conductive coating and the inner insulative coating together define an insulated electrical pathway from an upper end of the drill pipe to a lower end of the drill pipe.
[0005] Another exemplary embodiment of the present invention includes a plurality of the above described drill pipes adjacently connecting to form a drill string, wherein a connector is positioned between each adjacently connected drill pipe to electrically connect the insulated electrical pathway of each drill pipe to the insulated electrical pathway of the corresponding adjacent drill pipe to establish an insulated electrical pathway from an upper end of the drill string to a lower end of the drill string.
[0006] A further exemplary embodiment of the present invention includes the above described drill string, wherein each drill pipe inner diameter further comprises, an upper annular recess at an upper end of each drill pipe and a lower annular recess at a lower end of each drill pipe. The outer insulative coating is attached to the inner diameter, the upper annular recess and the lower annular recess of each drill pipe. An upper and a lower conductive sleeve is attached to the outer insulative coating in the upper and lower annular recess, respectively, of each drill pipe. The conductive coating is attached to the outer insulative coating and to the upper and lower conductive sleeves to establish an electrical pathway from the upper end to the lower end of each drill pipe. The inner insulative coating is attached to the conductive coating of each drill pipe, to insulate the electrical pathway of each drill pipe.
[0007] Another embodiment of the present invention includes a method of communicating to downhole oil or gas well equipment comprising: providing a generally cylindrical hollow drill pipe having an inner diameter; attaching an outer insulative coating to the inner diameter of the drill pipe; attaching a conductive coating to the outer insulative coating; and attaching an inner insulative coating to the conductive coating, such that the outer insulative coating, the conductive coating and the inner insulative coating together define an insulated electrical pathway from an upper end of the drill pipe to a lower end of the drill pipe.
[0008] Another embodiment of the present invention includes a method of communicating to downhole oil or gas well equipment comprising: providing a plurality of generally cylindrical hollow drill pipes wherein each drill pipe comprises an inner diameter; mating each drill pipe with a corresponding adjacent drill pipe to form a drill string; attaching an outer insulative coating to the inner diameter of each drill pipe; attaching a conductive coating to the outer insulative coating of each drill pipe; attaching an inner insulative coating to the conductive coating of each drill pipe, wherein for each drill pipe the outer insulative coating, the conductive coating and the inner insulative coating together define an insulated electrical pathway from an upper end of the drill pipe to a lower end of the drill pipe; and providing a connector that electrically connects the insulated electrical pathway of each drill pipe to the insulated electrical pathway of the corresponding adjacent drill pipe of each drill pipe to establish an insulated electrical pathway from an upper end of the drill string to a lower end of the drill string.
[0009] Another embodiment of the present invention includes a method of communicating to downhole oil or gas well equipment comprising: providing a plurality of the above described drill pipes, and forming in the inner diameter of each drill pipe an upper annular recess at an upper end of each drill pipe and a lower annular recess at a lower end of each drill pipe; attaching the outer insulative coating to the inner diameter, the upper annular recess and the lower annular recess of each drill pipe; attaching an upper and a lower conductive sleeve to the outer insulative coating in the upper and lower annular recess, respectively, of each drill pipe; attaching the conductive coating to the outer insulative coating and to the upper and lower conductive sleeves to establish an electrical pathway from the upper end to the lower end of each drill pipe; attaching the inner insulative coating to the conductive coating of each drill pipe, to insulate the electrical pathway of each drill pipe; and providing the connector that electrically connects the insulated electrical pathway of each drill pipe to the insulated electrical pathway of the corresponding adjacent drill pipe of each drill pipe to establish an insulated electrical pathway from an upper end of the drill string to a lower end of the drill string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0011] [0011]FIG. 1 is a cross-sectional view of a lower end of a first drill pipe and a cross-sectional view of an upper end of a second drill pipe;
[0012] [0012]FIG. 2 is a cross-sectional view of the drill pipes of FIG. 1 threadingly connected, wherein each drill pipe has a conductive coating electrically connected by a connector;
[0013] [0013]FIG. 3 is a cross-sectional view of the drill pipes of FIG. 1 threadingly connected, wherein each drill pipe has a first conductive coating and a second conductive coating, and wherein the corresponding first conductive coatings and the corresponding second conductive coatings are electrically connected by a connector;
[0014] [0014]FIG. 4A is a longitudinal cross-section of the connector of FIG. 2;
[0015] [0015]FIG. 4B is a transverse cross-section of the connector of FIG. 2, taken from line 4 B- 4 B of FIG. 4A;
[0016] [0016]FIG. 5 is a cross-sectional view of the drill pipes of FIG. 1 threadingly connected, wherein each drill pipe has a conductive coating electrically connected to an upper and a lower conductive sleeve and wherein a lower conductive sleeve of the fist drill pipe is connected to the upper conductive sleeve of the second drill pipe by the connector of FIGS. 4A and 4B; and
[0017] [0017]FIG. 6 is a cross-sectional view of the drill pipes of FIG. 1 threadingly connected, wherein each drill pipe has a first conductive coating electrically connected to a first upper and a first lower conductive sleeve and a second conductive coating electrically connected to a second upper and a second lower conductive sleeve, and wherein the first sleeve and the second sleeve are electrically connected by a connector.
DETAILED DESCRIPTION OF THE INVENTION
[0018] As shown in FIGS. 1 - 6 , the present invention is directed a drill pipe having an internally coated conductive material for forming an electrical pathway from an upper end of the drill pipe to a lower end of the drill pipe. The drill pipe of the current invention allows for communication between a well head and downhole equipment in an oil or gas well so that drilling parameters and geological parameters may be obtained downhole and transmitted to the well head for analysis.
[0019] [0019]FIG. 1 shows a lower end 10 of a first drill pipe 12 and an upper end 14 of a second drill pipe 16 . Although omitted for clarity, the first drill pipe 12 comprises an upper end that is similar to the upper end 14 of a second drill pipe 16 and the second drill pipe 16 comprises an lower end that is similar to the lower end 10 of the first drill pipe 12 . As such, reference to the lower end 10 and the upper end 14 in the following description is to be understood to apply equally to the first drill pipe 12 and to the second drill pipe 16 . In addition, the first drill pipe 12 and the second drill pipe 16 are shaped and formed similarly, such that reference to a drill pipe 22 in the following description is to be understood to apply equally to the first drill pipe 12 and to the second drill pipe 16 .
[0020] As depicted in FIG. 1, the drill pipe 22 comprises a body portion 20 that is generally cylindrical in shape and has a hollow center defined by an inner diameter 24 . The upper and lower ends 10 and 14 of the drill pipe 22 each comprise threads 18 . The threads 18 allow the upper end 10 of one drill pipe 22 to be connected to the lower end 14 of another drill pipe 22 . Drill pipes 22 that are connected in this way (as is shown in FIGS. 2 - 3 and 5 - 6 ) are typically collectively referred to as a drill string 26 . Although FIGS. 2 - 3 and 5 - 6 show the drill string 26 as having only two drill pipes 22 , the drill string may comprise any number of connected drill pipes 22 .
[0021] In an exemplary embodiment, the threads 18 are special tapered threads that, when engaged, provide a connection that is almost as strong as the body portion 20 of the drill pipe 22 and also provides a very reliable pressure seal for drilling fluids that are pumped through the drill string 26 during the drilling process.
[0022] In one embodiment, as depicted in FIG. 2, each drill pipe 22 in the drill string 26 comprises an outer insulative coating 28 attached to the inner diameter 24 of the drill pipe 22 , a conductive coating 30 attached to the outer insulative coating 28 , and a inner insulative coating 32 attached to the conductive coating 30 . As such, the outer insulative coating 28 , the conductive coating 30 and the inner insulative coating 32 of each drill pipe 22 together form an insulated electrical pathway from the upper end 14 of the drill pipe 22 to the lower end 10 of the drill pipe 22 , i.e. the outer insulative coating 28 insulates the conductive coating 30 from the body 20 of the drill pipe 22 , which is typically comprised of a metal material, and the inner insulative coating 32 insulates the conductive coating 30 from the drilling fluids.
[0023] As shown in FIGS. 2 - 3 and 5 - 6 when two drill pipes 22 are connected, a small gap 34 exists between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 . In one embodiment, a connector 36 is attached to the drill string 26 in the small gap 34 between adjacent drill pipes 22 to electrically connect the insulated electrically pathways of the adjacent drill pipes 22 . For example, in the depicted embodiment of FIG. 2, the connector 36 comprises a protruding section 38 that has a larger diameter than the inner diameter 24 of the drill pipes 22 , such that when the connector 36 is disposed between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 and the drill pipes 22 are connected, the connector 36 is trapped in the small gap 34 between the drill pipes 22 .
[0024] In one embodiment, the protruding section 38 of the connector 36 comprises a protruding shoulder 40 that mates with or abuts against a shoulder 42 in the upper end 14 of the drill pipe 22 to secure the connector to the drill string 26 when the connector 36 is disposed between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 .
[0025] To establish the electrical connection between the insulated electrically pathways of the adjacently connected drill pipes 22 , the connector 36 comprises a conducting material 44 that has a body portion 45 , an upper conducting contact 46 and a lower conducting contact 48 . When the connector 36 is disposed between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 , the upper conducting contact 46 establishes an electrical connection 50 with the conductive coating 30 in the lower end 10 of one drill pipe 22 and the lower conducting contact 48 establishes an electrical connection 52 with the conductive coating 30 in the upper end 14 of the adjacent drill pipe 22 . As such, an electrical pathway is established from the conductive coating 30 in the lower end 10 of one drill pipe 22 , to the upper conducting contact 46 , then to the connector conducting material body portion 45 , then to the lower conducting contact 48 , and then to the upper end 14 of the adjacent drill pipe 22 .
[0026] In one embodiment, the connector 36 is comprised of an insulative material, such that the electrical pathway from the upper conducting contact 46 , to the conducing material body portion 45 , to the lower conducting contact 48 , is insulated. For instance, the connector 36 may be formed in a molding process, such as injection molding, with the conducting material 44 being molded into the insulative material of the connector 36 . In one embodiment, the conducting material 44 is elastic, such that the upper conducting contact 46 and the lower conducting contact 48 compress when the electrical connections 50 and 52 are established between the adjacent drill pipes 22 .
[0027] The connector 36 may also comprise an upper annular groove 54 and a lower annular groove 56 . For instance, in the embodiment depicted in FIG. 2, the upper annular groove 54 is disposed above the upper conducting contact 46 , and hence above the electrical connection 50 , while the lower annular groove 56 is disposed below the lower conducting contact 48 , and hence below the electrical connection 52 . Disposed within each annular groove 54 and 56 is an elastomeric o-ring 58 . The o-ring 58 in the upper annular groove 54 creates a seal against the conductive coating 30 in the lower end 10 of one drill pipe 22 to prevent the drilling fluids from contaminating the electrical connections 50 and 52 from above, while the o-ring 58 in the lower annular groove 56 creates a seal against the conductive coating 30 in the upper end 14 of the adjacent drill pipe 22 to prevent the drilling fluids from contaminating the electrical connections 50 and 52 from below.
[0028] The connector 36 may comprise one conducting material 44 , or, as depicted in FIGS. 4A and 4B, the connector 36 may comprise a plurality of conducting materials 44 . For instance, in the depicted embodiment of FIGS. 4A and 4B, the connector 36 comprises six conducting materials 44 , each attached to the connector 36 and forming the electrical connections 50 and 52 as described above.
[0029] The drill string 26 may comprise a plurality of adjacently connected drill pipes 22 , wherein each adjacently connected drill pipe 22 has a the connector 36 disposed therebetween as described above, such that each connector 36 electrically connects the conductive coating 30 of one drill pipe 22 to the conductive coating 30 of its adjacent drill pipe 22 to establish an insulated electrical pathway from an upper end of the drill string 26 to a lower end of the drill string 26 .
[0030] As depicted in FIG. 3, each drill pipe 22 in the drill string 26 may comprise a second conductive coating 60 attached to the inner insulative coating 32 , and a second inner insulative coating 62 attached to the second conductive coating 60 , such that the inner insulative coating 32 , the second conductive coating 60 and the second inner insulative coating 62 together form a second insulated electrical pathway.
[0031] In such an embodiment, the connector 36 may have an inwardly stepped section 63 , containing a second conducting material 64 having a body portion 65 , an upper conducting contact 66 and a lower conducting contact 68 . The second conducting material 64 may be formed and attached to the conductor 36 as described above with respect to the conducting material 44 .
[0032] When the connector 36 is disposed between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 , the upper conducting contact 66 establishes an electrical connection 70 with the conductive coating 60 in the lower end 10 of one drill pipe 22 and the lower conducting contact 68 establishes an electrical connection 72 with the conductive coating 60 in the upper end 14 of the adjacent drill pipe 22 . As such, an electrical pathway is established from the conductive coating 60 in the lower end 10 of one drill pipe 22 , to the upper conducting contact 66 , then to the connector conducting material body portion 65 , then to the lower conducting contact 68 , and then to the upper end 14 of the adjacent drill pipe 22 . As described above and as shown in FIGS. 4A and 4B, the connector 36 may comprise one second conducting material 64 , or the connector 36 may comprise a plurality of second conducting materials 64 .
[0033] The drill string 26 may comprise a plurality of adjacently connected drill pipes 22 , wherein each adjacently connected drill pipe 22 has the connector 36 disposed therebetween as described above, such that each connector 36 electrically connects the conductive coating 60 of one drill pipe 22 to the conductive coating 60 of its adjacent drill pipe 22 to establish a second insulated electrical pathway from an upper end of the drill string 26 to a lower end of the drill string 26 . O-rings may be used, as described above, to prevent the drilling fluids from contaminating the electrical connections 70 and 72 .
[0034] Each drill pipe 22 in the drill string 26 may comprise a plurality of conductive coatings and each connector may comprise a corresponding plurality of inwardly stepped sections and conducting materials, such that the drill string 26 comprises a plurality of insulated electrical pathways from an upper end of the drill string 26 to a lower end of the drill string 26 .
[0035] In one embodiment, as depicted in FIG. 5, the lower end 10 and the upper end 14 of each drill pipe 22 in the drill string 26 comprises a lower annular recess 76 and an upper annular recess 78 . In such an embodiment, the outer insulative coating 28 is attached to the inner diameter 24 , the upper annular recess 78 and the lower annular recess 76 of each drill pipe 22 . An upper and a lower conducting sleeve 82 and 80 are attached to the outer insulative coating 28 in the upper annular recess 78 and the lower annular recess 76 , respectively. For instance, the upper and lower conducting sleeves 82 and 80 may be press fit into the upper and lower annular recesses 78 and 76 , respectively.
[0036] In this embodiment, the conductive coating 30 is attached to the outer insulative coating 28 and to the upper and lower conducting sleeves 82 and 80 to establish an electrical pathway from the upper end 14 to the lower end 10 of each drill pipe 22 . The inner insulative coating 32 is attached to the conductive coating 30 such that the conductive coating 30 is insulated.
[0037] As described above, to establish an electrical connection between the insulated electrically pathways of the adjacently connected drill pipes 22 , the connector 36 is disposed between the lower end 10 of one drill pipe 22 and the upper end 14 of the adjacent drill pipe 22 . When so positioned, the upper conducting contact 46 establishes an electrical connection 90 with the lower conducting sleeve 80 and the lower conducting contact 48 establishes an electrical connection 92 with the upper conducting sleeve 82 , such that an insulated electrical pathway is established from the conductive coating 30 in the lower end 10 of one drill pipe 22 , to the lower conducting sleeve 80 , then to the upper conducting contact 46 , then to the connector conducting material body portion 45 , then to the lower conducting contact 48 , then to the upper conducting sleeve 82 , and then to the upper end 14 of the adjacent drill pipe 22 .
[0038] The conducting sleeves 80 and 82 provide a more robust contact surface than the conductive coating. Hence the addition of the conducting sleeves 80 and 82 produces more secure electrical connection 90 and 92 with the connector 36 . O-rings may be used, as described above, to prevent the drilling fluids from contaminating the electrical connections 90 and 92 . In addition, rather than extending the outer insulative coating 28 into the upper and lower annular recesses 78 and 76 , the contact sleeves 82 and 80 may each comprise an insulative material on its outer surface.
[0039] In the embodiment depicted in FIG. 6, each drill pipe 22 in the drill string 26 comprises a second lower annular recess 86 and a second upper annular recess 88 . In this embodiment, a second lower conducting sleeve 100 and a second upper conducting sleeve 102 are attached to the second lower annular recess 86 and the second upper annular recess 88 , respectively, such as by press fitting. The second conductive coating 60 is attached to the inner insulative coating 32 and to the second upper and lower conducting sleeves 102 and 100 to establish a second electrical pathway from the upper end 14 to the lower end 10 of each drill pipe 22 . The second inner insulative coating 62 is attached to the second conductive coating 60 such that the second conductive coating 60 is insulated.
[0040] In this embodiment, the connector 36 may comprise the inwardly stepped portion 63 comprising the second conducting material 64 , such that the upper conducting contact 66 and a lower conducting contact 68 establish electrical contacts 110 and 112 , respectively, with the second lower conducting sleeve 100 and the second upper conducting sleeve 112 .
[0041] Each drill pipe 22 in the drill string 26 may comprise a plurality of conductive coatings and a plurality of corresponding upper and lower conducting sleeves; and each connector may comprise a corresponding plurality of inwardly stepped sections and conducting materials, such that the drill string 26 comprises a plurality of insulated electrical pathways from an upper end of the drill string 26 to a lower end of the drill string 26 .
[0042] In each of the embodiments described above, each coating may have a thickness in the range of approximately 0.006 inches to approximately 0.030 inches. In addition, each insulative coating may comprise a plastic polymer such as an epoxy, phenolic, teflon, or nylon. The insulative coatings may be spray applied. The conductive coatings may comprise a metal material, such as copper, aluminum, silver or gold, or a mixture of metal particles and a polymer. The conductive coatings may be applied by plating or spraying.
[0043] The preceding description has been presented with references to presently preferred embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, spirit and scope of this invention. Specifically, although drill strings having only one or two conductive pathways are described herein, it should be understood that the principles of the invention may be applied to form drill pipe and therefore drill strings having any arbitrary number of conductive pathways. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope. | A method and apparatus for communicating to downhole oil or gas well equipment are provided. The apparatus includes a drill pipe for an oil or gas well including a generally cylindrical hollow drill pipe having an inner diameter, an outer insulative coating attached to the inner diameter of the drill pipe, a conductive coating attached to the outer insulative coating, and an inner insulative coating attached to the conductive coating, wherein the outer insulative coating, the conductive coating and the inner insulative coating together define an insulated electrical pathway from an upper end of the drill pipe to a lower end of the drill pipe. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 08/195,123 filed Feb. 10, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention is in the area of telecommunication systems and pertains in particular to integration of telephone devices with computers by use of digital signal processors.
BACKGROUND OF THE INVENTION
Since the advent of personal computers, manufacturers have sought to integrate voice and data communication equipment. While early attempts at this integration met with mixed results, new products integrate all the functionality of a traditional phone with state-of-the-art, computer-supported switching systems, known in the art as private branch exchanges (PBXs).
One significant development in the art is digital transmission as the predominant method of signal transmission within a PBX. Digital techniques allow high-speed data transmission over twisted-pair wiring formerly used only for analog voice transmission. Integrated voice-data terminals, adapters within telephones, and stand-alone unit provide for sophisticated functions, such as simultaneous voice and data transmission.
A key element in development of digital PBX systems is digital signal processing (DSP) technology. A DSP unit is essentially a specialized microprocessor configured to process digitized analog signals. Unlike ordinary microprocessors, DSPs often have several paths of communication with peripherals, allowing them to do much of their system bus work without intervention by a CPU. They provide improved interrupt service and fast, real-time processing.
Telephone instruments have also evolved, becoming more intelligent and versatile. Most PBXs support industry-standard, single-line telephone sets with rotary dials or push-button, dual-tone multifrequency (DTMF) dial pads. The general trend, however, is toward proprietary electronic digital multibutton telephone sets with local microprocessors supporting enhanced features and functions. Such buttons can be programmed for different users, multiple line and trunk access from the same telephone, and alphanumeric displays that provide information about a call in progress.
PBX today often use multiple microprocessors for common control. A CPU or main microprocessor coordinates functions of other microprocessors and establishes call connections. Secondary microprocessors are located on other circuit cards and sometimes in electronic digital telephones.
Data transmissions switched through a PBX, and often through a local area network (LAN), can communicate with other data devices or computers connected to the system or via a public switched network, with a wide variety of remote data devices and computers. Modern PBXs offer features such as call forwarding, least-cost routing, station message recording, conferencing, hunting, and call restrictions.
FIGS. 1 and 2 show two PBX design options known to the inventors. FIG. 1 is an external block diagram of what might be termed a "Smart PBX" system. This design features one or more DSP cards in the PBX supporting voice mail, faxing, and other telecommunications operations. Control of the PCs is achieved through a LAN network. This Smart PBX allows efficient internal switching, it can use existing telephones, and voice mail and other functions are independent of the PCs, so they work even if a PC is not available. On the other hand, this solution requires major redesign of the PBX, with attendant development problems. There is also the expense of replacing the installed base of PBXs.
FIG. 2 is a block diagram illustrating another possible solution. In this system a DSP unit is provided in the PC as a separate module, such as an expansion card. Such a system would typically use an Integrated Services Digital Network (ISDN) interface between PBX and DSP. Specialized multimedia functions can be passed through to the telephone system.
The system of FIG. 2 can be built using existing cards, there is a relatively low investment in hardware, and there is a relatively low cost in providing the DSP by sharing the case and power with the PC. This design is not very suitable for workstations, however; the user must install the adaptor card; and the PC is not a good environment for analog circuits due to EMI and switching noise, for example.
At present there is no inexpensive and simple way to provide a state-of-the-art telecommunication system. The big deterrent to a Smart PBX system, as in FIG. 1, is the high cost of the PBX. And a telecommunications system where the DSP function is in the PC, as in FIG. 2, is not entirely suitable because PCs typically have limited space for adapters and installation of an adapter and setup is an inconvenience for the user. Moreover, PCs are an undesirable environment for analog circuits due to electromagnetic interference and switching noise.
What is needed is a solution wherein a user may conveniently add and replace functional modules as needed. This is provided in the present invention by making the telephone into the caretaker of the DSP and other functional modules. The only change required in the installed base is a new Smart Phone, which may be easily and quickly attached to both PC and PBX. Such an innovation allows for expansion into full-service, multimedia telecommunication.
SUMMARY OF THE INVENTION
In an embodiment of the present invention, a Smart Phone is provided comprising control circuitry configured for managing operations of the digital telephone; an electronic memory connected to the control circuitry; a microphone-speaker unit connected to the control circuitry for audio input and output, including a coder/decoder (CODEC) for conversions between analog and digital data forms; and a user input interface connected to the control circuitry including a keypad for dialing and function selection. A telephone line port is provided in the control circuitry for connecting the digital telephone to a telephone line, and a serial communication port in the control circuitry provides communication with external digital equipment. There is in addition at least one Digital Signal Processor (DSP) microprocessor connected to the control circuitry for processing digitized audio signals.
The Smart Phone becomes the central intelligent element in a business telephone system, providing a means for upgrading existing systems to multimedia capability at the least trouble and expense, making use of existing PBX and computer systems in LANs.
In various embodiments of the telephone and the resulting system, the Smart Phone has docking bays for engaging functional modules. In one embodiment the docking bays are configured to Personal Computer Memory Card International Association (PCMCIA) standard for compatible cards. DSP units, memory cards, and many other peripheral systems may thus be easily and inexpensively interfaced to the Smart Phone and the multimedia system.
In another embodiment, a physical window is provided in combination with a docking bay, affording access to an input area of a docked functional module, whereby a docked intelligent functional module may be employed to control the Smart Phone and the entire business telephone system through the input area of the intelligent module.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a Smart PBX system known to the inventors.
FIG. 2 is a block diagram of a telecommunication system with DSP module in the PC, also known to the inventors.
FIG. 3 is a block diagram of a Smart Phone system, according to an embodiment of the present invention.
FIG. 4 is a block diagram of the Smart Phone device in the system of FIG. 3.
FIG. 5 is a schematic diagram of a specialized interface between Smart Phone and PC, according to an embodiment of the present invention.
FIG. 6 is an isometric view of an exemplary Smart Phone according to an embodiment of the present invention, showing a user interface.
FIG. 7 is a block diagram of an application-specific integrated circuit (ASIC) for a Smart Phone, according to an embodiment of the present invention.
FIG. 8 is an approximation of pin count for a Smart Phone ASIC as shown in FIG. 7.
FIG. 9 is an isometric view of an alternative Smart Phone, showing a user interface incorporating a micro-personal digital assistant (μ-PDA), according to an embodiment of the invention.
FIG. 10 is a block diagram of a cordless Smart Phone in an alternative embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is a block diagram of a Smart Phone system 11 according to an embodiment of the present invention, having at least one Smart Phone 13 connected to a PBX 17 by preferably an ISDN (digital) line 16. This connection could alternately be an analog connection. PBX 17 is in turn connected on a LAN 18 to one or more PCs 21 and optionally one or more network servers 19. Each Smart Phone 13 is also connected by serial link 22 to a PC 21.
Smart Phone 13 comprises internal circuitry for communication with the PBX and the PC, and additionally one or more DSP functions may be hard wired into the Smart Phone circuitry or preferable reside on one or more removable, interchangeable modules.
In one embodiment, DSP units and other functional modules are implemented as PCMCIA cards. Such PCMCIA cards may be inserted into docking bays (not shown in FIG. 3) on the Smart Phone. The docking bays are configured to accept the standard physical design of PCMCIA cards, in this case preferable type II standard, including a multi-pin electrical connector. Since PCMCIA cards are designed for "hot" insertion, that is, a PCMCIA card can be slid into place while the power is on, one card slot can serve many functions within a single working session without rebooting the host PC.
Serial link 22 in one preferred embodiment is a standard RS-485 protocol link. It may be RS-232 in other embodiments. In an alternative preferred embodiment, this link may be a unique high-speed serial interface described more fully below with reference to FIG. 5.
FIG. 4 is a block diagram of Smart Phone 13 shown in FIG. 3. PBX 17 is shown connected to the Smart Phone by ISDN line 16, and PC workstation 21 is shown connected to the Smart Phone through RS-485 line 22, as seen also in FIG. 3.
PC workstation 21 in this embodiment has a Telephony Application Programming Interface (TAPI) that coordinates Windows applications running on the PC with call functions on the Smart Phone. Any number of different TAPI and other telemanagement-type programs can be added to the PC workstation.
In FIG. 4, the Smart Phone device is shown partitioned into two main components, a telephone unit 14 and a DSP module 15. The heat of telephone unit 14 is an ASIC 24, which receives and transmits over both ISDN line 16 and RS-485 line 22, oversees the conversion of incoming data into the required output, and handles communication with other elements. ASIC 24 is connected to an EEPROM 25, a coder/decoder module (CODEC) 26, a keypad controller 27 with an optional liquid crystal display (LCD) 28, and to a microcontroller 37.
EEPROM 25 holds instructions for the phone connection to PBX 17. CODEC 26 supports the phone sound system, performing digital-to-analog and analog-to-digital data conversions through non-linear compression and decompression processes.
Audio input is from a microphone 30 on the Smart Phone handset 29 or a microphone 33 for a speakerphone 32. Audio is output through an amplifier through handset speaker 31 or a main speaker 34 on the speakerphone. Optional auxiliary speakers 35 provide stereo sound, with main speaker 34 optionally serving as subwoofer.
Mask read-only memory (ROM) 36 holds code, including dual-tone, multi-frequency (DTMF) wavetables and sound system wave tables, for microcontroller 37 connected to the ASIC.
DSP module 15 in FIG. 4 comprises DSP 38, RAM 39, flash ROM 40, and an optional microprocessor 41. A variety of signal processing functions can be integrated into a Smart Phone system through the DSP. Flash ROM 40 holds DSP firmware and it can also be programmed to compensate for corrupted code in ROM by a method known to the inventors, which is the subject of a separate patent application.
RAM 39 is the DSP workspace. It also acts as a buffer, holding data from PC 21 until it can be converted by ASIC 24.
As mentioned in the FIG. 3 description above, one embodiment incorporates a PC-Smart Phone interface through an RS-485 port. Many PCs, however, do not have RS-485 ports. FIG. 5 shows a specialized interface 43, which solves this problem by providing a plug-in interface that can be easily and inexpensively installed on PCs without an RS-485 port.
The interface as shown in FIG. 5 has a data cable 22 comprising one pair of differential data lines plus ground. In another embodiment there might be two pairs of differential lines, to separately transmit and receive data, plus ground, allowing higher speed transmissions.
The specialized interface has a modified Super I/O chip 45 with plug-in connector (not shown) on the PC side. Three pins in the Super I/O chip are reserved for PC-Smart Phone communications: Tx for transmit, Rx for receive, and TxE for transmit enable. The modified Super I/O chip logic can be set for whatever communication protocols are desired. For example, in FIG. 5 four channels are assigned as follows: Ch 1, raw line data for communications such as voice and prerecorded data; Ch2, DSP channel for fax and modem communications; Ch3, microprocessor and commands for Smart Phone enhanced functions; and Ch4, sound access for sound card functions from the PC. On the Smart Phone side of the specialized interface, ASIC chip 24 mirrors the Super I/O chip interface logic as described above. An optocoupler 47 is optionally included on the Smart Phone side for enhanced noise immunity. A typical transmission protocol might send 1 bit for handshaking, 2 bits for channel assignment, and 16 bits for data.
FIG. 6 is an isometric view of an exemplary user interface for a Smart Phone 13, having docking bays 15 providing standard connectors for three PCMCIA cards 65, one of which is reserved for a DSP module as described for FIG. 4.
In an alternative embodiment the docking bays may be located elsewhere on the Smart Phone, such as on one side or the other. In yet another embodiment, the docking bay might be separate, intact unit that is mechanically and electrically attached to the base of the Smart Phone. One or more additional docking bays could feasibly be added to the Smart Phone, either as built-in or externally attached units.
In FIG. 6, Smart Phone 13 also has a handset 29 with the usual microphone and speaker (not shown) and operates also as a speakerphone with a combination mic/speaker 33 and a volume control slider 49. Smart Phone 13 has the following externally wired interfaces: handset line 51, ISDN line 16 to PBX, and RS-485 line 22 to PC.
Optional, plug-in speaker interfaces 57 are for stereo output. In a variation, one or more analog interfaces 58 and 59 might be added to expand multimedia applications. Push-button DTMF dial pad 53 and programmable function buttons 61 provide user access to make calls and select basic Smart Phone functions, such as transfer, hold, mute, redial, line selection, and speakerphone on/off. Light-emitting diodes 63 (LED) or other type of signal lights indicate which phone lines are in use and/or when the speakerphone is on. An optional LCD display 28 provides a visual interface for the user to monitor calls.
FIG. 7 is an internal block diagram of ASIC 24 of FIG. 4, with the features described relative to FIGS. 3 through 6. Internal communication is via internal bus (IBUS) 67. Use of the internal bus is controlled by a connect table 69, which is configured by an internal or external microprocessor, shown here as part of microcontroller 37. Table access register 71 provides a link for the microprocessor to perform this configuration. ASIC interface and components are described below:
ISDN "S" Interface 73.
Incoming and outgoing ISDN lines, LI and LO, link PBX 17 with the Smart Phone. An isolated power converter 75 supplies 5-volt dc power. Incoming signals pass through isolating pulse transformer 77 to ISDN receiver 81 and outgoing signals pass from ISDN transmitter 83 to isolating pulse transformer 79. An activation state controller 85 coordinates ISDN receiver and ISDN transmitter activity with the rest of ASIC 24. Receive data registers 87 and transmit data registers 89 temporarily store data for each bearer (B) channel, which can carry any kind of data (digitally encoded voice, FAX, text and numbers) and delta (D) channel, which carries call status and control signals and serves as a third data channel.
Multi-Protocol Controllers 91.
One or more multi-protocol controllers 91 provide serial data communications between PC 21 and other data terminal equipment via ISDN interface 73 and PC interface 93. The multi-protocol controllers handle asynchronous and synchronous formats, for example, high-level data link control (HDLC) and synchronous data link control (SDLC). This serial communication hardware, which appears to PC software as a standard PC serial interface register set, permits off-the-shelf communication software to run on the PC without modification.
PC Interface 93.
PC receiver 95 and PC transmitter 97 input and output data, respectively, from separate RS-485 data lines, PC serial data in (PCSDI) and PC serial data out (PCSDO). Although separate transmit and receive lines are preferred for high-speed, full-duplex communications, transmit and receive lines, in a variation, might be combined and connected to a single transceiver block in the ASIC. Such a connection would result in fewer wires in the PC interface but with somewhat increased ASIC complexity and decreased communication speed.
PC processor 99 responds to instructions from multi-protocol controllers 91 for disposition of the data and accesses address information from table access register 71 on the bus.
A phase-locked-loop (PLL) circuit with high-frequency oscillator (VCO) 100 locks on the PCSDI data stream. This recovered clock is used to clock incoming data and synchronize digital logic of the ASIC with Super I/O chip 45 in the PC, as shown in FIG. 5. Re-clocking PCSDI data in this manner permits operating the PC link at speeds greater than 50 Mbits/second. Very high-speed communication is necessary to permit real-time status reporting to Super I/O chip 45 of some of the attached devices on internal bus 67, for example, micro-protocol controllers 91 and PCMCIA interface 109 cards. Real-time status reporting is needed for software driver transparency.
On-board clock 101 runs ASIC digital logic when the PCSDI line is unavailable. Switchover between the two clock sources is done automatically by PC receiver 95.
Microprocessor Interface 103.
One or more microprocessors may interface with the ASIC. Location of the microprocessor can vary. For instance, one or more microprocessor could be outside the ASIC, on a separate chip on the circuit board or as part of a DSP module on a PCMCIA card, or a microprocessor could be implemented in the ASIC. In FIG. 7, a chip outside the ASIC contains micrcontroller 37 containing a microprocessor, RAM and ROM. Optional microprocessor 41 and flash ROM 40 outside the ASIC connect with microprocessor interface 103 as well. In one variation, a microprocessor 37 in the ASIC, performs limited DSP functions, while another microprocessor in a DSP module, optionally input through PCMCIA interface 109 (see below), might perform more complex functions. Many variations are possible due to modular design.
PCMCIA Interface 109.
An expansion bus 111 links PCMCIA connectors 113, 115, and 117 with internal PCMCIA address registers 119, control registers 121, and data registers 123. PCMCIA connector 117 is reserved for DSP module input, whereas PCMCIA connectors 113 and 115 are general-purpose expansion slots. Access to devices can be made software-transparent by including I/O and memory and address mapping logic in Super I/O chip 45 in the PC. When the Super I/O chip traps an I/O or memory access in a preprogrammed range, the Super I/O chip directs data access to the appropriate PCMCIA device plugged into one of the PCMCIA connectors 113, 115, or 117 (if DSP) of the Smart Phone.
CODEC Interface 125.
This interface connects to CODEC circuitry 26, which performs digital conversions on analog signals channeled through an analog multiplexer (MUX) 129 from phone audio system components and vice versa. The phone audio system includes a handset 29 with microphone 31 and speaker 30 and speakerphone 32 with microphone 34 and speaker 33, and optional satellite speakers/amplifiers 35. An optional analog sound line 58 allows for multimedia expansion, whereas an optional analog fax line 59 permits use of standard, standalone analog-type fax devices. Analog MUX controller 127 on the ASIC bus controls analog MUX 129 activities and provides a low-pass filter for output from speaker 33. A low-pass filter is used when the built-in speaker is employed as a woofer in conjunction with the optional satellite speakers. A speakerphone, although included as part of this embodiment, is not essential to Smart Phone operation. In a simpler variation, phone sound might consist of a single speaker-microphone pair in the handset.
LCD Display Interface 131.
This interface to an optional liquid crystal display 28 on the Smart Phone provides a means to visually monitor incoming calls.
Keypad Interface 133.
An interface with phone keypad controller 27 provides a means for the Smart Phone to respond to input from DTMF keypad 53 and to function buttons 61. When Smart Phone handset 29 is being used, a signal is sent to keypad interface 133. Keypad interface 133 also controls LED lights 63 on the Smart Phone keypad panel.
FIG. 8 is a tabulation of I/O pin count for one embodiment of the Smart Phone. The number of pins varies, of course, in different embodiments.
In summary, a Smart Phone 13 such as that described for FIGS. 3 through 8 has the following features:
Direct PC access to any Smart Phone via high-speed serial RS-485 line with optional, plug-in, specialized interface with modified Super I/O chip.
PBX with digital-type fax and modem that communicates with the Smart Phone through ISDN via a multiprotocol controller.
Modular docking bay on the Smart Phone with PCMCIA slots for DSP upgrades and multimedia expansion.
Software-transparent data communication between Smart Phone components such as multiprotocol communication controllers, PCMCIA I/O, and memory.
Synchronous data link control (SDLC) and asynchronous support.
High-quality analog sound input and mixing for speakerphone.
Standard analog phone device input ports, e.g., fax and modem.
Flash ROM reprogrammable from PC.
Phase-locked loop (PLL) support in ASIC.
A Smart Phone 13 such as that described in FIGS. 3 through 8 may be implemented with various levels of functionality tailored to the budget and needs of the purchaser. A lower-priced, basic Smart Phone model might only have a microprocessor residing inside or outside the ASIC. In addition to a fax/data ISDN line to a PBX, a PC interface and a speakerphone, basic Smart Phone functions can easily be expanded as needed with an inexpensive, low-end DSP chip, such as those currently available from Zilog and Motorola, to add features such as business audio (for tape recording), voice mail (with DTMF detection), data compression and decompression, and data encryption. The DSP can reside on a removable PCMCIA card that is plugged into a designated slot on the Smart Phone.
An upscaled Smart Phone model might add, to the above functions, capabilities for fax transmission and reception and V.32 bis data transmission mode, which will require a microprocessor and a high-quality DSP chip, such as those currently available from AT&T, ADI or TI. A top-of-the line Smart Phone product might offer, in addition to all of the above functions, multimedia I/O supported by stereo 16-bit digital/analog and analog/digital conversion.
FIG. 9 is an isometric view of a Smart Phone 137 according to an alternative embodiment wherein, in addition to the features described for FIGS. 3 through 8, a specialized portable computer unit 139, known to the inventors as a micro-personal digital assistant (μ-PDA), can be connected through a docking bay 141 with standard PCMCIA pin connectors in the Smart Phone. Such a μ-PDA 139 is shown docked in FIG. 9.
A typical μ-PDA user would be a business traveller who requires access to specific software applications such as spreadsheets, travel files with currency converters, fax programs, time zone clocks, address and telephone records, and the like.
A typical μ-PDA 139, which is about the size of a credit card, is modeled on a standard PCMCIA Type II form. It has a CPU, nonvolatile memory to store control routines for applications and data files, and a display overlaid with a touch-sensitive screen 143.
A physical window 147 in the Smart Phone housing allows touch-sensitive screen 143 to be used while the μ-PDA is docked. By so doing, a user may employ control routines stored and executable on the μ-PDA to control the phone system and all of the functions of the Smart Phone. For example, a user may access a list of business or personal contacts, select one, and a simple command will cause a call to be placed, including generating all of the dialing sequence and charge card numbers.
The embodiment of FIG. 9 is just one example of a Smart Phone configuration that can accommodate a μ-PDA.
FIG. 10 is a block diagram of a cordless Smart Phone 149 with interchangeable DSP module 151, according to an alternative embodiment of the invention. Cordless Smart Phone 149 has essentially the same features as the embodiments described above, and is capable of performing the same functions as those described for corded Smart Phone 13 in FIGS. 3 through 8. In addition, the user of a cordless Smart Phone 149 has the freedom to move about a room while using the device. In the cordless embodiment, a transceiver transmits and receives radio signals to and from a local PBX 153 through a miniature antenna inside the Smart Phone device.
Phone-PBX communications in the FIG. 10 example are through a personal communication system (PCS) with cordless telephony interface 155, such as well-known standard CT2. PBX 153 has optional fax 157 and printer 159 connections. A file server 161 is connected to PC 163 via a logical link through the PBX. For instance, a user might select a number to dial on the PC and the PBX will dial the number on the Smart Phone. One or more enhanced features on PCMCIA cards, including an optional DSP module, are plugged into PCMCIA docking bays located in the base or some other suitable location on the cordless Smart Phone unit.
As with the corded Smart Phone embodiment in FIGS. 3 through 8, one or more additional docking bays could feasibly be added to cordless Smart Phone 149, either as built-in or separate, mechanically attached units, to accommodate future PCMCIA card expansion needs. In a variation, a docking bay 141 for a μ-PDA device 139, as described for an alternative embodiment in FIG. 9, might be provided.
It will be apparent to one skilled in the art that there are a relatively large number of changes that may be made in the embodiments described without departing from the spirit and scope of the present invention. Some additions and alternatives have been mentioned above.
There are a number of equivalent ways the several features might be implemented without departing from the spirit and scope of the invention as well. There are, for example, numerous alternate configurations that would work with a Smart Phone. For example, the PBX might transmit digital and analog data. In particular, an analog line from the PBX might support older fax machines and other analog communication equipment that might be part of a user's system. Likewise, the PC might also have an analog interface so, for instance, a document scanner can read data into the PC and the data can be transmitted to the Smart Phone. In another configuration, a PBX is not even needed. Smart Phone input could instead be through standard public telephone lines, for example, ISDN lines. There are many sorts of cases and applications that might be used. Different embodiments can be rendered with different specifications. For instance, although it was originally conceived for a Smart Phone system embodiment, the specialized, plug-in RS-485 interface in FIG. 5 could become a hardware standard for PCs. There are many deviations that all fall within the spirit and scope of the invention. | A business telephone system employs digital signal processing in a digital telephone having a serial link for connection to a general-purpose computer. The Smart Phone is thus the central intelligence for the system, which may utilize a PBX connected in a LAN network to multiple computers, including file servers, and each computer may have one or more Smart Phones connected. In one embodiment, docking bays in the phone provide an ability to interchange functional modules, including DSP modules. The docking bays and functional modules may be configured to PCMCIA standards. In another embodiment, a docking bay, which may also be PCMCIA, has a physical window allowing access to an input area on a docked module, wherein the docked module is an intelligent module with a CPU, memory, and a bus structure, affording control of the smart phone and the entire system through the input interface of the docked module. | 7 |
[0001] The present invention relates to a method for producing an in particular thermally sprayed, thin-walled cylinder liner for insertion into a cylinder crankcase and to a cylinder liner produced with said method.
DESCRIPTION OF THE PRIOR ART
[0002] In engines without cylinder liners, a material must be used for the engine block that meets the primary requirements arising owing to direct contact with the friction partners of pistons and piston rings. In particular, high wear resistance and low friction are necessary. Of secondary importance are further requirements such as low weight, low material costs, low production costs and high thermal conductivity. Said requirements can be reconciled in linerless engines only with difficulty, if at all.
[0003] The use of cylinder liners in internal combustion engines makes it possible to use for the engine block a different material that meets only the critical requirements of the same. The cylinder liner however can be optimised specifically for the requirements of wear resistance and low friction. Since the proportion of material of the liner is relatively low compared to the engine block, materials of higher quality and therefore higher cost can also be used here without having too great a negative effect on total costs.
[0004] Methods for producing lightweight metal cylinder liners for thermal joining in cylinder crankcases consisting of iron or lightweight metal are known from the prior art (see for instance the brochure “Overhauling aluminium engines” from the company MSI Motor Service International GmbH, Issue 03/99). Such liners are produced e.g. by a process of spray compaction with subsequent machining. These liners, marketed under the brand name Alusil®, have however the disadvantage of a modest wear resistance on the cylinder running surface. Furthermore, a complex process of exposing silicon crystals is in this case necessary during final treatment of the cylinder running faces.
[0005] Aluminium-silicon cylinder liners marketed under the brand name Silitec® or cylinder running faces consisting of block alloys (Alusil®, Lokasil®) have high thermal conductivity. The wear resistance of the respective cylinder running faces is determined by the silicon particles present that project outwards after honing. With cast materials, a silicon content of no more than approximately 20% can be achieved by the process. Higher silicon contents can be achieved with spray-compacted materials, but this results in increasing component costs for process engineering reasons. Owing to the high mechanical loading in new engines, for example petrol engines having direct fuel injection or modern diesel engines, the mechanical strength values with conventional aluminium-silicon alloys are however marginal.
[0006] Furthermore, slip-fit liners consisting of grey cast iron are known as cylinder liners. The liners are manufactured mechanically from spun grey cast iron tubes. To achieve the required surface roughness and cylinder shape, the outer diameter is ground. To insert grey cast iron liners, it is necessary for the liner to have a larger diameter at room temperature than the bore of the cylinder crankcase. Then the diameter of at least one of the two bodies to be joined must be changed by thermal expansion in such a manner that the liner can be inserted securely into the cylinder crankcase. This generally takes place by heating the cylinder crankcase, since cooling of the liner alone is not sufficient owing to the inadequate thermal expansion coefficient of grey cast iron. This makes the insertion of grey cast iron liners complex and expensive.
[0007] Layers sprayed onto the cylinder running face are another known form of cylinder protection. DE 197 33 205 A1 discloses a coating of a cylinder running face of a piston engine based on iron, aluminium or magnesium, containing a hypereutectic aluminium-silicon alloy and/or an aluminium-silicon composite material, and a method for producing said coating. The coating is in this case applied directly to the inner wall of the cylinder bore in the engine block.
[0008] To this end, either an internal burner, which is attached to a rotating assembly and rotates about the centre axis of the cylinder bore, is introduced into the cylinder bore and moved axially, or the internal burner is introduced into the cylinder bore of the rotating crankcase and moved axially along the centre axis of the cylinder bore in order to spray the coating onto the cylinder wall. The cylinder surface must generally be prepared in a complex manner before coating, for example by roughening by means of high-pressure water jets or by introducing a defined profile with undercut sections by means of a turning process.
[0009] The production of the coating directly on the wall of the cylinder bore also requires either a complicated assembly having an internal burner, which itself rotates inside the bore in order to be able to apply the coating evenly, or it is necessary for the entire engine block with the cylinder bore to be rotated about a non-rotating internal burner. Both methods are complex and cost-intensive. Owing to the size of the coating assembly, only cylinder bores having a bore diameter of more than 80 mm can be coated reliably.
[0010] It is therefore the object of the present invention to provide a simpler method for producing an improved cylinder liner and a corresponding liner, with which the disadvantages listed above can be eliminated or at least reduced.
SUMMARY OF THE INVENTION
[0011] According to a first aspect of the invention, a method is provided for producing a cylinder liner, comprising: thermal spraying of a first material onto a mould body to form a wear- and corrosion-resistant first layer, the first sprayed material comprising at least 67% iron, Fe; no more than 3% carbon, C; between 0 and no more than 20% chromium, Cr; between 0 and no more than 10% nickel, Ni; and thermal spraying of a second material to form a second, outer layer on the first, inner layer, the second sprayed material comprising aluminium, an aluminium alloy or a multi-element material consisting of lightweight material and iron.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 shows a section of a cylinder liner according to one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The invention proposes a method for producing a cylinder liner by means of thermal spraying.
[0014] In the method according to the invention, a first material is provided to form a first, inner layer on a mould body, said material containing at least 67% Fe and no more than 3.0% C as essential elements. To improve the corrosion resistance of the first layer, up to 20% Cr and/or 10% nickel can be added to the alloy.
[0015] In a preferred embodiment, the first material contains at least 70% Fe, more preferably at least 80% Fe, even more preferably at least 90% Fe and further preferably at least 95% Fe. The carbon content should not be more than 3%, as otherwise the material is too hard and brittle and therefore difficult to work. There is a risk of layers flaking off or cracks forming. The carbon content is therefore preferably ≦2% and even more preferably ≦1%.
[0016] The material can also contain between 0 and no more than 30 % Cr and between 0 and no more than 10% Ni. These components normally serve to increase corrosion resistance but also mean higher material costs and higher manufacturing outlay for the post-machining of the running face e.g. by honing. However, it has been found that the first, inner layer of the cylinder liner produced according to the invention in this step exhibits no susceptibility to corrosion in current engine designs, even without the presence of the elements mentioned, so the material used only has to contain said elements in small amounts, if at all. Preferred ranges for said components are between 0 and 19%, more preferably between 0 and 5%, more preferably between 0 and 3%, even more preferably between 0 and 1% for Cr. Similarly, a range for Ni is preferably between 0 and 5%, more preferably between 0 and 3%, yet more preferably between 0 and 2%, even more preferably between 0 and 1%.
[0017] The material is present as solid or flux-cored wire before the coating process and is melted and applied to a rotating mould body by means of known wire-coating methods such as arc wire spraying or wire flame spraying or the like.
[0018] The material is applied to the outer face of the rotating mould body, which has a substantially cylindrical shape. With the proviso of the cylindrical shape, the further shape of the mould body, in particular the dimensions thereof, is only limited by the intended field of use. For instance, in particular the outer diameter of the mould body can be, in view of the different diameters of cylinder liners, within the range from approx. 20 mm to approx. 1000 mm, preferably between 60 mm and approx. 100 mm for the automotive field. The length of the mould body is upwardly unlimited, since a desired length of the cylinder liner can be produced by post-machining an initially obtained workpiece. The mould body only has to have the length of the desired cylinder liner and can therefore be from approx. 50 mm to approx. 5 m. For the production of cylinder liners for the automotive sector, the length of the mould body is from approx. 100 mm to approx. 400 mm, it being possible to produce 2 to 4 cylinder liners at once on one mould body.
[0019] The mould body can consist of any material that remains dimensionally stable under the applied process conditions, i.e. can withstand in particular the temperatures of the melted and applied material, for example temperatures of approx. 1400° C. for iron, and allows the first, inner layer to be detached after application. The outer face of the mould body can optionally be provided with a thin, inorganic separation layer.
[0020] In a further step, a second, outer layer is applied to the first, inner layer, which can still be on the mould body or can have been removed from the mould body beforehand, i.e. is present as a free body in the form of a sleeve. The outer diameter of the first layer is “as sprayed”, i.e. it is not machined before the second layer is applied.
[0021] The same thermal spraying method as in the first step or a different one can be used. This is selected depending on the material used and the other conditions prevailing during production.
[0022] The material applied in the second step is generally selected such that it has a thermal expansion coefficient that is as similar as possible to that of the cylinder crankcase. The material can for example be selected from aluminium or an aluminium alloy consisting of Al and Si or Al and Mn or Al and Mg or a multi-element layer consisting of an aluminium alloy and iron. This is particularly advantageous since such a combination is distributed in points over the surface during application, which provides lower surface roughness for a subsequent machining step, in particular grinding.
[0023] Layers having a porosity of <8% by volume, preferably <5% by volume, more preferably <3% by volume, and pore sizes of <15 μm, preferably <10 μm, more preferably <8 μm, can be achieved with the method according to the invention. This is much improved compared to inner coatings of the prior art, which provide a porosity of approximately >10% by volume and a pore size of approximately 20 μm.
[0024] If the second application step has been carried out on the mould body, the product so obtained can be left on the mould body or removed from the mould body before further processing steps.
[0025] According to a preferred embodiment of the method, the outer lateral surface, which is still rough after spraying, of the outer, second layer is machined by grinding or turning, as a result of which the desired outer diameter, the necessary cylindricity and the required surface roughness of the cylinder liner produced with the method according to the invention are achieved. The roughness depth (Rz) to be produced of the outer lateral surface is normally within the range of at most approximately 50 μm, preferably at most approximately 30 μm, more preferably at most 10 μm. The desired roughness depth can be achieved in each case by a suitable machining method such as fine-turning. If greater demands are made of the cylindricity, the outer lateral surface can also be ground.
[0026] The desired total length of the cylinder liner to be inserted into an engine can be produced by turning, milling or laser-cutting out of the cylinder liner produced.
[0027] According to one embodiment, the first, inner layer of the cylinder liner produced with the method according to the invention has a layer thickness of approximately 0.2 to 2.0 mm, preferably of 0.2 to 1 mm, more preferably of 0.2 to 0.8 mm. The second, outer layer of the cylinder liner produced with the method according to the invention has, after application, a layer thickness of approximately 0.2 to 2 mm, preferably of 0.3 to 2.0 mm, yet more preferably of 0.3 to 1.0 mm. The layer thickness of the outer layer is generally reduced by the machining steps of turning and/or grinding by approximately 0.1 mm to approximately 0.5 mm.
[0028] Consequently, the cylinder liner produced with the method according to the invention has a total wall thickness of 0.4 to no more than approximately 10 mm, preferably from approximately 1 mm to 2 or 3 mm.
[0029] The product obtained in this manner, if it is still on the mould body, is then removed from the latter for optional further treatment.
[0030] According to one embodiment, the method further comprises providing the cylinder liner produced with the method according to the invention with a bevel on the outer diameter and/or inner diameter at one or both axial ends. This not only makes it easier to join the liner, but also improves positioning of a honing tool for internal machining.
[0031] According to a further embodiment, the method further comprises providing cut-outs and/or overflow channels on the liner jacket, which can be produced by machining with geometrically defined cutting edges or thermal laser-cutting.
[0032] The cylinder liner produced with the method according to the invention can optionally be provided with pulsation bores or a collar at one end. The pulsation bores can be produced either by milling or by cutting with a laser; the collar can be produced for example by turning.
[0033] According to one embodiment, the method further comprises honing the inside of the formed cylinder liner after joining in the engine block, as a result of which the thickness of the first, inner layer can be reduced to as low as 0.05 mm in order to achieve better thermal conductivity.
[0034] According to a further aspect of the invention, a cylinder liner that has been produced by the above-described method is provided.
[0035] The cylinder liner produced with the method according to the invention is inserted into a cylinder bore of an engine after it has been completed and machined. This can take place in a conventional manner for example in the automotive field, by heating the engine block (aluminium) to a temperature of approx. 250° C. and introducing the liner into the cylinder bores. Owing to its intrinsic properties, however, the liner according to the invention can also be inserted into an engine block that has not been heated, by cooling the liner itself beforehand, for example to temperatures of approximately −20° C., or −30° C. or −40° C. as far as −78.5 ° C. (solid carbon dioxide) or preferably in liquid nitrogen to temperatures of approximately −20° C. etc. as far as −196° C. and then transferring it into the cylinder bore. This is not possible with a grey cast iron liner, since its expansion coefficient is too low. The liner according to the invention thereby makes handling easier and reduces the effort and cost of inserting the liner.
[0036] There are also advantages to a mechanical installation (“loose fit”) of the cylinder liner according to the invention, since the aluminium-containing outer layer expands during operation and ensures better contact with the cylinder bore wall, with associated improved dissipation of heat. The liner is fixed axially in the cylinder bore at room temperature by means of the collar.
EXAMPLE
[0037] Arc wire spraying was used to spray a 0.8 mm-thick first layer from a steel wire (99% Fe, 0.8% C, remainder impurities such as Mn, Cr, Ni) onto a metallic cylindrical mould body (diameter 80 mm, length 1000 mm). The 3.2 mm-thick solid wires were melted in the coating assembly at a feed rate of 1 m/min, a voltage of 36 V and a current of 800 A and sprayed onto the mould body, which was rotating at 150 rpm. The coating distance was 150 mm; the layer thickness of 0.8 mm was applied in 6 coating paths.
[0038] The first layer was removed from the mould body, clamped between 2 conical holders and provided with a 1.0 mm-thick AlSil2 layer likewise by means of arc wire spraying in a second coating installation. The 3.2 mm solid wires were guided into the coating assembly at a feed rate of 1.2 m/min and melted at 30 V and 650 A. The 1.0 mm-thick layer is applied in 4 coating paths at a rotation speed of 150 rpm.
[0039] The layer structure of both layers was analysed by means of metallographic experiments; the hardness of the St0.8 layer was 400 HV1, the AlSi12 layer 100 HV1. In both layers the porosity was <3%, the maximum pore size was 10 μm.
[0040] The finished sprayed, cylindrical component having an inner diameter of 80 mm, a total length of 180 mm and a wall thickness of 1.8 mm was removed from the coating installation, clamped into a lathe and turned cylindrically on the outer jacket. The surface roughness was Ra <6 μm, the liner was turned to an outer diameter of 83.6 mm.
[0041] Finally, the cylinder liner was cut to 142 mm and provided with a 30° bevel inside and outside at both ends by turning. | The invention relates to a method for producing a thermally sprayed, thin-walled cylinder liner for insertion into a cylinder crankcase and to a cylinder liner produced with said method. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/952,349, pending and allowed, filed Sep. 27, 2004, the entire disclosure of which is hereby incorporated by reference.
BACKGROUND
[0002] The present invention relates to a therapeutic pressure-relieving device and method for preventing and treating decubitus ulcers on a portion of a patient's body.
[0003] Decubitus ulcers (commonly referred to as “bedsores”) may form on parts or portions of a patient's body when in contact for a prolonged period of time with an object such as, for example, a bed, a wheelchair, or other type of furniture. The pressure exerted on the skin covering or surrounding the bony prominences on the portions of the patient's body that are in contact with a surface on the furniture may result in the skin becoming inflamed, and may obstruct or restrict the blood flow to the skin and/or the underlying tissue, causing the skin and underlying tissue to become ischemic, eventually resulting in the formation of decubitus ulcers. Decubitus ulcers can form in any area of tissue covering a bony prominence that is in contact with the surface of the bed or sofa or other furniture upon which the patient is resting, e.g., parts of the spine, heels, elbows, and shoulders, shoulder blades, as well as the sacral, trochanteric and ischial areas in the coccyx, hips and buttocks.
[0004] Specifically, although arterial inflow can continue and withstand pressure upwards of 170-mm Hg or greater, venous return or blood flow from a region is restricted or obstructed with pressures as low as 32-mm Hg on the skin and underlying tissue. The restriction or obstruction of the venous return of blood from the skin and underlying tissue may lead to the buildup of toxins and waste products that may lead to the formation of decubitus ulcers. Initially, pressure on the skin and tissue may lead to pink coloration and/or mild inflammation, which may disappear within a few hours of relieving pressure on the area. If pressure is not relieved, superficial lesions may form on the skin, then turning into ulcers which continue growing deeper until extending through the bone to internal organs, eventually becoming fatal to the patient.
[0005] A traditional means for preventing the formation of decubitus ulcers is to physically turn the patient from side to side at short intervals of time, thus alleviating the amount of time a specific body part is subjected to straining pressures. However, this method of prevention often proves ineffective since the turning of the patient only relieves pressure from certain regions of the body. Moreover, a patient will many times return to a default position even after having been rotated. In addition, since nurses or other aids must be present to physically rotate the patient, this method is laborious, time-consuming and costly.
[0006] An alternative method for preventing the formation of decubitus ulcers is the use of air mattresses. Since air mattresses reduce the solidity of the contact surface, the mattresses relieve some of the pressure on the patient's body. However, these devices can be costly and not readily available to all patients. Furthermore, the mattresses are not easily portable in case the patient is moved to another unit or bed.
SUMMARY
[0007] This invention relates to a therapeutic device and method for treating and preventing decubitus ulcers on parts or portions of a patient's body by alleviating pressure on the tissue covering and immediately surrounding the bony prominences in the body portion and by alleviating pressure on the blood vessels in the angiosomes in the body portion to allow blood flow to continue throughout the body portion, including venous return, as well as arterial inflow. The device may be configured to act upon a particular body portion. The device may include inflatable channels or pockets positioned within the device based on the distribution of one or more angiosomes in the body portion, and pressure relievers to protect the tissue covering and immediately surrounding the bony prominences in the body portion. The channels may be sequentially or periodically inflated and deflated to alleviate pressure on the body portion while allowing blood flow throughout the angiosomes.
[0008] In an example embodiment, the device may include a portable, washable, removable, durable garment that provides pressure relief from sacral, trochanteric and ischial pressure sores or decubitus ulcers. The device may use sequential air channel technology to relieve pressure and allow blood flow to and from the sacral, trochanteric and ischial regions of the coccyx, hips and buttocks based on the angiosome distribution or location of angiosomes in the coccyx, hips and buttocks.
[0009] The garment may include rib-shaped or rib-patterned inflatable cushions, pockets or channels radially oriented around a position of an angiosome in each area. The channels are sequentially inflated and deflated to vary and relieve pressure around a center of the angiosome and maximize blood flow around the angiosomes. Air, water or other fluids may be pumped into the channels and removed from the channels with a bedside pump or motor attached to ports that are connected to the channels in the garment. The garment may be made with plastic or another material that may be washable and collapsible for storage purposes. The garment may also be made with a breathable fabric. For example, an inner liner made out of cotton can be provided to line the interior of the garment. The inner liner may be washable and replaceable or disposable. The garment may also have one or more ports to releasably connect the pump or motor to the garment.
[0010] The pump or motor can inflate and/or deflate the channels in the garment through the ports on the garment. For example, the garment may have two ports, with each half of the channels in the garment being inflated and deflated by the pump through each of the ports. Specifically, one set of channels may be deflated through one port, while the channels in between the deflated channels are being inflated through the other port.
[0011] In an example embodiment, an apparatus includes a portable garment configured to be placed on a portion of a body to provide a varying pressure on the body portion. The provided pressure varying within a range sufficient for at least one of treating and preventing a decubitus ulcer in the body portion.
[0012] In an example embodiment, an apparatus includes a mechanism configured to alleviate pressure on a portion of a body. The mechanism provides a varying pressure on the body portion. The mechanism may include channels or pockets that are inflatable with a fluid (e.g., air or water), or with a gel-like substance (e.g., silicon or another pliable material or substance). The pressure provided by the sequential or periodic inflation and deflation of the channels or pockets may vary continuously, e.g., by fluctuating through a range of pressures, or it may vary periodically, providing different levels of pressure at different time periods. The mechanism is positioned based on, inter alia, the location or distribution of one or more angiosomes in the body portion.
[0013] In an example embodiment, an apparatus comprises a device including a plurality of inflatable channels configured to be periodically or sequentially inflated and deflated to provide a varying pressure on a portion of a body of a patient that varies within a range sufficient for at least one of treating and preventing a decubitus ulcer.
[0014] In an example embodiment, a garment for treating and preventing decubitus ulcers around one or more of the coccygeal, hip and buttocks areas of a patient's body includes one or more cushions in the garment, and one or more adjustable bands removably attaching the garment to the body. The cushions are positioned radially away from one or more of the sacrum, ischial and trochanter areas. The cushions are positioned in the garment as a function of the location or distribution of the angiosomes in one or more of the sacrum, ischial and trochanter areas.
[0015] In an example embodiment, an apparatus for treating and preventing decubitus ulcers around at least one of a coccygeal, buttocks and hip areas of a body includes a garment and a pump releasably connectable to the garment. The garment includes a plurality of inflatable channels and a plurality of pressure relievers. The channels are configured to be alternately inflated and deflated in order to provide a variety of pressures on a body portion in or around the coccygeal, buttocks and hip areas of the body. The channels and the pressure relievers are positioned in the garment based on the locations of angiosomes or angiosome distribution in one or more of the sacrum, ischial and trochanter regions in the coccygeal, buttocks and hip areas. The pump is configured to pump and remove air from the inflatable channels in the garment.
[0016] In an example embodiment, a method for treating and preventing decubitus ulcers on a portion of a body includes the step of sequentially or periodically inflating and deflating channels in a garment worn on the body portion. The maximum pressure provided by the channels in the garment on the body portion is sufficient to treat and/or prevent decubitus ulcers treating or preventing a decubitus ulcer on the body portion.
[0017] In an example embodiment, a method for treating and preventing decubitus ulcers on a portion of the body includes the step of sequentially or periodically inflating and deflating air channels in a garment worn on the body portion. The channels are positioned in the garment as a function of the location of angiosomes in the body portion.
[0018] In accordance with one or more further embodiments, methods and apparatus provide for: a garment sized and shaped to be worn by a patient; a first plurality of fluid channels and a second plurality of fluid channels coupled to the garment and disposed adjacent to one another, at least some of the first plurality of fluid channels being independently inflatable and deflatable as compared with at least some of the second plurality of fluid channels; and a fluid control mechanism coupled to the first and second plurality of fluid channels and operating to repeatably and sequentially inflate and deflate the independently inflatable and deflatable fluid channels from among the first and second plurality of fluid channels such that there is less than a predetermined level of pressure exerted on the patient's tissue under one or more of the deflated channels.
[0019] The predetermined level of pressure may be about 32 mm Hg.
[0020] The fluid control mechanism may operate to sequentially: inflate the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels while deflating the independently inflatable and deflatable fluid channels from among the second plurality of fluid channels; and deflate the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels while inflating the independently inflatable and deflatable fluid channels from among the second plurality of fluid channels.
[0021] According to one or more aspects, such inflation/deflation is carried out such that there is less than about 32 mm Hg pressure exerted on the patient's tissue under one or more of the deflated channels. According to one or more additional or alternative aspects, such inflation/deflation is carried out to provide a rocking motion for moving the patient from one position to another.
[0022] At least one of the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels may extend in a longitudinal direction; and at least two of the independently inflatable and deflatable fluid channels from among the second plurality of fluid channels extend along either side of the at least one of the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels. In such case, the fluid control mechanism may operate to sequentially and repeatably: inflate and deflate the at least one of the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels; and inflate and deflate the at least two of the independently inflatable and deflatable fluid channels from among the second plurality of fluid channels, such that there is less than about 32 mm Hg pressure exerted on the patient's tissue under the at least one of the independently inflatable and deflatable fluid channels from among the first plurality of fluid channels, while in a deflated state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 illustrates a bone structure of a lower portion of a human body.
[0024] FIG. 2 illustrates angiosome distribution and location, and locations of blood vessels and tissues surrounding bony prominences in the lower portion of a standing human body.
[0025] FIG. 3 illustrates angiosome distribution and location, and locations of blood vessels and tissues surround bony prominences in the lower portion of a seated human body.
[0026] FIG. 4 illustrates a perspective frontal view of an embodiment of a device for preventing and treating decubitus ulcers according to the present invention.
[0027] FIG. 5 illustrates a perspective rear view of the embodiment of the device for preventing and treating decubitus ulcers of FIG. 4 .
[0028] FIG. 6 illustrates a perspective rear view of a person in a standing position wearing the embodiment of the device for preventing and treating decubitus ulcers of FIG. 4 .
[0029] FIG. 7 illustrates a perspective frontal view of a person in a seated position wearing the embodiment of the device for preventing and treating decubitus ulcers of FIG. 4 .
[0030] FIG. 8 illustrates a partial view of a portion of an embodiment of a device for preventing and treating decubitus ulcers and a partial view of the underlying blood vessels and angiosomes, according to the present invention.
[0031] FIG. 9 illustrates a partial view of a portion of an embodiment of a device for preventing and treating decubitus ulcers and a partial view of the underlying blood vessels and angiosomes, according to the present invention.
[0032] FIG. 10 illustrates a frontal perspective view of an embodiment of a device for preventing and treating decubitus ulcers according to the present invention.
[0033] FIG. 11 illustrates a rear perspective view of an embodiment of a device for preventing and treating decubitus ulcers according to the present invention.
DETAILED DESCRIPTION
[0034] The present invention relates to a device and method for preventing and treating decubitus ulcers. FIGS. 1 through 3 illustrate the underlying anatomy and conditions that lead to the formation of decubitus ulcers. FIGS. 4 through 7 illustrate various aspects of the device and method according to the present invention.
[0035] As described above, a patient who is confined to a bed, a wheelchair or other types of furniture, and cannot move or be moved for prolonged periods of time, may be prone to decubitus ulcers (also referred to as bed sores or pressure sores) in the parts of their bodies having bony prominences that are subject to constant pressure when the parts of their bodies are resting or being constrained against a surface of the furniture. FIGS. 1 through 3 illustrates a basic bone structure, highlighting the bony prominences in the middle portion 5 of a person's body 1 over which pressure sores may form in tissue 3 , 7 and 11 after a period of continuous and static pressure to the overlying tissue, when a patient is left or restrained to lie or sit in a bed or in a chair for prolonged periods of time without movement. Ischial decubitus ulcers or pressure sores may form in the tissue 3 covering the ischium 4 in the buttocks 2 . Trochanteric decubitus ulcers or pressure sores may form in the tissue 7 covering the trochanters 6 (the broad flat bony prominence at the top of the femur 9 ) in the hips 8 . Sacral decubitus ulcers or pressure sores may form in the tissue 11 covering the sacrum or sacral 12 in the area of the coccyx 10 .
[0036] Decubitus ulcers 3 , 7 and 11 , may be prevented and/or treated with a device 20 that alleviates pressure on the tissue 3 , 7 and 11 that is on and surrounds the bony prominences 4 , 6 and 10 in a portion 5 of the body 1 , while allowing blood to flow through the angiosomes 18 and blood vessels 5 in the portion 5 of the body 1 , while the patient is resting or is confined or constrained in a particular position in or on a piece of furniture 13 .
[0037] There are angiosomes 18 distributed throughout the middle portion 5 of the body 1 , and through other parts or portions of the human body 1 . An angiosome 18 is a three dimensional block of tissue supplied by a single source artery. The distribution of angiosomes 18 refers to a mapping of blood vessels 19 in a block of tissue, or the tree-line pattern or arborization of blood vessels in a certain area, e.g., in the body portion 5 , or for the tissue 3 , 7 and 11 on and surrounding the ischial or ischium 4 , trochanteric 6 , and sacral or sacrum 12 . If external pressure cuts off the blood flow through one or more blood vessels 19 (e.g., venous return), then there may be a lack of nutrients and/or build up of toxins or waste product in the 3 dimensional block of tissue being serviced by those blood vessels 19 in a particular angiosome 18 , which may lead to the formation of decubitus ulcers in the tissue. Thus, if any device that purports to relieve pressure on a part or portion 5 of the body 1 cuts off blood flow in an angiosome 18 , the device may still affect the viability of the tissue being supplied by the blood vessels 19 in the angiosome 18 .
[0038] Thus, a device 20 that alleviates pressure on areas of tissue 3 , 7 and 11 while taking into account the location or distribution of angiosomes 18 and blood vessels 19 in a portion of a body 1 , will be able to alleviate pressure, while allowing for blood flow to continue in the portion 5 of the body 1 . Since the mapping of blood vessels 19 or distribution of angiosomes 18 tends to be similar from person to person, it is possible to standardize a design of a device 20 based on the location or distribution of angiosomes 18 and blood vessels 19 in a portion 5 of the body 1 , and use the device 20 on more than one person.
[0039] The device 20 illustrated in FIGS. 4 through 9 is configured to alleviate pressure on a middle portion 5 of the body 1 including the buttocks 2 , hips 8 and coccyx 10 . The device 20 includes a garment 25 and a pump 50 releasably attached or coupled or connected thereto to pump air, water or other fluids or gel-like substances and/or remove such fluids or substances from the garment 25 when the pump 50 is activated or actuated. The garment 25 is portable and configured to fit around the waist 15 , and may be worn as a pair of shorts 26 on the body 1 , alleviating pressure on and around the trochanteric bony prominences 6 in the hips 8 , the ischial bony prominences 4 in the buttocks 2 , and the sacral bony prominences 12 in the coccyx 10 , and allowing blood flow based on the distribution of angiosomes 18 and the blood vessels 19 in the angiosomes 18 in the body portion 5 .
[0040] The garment 25 provides pressure varying in a range sufficient for treating and/or preventing decubitus ulcers in the body portion 5 . Unlike products that provide higher pressures that periodically cut off blood flow to simulate the pumping action of arterial inflow to prevent and/or treat deep vein thrombosis, the maximum pressure provided by the device 20 on the body portion 5 is set below the pressure for preventing and/or treating deep vein thrombosis.
[0041] The garment 25 includes sequential air technology to provide varying pressure on the body portion 5 , based on the location or distribution of angiosomes 18 in the body portion 5 to allow for maximal blood flow throughout the angiosomes 18 in the body portion 5 , including through the blood vessels 19 therein. The sequential air technology includes sequentially or periodically inflating and deflating channels 30 in garment 25 . The channels 30 may be integrated or intertwined in a middle layer 22 or an outer layer 21 in the garment 25 , and channels 30 may also refer to or include pockets or cushions.
[0042] The channels 30 are inflatable with a fluid, e.g., air or water, or with a gel-like substance, e.g., a silicon-based gel. The channels 30 are positioned in the garment 25 based on the location or distribution of angiosomes 18 in the body portion 5 , and the blood vessels 19 in the body portion 5 . The channels 30 are configured to be sequentially or periodically inflated and deflated. The channels 30 may provide a fluctuating pressure by continuously inflating or deflating, or the channels may provide an otherwise varying pressure by remaining inflated and then deflated for certain periods of time, e.g., 5 minutes in each phase. The pressure applied by the inflated channels 30 on the body portion 5 and/or the pressure on the parts of the body portion 5 under the deflated channels 30 may be configured or set not to exceed the pressure that stops blood flow in the blood vessels, e.g., 32 mm Hg. The time periods and patterns of inflation and/or deflation of channels 30 may be configured to minimize the obstruction or reduction of blood flow in the blood vessels 19 , and blood supply in the angiosomes 18 in the body portion 5 .
[0043] Some of the channels 38 may be rib-shaped, parallel to one another, and arranged in a rib-like pattern, as illustrated in FIG. 5 . Additionally, at least some of the channels 30 may be configured to be offset from the locations of angiosomes 18 or blood vessels 19 when the garment 25 is on the body portion 5 . If the channels 30 were positioned in the garment 25 to cross blood vessels 19 , then inflation of the channels 30 may obstruct or restrict blood flow through the blood vessels 19 . In order to allow or promote maximal blood flow through the blood vessels 19 and angiosomes 18 , some of the channels 30 may be positioned or configured to run adjacent to or parallel to blood vessels 19 in the angiosomes 18 , as illustrated in FIGS. 8 and 9 . The parallel placement of channels 30 helps to minimize any interruption or disturbance to the blood flow in the body portion 5 , when the channels 30 are being inflated and/or deflated.
[0044] Some or all of the channels 30 may be spaced apart from one another, as illustrated in FIG. 9 . Some or all of the channels 30 may be interwoven or intertwined, as illustrated in FIG. 8 . Even if the channels are interwoven or intertwined, as illustrated in FIG. 8 , there is no or little pressure (e.g., less than 32 mm Hg) on the blood vessels 19 under the deflated channels 36 , in part due to the support provided by inflated channels 37 , to allow blood flow, including venous return as well as arterial inflow to continue through the blood vessel 19 .
[0045] The garment 25 may also include pressure relievers 44 , and 42 to protect the underlying tissue from any excess pressure, such as pressure from contact with a surface of the furniture 13 . Pressure relievers 44 , 46 and 42 may include or be made with a cushion or padding that alleviates some of the excess pressure on the tissue 3 , 7 or 11 , when in contact with a surface of the furniture 13 . Alternatively, pressure relievers 44 , 46 and 42 may lack any cushion or padding, but be surrounded by padded support, and the surrounding channels 30 , so that the tissue thereunder does not come into contact or encounters minimal pressure from the garment 25 and from any surface on the furniture 13 . The pressure relievers 44 , 46 and 42 may not be inflated or inflatable to reduce or eliminate pressure placed on the underlying tissue.
[0046] Pressure reliever 44 is positioned in garment 25 to protect at least part or all of the tissue 3 in the area of the ischium bony prominence 4 in the buttocks 2 . Pressure reliever 46 is positioned in garment 25 to protect at least part or all of the tissue 7 in the area of the trochanteric bony prominence 6 in the hips 8 . Pressure reliever 42 is positioned in garment 25 to protect at least part of or all of the tissue 11 in the area of the sacral bony prominence 12 in the coccyx 10 . The garment 25 may include a sacral ring 48 to surround or encircle pressure reliever 42 . The sacral ring 48 may provide extra support for the garment 25 . For example, if the sacral ring 48 is integrated with the outer layer 21 , the sacral ring 48 may maintain the integrity of the garment 10 around the sacrum 12 . The sacral ring 48 may be made of a rigid material or a more flexible material, such as, e.g., plastic. Alternatively, the garment 25 may have no sacral pressure reliever 42 , but the tissue in the sacral area 11 may be protected from excess pressure by the sacral ring 48 alone, for example, if it is of sufficient thickness to protect tissue 11 from direct contact with a surface of furniture 13 .
[0047] Some of the channels 30 in the garment 25 may include one or more channels 35 configured around the pressure relievers 44 , 46 and 42 . The channels 35 may be configured or positioned to be offset from the center of the tissue on and surrounding a bony prominence, e.g., centers 45 , 47 and 43 of the areas of tissue 3 , 7 and 11 , covering the ischium, trochanteric and sacral bony prominences 4 , 6 and 12 , in the region of the buttocks 2 , hips 8 and coccyx 10 , respectively, also referred to as the ischial, trochanteric and sacral areas of the body portion 5 . The channels 35 may be referred to as additional channels, and may be positioned to extend radially from the centers 45 , 47 and 43 when the garment 25 is on the body portion 5 . The channels 35 arranged radially around the pressure relievers 44 , 46 and 42 , and around the tissue centers 45 , 47 and 43 , may extend radially through the part of tissue 3 , 7 and 11 that surround the centers 45 , 47 and 43 (which may also be referred to as pressure centers). The remainder of the channels 30 may be positioned in rib-like patterns outside of the pressure relievers 44 , 46 and 42 , and the additional channels 35 positioned around the pressure relievers 44 , 46 and 42 .
[0048] The device 20 also includes a pump 50 releasably connectable to the garment 25 via one or more valves or ports on garment 25 . The pump 50 may be small and lightweight, to be portable, and may be configured to be releasably attachable to one or more pieces of furniture (including a chair 13 , or for example, the intravenous pole), or directly to the person using the garment 25 , e.g., as on a belt around the waist 15 .
[0049] As illustrated in FIGS. 4 through 6 , pump 50 is releasably connectable to ports 27 and 28 on garment 25 . The pump 50 is configured to periodically or sequentially inflate and deflate one or more of the channels 30 in the garment 25 through valves or ports 27 and 28 on garment 25 , e.g., by pumping and/or removing air, water or other fluids or gel-like substances into and/or out of the channels 30 through ports 27 and 28 . The pump 50 may be configured to be able to regulate the amount of fluids or substance being pumped or removed from channels 30 . The pump 50 may also be configured to time the periods for each of the inflation and deflation cycles. The pump 50 may be configured to inflate and deflate all of the channels at the same time. Alternatively, the pump 50 may be configured to inflate one subset of channels 30 through port 27 while deflating another subset of channels 30 through port 28 . As illustrated in FIGS. 8 and 9 with arrows indicating directions of fluid movement, one subset of channels 37 may be inflated through port 27 while another subset of channels 36 , alternating between channels 37 , are being deflated through port 28 .
[0050] Alternatively, the first subset of channels 30 may be configured to be one side of the garment 25 , and the second subset of channels 30 may be configured to be on another side of the garment 25 . The sequential or periodic inflation and/or deflation of the first and second subsets of channels 30 under this configuration provides a rocking motion, and may be implemented to periodically move the patient from one position to another. The pump 50 may be supplied with additional ports (not shown), so that the pump 50 may be configured to act on one set of channels 30 at a time, for example, leaving a third subset of channels entirely deflated if it is on a portion of the body not in contact with a piece of furniture 13 . In any case, alternately inflating and deflating different portions of garment 25 or different subsets of channels 30 according to different patterns will prevent pressure from inflated channels remaining on any specific location of the body portion 5 for an extended amount of time.
[0051] The garment 25 itself may be made with a durable washable material, e.g., plastic. The garment 25 may be configured with layers, as illustrated in FIG. 4 . The channels 30 may be integrated into a middle layer 22 of garment 25 . Outer layer 21 may provide a protective plastic covering over the channels 30 and the remainder of the garment 25 . The outer layer 21 may have holes or pores 29 to allow air to pass through to and from the middle layer 22 , the inner layer 23 and the body portion 5 . Outer layer 21 may be detachable from the rest of the garment 25 , to be washed or rinsed off, or replaced.
[0052] The inner layer 23 may include a liner or lining 24 that is made with a breathable or softer or hypoallergenic fabric or other material, e.g., cotton, nylon, polyester, rayon, or lycra, or a combination or blend of any two or more of the foregoing materials. The lining 24 may be releasably attachable to the inner layer 23 of the garment 25 . The lining 24 may cover all or part of the inner layer 23 of the garment 25 . The lining may be removable to be washable or disposable, and in any case, replaceable.
[0053] The garment 25 may be releasably attachable to the body portion 5 via one or more straps 60 on a front side 70 of the garment 25 , as illustrated in FIG. 4 . The straps 60 may be elastic bands 61 or otherwise adjustable, as adjustable band 62 . The straps 60 may be made with a material including cotton, to increase the comfortability of the device 20 . The straps 60 may make it easier for the garment 25 to be placed on or removed from the body portion 5 .
[0054] The straps 60 may be spaced apart from one another in order to permit the frontal area of the body portion 5 to remain exposed for further examination and follow up by a doctor, nurse or other care giver. The straps also provide a way of attaching the garment 25 to the body portion 5 , without unnecessarily covering the frontal area of the body portion 5 . The straps 60 may allow the person wearing the garment 25 to be more comfortable and cooler, then if the frontal area of the body portion 5 were fully covered as well.
[0055] The straps 60 may be permanently attached at a distal end 64 to a first side 72 of the garment 25 , and releasably attached at a proximal end 65 to an opposite side 73 of the front side 70 of the garment 25 . The straps 60 may be releasably attachable with velcro 63 on sides 73 , or with buttons, snaps, zippers and other modes of releasably attaching or fastening the straps 60 to the sides 73 of the garment 25 .
[0056] The device 20 illustrated in FIGS. 4 through 9 is configured for body portion 5 , including the buttocks 2 , hips 8 , and coccyx 10 . As illustrated in FIG. 10 , the device 20 may extend further down the legs and further along the arms, with channels 30 and pressure relievers 41 and 49 for the elbows and calves. As illustrated in FIG. 11 , device 20 may include a garment 80 configured to fit on an upper body portion, with shoulder blade pressure relievers 84 , and with elbow pressure relievers 82 . The device 20 may be configured with pressure relievers in a variety of locations, and a variety of patterns for the distribution of channels 30 , depending on the position of the body 1 , the type of furniture 13 , and other conditions.
[0057] In the preceding specification, the present invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. | An apparatus for treating or preventing decubitus ulcers includes: a garment sized and shaped to be worn by a patient; a first plurality of fluid channels and a second plurality of fluid channels coupled to the garment and disposed adjacent to one another, at least some of the first plurality of fluid channels being independently inflatable and deflatable as compared with at least some of the second plurality of fluid channels; and a fluid control mechanism coupled to the first and second plurality of fluid channels and operating to repeatably and sequentially inflate and deflate the independently inflatable and deflatable fluid channels from among the first and second plurality of fluid channels such that there is less than a predetermined level of pressure exerted on the patient's tissue under one or more of the deflated channels. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to curable resin compositions to be used for forming coating with excellent abrasion resistance on the surface of plastic, inorganic glasses or metals.
Transparent plastics or so-called organic glasses are light materials having high impact strength and excellent workability and therefore are used in various fields such as glasses (panes and windshields) for vehicles interior decorations of buildings, glasses for meters and gauges, lenses of eyeglasses, etc. However, although plastics are tough and do not easily crack, they are inferior in surface hardness, especially in abrasion resistance and are easily scratched.
On the other hand, the inorganic glass has excellent resistance against scratch or abrasion, but it is dissatisfactory in that due to its poor impact strength it easily breaks and it is ground by repeated light impact applied on the surface thereof and is frosted. Most of metals are dissatisfactory, too, in that the surface thereof is rather easily scratched and abraded.
A measure often resorted to in order to improve abrasion resistance of the surface of solid materials is to coat the surface with a coating materials having good abrasion resistance. Hitherto, many attempts have been made to find excellent coating materials.
Among the known synthetic plastics, three dimensional polymers such as polymers of diethyleneglycol bis-allyl-carbonate or polyester resins and other thermosetting resins have the best abrasion resistance. And there has been found no coating materials having abrasion resistance superior to that of those polymers and comparable to that of inorganic glasses. Moreover, coating materials must be excellent in not only abrasion resistance but also in other various properties such as thermal resistance, chemical resistance, weatherability, etc. and thus these properties must be well balanced. Otherwise they cannot be used for practical purpose. From this view point, all the prior art coating materials are dissatisfactory and scarcely useful.
Accordingly the object of this invention is to provide a curable resin composition used for forming a coating having superior abrasion resistance well-balanced with other practical properties.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a curable resin composition to be used for forming abrasion-resistant coating comprising:
A. a prepolymer derived from glycidol, wherein said prepolymer may contain monoglycidol, by heating it together with a catalyst and a solvent,
B. a curing catalyst, and
C. a solvent.
According to one aspect of this invention, there is further provided a curable resin composition to be used for forming abrasion-resistant coating containing, in addition to the above-mentioned (A), (B) and (C),
D. at least one compound selected from the group consisting of:
i. silicon compounds represented by any of the general formula ##STR1## wherein R 1 , R 2 and R 3 are respectively either C 1-6 alkoxy or alkoxyalkoxy and all of these may be the same, R 4 is C 1-6 alkylene, and X is either of hydrogen and methyl, or hydrolysates thereof, and
ii. a polymer or copolymer of a polymerizable monomer containing at least one group selected from vinyl, allyl and hydrocarbyl having a triple bond in the molecule thereof.
In the composition of this invention, as mentioned above, each component is present in the following mixing ratio by weight. That is, of the total amount of (A) plus (C), (A) occupies 95-50% and (C) occupies 5-50%. (B) is added in a proportion of 0.05-10% of the total amount of (A) plus (C). (D), if used, is added, in a proportion of 5-40% of the total amount of (A) plus (C).
DETAILED DESCRIPTION OF THE INVENTION
The compositions of this invention are prepared as explained below:
The prepolymer (A) can be prepared by heating glycidol together with a catalyst and a solvent to polymerize it. Examples of the catalyst used for this purpose include acids such as perchloric acid, hydrochloric acid, sulfuric acid, chlorosulfonic acid, p-toluenesulfonic acid, polyphosphoric acid, pyrophosphoric acid, iodic anhydride, trichloroacetic acid, periodic acid, etc.; halogens such as iodine and bromine; Lewis acids such as tin tetrachloride, boron trifluoride, titanium tetrachloride, aluminum trichloride, ion trichloride, etc. and complexes thereof with an organic ether or alcohol and the like; metal salts of organic acids such as cobalt laurate, zinc laurate, cobalt naphthenate, zinc naphthenate, cobalt octylate, zinc octylate, etc. Examples of the solvent (C) usable in the preparation of prepolymer (A) include methanol, ethanol, propyl alcohol, butyl alcohol, hexyl alcohol, benzyl alcohol, benzene, xylene, phenol, toluene, glycerine, ethylene glycol, diethylene glycol, triethylene glycol, dioxane, acetone, chloroform, water, etc.
The molecular weight of the prepolymer is not specifically defined. But, for instance, in the case of a solution consisting of 90% glycidol and the balance of a catalyst and a solvent, prepolymer (A) can be defined as that which is obtained when the polymerization reaction is conducted until the viscosity reaches a value within a range of 30 - 1000 cp and more preferably 50 - 400 cp, and most preferably 100 - 300 cp.
The curable resin composition according to this invention is a mixture of (A), (B) and (C), wherein catalyst (B) and solvent (C) are selected from the same groups of catalyst and solvent respectively as those previously listed with respect to the preparation of prepolymer (A). When prepolymer (A) is prepared in the manner as described above, the resulting reaction product generally contains all of (A), (B) and (C). In practice, however, the curable resin composition may be frequently prepared by mixing the reaction product containing prepolymer (A) prepared as above with additional amounts of (B) and (C).
Examples of compound (D) used in this invention include:
i. (I) vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane; (II) methacryloxymethyl-trimethoxysilane, methacryloxymethyl-triethoxysilane, methacryloxymethyl-tripropoxysilane, acryloxymethyl-trimethoxysilane, acryloxymethyl-triethoxysilane, acryloxymethyl-tripropoxysilane, α-methacryloxyethyl-trimethoxysilane, α-methacryloxyethyl-triethoxysilane, α-methacryloxyethyl-tripropoxysilane, β-methacryloxyethyl-trimethoxysilane, β-methacryloxyethyl-triethoxysilane, β-methacryloxyethyl-tripropoxysilane, α-methacryloxypropyl-trimethoxysilane, α-methacryloxypropyl-triethoxysilane, α-methacryloxypropyl-tripropoxysilane, β-methacryloxypropyl-trimethoxysilane, β-methacryloxypropyl-triethoxysilane, β-methacryloxypropyl-tripropoxysilane, γ-methacryloxypropyl-trimethoxysilane, γ-methacryloxypropyl-triethoxysilane, γ-methacryloxypropyl-tripropoxysilane; (III) glycidoxymethyl-trimethoxysilane, glycidoxymethyl-triethoxysilane, glycidoxymethyl-tripropoxysilane, α-glycidoxyethyl-trimethoxysilane, α-glycidoxyethyl-triethoxysilane, α-glycidoxyethyl-tripropoxysilane, β-glycidoxyethyl-trimethoxysilane, β-glycidoxyethyl-triethoxysilane, β-glycidoxyethyl-tripropoxysilane, γ-glycidoxypropyl-trimethoxysilane, γ-glycidoxypropyl-triethoxysilane, γ-glycidoxypropyl-tripropoxysilane, β-glycidoxypropyl-trimethoxysilane, β-glycidoxypropyl-triethoxysilane, β-glycidoxypropyl-tripropoxysilane, α-glycidoxypropyl-trimethoxysilane, α-glycidoxypropyl-triethoxysilane, α-glycidoxypropyl-tripropoxysilane; (IV) 3,4-epoxycyclohexylmethyl-trimethoxysilane, 3,4-epoxycyclohexylmethyl-triethoxysilane, 3,4-epoxycyclohexylmethyl-tripropoxysilane, α-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, α-(3,4-epoxycyclohexyl)ethyl-triethoxysilane, α-(3,4-epoxycyclohexyl)ethyl-tripropoxysilane, β-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-triethoxysilane, β-(3,4-epoxycyclohexyl)ethyl-tripropoxysilane, α-(3,4-epoxycyclohexyl)propyl-trimethoxysilane, α-(3,4-epoxycyclohexyl)propyl-triethoxysilane, α-(3,4-epoxycyclohexyl)propyl-tripropoxysilane, β-(3,4-epoxycyclohexyl)propyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)propyl-triethoxysilane, β-(3,4-epoxycyclohexyl)propyl-tripropoxysilane, γ-(3,4-epoxycyclohexyl)propyl-trimethoxysilane, γ-(3,4-epoxycyclohexyl)propyl-triethoxysilane, γ-(3,4-epoxycyclohexyl)propyl-tripropoxysilane; (V) methyl silicate, ethyl silicate, propyl silicate, butyl silicate; and hydrolysates of these silicon compounds;
ii. a polymer or copolymer of any of dipropargyl maleate, dipropargyl fumarate, triallyl cyanurate, triacryl formal, diallyl maleate, diallyl itaconate, diallyl succinate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, diethyleneglycol bis(allylcarbonate), diallyl benzenephosphate, diallyl benzenephosphonate, diethyleneglycol dimethacrylate, diethyleneglycol diacrylate, neopentyl glycol dimethacrylate, neopentylglycol diacrylate, hexanediol dimethacrylate, pentanediol dimethacrylate, pentanediol diacrylate, butanediol dimethacrylate, butanediol diacrylate, ethyleneglycol dimethacrylate, ethyleneglycol diacrylate, propyleneglycol dimethacrylate, propyleneglycol diacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, cyclohexyl methacrylate, cyclohexyl acrylate, glycidyl methacrylate, glycidyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, acrylic acid, methacrylic acid, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, vinyltoluene, vinylcarbazole, vinylpyrrolidone, α-methyl styrene, maleic anhydride, etc.
When a hydrolysate of a silicon compound described in (i) above is used, it can be prepared by subjecting the silicon compound mixed with water and a water-soluble solvent such as water-soluble alcohols, dioxane, acetone, phenol, etc. to hydrolysis it in in the presence of a hydrolysis catalyst such as sulfuric acid, hydrochloric acid, chlorosulfonic acid, sulfuryl chloride, iron chloride, ethyl borate, naphthenic acid salt, ammonia, potassium hydroxide, sodium hydroxide, etc.
In order to prepare the polymer or copolymer described in (ii) above, a starting monomer may have previously been polymerized or copolymerized by heating it together with a radical polymerization catalyst or otherwise by applying light or an ionizing radiation thereto and the resulting polymer or copolymer is added to a mixture of (A), (B) and (C). Alternatively, the monomer per se may be added to a mixture of (A), (B) and (C) and the resulting mixture is subjected to polymerization by heating it with a radical polymerization catalyst or by applying light or an ionizing radiation thereto to provide a coating composition containing (A), (B), (C) and (D). The term "light or an ionizing radiation" used herein means visible and ultraviolet rays from a low-pressure or high-pressure mercury lamp, etc., sunbeam, α-rays, β-rays, γ-rays, electron beams, X-rays, neutron beams, mixed radiations emitted from a nuclear reactor, nuclear fission products, etc., wherein the wavelength of light may vary within a range of 1500 - 7000A and the dose rate in irradiation may vary within a range of 1 × 10 2 - 5 × 10 9 rad per hour. The radical polymerization catalyst used in this invention includes any polymerization initiator generally capable of initiating polymerization reaction of radically polymerizable monomers such as peroxides, hydroperoxides, dinitriles, redox catalysts, etc.
According to this invention, addition of a compound or compounds of Group (D) which are optionally employed can impart a wide variety of properties to the resulting resin composition or the cured coating depending on particular use and properties required of the coated products. Thus, addition of a selected compound or compounds of Group (D) improves, for example, uniformity of the cured coating of neat (A); imparts flexibility; partially improves chemical resistance against some special reagents or solvent resistance; improves heat resistance, weatherability, abrasion resistance, workability, etc.; improves easiness in application of the coating composition; or improves the adhesive strength to the particular substrate depending on the employed substrate. Accordingly, a compound or compounds of group (D) may be suitablly selected for use depending on the requirements in particular applications.
The curable composition prepared as described above may be applied to various substrates by using various procedures to form a coating well-bonded to the substrate and having excellent abrasion resistance as well as good thermal resistance, chemical resistance, weatherability, etc. For this purpose, the curable composition of this invention may be applied on the surface of various substrate such as transparent or opaque plastics, inorganic glass, mirror materials, metals, etc. and then heated to a temperature within a range of 60° - 200° C. Also the curable composition of this invention may be applied on the inner surface of a mold and heated to a temperature of 60° - 200° C, after which a curable or polymerizable material is poured in the cavity of the mold and polymerized, followed by releasing from the mold; or otherwise the curable composition of this invention may be applied on a smooth-surfaced body and heated to 60° - 200° C to form a cured coating, which is then removed from the body, and the removed coating can be bonded to a solid body of plastics, inorganic glasses, mirrors or metals. Thus coating having excellent abrasion resistance, thermal resistance, chemical resistance, weatherability can be formed on various kinds of materials by using the composition of this invention.
The composition of this invention has good adhesion or bonding strength to organic and inorganic materials, and there is not necessity of precoating the substrate. In special cases, however, some kind of precoating may be provided before the composition of this material is applied.
Now the invention is illustrated by way of working examples, which are not limiting this invention. In the examples, with respect to proportion of materials, parts are by weight, if not specifically defined.
Also in the examples, abrasion resistance of the formed coating films was tested in accordance with the sand-falling method of ASTM D673-44 and "haze value" was determined according to the procedures of ASTM-D1003-61.
Surface hardness was tested by the method of JIS K5651, which is as follows.
The lead of a standard test pencil is exposed in the length of 3 mm without sharpening, the end surface of the exposed cylindrical lead is whetted flat on sand paper so that the circular peripheral edge of the end surface becomes sharp. The thus prepared pencil is positioned slant at the angle of 45° to the surface of a specimen to be tested. The end of the pencil lead is loaded with 1 kg, and the specimen is moved horizontally. The same test is repeated 5 times in different places on the surface. If scratches or break of the coating reaching the substrate is observed in two or more of 5 runs, the test is repeated with a pencil of one grade lower hardness. The hardness of the pencil, with which scratch is observed in less than 2 runs out of 5 runs, is indicated as the hardness of the tested specimen.
EXAMPLE 1
To 100 parts of glycidol, 10 parts of a 0.1% perchloric acid solution in ethyl alcohol was added, and the mixture was heated at 50° C for 14 hours to prepare a prepolymer solution. To this solution were added 10 parts of a solution containing 1% FC-430 surfactant (made by Hishie Chemical Co., Ltd.), in ethyl alcohol, 50 parts of ethyl alcohol and 10 parts of a 5% perchloric acid solution in ethyl alcohol.
The resulting solution was applied by dipping on the surface of a plate (3mm thick) of diethyleneglycol bis(allylcarbonate) polymer and the plate was heated at 120° C for 5 hours to provide a transparent hard coating. This coating was 10μ thick and had pencil hardness of 3H. The haze value measured after the sand-falling test was 20.1% for the coating while the value for the substrate was 28.4%, which means the abrasion resistance was much improved.
EXAMPLE 2
To 100 parts of tetraethoxysilane, 100 parts of a 30% benzyl alcohol solution in methyl alcohol and 40 parts of an aqueous 0.1% hydrochloric acid solution were added, and the mixture was warmed at 50° C for not less than 30 hours to obtain a solution of hydrolysate of tetraethoxysilane.
To 100 parts of a glycidol prepolymer solution prepared in the same manner as Example 1 were added 20 parts of said hydrolysate solution, 50 parts of ethyl alcohol and 10 parts of a 5% perchloric acid solution in ethyl alcohol. The resulting solution was applied by spraying on the surface of a plate (3mm thick) of diethylene glycol bis(allylcarbonate) polymer and then heated at 110° C for 4 hours to provide a transparent hard coating, which was 10μ thick and had pencil hardness of 6H. The haze value measured after the sand-falling test was 10.6%, which means that the abrasion resistance was remarkably improved. Also it was found that the coating was excellent in weatherability, water resistance and chemical resistance, too.
EXAMPLE 3
To 100 parts of a glycidol prepolymer solution which has been prepared in the same manner as Example 1, 10 parts of acrylic acid, 10 parts of acrylamide, 5 parts of a 1.0% cobalt naphthenate solution in benzene, 10 parts of a 5% perchloric acid solution in ethyl alcohol and 40 parts of ethyl alcohol were added and a dose of 5 × 10 5 roentgens of γ-rays emitted from cobalt 60 were applied to the resulting mixture at a dose rate of 1 × 10 5 roentgens per hour to provide a composition comprising the glycidol prepolymer, acrylic acid-acrylamide copolymer, catalyst and solvent.
The thus obtained curable composition was applied on the surface of the polycarbonate resin and heated at 120° C for 5 hours, thereby a transparent hard coating was obtained. The coating was 10μ thick and had pencil hardness of 6H. The haze value measured after the sand-falling test was 12.6%, which means that the coating remarkably improved abrasion resistance of the polycarbonate resin. Also it was found that the coating was excellent in weatherability, chemical resistance, etc., too.
EXAMPLE 4
To 100 parts of glycidol, 10 parts of a 0.1% perchloric acid solution in ethyl alcohol was added, and the mixture was heated at 50° C for 14 hours to prepare a prepolymer solution. To this solution were added 10 parts of a solution containing 1% FC-430 surfactant in ethyl alcohol, 50 parts of ethyl alcohol and 10 parts of 5% perchloric acid solution in ethyl alcohol and mixed well.
To 100 parts of this solution, 30 parts of vinyltriethoxisilane was added and mixed well. The mixture (coating solution) was applied on the surface of a plate (3mm thick) of diethyleneglycol bis(allylcarbonate) polymer by spraying, and the plate was heated at 100° C for 5 hours to provide a transparent hard coating. This coating was 10μ thick and had pencil hardness of 4H. The haze value after the sand-falling test was 19.4%.
EXAMPLE 5
To 100 parts of the coating composition prepared in the same way as in Example 4, further 20 parts of β-methacryloxyethyl-trimethoxysilane was added and mixed well.
This mixture (solution) was applied on the surface of a plate (ca. 3 mm in thickness) of polymethyl methacrylate by spraying, and the plate was heated at 100° C for 4 hours to provide a transparent hard coating.
This coating was 20μ in thickness and had pencil hardness of 4H. The haze value after the sand-falling test was 19.6%. This means remarkable improvement in the surface hardness when it is considered the fact that the haze value of the polymethyl methacrylate substrate is 56%.
EXAMPLE 6
The glycidol prepolymer solution was prepared in the same way as in Example 4, and to this solution, 10 parts of a solution containing 1% FC-430 surfactant in chloroform/acetone (1:1 by volume) was added. To 100 parts of this solution, further 20 parts of γ-glycidoxypropyl-triethoxysilane was added and mixed well.
This mixture was applied on the surface of a plate (ca. 3 mm in thickness) of the polycarbonate resin, and the plate was heated at 120° C for 3 hours to provide a 13 mm thick transparent hard coating on it.
The pencil hardness of this coating was 5H. The haze value after the sand-falling test was 17.2%, while that of the polycarbonate substrate is 60%.
EXAMPLE 7
To 100 parts of the coating composition prepared in the same way as in Example 6, further 30 parts of β-(3,4-epoxycyclohexyl)ethyltrimethoxisilane was added and mixed well.
This mixture was applied on the surface of a plate (ca. 1 mm in thickness) of transparent polyvinyl chloride, and the plate was heated at 100° C for 4 hours to provide a transparent hard coating of 18μ thickness.
The pencil hardness was 4H. The haze value after the sand-falling test was 18.9%, while that of the polyvinyl chloride is 52%.
EXAMPLE 8
To 100 parts of the coating composition prepared by the procedures of Example 4, 5 parts of dipropargyl maleate, 5 parts of diethyleneglycol dimethacrylate and 10 parts of hydroxypropyl methacrylate were added and mixed well. To this mixture, further 5 parts of a 3% boron trifluoride-ethyl ether complex solution in n-butyl alcohol and 5 parts of 1% cobalt naphthenate solution in ethyl alcohol were added and mixed. The thus prepared mixture (solution) was irradiated with 1 × 10 6 roentgens of gamma rays from cobalt-60 at a dose of 1 × 10 6 roentgens.
The thus prepared coating composition was applied on the surface of a plate (3 mm thick) of polymethyl methacrylate, and the plate was heated at 100° C for 4 hours to provide a 10μ thick transparent hard coating.
The pencil hardness of this surface was 3H, and the haze value after the sand-falling test was 19.6%. This coating proved to be much improved in water resistance in comparison with the coating of Example 1 in the weathering test.
EXAMPLE 9
The coating composition of Example 1 was applied on the surface of an ordinary glass plate (3 mm thick) and cured in the same manner as in Example 1. The transparency of the substrate glass was well retained.
EXAMPLE 10
The coating composition of Example 1 was applied on the polished mirror surface of an aluminum plate (0.5 mm) and cured in the same manner as in Example 1. The reflection of the substrate mirror surface was retained, and the mirror surface was well protected against abrasion and oxidation. | A curable resin composition for forming transparent abrasion-resistant coating on the surface of organic and inorganic materials comprising glycidol prepolymer. The composition can contain polymerizable alkoxysilane compounds in addition to glycidol prepolymer. The resulting coating has abrasion resistance far better than most known organic resins. | 2 |
[0001] This application claims the benefit of U.S. Provisional Application No. 60/231,886 filed Sep. 15, 2000, the contents of which are hereby incorporated by reference into this application.
[0002] Throughout this application, various publications are referenced by author and date within the text. All patents, patent applications and publications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
TECHNICAL FIELD
[0003] This invention relates to antiretroviral drug susceptibility and resistance tests to be used in identifying effective drug regimens for the treatment of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). The invention further relates to the means and methods of monitoring the clinical progression of HIV infection and its response to antiretroviral therapy using phenotypic or genotypic susceptibility assays. The invention also relates to novel vectors, host cells and compositions for carrying out phenotypic susceptibility tests. The invention further relates to the use of various genotypic methodologies to identify patients whose infection has become resistant to a particular antiretroviral drug regimen. This invention also relates to the screening of candidate antiretroviral drugs for their capacity to inhibit viruses, selected viral sequences and/or viral proteins. More particularly, this invention relates to the determination of non-nucleoside reverse transcriptase inhibitor resistance using phenotypic susceptibility tests and/or genotypic tests.
BACKGROUND OF THE INVENTION
[0004] HIV infection is characterized by high rates of viral turnover throughout the disease process, eventually leading to CD4 depletion and disease progression. Wei X, Ghosh S K, Taylor M E, et al. (1995) Nature 343, 117-122 and Ho D D, Naumann A U, Perelson A S, et al. (1995) Nature 373, 123-126. The aim of antiretroviral therapy is to achieve substantial and prolonged suppression of viral replication. Achieving sustained viral control is likely to involve the use of sequential therapies, generally each therapy comprising combinations of three or more antiretroviral drugs. Choice of initial and subsequent therapy should, therefore, be made on a rational basis, with knowledge of resistance and cross-resistance patterns being vital to guiding those decisions. The primary rationale of combination therapy relates to synergistic or additive activity to achieve greater inhibition of viral replication. The tolerability of drug regimens will remain critical, however, as therapy will need to be maintained over many years.
[0005] In an untreated patient, some 10 10 new viral particles are produced per day. Coupled with the failure of HIV reverse transcriptase (RT) to correct transcription errors by exonucleolytic proofreading, this high level of viral turnover results in 10 4 to 10 5 mutations per day at each position in the HIV genome. The result is the rapid establishment of extensive genotypic variation. While some template positions or base pair substitutions may be more error prone (Mansky L M, Temin H M (1995) J Virol 69, 5087-5094) (Schinazi R F, Lloyd R M, Ramanathan C S, et al. (1994) Antimicrob Agents Chemother 38, 268-274), mathematical modeling suggests that, at every possible single point, mutation may occur up to 10,000 times per day in infected individuals.
[0006] For antiretroviral drug resistance to occur, the target enzyme must be modified while preserving its function in the presence of the inhibitor. Point mutations leading to an amino acid substitution may result in change in shape, size or charge of the active site, substrate binding site or surrounding regions of the enzyme. Mutants resistant to antiretroviral agents have been detected at low levels before the initiation of therapy. (Mohri H, Singh M K, Ching W T W, et al. (1993) Proc Natl Acad Sci USA 90, 25-29) (Nájera I, Richman D D, Olivares I, et al. (1994) AIDS Res Hum Retroviruses 10, 1479-1488) (Nájera I, Holguin A, Quiñones-Mateu E, et al. (1995) J Virol 69, 23-31). However, these mutant strains represent only a small proportion of the total viral load and may have a replication or competitive disadvantage compared with wild-type virus. (Coffin J M (1995) Science 267, 483-489). The selective pressure of antiretroviral therapy provides these drug-resistant mutants with a competitive advantage and thus they come to represent the dominant quasispecies (Frost S D W, McLean A R (1994) AIDS 8, 323-332) (Kellam P, Boucher C A B, Tijnagal J M G H (1994) J Gen Virol 75, 341-351) ultimately leading to drug resistance and virologic failure in the patient.
[0007] Non-nucleoside Reverse Transcriptase Inhibitors
[0008] Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are a chemically diverse group of compounds which are potent inhibitors of HIV-1 RT in vitro. These compounds include pyridinone derivatives, bis(heteroaryl)piperazines (BHAPs) such as delavirdine and atevirdine, the dipyridodiazepinone nevirapine, the thymine derivative groups TSAO and HEPT, an α-anilino phenylacetamides (α-APA) compound loviride, and the quinoxaline-class inhibitors such as (HBY-097), the benzodiazepin-one and -thione (TIBO) compounds and the pyridinone derivatives (L-697,661). For overviews see (DeClercq E. (1996) Rev Med Virol 6, 97-117) (Emini E A (1996) Antiviral Drug Resistance, ed. D D Richman, John Wiley & Sons, Ltd. High-level resistance to individual compounds appears to develop rapidly, often within a few weeks of initiating monotherapy, frequently involving only single-point mutations and in many cases leading to considerable cross-resistance to other NNRTIs. Most mutations reported occur in the codon groups 100-108 and 181-190 which encode for the two β-sheets adjacent to the catalytic site of the RT enzyme (Kohlstaedt L A, Wang J, Friedman J M, et al. (1992) Science 256, 1783-90) The NNRTI binding pocket, as it has been described, is a hydrophobic non-substrate binding region of RT where these agents directly interact with RT. They inhibit activity by interfering with mobility of the ‘thumb’ subdomain, or disrupting the orientation of conserved aspartic acid side chains essential for catalytic activity (D'Aquilla R T. (1994) Clin Lab Med 14, 393-423) (Arnold E., Ding J., Hughes S H, et al. (1995) Curr Opin Struct Biol 5, 27-38).
[0009] Mutations conferring reduced susceptibility to nevirapine have been described at codons 98, 100, 103, 106, 108, 181, 188 and 190 (Richman D D, Havlir D, Corbeil J. (1994) J Virol 68, 1660-1666). The most frequently selected variant during nevirapine monotherapy is a Tyr 181 _Cys (Y181C) mutation which results in a 100-fold reduction in sensitivity to this agent, with reduced susceptibility to the pyridinone derivatives L-696,229 and L-697,661 (Arnold, Ibid). TSAO also has limited activity in the presence of the 181 mutation, but maintains activity in the presence of mutations at codons 100 and 103 and in vitro selects for a unique mutation, GLU 138 _Lys (E138K), in the region where it most closely interacts with RT (Richman, D D, Ibid) (Richman D D, Shih C-K, Lowy I, et al. (1991) Proc Natl Acad Sci USA 88, 11241-11245).
[0010] Resistance to loviride when used as monotherapy develops in most patients by week 24. It has been mapped to a range of codons 100-110; 181-190), most commonly codon 103 (Staszewski S, Miller V, Kober A, et al. (1996) Antiviral Ther 1, 42-50. During combination therapy using loviride with zidovudine or zidovudine plus lamivudine, variants at codons 98 and 103 were the most frequent mutations defected at 24 weeks (Staszewski S, Miller V, Rehmet S, et al. (1996) AIDS 10, F1-7).
[0011] Although the 101, 103 and 181 mutations also confer cross-resistance to BHAPs, (Balzarini J, Karlsson A, Pérez-Pérez M-J, et al. (1992) Virology 192, 246-253) the characteristic P236L substitution selected for by these agents in vitro appears to sensitize RT to some other NNRTIs, reducing the IC50 for nevirapine, for example, 7- to 10-fold, without influencing sensitivity to nucleoside analogues (Staszewski S., Ibid). This mutation at codon 236 has not been observed in clinical isolates during atevirdine therapy, although other resistance-conferring mutations at codons 103 and 181 have been reported during monotherapy as well as at codons 101, 188, 233 and 238 during combination therapy with zidovudine.
[0012] While HBY-097 may initially select for a mutation at codons 190 in vitro, further passage consistently selects for mutations at RT codon 74 and 75, with some mutant viruses showing decreased sensitivity to didanosine and stavudine, but not zidovudine (Kleim J-P, Rösner M, Winkler I, et al. (1995) J Acquir Immune Defic Syndr 10 Suppl 3, 2). Mutation at codon 181 has been reported to antagonize zidovudine resistance due to the typical 41 and 215 codon mutations, (Zhang D, Caliendo A M, Eron J J, et al. (1994) Antimicrob Agents Chemother 38, 282-287) suggesting that combination therapy with some NNRTIs and zidovudine may be feasible. Although an HIV mutant with triple resistance to zidovudine, didanosine and nevirapine has been described in vitro, (Larder B A, Kellam P, Kemp S D (1993) Nature 365, 451-453) treatment with this triple combination does provide superior immunological and virological responses to treatment with zidovudine plus didanosine alone over a 48-week period in patients with CD4 cell counts <350/mm 3 .
[0013] Combination therapy with zidovudine and the pyridinone derivative L-697,661 prevents the appearance of the codon 181 mutation typically selected during monotherapy with this NNRTI, delaying the appearance of high-level resistance to this compound. Changes in susceptibility to zidovudine were not examined in this study. (Staszewski S, Massari F E, Kober A, et al. (1995) J Infect Dis 171, 1159-1165). Concomitant or alternating zidovudine therapy does not delay the appearance of resistance during nevirapine therapy; (Richman D D, Ibid) (Nunberg J H, Schleif W A, Boots E J, et al. (1990) J Virol 65, 4887-4892) (DeJong M D, Loewenthl M, Boucher C A B, et al. (1994) J Infect Dis 169, 1346-1350) (Cheeseman S H, Havlir D, McLaughlin M M, et al. (1995) J Acquir Immune Defic Syndr 8, 141-151) however, the 181 mutant is not being observed during combination, the most common change being at codon 190 (Richman D D, Ibid). This suggests that the codon 181 mutation which is antagonistic to zidovudine resistance in vitro is not compatible, or not preferred in vivo, selection favoring other mutations which allow for reduced susceptibility to this NNRTI concomitant with zidovudine resistance.
[0014] The rapid development of reduced susceptibility to the NNRTIs suggests limited utility of these agents, particularly as monotherapies, and has led to the modification of these molecules in an attempt to delay the appearance of drug-resistant virus. A ‘second generation’ NNRTI, the pyridinone derivative L-702,019, demonstrated only a 3-fold change in IC 50 between wild-type and codon 181 mutant HIV-1, and required multiple mutations to engender high-level resistance (Goldman M E, O'Brien J A, Ruffing T L, et al. (1993) Antimicrob Agents Chemother 37, 947-949).
[0015] Integrase
[0016] Integration of viral DNA into the host chromosome is a necessary process in the HIV replication cycle (Brown, P. O., 1997, in Retroviruses; Coffin, J. M., Hughes, S. H. & Varmus, H. E., eds., Cold Spring Harbor Lab. Press, Plainview, N.Y., 161-203). The key steps of DNA integration are carried out by the viral integrase protein, which, along with protease and reverse transcriptase, is one of three enzymes encoded by HIV. Combination antiviral therapy with protease and reverse transcriptase inhibitors has demonstrated the potential therapeutic efficacy of antiviral therapy for treatment for AIDS (Vandamme, A. M., Van Vaerenbergh, K. & De Clerq, E., 1998, Antiviral Chem. Chemother. 9, 187-203). However, the ability of HIV to rapidly evolve drug resistance, together with toxicity problems, requires the development of additional classes of antiviral drugs. Integrase is an attractive target for antivirals because it is essential for HIV replication and, unlike protease and reverse transcriptase, there are no known counterparts in the host cell. Furthermore, integrase uses a single active site to accommodate two different configurations of DNA substrates, which may constrain the ability of HIV to develop drug resistance to integrase inhibitors. However, unlike protease and reverse transcriptase, for which several classes of inhibitors have been developed and cocrystal structures have been determined, progress with the development of integrase inhibitors has been slow. A major obstacle has been the absence of good lead compounds that can serve as the starting point for structure-based inhibitor development. Although numerous compounds have been reported to inhibit integrase activity in vitro, most of these compounds exhibit little specificity for integrase and are not useful as lead compounds (Pommier, Y., Pilon, A. A., Bajaj K, K., Mazumder, A. & Neamati, N., 1997, Antiviral Chem. Chemother 8 ).
[0017] HIV-1 integrase is a 32-kDa enzyme that carries out DNA integration in a two-step reaction (Brown, P. O., ibid.). In the first step, called 3′ processing, two nucleotides are removed from each 3′ end of the viral DNA made by reverse transcription. In the next step, called DNA strand transfer, a pair of transesterification reactions integrates the ends of the viral DNA into the host genome. Integrase is comprised of three structurally and functionally distinct domains, and all three domains are required for each step of the integration reaction (Engelman, A. Bushman, F. D. & Craigie, R., 1993, EMBO J. 12, 3269-3275). The isolated domains form homodimers in solution, and the three-dimensional structures of all three separate dimers have been determined (Dyda, F., Hickman, A. B. Jenkins, T. M., Engelman, A., Craigie, R. & Davies, D. R., 1994, Science 226, 1981-1986; Goldgur, Y. Dyda, Hickman, A. B., Jenkins, T. M., Craigie, R. & Davies, D. R., 1998, Proc. Natl. Acad. Sci., USA 95, 9150-9154; Maignan, S., Guilloteau, J. P., Zhou-Liu, Q., Clement-Mella, C. & Mikol, V., 1998 , J Mol. Biol. 282, 259-368; Lodi, P. J., Ernst, J. A., Kuszewski, J., Hickman, A. B., Engelman, A., Craigie, R., Clore, G. M. & Gronenborn, A. M. 1995 Biochemistry 34, 9826-9833; Eijkelenboom, A. P., Lutzke, R. A., Boelens, R., Plasterk, R. H., Kaptein, R. & Hard, K. 1995 Nat. Struct. Biol. 2, 807-810; Cai, M. L., Zheng, R., Caffrey, M., Craigie, R., Clore, G. M. & Gronenborn, A. M., 1997 Nat. Struct. Biol. 4, 839-840). Although little is known concerning the organization of these domains in the active complex with DNA substrates, integrase is likely to function as at least a tetramer (Dyda, F., Hickman, A. B. Jenkins, T. M., Engelman, A., Craigie, R. & Davies, D. R., 1994, Science 226, 1981-1986). Extensive mutagenesis studies mapped the catalytic site to the core domain (residues 50-212), which contains the catalytic residues D64, D116, and E152 (Engelman, A. & Craigie R., 1992, J. Virol. 66, 6361-6369; Kulkosky, J., Jones, K. S., Katz, R. A., Mack, J. P. & Skalka, A. M., 1992, Mol. Cell Biol 12, 2331-2338). The structure of this domain of HIV-1 integrase has been determined in several crystal forms (Dyda, F., Hickman, A. B. Jenkins, T. M., Engelman, A., Craigie, R. & Davies, D. R., 1994, Science 226, 1981-1986; Goldgur, Y. Dyda, Hickman, A. B., Jenkins, T. M., Craigie, R. & Davies, D. R., 1998, Proc. Natl. Acad. Sci., USA 95, 9150-9154; Maignan, S., Guilloteau, J. P., Zhou-Liu, Q., Clement-Mella, C. & Mikol, V., 1998, J Mol. Biol. 282, 259-368).
[0018] Hazuda et al. (Science 287: 646-650, 2000) have described compounds (termed L-731, 988 and L-708,906) which specifically inhibit the strand-transfer activity of HIV-1 integrase and HIV-1 replication in vitro. Viruses grown in the presence of these inhibitors display reduced inhibitor susceptibility and bear mutations in the integrase coding region at amino acid positions 66 (T66I), 153 (S153Y), and 154 (M154I). Site-directed mutants of a laboratory strain of HIV-1 (HXB2) with these amino acid changes confirmed their direct role in conferring reduced integrase inhibitor susceptibility. In addition some of these mutants displayed delayed growth kinetics, suggesting that viral fitness was impaired.
[0019] It is an object of this invention to provide a drug susceptibility and resistance test capable of showing whether a viral population in a patient is resistant to a given prescribed drug. Another object of this invention is to provide a test that will enable the physician to substitute one or more drugs in a therapeutic regimen for a patient that has become resistant to a given drug or drugs after a course of therapy. Yet another object of this invention is to provide a test that will enable selection of an effective drug regimen for the treatment of HIV infections and/or AIDS. Yet another object of this invention is to provide the means for identifying the drugs to which a patient has become resistant, in particular identifying resistance to non-nucleoside reverse transcriptase inhibitors. Still another object of this invention is to provide a test and methods for evaluating the biological effectiveness of candidate drug compounds which act on specific viruses, viral genes and/or viral proteins particularly with respect to viral drug resistance associated with non-nucleoside reverse transcriptase inhibitors. It is also an object of this invention to provide the means and compositions for evaluating HIV antiretroviral drug resistance and susceptibility. This and other objects of this invention will be apparent from the specification as a whole.
SUMMARY OF THE INVENTION
[0020] The present invention relates to methods of monitoring, using phenotypic and genotypic methods, the clinical progression of human immunodeficiency virus infection and its response to antiviral therapy. The invention is also based, in part, on the discovery that genetic changes in HIV reverse transcriptase (RT) which confer resistance to antiretroviral therapy may be rapidly determined directly from patient plasma HIV RNA using phenotypic or genotypic methods. The methods utilize polymerase chain reaction (PCR) based assays. Alternatively, methods evaluating viral nucleic acid of viral protein in the absence of an amplification step could utilize the teaching of this invention to monitor and/or modify antiretroviral therapy. This invention is based in part on the discovery of a mutation at codon 225 either alone or in combination with a mutation at codon 103 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (efavirenz) treated patient(s) in which the presence of the mutations correlate with an increase in delavirdine susceptibility and little or no change in nevirapine susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of therapy. The development of the mutant at codon 225 in addition to the mutation at codon 103 in HIV RT was found to be an indicator of the development of resistance and ultimately of immunological decline. This invention is based in part on the discovery of a mutation at codon 236 of RT was discovered to occur in non-nucleoside reverse transcriptase inhibitor (NNRTI) treated patients in which the presence of the mutation correlates with decreased susceptibility to delavirdine and no reduction in nevirapine susceptibility. The development of the codon 190 and 103 and/or 101 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline. This invention is based in part on the discovery of a mutation at codon 190 either alone or in combination with a mutation at codon 190 either alone or in combination with a mutation at codon 103 and/or 101 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (efavirenz) treated patient(s) in which the presence of the mutations correlate with an increase in delavirdine susceptibility and a decrease in nevirapine susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of NNRTI therapy. The development of the codon 236 and 103 and/or 181 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline.
[0021] This invention is based in part on the discovery of a mutation at codon 230 either alone or in combination with a mutation at codon 181 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (nevirapine) treated patient(s) in which the presence of the mutations correlate with a significant decrease in both delavirdine and nevirapine susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of NNRTI theraphy. The development of the codon 230 and 181 mutations in HIV RT were found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline. This invention is based in part on the discovery of a mutation at codon 181 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (nevirapine) treated patient(s) in which the presence of the mutation correlates with a moderate decrease in delavirdine susceptibility and a significant decrease in nevirapine susceptibility and no change in efavirenz susceptibility. The mutation was found in plasma HIV RNA after a period of time following initiation of NNRTI therapy. The development of the codon 181 mutation in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibiltiy/resistance which has been associated with virologic failure and subsequent immunological decline. This invention is based in part on the discovery of a mutation at codon 188 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (efavirenz) treated patient(s) in which the presence of the mutation correlates with a slight decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility. The mutation was found in plasma HIV RNA after a period of time following initiation of NNRTI therapy. The development of the codon 188 mutation in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with viologic failure and subsequent immunological decline. This invention is based in part on the discovery lof a mutation at codon 188 of HIV reverse transcriptase in patient(s) with no previously reported exposure to non-nucleoside reverse transcriptase inhibitors in which the presence of the mutations correlate with a moderate decrease in delavirdine susceptibility and a substatial decrease in nevirapine susceptibility and a moderate decrese in efavirenz susceptibility. The mutation was found in plasma HIV RNA after a period of time following initiation of anti-retroviral therapy. The development of the codon 138 and 188 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline. This invention is based in part on the discovery of a mutation at codon 98 of HIV reverse transcriptase in patient(s) with no previously reported exposure to non-nucleoside reverse transcriptase inhibtors in which the presence of the mutation correlates with slight decrease in delavirdine, nevirapine and efavirenz susceptibility. The mutation was found in plasma HIV RNA after a period of time following initiation of anti-retroviral therapy. The development of the codon 98 mutation in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline.
[0022] This invention is based in part on the discovery of a mutation at codon 98 either alone or in combination with a mutation at codon 190 of HIV reverse transcriptase in patient(s) whose anti-retroviral treatment was unknown in which the presence of the mutations correlate with an increase in delavirdine susceptibility and substantial decrease in both nevirapine and efavirenz susceptibiltiy. The mutations were found in plasma HIV RNA. The development of the mutant at codon 98 in addition to the mutation at codon 190 in HIV RT was found to be an indicator of the development of resistance and ultimately of immunological decline. This invention is based in part on the discovery of a mutation at codon 181 either alone or in combination with a mutation at codon 98 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (delavirdine) treated patient(s) in which the presence of the mutations correlate with an significant decresase in delavirdine susceptibility and a substantial decrease in efavirenz susceptibility. The mutations were found in plasma HIV RNA sfter a period of time following initiation of therapy. The development of the mutant at codon 98 in addition to the mutation at codon 181 in HIV RT was found to be an indicator of the development of resistance and ultimately of immunological decline. This invention is based in part on the discovery of a mutation at codon 101 either alone or in combination with a mutation at codon 190, for example 190s of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (efavirenz) treated patient(s) in which the presence of the mutations correlate with no change in delavirdine susceptibiltiy and a substantial decrease in both nevirapine and efavirenz susceptibiltiy. The mutations were found in plasma HIV RNA after a period of time following initiation of therapy. The development of the mutant at codon 101 in addition to the mutation at codon 190, for example 190s in HIV RT was found to be an indicator of the development of resistance and ultimately of immuological decline. This invention is based in part on the discovery of a mutation at codon 108 of HIV reverse transcriptase in patient(s) with no previously reported exposure to non-nucleoside reverse transcriptase inhibitor in which the presence of the mutation correlates with no change in delavirdine susceptibility and a slight decrease in nevirapine susceptibility and no change in efavirenz susceptibility. The mutation was found in plasma HIV RNA after a period of time following initiation of anti-retroviral therapy. The development of the codon 108 mutation in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline.
[0023] This invention is based in part on the discovery of a mutation at codon 101 either alone or in combination with a mutation at codon 103 and/or 190 of HIV reverse transcriptase in patients with no previously reported exposure to non-nucleoside reverse transcriptase inhibitors in which the presence of the mutatins correlate with changes in delavirdine, nevirapine and efavirenz susceptibility. Specifically, the presence of mutations at 101 and 190, for example 190A, correlates with no change in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a significant decrease in efavirenz susceptibility. The presence of mutations at 103 and 190 correlates with a moderate decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibiltiy and a significant decresase in efavirenz susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of anti-retroviral therapy. The development of the codon 101 and 103 and/or 190 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibiltiy/resistance which has been associated with virologic failure and subsequent immunological decline. This invention is based in part on the discovery of a mutation at codon 106 either alone or in combination with a mutation at codon 189 and/or 181 and 227 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (nevirapine) treated patient(s) in which the presence of the mutations correlate with changes in delavirdine, nevirapine and efavirenz susceptibility. Specifically, the presence of mutations at 106 and 181 correlates with a significant decrease in delavirdine susceptibility, a substantial decresase in neviradine susceptibility and a slight decrease in efavirenz susceptibility. The presence of mutations at 106 and 189 correlates with a slight decrease in delavirdine susceptibility, a moderate decresase in nevirapine susceptibitlity and no change in efavirenz susceptibility. The presence of mutations at 106 and 227 correlates with a slight decrease in delavirdine susceptibility, a substantial decresase in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. The presence of mutations at 181 and 227 correlates with an increase in delavirdine susceptibility, a significant decrease in nevirapine susceptibility and an incease in efavirenz susceptibility. The presence of mutations at 106 and 181 and 227 correlates with a moderate decrease in delavirdine susceptibility , a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of NNRTI therapy. The development of the codon 106 and 189 and/or 181 and 227 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immuological decline. This invention is based in part on the discovery of a mutation at codon 103 either alone or in combination with a mutation at codon 100 and/or 188 of HIV reverse transcriptase in non-nucleoside reverse transcriptase inhibitor (nevirapine) treated patient(s) in which the presence of the mutations correlate with changes in delavirdine, nevirapine and efavirenz susceptibility. Specifically, the presence of mutations at 103 and 188 correlates with a substantial decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a substantial decrease in efaviranz susceptibility. The presence of mutations at 100 and 103 correlates with a substantial decrease in delavirdine susceptibility, a moderate decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. The presence of mutations at 103 and 100 and 188 correlates with a substantial decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. The mutations were found in plasma HIV RNA after a period of time following initiation of NNRTI therapy. The developemnt of the codon 103 and 100 and/or 188 mutations in HIV RT was found to be an indicator of the development of alterations in phenotypic susceptibility/resistance which has been associated with virologic failure and subsequent immunological decline.
[0024] In a further embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 225 in combination with mutations at other codons including 103 of HIV RT which correlate with a specific pattern of resistance to antiretroviral therapies and subsequent immunologic decline. In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 236 either alone or in combination with mutations at other codons including 103 and/or 181 of HIV RT which correlate with resistance to antiretroviral therapy and immunologic decline. In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 190 (G190S) either alone or in combination with mutation at codon 101 (K101E) of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0025] In still another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 190 (G190A) either alone or in combination with mutation at codon 103 (K103N) of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0026] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 230 either alone or in combination with mutation at codon 181 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0027] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect a mutation at codon 181 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0028] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect a mutation at codon 188 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0029] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 138 either alone or in combination with mutation at codon 188 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0030] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect a mutation at codon 98 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0031] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 98 either alone or in combination with mutation at codon 190 of HIV RT which correlates with resistance to antiretroviral therapy and immuolgoic decline.
[0032] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 181 either alone or in combination with mutation at codon 98 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0033] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 101 either alone or in combination with mutation at codon 190, for example 190s of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0034] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect a mutation at codon 108 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0035] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 101 either alone or in combination with mutations at codon 103 and/or 190 of HIV RT which correlates with resistance to antiretoviral therapy and immunologic decline.
[0036] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 106 either alone or in combination with mutations at codon 189 and/or 181 and 227 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic decline.
[0037] In yet another embodiment of the invention, PCR based assays, including phenotypic and genotypic assays, may be used to detect mutations at codon 188 either alone or in combination with mutation at codon 100 and /or 103 of HIV RT which correlates with resistance to antiretroviral therapy and immunologic declaine. Once mutations at codon 225 and 103 have been detected in a patient undergoing NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 236 and/or 103 and/or 181 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 190 and/or 103 and/or 101 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 230 and/or 181 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once a mutation at codon 181 has been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once a mutation at codon 188 has been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 138 and/or 188 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once a mutation at codon 98 has been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 98 and/or 190 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 181 and/or 98 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therpeutic regimen must be considered. Similarly, once mutations at codon 101 and/or 190, for example 190S, have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once a mutation at codon 108 has been detected in a patient underfoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 101 and/or 103 and/or 190, for example 190A, have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 106 and/or 189 and/or 181 and/or 227 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. Similarly, once mutations at codon 188 and/or 100 and/or 103 have been detected in a patient undergoing certain NNRTI antiretroviral therapy, an alteration in the therapeutic regimen must be considered. The timing at which a modification of the therapeutic regimen should be made, following the assessment of the antiretroviral therapy using PCR based assays, may depend on several factors including the patient's viral load, CD4 count, and prior treatment history.
[0038] In another aspect of the invention there is provided a method for assessing the effectiveness of a non-nucleoside reverse transcriptase antiretroviral drug comprising: (a) introducing a resistance test vector comprising a patient-derived segment and an indicator gene into a host cell; (b) culturing the host cell from step (a); (c) measuring expression of the indicator gene in a target host cell wherein expression of the indicator gene is dependent upon the patient derived segment; and (d) comparing the expression of the indicator gene from step (c) with the expression of the indicator gene measured when steps (a)-(c) are carried out in the absence of the NNRTI anti-HIV drug, wherein a test concentration of the NNRTI, anti-HIV drug is presented at steps (a)-(c); at steps (b)-(c); or at step (c).
[0039] This invention also provides a method for assessing the effectiveness of non-nucleoside reverse transcriptase antiretroviral therapy in a patient comprising: (a) developing a standard curve of drug susceptibility for an NNRTI anti-HIV drug; (b) determining NNRTI anti-HIV drug susceptibility in the patient using the susceptibility test described above; and (c) comparing the NNRTI anti-HIV drug susceptibility in step (b) with the standard curve determined in step (a), wherein a decrease in NNRTI antiHIV susceptibility indicates development of anti-HIV drug resistance in the patient.
[0040] This invention also provides a method for evaluating the biological effectiveness of a candidate HIV antiretroviral drug compound comprising: (a) introducing a resistance test vector comprising a patient-derived segment and an indicator gene into a host cell; (b) culturing the host cell from step (a); (c) measuring expression of the indicator gene in a target host cell wherein expression of the indicator gene is dependent upon the patient derived segment; and (d) comparing the expression of the indicator gene from step (c) with the expression of the indicator gene measured when steps (a)-(c) are carried out in the absence of the candidate anti-viral drug compound, wherein a test concentration of the candidate anti-viral drug compound is present at steps (a)-(c); at steps (b)-(c); or at step (c).
[0041] The expression of the indicator gene in the resistance test vector in the target cell is ultimately dependent upon the action of the patient-derived segment sequences. The indicator gene may be functional or non-functional.
[0042] In another aspect this invention is directed to antiretroviral drug susceptibility and resistance tests for HIV/AIDS. Particular resistance test vectors of the invention for use in the HIV/AIDS antiretroviral drug susceptibility and resistance test are identified.
[0043] In yet another aspect this invention provides for the identification and assessment of the biological effectiveness of potential therapeutic antiretroviral compounds for the treatment of HIV and/or AIDS. In another aspect, the invention is directed to a novel resistance test vector comprising a patient-derived segment further comprising one or more mutations on the RT gene and an indicator gene.
[0044] In yet another aspect of the invention, a method of assessing the effectiveness of non-nucleoside reverse transcriptase antiretroviral therapy of an HIV-infected patient is provided comprising:
[0045] (a) collecting a plasma sample from the HIV-infected patient; and
[0046] (b) evaluating whether the plasma sample contains nucleic acid encoding HIV integrase having a mutation at codon 66;
[0047] in which the presence of the mutation correlates with an increased susceptibility to delavirdine, nevirapine, and efavirenz.
[0048] In another preferred embodiment of the invention, the method of assessing the effectiveness of non-nucleoside reverse transcriptase antiretroviral therapy is provided, wherein the mutation at codon 66 codes for isoleucine (I).
[0049] In another preferred embodiment of the invention, the method of assessing the effectiveness of non-nucleoside reverse transcriptase antiretroviral therapy is provided, wherein the mutation at codon 66 is a substitution of isoleucine (I) for threonine (T).
[0050] In another preferred embodiment of the invention, the method of assessing the effectiveness of non-nucleoside reverse transcriptase antiretroviral therapy is provided, wherein the HIV-infected patient is being treated with an antiretroviral agent.
[0051] In another preferred embodiment of the invention, a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient is provided comprising:
[0052] (a) collecting a biological sample from an HIV-infected patient; and
[0053] (b) evaluating whether the biological sample comprises nucleic acid encoding HIV integrase having a mutation at codon 66 ;
[0054] in which the presence of the mutation correlates with a decreased susceptibility to integrase inhibitor L-731,988.
[0055] In another preferred embodiment of the invention, the method of assessing the effectiveness of antiretroviral therapy is provided, wherein the mutation at codon 66 codes for isoleucine (I).
[0056] In another preferred embodiment of the invention, the method of assessing the effectiveness of antiretroviral therapy is provided, wherein the mutation at codon 66 is a substitution of isoleucine (I) for threonine (T).
[0057] In another preferred embodiment of the invention, the method of assessing the effectiveness of antiretroviral therapy is provided, wherein the HIV-infected patient is being treated with an antiretroviral agent.
[0058] In another preferred embodiment of the invention, the method of assessing the effectiveness of antiretroviral therapy is provided, wherein the presence of the mutation further correlates with an increased susceptibility to delavirdine, nevirapine, and efavirenz.
[0059] In yet another aspect of the invention, a method for assessing the biological effectiveness of a candidate HIV antiretroviral drug compound comprising:
[0060] (a) introducing a resistance test vector comprising a patient-derived segment further comprising nucleic acid encoding HIV integrase having a mutation at codon 66;
[0061] (b) culturing the host cell from step (a);
[0062] (c) measuring the indicator in a target host cell; and
[0063] (d) comparing the measurement of the indicator from step (c) with the measurement of the indicator measured when steps (a)-(c) are carried out in the absence of the candidate antiretroviral drug compound;
[0064] wherein a test concentration of the candidate antiretroviral drug compound is present at steps (a)-(c); at steps (b)-(c); or at step (c).
[0065] In another preferred embodiment of the invention, the method for assessing the biological effectiveness is provided, wherein the mutation at codon 66 codes for isoleucine (I).
[0066] In another preferred embodiment of the invention, the method for assessing the biological effectiveness is provided, wherein the mutation at codon 66 is a substitution of isoleucine (I) for threonine (T).
[0067] In another preferred embodiment of the invention, the method for assessing the biological effectiveness is provided, wherein the indicator is an indicator gene.
[0068] In another preferred embodiment of the invention, the method for assessing the biological effectiveness is provided, wherein the indicator gene is a nonfunctional indicator gene.
[0069] In yet another aspect of the invention, a resistance test vector is provided comprising an HIV patient-derived segment further comprising nucleic acid encoding HIV integrase having a mutation at codon 66 and an indicator gene, wherein the expression of the ofindicator gene is dependent upon the patient derived-segment.
[0070] In yet another aspect of the invention, the resistance test vector is provided, wherein the patient-derived segment having a mutation at codon 66 codes for isoleucine (I).
[0071] In yet another aspect of the invention, the resistance test vector is provided, wherein the mutation at codon 66 is a substitution of isoleucine (I) for threonine (T).
BRIEF DESCRIPTION OF THE DRAWINGS
[0072] [0072]FIG. 1
[0073] Resistance Test Vector. A diagrammatic representation of the resistance test vector comprising a patient derived segment and an indicator gene.
[0074] [0074]FIG. 2
[0075] Two Cell Assay. Schematic Representation of the Assay. A resistance test vector is generated by cloning the patient-derived segment into an indicator gene viral vector. The resistance test vector is then co-transfected with an expression vector that produces amphotropic murine leukemia virus (MLV) envelope protein or other viral or cellular proteins which enable infection. Pseudotyped viral particles are produced containing the protease (PR) and the reverse transcriptase (RT) gene products encoded by the patient-derived sequences. The particles are then harvested and used to infect fresh cells. Using defective PR and RT sequences it was shown that luciferase activity is dependent on functional PR and RT. PR inhibitors are added to the cells following transfection and are thus present during particle maturation. RT inhibitors, on the other hand, are added to the cells at the time of or prior to viral particle infection. The assay is performed in the absence of drug and in the presence of drug over a wide range of concentrations. The amount of luciferase is determined and the percentage (%) inhibition is calculated at the different drug concentrations tested.
[0076] [0076]FIG. 3
[0077] Examples of phenotypic drug susceptibility profiles. Data are analyzed by plotting the percent inhibition of luciferase activity vs. log 10 concentration (uM). This plot is used to calculate the drug concentration that is required to inhibit virus replication by 50% (IC 50 ) or by 95% (IC 95 ). Shifts in the inhibition curves towards higher drug concentrations are interpreted as evidence of drug resistance. Three typical curves for a nucleoside reverse transcriptase inhibitor (AZT), a non-nucleoside reverse transcriptase inhibitor (delavirdine), and a protease inhibitor (ritonavir) are shown. A reduction in drug susceptibility (resistance) is reflected in a shift in the drug susceptibility curve toward higher drug concentrations (to the right) as compared to a baseline (pre-treatment) sample or a drug susceptible virus control, such as PNL4-3 or HXB-2, when a baseline sample is not available.
[0078] [0078]FIG. 4
[0079] Phenotypic drug susceptibility and resistance profile: patient 487. A PCR-based phenotypic susceptibility assay was carried out giving the phenotypic drug susceptibility and resistance profile showing increased resistance to both delavirdine and nevirapine. This is an example of the first pattern of NNRTI susceptibility/resistance. Evaluation of this virus from plasma showed HIV reverse transcriptase having mutations at codons 184 (M184V) associated with 3TC resistance and at 103 (K103N) associated with both delavirdine and nevirapine resistance.
[0080] [0080]FIG. 5
[0081] Phenotypic drug susceptibility and resistance profile of site directed reverse transcriptase mutants. A PCR-based phenotypic susceptibility assay was carried out giving the phenotypic drug susceptibility and resistance profile for site directed mutants having mutations at codons 103 and 181 (K103N; Y181C) demonstrating resistance to both delavirdine and nevirapine. The double mutant demonstrates the additive effect of both mutations resulting in a further increase in resistance.
[0082] [0082]FIG. 6
[0083] Phenotypic drug susceptibility and resistance profile: Patient 268. A PCR-based phenotypic susceptibility assay was carried out giving the phenotypic drug susceptibility and resistance profile showing the evaluation of virus from plasma with HIV reverse transcriptase having phenotypic resistance to delavirdine but not nevirapine. This is an example of the second pattern of NNRTI susceptibility/resistance. This patient virus is resistant to all of the protease inhibitors tested and also has significant resistance to AZT and 3TC and shows slight shifts in susceptibility to ddC, ddI, and d4T. Evaluation of this virus from plasma using a PCR and sequencing based genotypic assay showed HIV reverse transcriptase having mutations at codons 103 and 236 (K103N; P236L). The P236L mutation was previously reported to cause delavirdine resistance and nevirapine hypersensitivity (Dueweke T J et al. (1993) Proc Natl Acad Sci 90, 4713-4717). However, in this patient sample, while there was delavirdine resistance nevirapine susceptibility was the same as wild type.
[0084] [0084]FIG. 7
[0085] Phenotypic drug susceptibility and resistance profile of site-directed reverse transcriptase mutant (P236L). A PCR-based phenotypic susceptibility assay was carried out giving the phenotypic drug susceptibility and resistance profile showing the susceptibility to delavirdine and nevirapine of the P236L site-directed mutagenesis mutant. This result is identical to that observed in the patient virus sample shown in FIG. 6. The next two panels show the K103N site-directed mutagenesis mutant and the two panels below show the double mutant K103N+P236L. The P236L mutation is additive to the K103N causing severe resistance to delavirdine while having no effect on nevirapine resistance due to K103N. The right side of the figure shows a similar result when the P236L mutation is added to the Y181→C mutation.
[0086] [0086]FIG. 8A
[0087] Phenotypic Drug Susceptibility and Resistance Profile: Patients 302 . This is one example of the third pattern of NNRTI susceptibility/resistance. Phenotypic analysis of the patient virus demonstrated reduced susceptibility to both delavirdine and nevirapine. This pattern is characterized by a larger reduction of nevirapine susceptibility compared to the reduction of delavirdine susceptibility. Genotypic analysis of the patient virus demonstrated the presence of the RT mutations K103N associated with nevirapine and delavirdine resistance and P225H.
[0088] [0088]FIG. 8B
[0089] Phenotypic Drug Susceptibility and Resistance Profile: Patients 780. This is a second example of the third pattern of NNRTI susceptibility/resistance. Phenotypic analysis of the patient virus demonstrated reduced susceptibility to both delavirdine and nevirapine. This pattern is characterized by a larger reduction of nevirapine susceptibility compared to the reduction of delavirdine susceptibility. Genotypic analysis of the patient virus demonstrated the presence of the RT mutations K103N associated with nevirapine and delavirdine resistance and P225H.
[0090] [0090]FIG. 8C
[0091] Phenotypic Drug Susceptibility and Resistance Profile: Individual Virus Clones of Patient 302. Genotypic analysis of individual virus clones from patient 302 revealed viruses containing the K103N mutation without the P225H mutation (K103N, I135M, R211K) and viruses containing the K103N mutation with the P225H mutation (K103N, P225H). Phenotypic characterization of these virus clones indicates that the P225H mutation reduces the amount delavirdine resistance associated with the K103N mutation (compare bottom panels), but does not alter the amount of nevirapine resistance associated with the K103N mutation (compare top panels).
[0092] [0092]FIG. 8D
[0093] Phenotypic Drug Susceptibility and Resistance Profile: Site Directed Reverse Transcriptase Mutants. Phenotypic characterization of a virus containing the site directed RT mutation P225H indicates that this mutation increases susceptibility to delavirdine, but not nevirapine (compare top panels). Phenotypic characterization of a virus containing the site directed RT mutations P225H plus K013N or P225H plus Y181C indicate that the P225H mutation decreases the amount of delavirdine resistance associated with either K103N or Y181C, but does not decrease the amount of nevirapine resistance associated with K103N or Y181C. to delavirdine, but not nevirapine (compare corresponding middle and bottom panels).
[0094] [0094]FIG. 9A
[0095] Phenotypic Drug Susceptibility and Resistance Profile: Patients 644. This is one example of the fourth pattern of NNRTI susceptibility and resistance. Phenotypic analysis of the patient virus demonstrated by a large reduction in susceptibility to nevirapine, but not delavirdine. Genotypic analysis of the patient virus demonstrated the presence of the RT mutations G190S, as well as the K101E mutation associated with reductions in susceptibility to atevirdine, DMP266, L-697,661 and UC-10,38,57 (Schinazi, Mellors, Larder resistance table).
[0096] [0096]FIG. 9B
[0097] Phenotypic Drug Susceptibility and Resistance Profile: Site Directed Reverse Transcriptase Mutants. Phenotypic characterizations of viruses containing either site directed RT mutations G190A, or G190S indicate that these mutations greatly reduce susceptibility to nevirapine, and slightly increase susceptibility to delavirdine (compare top panels)
[0098] [0098]FIG. 10
[0099] Integrase inhibitor and NNRTI susceptibility of the T66I integrase site-directed mutant.
DETAILED DESCRIPTION OF THE INVENTION
[0100] The present invention relates to methods of monitoring the clinical progression of HIV infection in patients receiving antiretroviral therapy, particularly non-nucleoside reverse transcriptase inhibitor antiretroviral therapy.
[0101] In one embodiment, the present invention provides for a method of assessing the effectiveness of antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at one or more positions in the RT. The mutation(s) correlate positively with alterations in phenotypic susceptibility/resistance.
[0102] In a specific embodiment, the invention provides for a method of assessing the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon 225 and 103. This invention established, using a phenotypic susceptibility assays, that mutations at codon 225 either alone or in combination with a mutation at codon 103 of HIV reverse transcriptase are correlated with an increase in delavirdine susceptibility, little or no change in nevirapine susceptibility and little or no change in efavirenz susceptibility.
[0103] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 236 and 103 and/or 181. This invention established, using a phenotypic susceptibility assay, that mutations at codon 236 either alone or in combination with a mutation at codon 103 and/or 181 of HIV reverse transcriptase are correlated with a decrease in delavirdine susceptibility (increased resistance) and no change in nevirapine susceptibility. The 236 mutation alone or on a Y181C background has no effect on efavirenz susceptibility but restores a significant portion of the loss of susceptibility caused by a 103N mutation.
[0104] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 230 and/or 181. This invention established, using a phenotypic susceptibility assay, that mutations at codon 230 either alone or in combination with a mutation at codon 181 of HIV reverse transcriptase are correlated with a significant decrease in delavirdine susceptibility (increased resistance), significant decrease in nevirapine susceptibility.
[0105] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon 181. This invention established, using a phenotypic susceptibility assay, that a mutation at codon 181 of HIV reverse transcriptase is correlated with a moderate decrease in delavirdine susceptibility (increased resistance), significant decrease in nevirapine susceptibility and no change in efavirenz susceptibility.
[0106] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient, and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon 188. This invention established, using a phenotypic susceptibility assay, that a mutation at codon 188 of HIV reverse transcriptase are correlated with a slight decrease in delavirdine susceptibility (increased resistance), a substantial decrease in nevirapine susceptibility and a significant decrease in efavirenz susceptibility.
[0107] In other specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 138 and/or 188. This invention established, using a phenotypic susceptibility assay, that mutations at codon 138 either alone or in combination with a mutation at codon 188 of HIV reverse transcriptase are correlated with a moderate decrease in delavirdine susceptibility (increased resistance), a substantial decrease in nevirapine susceptibility and a moderate decrease in efavirenz susceptibility.
[0108] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 98. This invention established, using a phenotypic susceptibility assays, that mutations at codon 98 of HIV reverse transcriptase are correlated with a slight decrease in delavirdine susceptibility (increase resistance) , a slight decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility.
[0109] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 98 and/or 190. This invention established, using a phenotypic susceptibility assay, that mutations at codon 98 either alone or in combination with a mutation at codon 190 of HIV reverse transcriptase are correlated with an increase in delavirdine susceptibility (decreased resistance), a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In other specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 181 and/or 98. This invention established, using a phenotypic susceptibility assay, that mutations at codon 181 either alone or in combination with a mutation at codon 98 of HIV reverse transcriptase are correlated with a significant decrease in delavirdine susceptibility (increased resistance), a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient ; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 101 and/or 190, for example 190S. This invention established, using a phenotypic susceptibility assay, that mutations at codon 101 either alone or in combination with a mutation at codon 190 of HIV reverse transcriptase are correlated with no change in delavirdine susceptibility (wild-type), a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 108. This invention established, using a phenotypic susceptibility assay, that a mutation at codon 108 of HIV reverse transcriptase are correlated with a no change in delavirdine susceptibility (wild-type), a slight decrease in nevirapine susceptibility and no change in efavirenz susceptibility. In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 101 and 103 and/or 190. This invention established, using a phenotypic susceptibility assay, that mutations at codon 101 either alone or in combination with a mutation at codon 103 and/or 190 of HIV reverse transcriptase are correlated with a either no change (101 and 190) or a moderate decrease (103 and 190, for example 190A) in delavirdine susceptibility (increased resistance), a substantial decrease in nevirapine susceptibility and a significant decrease in efavirenz susceptibility.
[0110] In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 106 and/or 189 and/or 181 and/or 227. This invention established, using a phenotypic susceptibility assay, that mutations at codon 106 either alone or in combination with a mutation at codon 189 and/or 181 and/or 227 of HIV reverse transcriptase are correlated with changes in delavirdine, nevirapine and efavirenz susceptibility. Specifically, the presence of mutations at 106 and 181 correlates with a significant decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. The presence of mutations at 106 and 189 correlates with a slight decrease in delavirdine susceptibility, a moderate decrease in nevirapine susceptibility and no change in efavirenz susceptibility. The presence of mutations at 106 and 227 correlates with a slight decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. The presence of mutations at 181 and 227 correlates with an increase in delavirdine susceptibility, a significant decrease in nevirapine susceptibility and an increase in efavirenz susceptibility. The presence of mutations at 106 and 181 and 227 correlates with a moderate decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. In another specific embodiment, the invention provides for a method of evaluating the effectiveness of NNRTI antiretroviral therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; and (ii) determining whether the biological sample comprises nucleic acid encoding HIV RT having a mutation at codon(s) 188 and 100 and/or 103. This invention established, using a phenotypic susceptibility assay, that mutations at codon 188 either alone or in combination with a mutation at codon 100 and/or 103 of HIV reverse transcriptase are correlated changes in delavirdine, nevirapine and efavirenz susceptibility. Specifically, the presence of mutations at 103 and 188 correlates with a substantial decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a substatntial decrease in efavirenz susceptibility. The presence of mutations at 100 and 103 correlates with a substantial decrease in delavirdine susceptibility, a moderate decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. The presence of mutations at 103 and 100 and 188 correlates with a substantial decrease in delavirdine susceptibility, a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. Under the foregoing circumstances, the phenotypic susceptibility/resistance profile and genotypic profile of the HIV virus infecting the patient has been altered reflecting some change in the response to the antiretroviral agent. In the case on NNRTI antiretroviral therapy, the HIV virus infecting the patient may be resistant to one or more but not another of the NNRTIs as described herein. It therefore may be desirable after detecting the mutation, to either increase the dosage of the antiretroviral agent, change to another antiretroviral agent, or add one or more additional antiretroviral agents to the patient's therapeutic regimen. For example, if the patient was being treated with efavirenz (DMP-266) when the 225 mutation arose, the patient's therapeutic regimen may desirably be altered by either (i) changing to a different NNRTI antiretroviral agent, such as delavirdine or nevirapine and stopping efavirenz treat; or (ii) increasing the dosage of efavirenz; or (iii) adding another antiretroviral agent to the patient's therapeutic regimen. The effectiveness of the modification in therapy may be evaluated by monitoring viral burden such as by HIV RNA copy number. A decrease in HIV RNA copy number correlates positively with the effectiveness of a treatment regiment.
[0111] The phrase “correlates positively,” as used herein, indicates that a particular result renders a particular conclusion more likely than other conclusions.
[0112] Another preferred, non-limiting, specific embodiment of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a biological sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the biological sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises that RT gene; (iii) performing PCR using primers that result in PCR products comprising wild type or mutant 225 and 103 codons; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 225 or 103 or both. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (I) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codons 103 and/or 181 and 236; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 236 and 103 and/or 181.
[0113] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (I) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises that RT gene: (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 101 and 190 (G190S); and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 190 (G190S) and 101.
[0114] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 103 and 190 (G190A) and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 190 (G190A) and 103. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 230 and 181, and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 230 and 181.
[0115] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutation at 181; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 181. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutation at codon 188 ; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 188. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 138 and 188; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 138 and 188.
[0116] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PR using primers that result in PCR products comprising the wild type or mutation at codon 98 and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 98. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 98 and 190; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 190 and 98. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 98 and 181; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 98 and 181.
[0117] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 101 and 190; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 190, for example 190S and 101.
[0118] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or a mutation at codon 108; and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 108. Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or a mutation at codon 101 and 103 and 190 and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 101 and 103 and 190, for example 190A.
[0119] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises that RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 106 and and 189 and 181 and 227 and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 106 and 189 and 181 and 227.
[0120] Yet another preferred, non-limiting specific embodiment, of the invention is as follows: A method of assessing the effectiveness of NNRTI therapy of a patient comprising (i) collecting a plasma sample from an HIV-infected patient; (ii) amplifying the HIV-encoding RNA in the plasma sample by converting the RNA to cDNA and amplifying HIV sequences using HIV primers that result in a PCR product that comprises the RT gene; (iii) performing PCR using primers that result in PCR products comprising the wild type or mutations at codon 188 and 100 and 103 and (iv) determining, via the products of PCR, the presence or absence of a mutation at codon 188 and 100 and 103. The presence of the mutation at codon 225 and 103 of HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy may require alteration, since as shown by this invention mutation at codon 103 reduces susceptibility which susceptibility can in part be restored by mutation at codon 225. Using the methods of this invention change in the NNRTI therapy would be indicated. Similarly, using the means and methods of this invention the presence of the mutation at codon 236 and 103 and/or 181 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 190 (G190A) and 103 (K103N) of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 190 (G190S) and 101 (K101E) of the HIV RT indicate that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 230 and 181 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the a mutation at codon 181 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 188 of the HIV RT indicates that the effectiveness of the current of prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 138 and 188 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 98 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 98 and 190 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 181 and 98 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 101 and 190, for example 190S, of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of a mutation at codon 108 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at 101 and 103 and 190, for example 190A, of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of this invention the presence of the mutation at codon 106 and 189 and 181 and 227 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished. Similarly, using the means and methods of the invention the presence of the mutation at codon 188 and 100 and 103 of the HIV RT indicates that the effectiveness of the current or prospective NNRTI therapy has been diminished.
[0121] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of evaluating the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 236 and 103 and/or 181. Using the phenotypic susceptibility assay, it was observed that the presence of the three mutations correlates positively with delavirdine resistance. Using the phenotypic susceptibility assay, it was observed that the presence of the three mutations correlates positively with nevirapine resistance. In another embodiment, the mutated codon 236 of HIV RT encodes leucine (L). In a further embodiment, the reverse transcriptase has a mutation at codon 103, a mutation at codon 181 or a combination thereof in addition to the mutation at codon 236 of HIV RT. In a still further embodiment, the mutated codon 103 encodes an asparagine (N) and the mutated codon at 181 encodes a cysteine (C).
[0122] Another preferred, non-limiting, specific embodiment of the invention is a follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 225 and 103. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 225 alone or in combination with a mutation at codon 103 of HIV RT cause an increase in delavirdine susceptibility while having no effect on nevirapine susceptibility. In yet another embodiment, the mutated codon 225 codes for a histidine, codon 230 codes for a luecine and codon 181 codes for a cysteine.
[0123] This invention provides a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 181. Using the phenotypic susceptibility assay it was observed that the presence of mutations at codon 181 correlates positively with a moderate decrease in delavirdine susceptibility and a significant decrease in nevirapine susceptibility and no change in efavirenz susceptibility. In an embodiment, the mutated codon 181 for a isoleucine.
[0124] This invention provides a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 188. Using the phenotypic susceptibility assay it was observed that the presence of mutations at codon 188 correlates positively with a slight decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and significant decrease in efavirenz susceptibility. In an embodiment, the mutated codon 188 codes for a cysteine, histidine, or leucine.
[0125] This invention provides a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 190. Using the phenotypic susceptibility assay it was observed that the presence of mutations at codon 190 correlates positively with a slight increase in delavirdine susceptibility and a large decrease in nevirapine susceptibility. In an embodiment, the mutated codon 190 codes for an alanine or a serine.
[0126] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 230 and 181. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 230 alone or in combination with a mutation at codon 181 of HIV RT causes a significant decrease in delavirdine susceptibility and a significant decrease in nevirapine susceptibility.
[0127] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 138 and 188. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 138 alone or in combination with a mutation at codon 188 of HIV RT causes a moderate decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a moderate decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 138 codes for a alanine and codon 188 codes for a leucine.
[0128] This invention provides a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 98. Using the phenotypic susceptibility assay it was observed that the presence of mutations at codon 98 correlates positively with a slight decrease in delavirdine susceptibility and a slight decrease in delavirdine susceptibility and a slight decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. In an embodiment, the mutated codon 98 codes for glycine.
[0129] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 98 and 190. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 98 alone or in combination with a mutation at codon 190 of HIV RT causes an increase in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 190 codes for a serine and codon 98 for a glycine.
[0130] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 181 and 98. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 181 alone or in combination with a mutation at codon 98 of HIV RT causes a significant decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 98 codes for a glycine and codon 181 codes for a cysteine.
[0131] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 101 and 190, for example 190S. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 101 alone or in combination with a mutation at codon 190 of HIV RT causes no change in delavirdine susceptibility and a substantial decease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 190 codes for a serine and codon 101 codes for a glutamine acid.
[0132] This invention provides a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 108. Using the phenotypic susceptibility assay it was observed that the presence of mutations at codon 108 correlates positively with no change in delavirdine susceptibility and a slight decrease in nevirapine susceptibility and no change in efavirenz susceptibility . In an embodiment, the mutated codon 108 codes for a isoleucine.
[0133] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 101 and 190, for example 190A. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 101 alone or in combination with a mutation at codon 190 of HIV RT causes no change in delavirdine susceptibility and a substantial decease in nevirapine susceptibility and a significant decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 190 codes for a glycine and codon 101 codes for a glutamine acid.
[0134] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 103 and 190. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 103 alone or in combination with a mutation at codon 190 of HIV RT causes a moderate decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a significant decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 190 codes for a alanine and codon 103 codes for a asparagine.
[0135] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 106 and 181. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 106 alone or in combination with a mutation at codon 181 of HIV RT causes a significant decease in delvaridine susceptibility and a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 106 codes for a alanine and codon 181 codes for a cysteine.
[0136] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 106 and 189. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 106 alone or in combination with a mutation at codon 189 of HIV RT causes a slight decrease in delavirdine susceptibility and a moderate decrease in nevirapine susceptibility and no change in efavirenz susceptibility. In yet another embodiment, the mutated codon 189 codes for a leucine and a codon 106 codes for a alanine.
[0137] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 106 and 227. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 106 alone or in combination with a mutation at codon 227 of HIV RT causes a slight decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a slight decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 227 codes for a leucine and codon 106 codes for a alanine.
[0138] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological cample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 181 and 227. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 181 alone or in combination with a mutation at codon 227 of HIV-RT causes an increase in delavirdine susceptibility and an significant decrease in nevirapine susceptibility and and an increase in efavirenz susceptibility.
[0139] In yet another embodiment, the mutated codon 227 codes for a leucine and codon 181 codes for cysteine.
[0140] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 106 and 181 and 227. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 106 alone or in combination with a mutation at codon 181 and 227 of HIV RT causes a moderate decrease in delavirdine susceptibility and a slight decrease in efavirenz susceptibility.
[0141] In yet another embodiment, the mutated codon 106 codes for a alanine, codon 181 codes for a cysteine and codon 227 codes for a leucine.
[0142] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 103 and 188. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 103 alone or in combination with a mutation at codon 188 of HIV RT causes a substantial decrease in delavirdine susceptibility and a substantial decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility. In yet another embodiment, the mutated codon 188 codes for a leucine and codon 103 codes for a asparagine.
[0143] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 100 and 103. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 100 alone or in combination with a mutation at codon 103 of HIV RT causes a substantial decrease in delavirdine susceptibility and a moderate decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility.
[0144] In yet another embodiment, the mutated codon 100 codes for a isoleucine, codon 103 codes for a asparagine.
[0145] Another preferred, non-limiting, specific embodiment of the invention is as follows: a method of assessing the effectiveness of antiretroviral therapy of an HIV-infected patient comprising: (a) collecting a biological sample from an HIV-infected patient; and (b) determining whether the biological sample comprises nucleic acid encoding HIV reverse transcriptase having a mutation at codon 100 and 103 and 188. Using the phenotypic susceptibility assay, it was observed that the presence of the mutations at codons 100 alone or in combination with a mutation at codon 103 and 188 of HIV RT causes a substantial decrease in delavirdine susceptibility and a moderate decrease in nevirapine susceptibility and a substantial decrease in efavirenz susceptibility.
[0146] In yet another embodiment, the mutated codon 100 codes for a isoleucine, codon 103 codes for a asparagine and codon 188 codes for a leucine.
[0147] This invention also provides the means and methods to use the resistance test vector comprising an HIV gene further comprising an NNRTI mutation for drug screening. More particularly, the invention describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 225 and 103 for drug screening. The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 236 and 103 and/or 181. The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 190 (G190A) and 103 (K103N). The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 190 (G190S) and 101 (K101E).
[0148] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 230 and 181.
[0149] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having a mutation at codon 181.
[0150] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having a mutation at codon 188.
[0151] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 138 and 188.
[0152] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having a mutation at 98.
[0153] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 98 and 190.
[0154] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 181 and 98.
[0155] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 101 and 190, for example 190S.
[0156] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having a mutation at codon 108.
[0157] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 101 and 103 and/or 190, for example 190A.
[0158] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 106 and 189 and/or 181 and/or 227.
[0159] The invention also describes the resistance test vector comprising the HIV reverse transcriptase having mutations at codons 188 and 100 and/or 103.
[0160] The invention further relates to novel vectors, host cells and compositions for isolation and identification of the non-nucleoside HIV-1 reverse transcriptase inhibitor resistance mutant and using such vectors, host cells and compositions to carry out anti-viral drug screening. This invention also relates to the screening of candidate drugs for their capacity to inhibit said mutant.
EXAMPLE 1
Phenotypic Drug Susceptibility and Resistance Test Using Resistance Test Vectors
[0161] Phenotypic drug susceptibility and resistance tests are carried out using the means and methods described in PCT International Application No. PCT/US97/01609, filed Jan. 29, 1997 which is hereby incorporated by reference.
[0162] In these experiments patient-derived segment(s) corresponding to the HIV protease and reverse transcriptase coding regions were either patient-derived segments amplified by the reverse transcription-polymerase chain reaction method (RT-PCR) using viral RNA isolated from viral particles present in the serum of HIV-infected individuals or were mutants of wild type HIV-1 made by site directed mutagenesis of a parental clone of resistance test vector DNA. Isolation of viral RNA was performed using standard procedures (e.g. RNAgents Total RNA Isolation System, Promega, Madison Wis. or RNAzol, Tel-Test, Friendswood, Tex.). The RT-PCR protocol was divided into two steps. A retroviral reverse transcriptase [e.g. Moloney MuLV reverse transcriptase (Roche Molecular Systems, Inc., Branchburg, N.J.), or avian myeloblastosis virus (AMV) reverse transcriptase, (Boehringer Mannheim, Indianapolis, Ind.)] was used to copy viral RNA into cDNA. The cDNA was then amplified using a thermostable DNA polymerase [e.g. Taq (Roche Molecular Systems, Inc., Branchburg, N.J.), Tth (Roche Molecular Systems, Inc., Branchburg, N.J.), PrimeZyme (isolated from Thermus brockianus, Biometra, Gottingen, Germany)] or a combination of thermostable polymerases as described for the performance of “long PCR” (Barnes, W.M., (1994) Proc. Natl. Acad. Sci, USA 91, 2216-2220) [e.g. Expand High Fidelity PCR System (Taq+Pwo), (Boehringer Mannheim. Indianapolis, Ind.) OR GeneAmp XL PCR kit (Tth+Vent), (Roche Molecular Systems, Inc., Branchburg, N.J.)].
[0163] The primers, ApaI primer (PDSApa) and AgeI primer (PDSAge) used to amplify the “test” patient-derived segments contained sequences resulting in ApaI and AgeI recognition sites being introduced into the 5′ and 3′ termini of the PCR product, respectively as described in PCT International Application No. PCT/US97/01609, filed Jan. 29, 1997.
[0164] Resistance test vectors incorporating the “test” patient-derived segments were constructed as described in PCT International Application No. PCT/US97/01609, filed Jan. 29, 1997 using an amplified DNA product of 1.5 kB prepared by RT-PCR using viral RNA as a template and oligonucleotides PDSApa (1) and PDSAge (2) as primers, followed by digestion with ApaI and AgeI or the isoschizimer PINAI. To ensure that the plasmid DNA corresponding to the resultant resistance test vector comprises a representative sample of the HIV viral quasi-species present in the serum of a given patient, many (>100) independent E. coli transformants obtained in the construction of a given resistance test vector were pooled and used for the preparation of plasmid DNA.
[0165] A packaging expression vector encoding an amphotrophic MuLV 4070A env gene product enables production in a resistance test vector host cell of resistance test vector viral particles which can efficiently infect human target cells. Resistance test vectors encoding all HIV genes with the exception of env were used to transfect a packaging host cell (once transfected the host cell is referred to as a resistance test vector host cell). The packaging expression vector which encodes the amphotrophic MuLV 4070A env gene product is used with the resistance test vector to enable production in the resistance test vector host cell of infectious pseudotyped resistance test vector viral particles.
[0166] Resistance tests performed with resistance test vectors were carried out using packaging host and target host cells consisting of the human embryonic kidney cell line 293 (Cell Culture Facility, UC San Francisco, SF, Calif.) or the Jurkat leukemic T-cell line (Arthur Weiss, UC San Francisco, SF, Calif.).
[0167] Resistance tests were carried out with resistance test vectors using two host cell types. Resistance test vector viral particles were produced by a first host cell (the resistance test vector host cell) that was prepared by transfecting a packaging host cell with the resistance test vector and the packaging expression vector. The resistance test vector viral particles were then used to infect a second host cell (the target host cell) in which the expression of the indicator gene is measured.
[0168] The resistance test vectors containing a functional luciferase gene cassette were constructed and host cells were transfected with the resistance test vector DNA. The resistant test vectors contained patient-derived reverse transcriptase and protease sequences that were either susceptible or resistant to the antiretroviral agents, such as nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. The resistance test vector viral particles produced by transfecting the resistance test vector DNA into host cells, either in the presence or absence of protease inhibitors, were used to infect target host cells grown either in the absence of NRTI or NNRTI or in the presence of increasing concentrations of the drug. The amount of luciferase activity produced in infected target host cells in the presence of drug was compared to the amount of luciferase produced in infected target host cells in the absence of drug. Drug resistance was measured as the amount of drug required to inhibit by 50% the luciferase activity detected in the absence of drug (inhibitory concentration 50%, IC50). The IC50 values were determined by plotting percent drug inhibition vs. log 10 drug concentration.
[0169] Host cells were seeded in 10-cm-diameter dishes and were transfected several days after plating with resistance test vector plasmid DNA and the envelope expression vector. Transfections were performed using a calcium-phosphate precipitation procedure. The cell culture media containing the DNA precipitate was replaced with fresh medium, from one to 24 hours, after transfection. Cell culture media containing resistance test vector viral particles was harvested one to four days after transfection and was passed through a 0.45-mm filter before being stored at −80° C. HIV capsid protein (p24) levels in the harvested cell culture media were determined by an EIA method as described by the manufacturer (SIAC; Frederick, Md.). Before infection, target cells (293 and 293/T) were plated in cell culture media. Control infections were performed using cell culture media from mock transfections (no DNA) or transfections containing the resistance test vector plasmid DNA without the envelope expression plasmid. One to three or more days after infection the media was removed and cell lysis buffer (Promega) was added to each well. Cell lysates were assayed for luciferase activity (FIG. 3). The inhibitory effect of the drug was determined using the following equation:
% luciferase inhibition=1−(RLUluc [drug]÷RLUluc)×100
[0170] where RLUluc [drug] is the relative light unit of luciferase activity in infected cells in the presence of drug and RLUluc is the Relative Light Unit of luciferase activity in infected cells in the absence of drug. IC50 values were obtained from the sigmoidal curves that were generated from the data by plotting the percent inhibition of luciferase activity vs. the log10 drug concentration. The drug inhibition curves are shown in (FIG. 3).
EXAMPLE 2
Correlating Phenotypic Susceptibility and Genotypic Analysis
[0171] Phenotypic Susceptibility Analysis of Patient HIV Samples
[0172] Resistance test vectors are constructed as described in example 1. Resistance test vectors, or clones derived from the resistance test vector pools, are tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs may comprise members of the classes known as nucleoside-analog reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PRIs). The panel of drugs can be expanded as new drugs or new drug targets become available. An IC50 is determined for each resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested is examined and compared to known patterns of susceptibility. A patient sample can be further examined for genotypic changes correlated with the pattern of susceptibility observed.
[0173] Genotypic Analysis of Patient HIV Samples
[0174] Resistance test vector DNAs, either pools or clones, are analyzed by any of the genotyping methods described in Example 2. In one embodiment of the invention, patient HIV sample sequences are determined using viral RNA purification, RT/PCR and ABI chain terminator automated sequencing. The sequence that is determined is compared to control sequences present in the database or is compared to a sample from the patient prior to initiation of therapy, if available. The genotype is examined for sequences that are different from the control or pre-treatment sequence and correlated to the observed phenotype.
[0175] Phenotypic Susceptibility Analysis of Site Directed Mutants
[0176] Genotypic changes that are observed to correlate with changes in phenotypic patterns of drug susceptibility are evaluated by construction of resistance test vectors containing the specific mutation on a defined, wild-type (drug susceptible) genetic background. Mutations may be incorporated alone and/or in combination with other known drug resistance mutations that are thought to modulate the susceptibility of HIV to a certain drug or class of drugs. Mutations are introduced into the resistance test vector through any of the widely known methods for site-directed mutagenesis. In one embodiment of this invention the mega-primer PCR method for site-directed mutagenesis is used. A resistance test vector containing the specific mutation or group of mutations is then tested using the phenotypic susceptibility assay described above and the susceptibility profile is compared to that of a genetically defined wild-type (drug susceptible) resistance test vector which lacks the specific mutations. Observed changes in the pattern of phenotypic susceptibility to the antiretroviral drugs tested is attributed to the specific mutations introduced into the resistance test vector.
EXAMPLE 3
Correlating Phenotypic Susceptibility and Genotypic Analysis: P225H
[0177] Phenotypic Analysis of Patient 97-302
[0178] A resistance test vector was constructed as described in example 1 from a patient sample designated as 97-302. This patient had been treated with d4T, indinavir and DMP-266 for a period of approximately 10 months. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The patient derived segment was inserted into a indicator gene viral vector to generate a resistance test vector designated RTV-302. RTV-302 was tested using a phenotypic susceptibility assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for each drug tested. Susceptibility of the patient virus to each drug was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient sample RTV-302 in which there was significant decrease in nevirapine susceptibility (increased resistance) and modest decrease in delavirdine susceptibility (See FIG. 8A) Patient sample 97-302 was examined further for genotypic changes associated with the observed pattern of susceptibility.
[0179] Determination of Genotype of Patient 97-302
[0180] RTV-302 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The nucleotide sequence was examined for sequences that are different from the control sequence. RT mutations were noted at positions K103N, I135M, T200A, and P225H. K103N is associated with resistance to the NNRTIs and has been shown using the phenotypic susceptibility assay to be associated with reduced susceptibility to both delavirdine and nevirapine to an equal extent. The mutations at I135M and T200A are known polymorphisms of the wild-type (drug-sensitive) variants of HIV. The mutation, P225H, was characterized using site directed mutagenesis and phenotypic susceptibility testing to correlate the changes at amino acid 225 with changes in NNRTI phenotypic susceptibility.
[0181] Site Directed Mutagenesis
[0182] Resistance test vectors were constructed containing the P225H mutation alone and in combination with other known drug resistance mutations (K103N, Y181C) known to modulate the HIV susceptibility to NNRTIs. Mutations were introduced into the resistance test vector using the mega-primer PCR method for site-directed mutagenesis. (Sakar G and Sommar SS (1994) Biotechniques 8(4), 404-407). A resistance test vector containing the P225H mutation (P225H-RTV) was tested using the phenotypic susceptibility assay described above and the results were compared to that of a genetically defined resistance test vector that was wild type at position 225. The pattern of phenotypic susceptibility to the NNRTI, delavirdine in the P225H-RTV was altered as compared to wild type. In the context of an otherwise wild type background (i.e. P225H mutation alone) the P225H-RTV was more susceptible to delavirdine than the wild type control RTV. No significant change in nevirapine susceptibility was observed in the P225H-RTV. The P225H mutation was also introduced into a RTV containing additional mutations at K103N, Y181C or both (K103N+Y181C) In all cases, RTVs were more susceptible to inhibition by delavirdine if the P225H mutation was present as compared to the corresponding RTV lacking the P225H mutation (FIG. 8D). In all cases the P225H mutation did not significantly change nevirapine susceptibility (FIG. 8D).
EXAMPLE 4
Correlating Phenotypic Susceptibility and Genotypic Analysis: P236L
[0183] Phenotypic Analysis of HIV Patient 97-268
[0184] A resistance test vector was constructed as described in Example 1 from a patient sample designated 97-268. This patient had been treated with AZT and 3TC (NRTIs), indinavir and saquinavir (PRIs) and delavirdine (an NNRTI) for periods varying from 1 month to 2 years. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and amino acids 1-313 of RT. The patient derived segment was inserted into a indicator gene viral vector to generate a resistance test vector designated RTV-268. RTV-268 was then tested using the phenotypic susceptibility assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for each drug tested. Susceptibility of the patient virus to each drug was examined and compared to the susceptibility of a reference virus. A pattern of susceptibility to the NNRTIs was observed for the patient sample RTV-268 in which the virus sample was observed to be resistant to delavirdine with no resistance to delavirdine. The sample was examined further for genotypic changes associated with the pattern of susceptibility.
[0185] Genotype of HIV Patient 97-268
[0186] RTV-268 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of wild type clade B HIV-1. The nucleotide sequence was evaluated for sequences different from the control sequence. RT mutations were noted at positions M41L, D67N, M184V, T200A, E203D, L210W, T215Y, K219Q, and P236L compared to the control sequence. The mutations at T200A and E203D are known polymorphisms in wild-type (drug-sensitive) variants of HIV. Mutations at positions M41L, D67N, L210W, T215Y, and K219Q are associated with AZT resistance. The mutation at M184V is associated with 3TC resistance. The mutation at P236L is associated with resistance to delavirdine and increased susceptibility to nevirapine (Dueweke et al., Ibid.). In contrast to previous reports, the RTV-268 sample showed no change in nevirapine susceptibility. The mutation, P236L, was characterized using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate changes at amino acid 236 with changes in phenotypic susceptibility.
[0187] Site Directed Mutagenesis
[0188] Resistance test vectors were constructed containing the P236L mutation alone and in combination with other known drug resistance mutations (K103N, Y181C) that are known to modulate the susceptibility of HIV-1 to NNRTIs. Mutations were introduced into the resistance test vector using the mega-primer PCR method for site-directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the P236L mutation (P236L-RTV) was tested using the phenotypic susceptibility assay and the results were compared to that of a genetically defined resistance test vector that was wild type at position 236. P236L-RTV exhibited changes in NNRTI phenotypic susceptibility. In the context of an otherwise wild type background (i.e. P236L mutation alone) the P236L-RTV is less susceptible to delavirdine than a wild type reference RTV. In contrast to Dueweke et al. no significant change in nevirapine susceptibility was observed for P236L-RTV. The P236L mutation was also introduced into a RTV containing mutations at K103N, Y181C or both (K103N+Y181C). In all cases, the RTV's were less susceptible (more resistant) to delavirdine if the P236L mutation was present as compared to the corresponding RTV lacking the P236L mutation. In all cases the P236L mutation did not significantly alter nevirapine susceptibility.
EXAMPLE 5
Correlating Phenotypic Susceptibility and Genotypic Analysis: G190S
[0189] Phenotypic Analysis of HIV Patient 97-644
[0190] A resistance test vector was constructed as described in Example 1 from a patient sample designated 97-644. This patient had been treated with d4T (NRTI), indinavir (PRI) and efavirenz (NNRTI) for a period varying from 5 to 17 months. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and amino acids 1-313 of RT. The patient derived segment was inserted into a indicator gene viral vector to generate a resistance test vector designated RTV-644. RTV-644 was then tested using the phenotypic susceptibility assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for each drug tested. Susceptibility of the patient virus to each drug was examined and compared to the susceptibility of a reference virus. A pattern of susceptibility to the NNRTIs was observed for the patient sample RTV-644 in which the virus sample was observed to be resistant to nevirapine with little or no resistance to delavirdine. The sample was examined further for genotypic changes associated with the pattern of susceptibility.
[0191] Genotype of HIV Patient 97-644
[0192] RTV-644 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of wild type clade B HIV-1. The nucleotide sequence was evaluated for sequences different from the control sequence. RT mutations were noted at positions K101E and G190S compared to the control sequence. The mutations at T200A and E203D are known polymorphisms in wild-type (drug-sensitive) variants of HIV. The mutation at K101E is associated with resistance to some but not all NNRTIs. The mutation, G190A but not specifically G190S is associated with nevirapine and loviride resistance. The mutations G190S and G190A were characterized using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate changes at amino acid 190 with changes in phenotypic susceptibility.
[0193] Site Directed Mutagenesis
[0194] Resistance test vectors were constructed containing the G190S and G190A mutations. Mutations were introduced into the resistance test vector using the mega-primer PCR method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the G190S or G190A mutations (G190S-RTV, or G190A-RTV) were tested using the phenotypic susceptibility assay and the results were compared to that of a genetically defined resistance test vector that was wild type at position G190. G190S-RTV and G190A-RTV exhibited changes in NNRTI phenotypic susceptibility. In the context of an otherwise wild type background these RTVs were markedly less susceptible to nevirapine and slightly more susceptible to delavirdine than a wild type reference RTV.
EXAMPLE 6
[0195] Predicting Response to Non-nucleoside Reverse Transcriptase Inhibitors by Characterization of Amino Acid Changes in HIV-1 Reverse Transcriptase
[0196] Phenotypic and Genotypic Correlation of Mutations at Amino Acid 236 of HIV-1 Reverse Transcriptase
[0197] In one embodiment of this invention, changes in the amino acid at position 236 of the reverse transcriptase protein of HIV-1 is evaluated using the following method comprising: (i) collecting a biological sample from an HIV-1 infected subject; (ii) evaluating whether the biological sample contains nucleic acid encoding HIV-1 reverse transcriptase having a mutation at codon 236. The presence of a mutation at codon 236 (P236L) is correlated with a reduction in delavirdine susceptibility and little or no change in nevirapine susceptibility.
[0198] The biological sample comprises whole blood, blood components including peripheral mononuclear cells (PBMC), serum, plasma (prepared using various anticoagulants such as EDTA, acid citrate-dextrose, heparin), tissue biopsies, cerebral spinal fluid (CSF), or other cell, tissue or body fluids. In another embodiment, the HIV-1 nucleic acid (genomic RNA) or reverse transcriptase protein can be isolated directly from the biological sample or after purification of virus particles from the biological sample. Evaluating whether the amino acid at position 236 of the HIV-1 reverse transcriptase is mutated, can be performed using various methods, such as direct characterization of the viral nucleic acid encoding reverse transcriptase or direct characterization of the reverse transcriptase protein itself. Defining the amino acid at position 236 of reverse transcriptase can be performed by direct characterization of the reverse transcriptase protein by conventional or novel amino acid sequencing methodologies, epitope recognition by antibodies or other specific binding proteins or compounds. Alternatively, the amino acid at position 236 of the HIV-1 reverse transcriptase protein can be defined by characterizing amplified copies of HIV-1 nucleic acid encoding the reverse transcriptase protein. Amplification of the HIV-1 nucleic acid can be performed using a variety of methodologies including reverse transcription-polymerase chain reaction (RT-PCR), NASBA, SDA, RCR, or 3SR as would be known to the ordinarily skilled artisan. Evaluating whether the nucleic acid encoding HIV reverse transcriptase has a mutation at codon 236 can be performed by direct nucleic acid sequencing using various primer extension-chain termination (Sanger, ABI/PE and Visible Genetics) or chain cleavage (Maxam and Gilbert) methodologies or more recently developed sequencing methods such as matrix assisted laser desorption-ionization time of flight (MALDI-TOF) or mass spectrometry (Sequenom, Gene Trace Systems). Alternatively, the nucleic acid sequence encoding amino acid position 236 can be evaluated using a variety of probe hybridization methodologies, such as genechip hybridization sequencing (Affymetrix), line probe assay (LiPA; Murex), and differential hybridization (Chiron).
[0199] In a preferred embodiment of this invention, evaluation of whether amino acid position 236 of HIV-1 reverse transcriptase was wild type or mutant was carried out using a phenotypic susceptibility assay using resistance test vector DNA prepared from the biological sample. In one embodiment, plasma sample was collected, viral RNA was purified and an RT-PCR methodology was used to amplify a patient derived segment encoding the HIV-1 protease and reverse transcriptase regions. The amplified patient derived segments were then incorporated, via DNA ligation and bacterial transformation, into an indicator gene viral vector thereby generating a resistance test vector.
[0200] Resistance test vector DNA was isolated from the bacterial culture and the phenotypic susceptibility assay was carried out as described in Example 1. The results of the phenotypic susceptibility assay with a patient sample having a P236L mutation. The nucleic acid (DNA) sequence of the patient derived HIV-1 protease and reverse transcriptase regions from patient sample 268 was determined using a fluorescence detection chain termination cycle sequencing methodology (ABI/PE). The method was used to determine a consensus nucleic acid sequence representing the combination of sequences of the mixture of HIV-1 variants existing in the subject sample (representing the quasispecies), and to determine the nucleic acid sequences of individual variants.
[0201] Phenotypic susceptibility profiles of patient samples and site directed mutants showed that delavirdine and nevirapine susceptibility correlated with the absence of RT mutations at positions 103, 181 or 236 of HIV-1 reverse transcriptase. Phenotypic susceptibility profiles of patient samples and site directed mutants showed a significant reduction in delavirdine susceptibility (increased resistance) and little or no reduction in nevirapine susceptibility correlated with a mutation in the nucleic acid sequence encoding the amino acid leucine (L) at position 236 of HIV-1 reverse transcriptase and the absence of mutations at positions 103 and 181.
[0202] Phenotypic susceptibility profiles of patient samples and site directed mutants showed no additional reduction in delavirdine or nevirapine susceptibility (increased resistance) with the amino acid proline at position 236 when the RT mutations at positions 103, 181 or 103 and 181 were present (K103N, Y181C, or K103N+Y181C). However, phenotypic susceptibility profiles of patient samples and site directed mutants showed an additional reduction in delavirdine susceptibility (increased resistance) and little or no additional reduction in nevirapine susceptibility with the amino acid leucine (L) at position 236 in addition to the RT mutations associated with NNRTI resistance (K103N, Y181C, or K103N+Y181C).
[0203] Phenotypic and Genotypic Correlation of Mutations at Amino Acid 225 of HIV-1 Reverse Transcriptase
[0204] Phenotypic susceptibility profiles of patient samples and site directed mutants showed no change in susceptibility to delavirdine or nevirapine when the amino acid proline (P) was present at position 225 of HIV-l reverse transcriptase in the absence of RT mutations associated with NNRTI resistance (K103N, Y181C). However, phenotypic susceptibility profiles of patient samples and site directed mutants showed an increase in delavirdine susceptibility and little or no change nevirapine susceptibility when the amino acid histidine (H) was present at position 225 in the absence of RT mutations (K103N, Y181C) associated with NNRTI resistance.
[0205] Phenotypic susceptibility profiles of patient samples and site directed mutants showed no additional reduction in delavirdine susceptibility or nevirapine susceptibility when the amino acid proline (P) at position 225 was present in addition to the RT mutations associated with NNRTI resistance (K103N, Y181C, or K103N+Y181C). In contrast phenotypic susceptibility profiles of patient samples and site directed mutants showed an increase in delavirdine susceptibility and little or no change in nevirapine susceptibility when the amino acid histidine (H) was present at position 225 in the presence of RT mutations associated with NNRTI resistance (K103N, Y181C, or K103N+Y181C).
[0206] Phenotypic and Genotypic Correlation of Mutations at Amino Acid 190 of HIV-1 Reverse Transcriptase
[0207] Phenotypic susceptibility profiles of patient samples and site directed mutants showed no change in susceptibility to delavirdine or nevirapine when the amino acid glycine (G) at position 190 was present in the absence of RT mutations associated with NNRTI resistance (K103N, Y181C). Phenotypic susceptibility profiles of site directed mutants showed an increase in delavirdine susceptibility and a decrease in nevirapine susceptibility when the amino acid alanine (A) was present at position 190 in the absence of RT mutations associated with NNRTI resistance. Phenotypic susceptibility profiles of patient samples and site directed mutants showed an increase in delavirdine susceptibility and a decrease in nevirapine susceptibility when the amino acid serine (S) was present at position 190 in the absence of RT mutations associated with NNRTI resistance.
EXAMPLE 8
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: Y181I
[0208] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-964 HIV Samples
[0209] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-964. This patient had been previously treated with ddI, d4T, AZT, 3TC, ddC, (NRTIs), saquinavir and nelfinavir (PRIs) and nevirapine (an NNRTI) and HU. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequence coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vector designated RTV-964. RTV-964 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-964 in which there was a moderate decrease (10-fold) in delavirdine susceptibility and a significiant decrease (750-fold) in nevirapine susceptibility.
[0210] Determination of Genotype of Patient HIV Samples
[0211] RTV-964 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions M41L, K43E, D67N, K70R, L74I, V75S, Y181I, R211T, T215Y, D218E, and K219Q compared to the control sequence. M41L, D67N, K70R, L74I, V75S, T215Y, and K219Q are associated with NRTI resistance. A mutation at R211T is a known polymorphism in the sequence among different wild-type (drug-sensitive) variants of HIV. Y181I had previously been shown to be associated with high level resistance to nevirapine. We examined the mutation, Y181I, using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0212] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0213] The Y181I mutation was introduced into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid). A resistance test vector containing the Y181I mutation (Y181I-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 181. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the Y181I-RTV. On a wild type background (i.e. Y181I mutation alone) the Y181I-RTV displayed a moderate loss of susceptibility (20-fold) to delavirdine and a significant loss of susceptibility (740-fold) to nevirapine compared to a wild type control RTV. The Y181I-RTV showed wild-type susceptibility (1.4-fold) to efavirenz.
EXAMPLE 9
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: Y188
[0214] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 97-300HIV Samples
[0215] A resistance test vector was constructed as described in Example 1 from a patient sample designated 97-300. This patient had been previously treated with d4T and 3TC (NRTIs), indinavir (a PRI) and efavirenz (an NNRTI). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vector designated RTV-300. RTV-300 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine, efavirenz and nevirapine) and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drug tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-300 in which there was moderate decrease (25-fold) in delavirdine sisceptibility and a substantial decrease (greater than 800-fold) in nevirapine susceptibility.
[0216] Determination of Genotype of Patient HIV Samples
[0217] RTV-300 DNA analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequence that are different from the control sequence. Mutations were noted at positions K32N, M184V and Y188L compared to the control sequence. The mutation at M184V is associated with 3TC resistance. Y188L had previously been shown to be associated with high level resistance to efavirenz. Other mutations at position Y188 (i.e Y188C and Y188H) have been reported to have been selected for by treatment with several NNRTIs (E-ePseU, E-EPS, HEPT, Nevirapine, BHAP, U-8720E, TIBO R82913, Loviride). We examined the mutation, Y188L, using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0218] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Antiretroviral Drugs in HIV
[0219] The Y188L mutation was introduced into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the Y188L mutation (Y188L-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 188. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the Y188L-RTV. On a wild type background (i.e. Y188L mutation alone) the Y188L-RTV displayed a slight loss of susceptibility (9-fold) to delavirdine and substantial loss of susceptibility (greater than 800-fold) to nevirapine and a significant loss of susceptibility (109-fold) to efavirenz compared to a wild type control RTV. The approximate 100-fold loss of susceptibility to efavirenz was not as high as had been previously reported.
[0220] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Pnenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0221] The Y188C mutation was introduced into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the Y188C mutation (Y188C-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 188. We determined the pattern of phenotypic susceptibility to the NNRTIs., delavirdine, nevirapine and efavirenz, in the Y188C-RTV. On a wild type background (i.e. Y188C mutation alone) the Y188C-RTV displayed a slight loss of susceptibility (3-fold) to delavirdine and a moderate loss of susceptibility (30-fold) to nevirapine and efavirenz (20-fold) compared to a wild type control RTV.
[0222] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0223] The Y188H mutation was introduced into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the Y188H mutation (Y188H-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 188. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine and nevirapine, in the Y188H-RTV. On a wild type background (i.e. Y188H mutation alone) the Y188H-RTV displayed a moderate loss of susceptibility (3.5-fold) to nevirapine compared to a wild type control RTV. The phenotypic susceptibility of Y188H to efavirenz was not determined.
EXAMPLE 10
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: E138 and Y188
[0224] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 97-209 HIV Samples
[0225] A resistance test vector was constructed as described in Example 1 from a patient sample designated 97-209. This patient had been previously treated with AZT, ddI, d4T and 3TC (NRTIs), indinavir (a PRIs) and adefovir. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate resistance test vector designated RTV-209. RTV-209 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine, efavirenz and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-209 in which there was a moderate decrease (75-fold) in delavirdine susceptibility and a substantial decrease (greater than 800-fold) in nevirapine susceptibility.
[0226] Determination of Genotype of Patient HIV Samples
[0227] RTV-209 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions A62V, S68G, V76I, F77, F116Y, E138A, Q151M, M184V, Y188L and E291D compared to the control sequence. The mutations at A62V, V75I, F77L, F116Y, Q151M and M184V are associated with NRTI resistance. A mutation at E138K had previously been shown to be associated with resistance to several NNRTIs and a mutation at Y188L had previously been shown to be associated wiht a decrease in susceptibility to efavirenz. We examined the mutations Y188L and E138A using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0228] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Antiretroviral Drugs in HIV
[0229] The E138A mutation alone and in combination with Y188L was introduced into resistance test vectors using the megaprimer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the E138A mutation (E138A-RTV) or the E138 mutation along with the Y1881 mutation (E138A-Y188L-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at positions 188 and 138. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the E138A-RTV, Y188L-RTV and E138-Y188L-RTV. On a wild type background (i.e. E138A mutation alone) the E138A-RTV displayed wild-type susceptibility to delavirdine (1.6-fold), nevirapine (1.3-fold) and efavirenz (1.4-fold). The Y188L-RTV displayed a slight loss of susceptibility (greater than 800-fold) to nevirapine and a significant loss of susceptibility (110-fold) to efavirenz. The E138A-Y188L-RTV displayed a moderate loss of susceptibility (75-fold) to delavirdine and efavirenz (88-fold) and a substantial loss of susceptibility to nevirapine (greater than 800-fold) compared to a wild type control RTV. The combination of mutations resulted in an increased effect on delavirdine susceptibility compared to the effect observed for each mutation alone.
EXAMPLE 11
Using Resistance Test Vectors and SiteDirected Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: A98
[0230] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-675 HIV Samples
[0231] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-675. This patient had been previously treated with ddI, AZT, and 3TC (NRTIs), and saquinavir and nelfinavir (PRIs). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vector designated RTV-675. RTV-675 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine, efavirenz and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir) An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-675 in which wild-type susceptibility (2.1-fold) was observed for delavirdine and a slight decrease (6-fold) in nevirapine susceptibility was observed.
[0232] Determination of Genotype of Patient HIV Samples
[0233] RTV-675 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions M41L, S48t, L74V, A98G, M184V and T215Y are associated with NRTI resistance. A mutation at A98G had previously been shown to be associated with resistance to nevirapine. We examined the mutation A98G using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0234] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Antiretroviral Drugs in HIV
[0235] The A98G mutation into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the A98G mutation (A98G-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 98. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the A98G-RTV. On a wild type background (i.e. A98G mutation alone) the A98G RTV displayed a slight loss of susceptibility to delavirdine (3-fold), nevirpine (8-fold) and efavirenz (3-fold) compared to a wild type control RTV.
EXAMPLE 12
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: A98 and G190
[0236] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient B HIV Samples
[0237] A resistant test vector was constructed as described in Example 1 from a patient sample designated B. The anti-retroviral treatment this patient received is unknown. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistant test vector designated RTV-B. Individual clones of the RTV-B pool were selected and then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector clone for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-B clone 1 in which there was an increase in susceptibility (0.55-fold) to delaviridine, a substantial loss of susceptibility (640-fold) to nevirapine and significant loss of susceptibility (250-fold) to efavirenz.
[0238] Determination of Genotype of Patient HIV Samples
[0239] RTV-B clone 1 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions M41L, A98G, M184V, L210W, R211?, T215Y, E297A and G190S compared to the control sequence. M41L, M184V, L210W and T215Y are associated with NRTI resistance. A mutation at A98G had previously been shown to be associated with resistance to nevirapine. A mutation at position G190A had previously been shown to be associated with changes in susceptibility to nevirapine. Other changes at position 190 (i.e. E, Q, and T) have also been reported. We examined the mutations A98G and G190S, using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0240] Site Sirected Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-viral Drugs in HIV
[0241] The A98 and G190S mutations were introduced alone or in combination into the resistance test vector using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the A98G mutation (A98G-RTV), the G190S mutation (G190S-RTV) and both mutations (A98G-G190S-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 98 and 190. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the three vectors. On a wild type background (i.e. A98G mutation alone) the A98G-RTV displayed a slight loss of susceptibility to delavirdine (3-fold), nevirapine (8-fold) and efavirenz (3-fold) compared to a wild type control RTV. On a wild type background (i.e. G190S mutation alone) the G190S-RTV displayed increased susceptibility (0.5-fold) to delavirdine, a moderate loss of susceptibility (75-fold) to nevirapine and a slight loss of susceptibility (8-fold) to efavirenz compared to a wild type control RTV. The A98G-G190S-RTV displayed increased susceptibility (0.8-fold) to delavirdine, but a substantial loss of susceptibility to both nevirapine (greater than 800-fold) and efavirenz (greater than 250-fold) compared to a wild type control RTV. Although only a slight loss of susceptibility to efavirenz was observed for the individual mutations, the combination of A98G and G190S resulted in a substantial loss of susceptibility to efavirenz. Likewise, this combination of mutation resulted in a greater loss of susceptibility to nevirapine than the sum of the two mutations alone.
EXAMPLE 13
Using Resistance Test Vectors and Site Directed Mutants Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: Y181 and A98
[0242] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-1057 Samples
[0243] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-1057. This patient had been previously treated with ddI, d4T, AZT, and 3TC (NRTIs), saquinavir and indinavir (PRIs) and delavirdine (an NNRTI). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 RT. The PDS was inserted into an indicator gene viral vector to generate resistance test vector designated RTV-1057. RTV-1057 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI, and ddC), NNRTIs (delavirdine, efavirenz and nevirapine) and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-1057 in which there was a moderate decrease in delavirdine (35-fold) susceptibility and a significant decrease (610-fold) in nevirapine susceptibility.
[0244] Determination of Genotype of Patient HIV Samples
[0245] RTV-1057 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database, Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions T 39 A, M41L, A62V, D67E, T69SST, A98G, I135T, Y181C, T200I and T215Y compared to the control sequence M41L, A62V, D67E, T69SST, and T215Y are associated with NRTI resistance. Mutations at positions I135T and T200I are known polymorphisms in the sequence among different wild-type (drug-sensitive) variants of HIV. Y181C and A98G have been previously shown to be associated with resistance to certain NNRTIs. We examined the mutations Y181C and A98G using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0246] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0247] The Y181C and A98G mutations were introduced alone and in combination into resistance test vectors using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the Y181C mutation (Y181C-RTV) and the A98G mutation (A98G-RTV) and both mutations (Y181C-A98G-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 181 and 98. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, neviraphine and efavirenz, in the three vectors. On a wild type background (i.e. Y181C mutation alone) the Y181C-RTV displayed moderate loss of susceptibility (35-fold) to delavirdine, a significant loss of susceptibility (161-fold) to nevirapine and a slight loss of susceptibility (3-fold) to efavirenz compared to a wild type control RTV. The A98G-RTV displayed a slight loss of susceptibility to delavirdine (3-fold), nevirapine (8-fold) and efavirenz (3-fold) compared to a wild type control RTV. The Y181C-A98G-RTV displayed significant loss of susceptibility (240-fold) to delavirdine, a substantial loss of susceptibility (greater than 800-fold) to nevirapine and a slight loss of susceptibility (7-fold) to efavirenz compared to a wild type control RTV. THese data indicated that the comination of the two mutations, Y181C and A98G, resulted in a greater loss of susceptibility to both delavirdine and nevirapine than the sum of effects observed for these two mutations individually.
EXAMPLE 14
Using Resistant Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: K101 and G190
[0248] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patients 98-644 and 98-1060 HIV Samples
[0249] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-644.
[0250] This patient had been previously treated with d4T (an NNRTI) , indinavir (a PRI and efavirenz (an NNRTI). A second resistance test vector was constructed as described in Example 1 from a patient sample designated 98-1060. This patient had been previously treated with d4T (an NNRTI). indinavir (a PRI) and efavirnez (an NNRTI). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate resistance test vectors designated RTV-644 and RTV-1060. RTV-644 and RTV-1060 were then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NNRTIs (AZT, 3TC, d4T, ddI, and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptiblity to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-644 in which there was a very slight (2.5-fold) decrease in delavirdine susceptibility and a significant (600-fold) decrease in nevirapine susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-644 in which there was a very slight (2.5-fold) decrease in delavirdine susceptibility and a signigicant (600-fold) decrease in nevirapine susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-1060 in which wild-type susceptibility (1.5-fold) to delavirdine was observed. A significant decrease in efavirenz susceptibility (900-fold) and a substantial decrease to nevirapine (greater than 800-fold) susceptibility was observed for RTV-1060.
[0251] Determination of Genotype of Patient HIV Samples
[0252] RTV-644 and RTV-1060 DNA were analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions K101E and G190S for RTV-644 compared to the control sequence and mutations were noted at positions K101E, G190S, T200A and T215Y for RTV-1060 compared to the control sequence. The sequence at position T215 was a mixture of wild-type and mutation. A mutation at position K101E had been previously shown to be associated with resistance to several NNRTIs including high level resistance to delavirdine. A mutation at position G190A had previously been shown to be associated with changes in susceptibility to nevirapine. Other changes at position 190 (i.e. E, Q and T) have also been reported. We examined the mutations K101E and G190S, using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0253] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Antiretroviral Drugs in HIV
[0254] The K101E and G190S mutations were introduced alone and in combination into resistance test vectors using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the K101E mutation (K101E-RTV), the G190S mutation (G190S-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at positions 101 and 190. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in all three vectors. On a wild type background (i.e. K101E mutation alone) the K101E-RTV displayed a slight loss of susceptibility (5-fold) to delavirdine and efavirenz (5-fold) and a moderate loss of susceptibility (12-fold) to nevirapine compared to a wild type control RTV. The K101E-G190S-RTV displayed increased susceptibility to delavirdine (0.5-fold), a moderate loss of susceptibility to nevirapine (75-fold) and a slight loss of susceptibility (7.6-fold) to efavirenz compared to a wild type control RTV. The K101E-G190S-RTV displayed wild-type susceptibility (1.4-fold) to delavirdine and a substantial loss of susceptibility to both nevirapine (greater than 800-fold) and efavirenz (greater than 250-fold) compared to a wild type control RTV.
[0255] In this example, the combination of mutations, G190S and K101E, displayed a novel phenotypic pattern. The combination resulted in the reversal of the effect on delavirdine susceptibility observed for the G190S mutation alone and a greater than additive effect on the susceptibility for both nevirapine and efavirenz.
EXAMPLE 15
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: V108I
[0256] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-652 HIV Samples
[0257] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-652. This patient had no previous anti-retroviral treatment. Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 or RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vector designated RTV-652. RTV-652 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of hte classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-652 in which increase susceptibility (0.97-fold) to delavirdine was observed and a slight decrease (5-fold) in nevirapine susceptibility was observed.
[0258] Determination of Genotype of Patient HIV Samples
[0259] RTV-652 DNA was analyzed by ABI chain terminator automated sequecing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are diffrent from the control sequence. Mutations were noted at positions M41L, V108I, I135T, L210W, R211K and T215D compared to the control sequence. M41L, L210W and T215D are associated with NRTI resistance. Mutations at positions I135T and R211K are known polymorphisms in the sequence among different wild-type (drug-sensitive) variants of HIV. V108I is known to be associated with resistance to several NNRTIs. We examined the mutation V108I using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0260] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Antiretroviral Drugs in HIV
[0261] The V108I mutation was introduced into the resistance test vector using the mega-primer method for site directed mutagenesis (Sakar and Sommar, Ibid.). A resistance test vector containing the V108I mutation (V108I-RTV) was then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at position 108. We determined the pattern of phenotypic susceptibility to the NNRTIs, delaviridine, nevirapine and efavirenz, in the V108I -RTV. On a wild type background (i.e. V108I mutation alone) the V108I -RTV displayed wild-type susceptibility (1.3-fold) to delaviridine and efavirenz (1.7-fold) and a slight loss of susceptibility (3-fold) to nevirapine compared to a type control RTV.
EXAMPLE 16
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: K103 and K101 and G190
[0262] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-955 HIV Samples
[0263] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-955. This patient had been previously treated with nelfinavir (a PRI) Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vectors designated RTV-955. RTV-955 was then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delaviridine, efavirenz and nevirapine) , and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-955 in which there was a slight decrease (4-fold) in delaviridine susceptibility and a significant decrease (530-fold) in nevirapine susceptibility.
[0264] Determination of Genotype of Patient HIV Samples
[0265] RTC-955 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions K20R, V35I, A62V, D67N, T69D, V75I, F77, K101E, K103N, Y115F, F116Y, Q151M, I167V, Y181C, M184V, G190A, I202V, R211K, F214L, T215V, and K219Q compared to the control sequence. Mutations at positions K101E, K103N, Y181C, G190A, and F214L were mixtures of wild-type and the mutation. A62V, D67N, T69D, V75I, F77, Y115F, F116Y, Q151M, M184V, T215V and K219Q are associated with NRTI resistance. Mutations at V35I, R211K and F214L are known polymorphism in the sequence among different wild-type (drug sensitive) variants of HIV. a mutation at position K101E had been previously shown to be associated with resistance to the NNRTIs. A mutation at Y181I had previously been shown to be associated with high level resistance to nevirapine. A mutation at K103N had previously been shown to be associated with resistance to the three NNRTIs, delaviridine and nevirapine and efavirenz. We examined the mutations K101E, J103N and G190A using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0266] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0267] The K101E, K103N and G190A mutations were introduced alone and in combination into resistance test vectors using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the K101E mutation (K101E-RTV), the K103N mutation (K0103N-RTV), the G190 mutation (g190A-RTV and two mutations (K101E-G190A-RTV) and (K103N-G190A-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at positions 101, 103 and 190. We determined the pattern of phenotypic susceptibility to the NNRTIs, delaviridine, nevirapine, and efavirenz, in all 5 vectors. On a wild type background (i.e. K101E mutation alone) the K101E-RTV displayed a slight loss (5-fold) os susceptibility to delavirdine and efavirenz (5-fold) and a moderate loss of susceptibility (12-fold) to nevirapine (55-fold) and efavirenz(30-fold) compared to a wild type control RTV. On a wild type background (i.e. G190A mutation alone) the G190A-RTV displayed increased susceptibility (8-fold) efavirenz compared to a wild type control RTV. The K101E-G190A-RTV displayed wild-type susceptibility (2-fold) to delavirdine, substantial loss of susceptibility (greater than 800-fold) to nevirapine and a significant loss of susceptibility (120-fold) to efavirenz compared to a wild type control RTV. The K103N-G190-RTV displayed a moderate loss of susceptibility (40-fold) to delavirdine, substantial loss of susceptibility (greater than 800-fold) to nevirapine and a significant loss of susceptibility (215-fold) to efavirenz compared to a wild type control RTV. The introduction of a second mutation to a vector containing the G190A resulted in the reversal of the effect on delavirdine susceptibility observed for the G190A mutation alone. The G190-a mutation displayed an increased susceptibility to delviridine. However, the addition of either KLOE or K103N to the G190A mutation resulted in a slight loss of susceptibility to delavirdine. Furthermore, the combination of G190A and K101E resulted in a greater than additive effect on the loss of susceptibility to nevirapine and efavirenz. Lastly, these data indicated that the combination of the two mutations G190A and K103N resulted in a greater loss of susceptibility to both nevirapine and efavirenz than the sum of effects observed for these two mutations individually.
EXAMPLE 17
Using Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility an Resistance in HIV: V106 and V189 and V181 and F227
[0268] Preparation of Resistant Test Vectors and Phenotypic Analysis of Patient 98-1033 and 98-757 HIV Samples
[0269] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-1033. This patient had been previously treated with AZT, d$T, 3TC and ddI (NRTI), saquinavir, indinavir and nelfinavir (PRIs and nevirapine (an NNRTI). a second resistance test vector was constructed as described in Example 1 from a sample obtained from the same patient at a different time point and designated 98-757. This patient had received an additional 8 weeks of treatment with nevirapine 9an NNRTI) d4T (an NRTI), and saquinavir and nelfinavir (PRIs). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of PR and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate resistance test vectors designated RTV-1033 and RTV-757. RTV-1033 and RTV-757 were then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. This panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), and PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-1033 in which there was a moderate decrease (30-fold) in delavirdine susceptibility and a substantial decrease (greater than 800-fold) in nevirapine susceptibility and a significant decrease (200-fold) in efavirenz susceptibility. A pattern of susceptibility to the NNRTIs was observed for patient RTV-757 in which there was a slight decrease (10-fold) in delavirdine susceptibility and a substantial decrease (greater than 800-fold) in nevirapine susceptibility.
[0270] Determination of Genotype of Patient HIV Samples
[0271] RTV-1033 and RTV-757 DNA were analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV Sequence Database Los Alamos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions V35I, D67N, T69D, K70R, V106A, V189L, T200A, I202T, R211K, T215F, D218E, K219Q, H221Y, F227L, L228H and R284 for RTV-1033 compared to the control sequence. Mutations were noted at positions V35I, D67N, T69D, K70R, V106A, V108I, L109V, Y108C, V189L, T200A, I202T, R211K, T215F, D218E, K219Q, H221Y, L228H, L283I and R284K for RTV-757 compared to the control sequence. The sequences at positions V106A, V108I and L109V were a mixture of wild-type and mutation. D67N, T69D, K70R, T215F and K219Q are associated with NRTI resistance. Mutations at V35I, T200A, R211K and R284K are known polymorphisms in the sequence among different wild-type (drug-sensitive) variants of HIV. A mutation at V106A had previously been shown to be associated with increase resistance to nevirapine. A mutation at V189I had previously been shown to be associated with NNRTI resistance but a mutation to L at this position had not been previously reported to be associated with NNRTI resistance. A mutation at V108I had previously been shown to be associated with increased resistance to both delavirdine and nevirapine. A mutation at Y181C had also previously been shown to be associated with increased resistance to both delavirdine and nevirapine. We examined the mutations V106A, V189L, V181C and F227L using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0272] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Susceptibility to Anti-retroviral Drugs in HIV
[0273] The mutations V106A, V189L, V181C an F227L were introduced alone and in combination into resistance test vectors using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the V106A mutation (V106A-RTV), the V189L mutation (V189L-RTV), the V181C mutation (V181C-RTV) and F227L mutation (F2271-RTV) and two mutations (V106A-Y181C-RTV) and (V106A-V189L-RTV) and (V106A-F227-RTV) and (V181C-F227-RTV) and three mutations, (V106A-Y181C-F227L-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at positions 106, 189, 181 and 227. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in all nine vectors. On a wild type background (i.e. V106A mutation alone) the V106A-RTV displayed a slight loss (5-fold) of susceptibility to delavirdine and a moderate loss of susceptibility (60-fold) to nevirapine and wild-type susceptibility (1.7-fold) to efavirenz compared to a wild type control RTV. On a wild type background (i.e. V189L mutation alone) the V189-RTV displayed wild type susceptibility to delavirdine (1.8-fold), nevirapine (1.3-fold) and efavirenz (1.3-fold) compared to a wild type control RTV. On a wild type background (i.e. V181C mutation alone) the Y181C-RTV displayed a significant loss of susceptibility (100-fold) to delavirdine and a substantial loss of susceptibility (greater than 800-fold) to nevirapine and a slight loss of susceptibility (4-fold) to efavirenz compared to a wild type control RTV. On a wild type background (i.e. F227L mutation alone) the F227L-RTV displayed increased susceptibility (0.03-fold) to delavirdine and efavirenz (0.48-fold) and a slight loss of susceptibility (3-fold) to nevirapine compared to a wild type control RTV. The V106A-Y181C-RTV displayed a significant loss of susceptibility (100-fold) to delavirdine, a substantial loss of susceptibility (greater than 800-fold) to nevirapine and slight loss of susceptibility (4-fold) to efavirenz compared to a wild type control RTV. The V106A-V189L-RTV displayed a slight loss of susceptibility (3-fold) to delavirdine, a moderate loss of susceptibility (50-fold) to nevirapine and wild-type susceptibility (1-fold) to efavirenz compared to a wild type control RTV. The V106A-F227-RTV displayed a slight loss of susceptibility (3-fold) to delavirdine, a substantial loss of susceptibility (greater than 800-fold) to nevirapine and a slight loss of susceptibility (8-fold) to efavirenz compared to a wild type control RTV. The Y181C-F227L-RTV displayed increased susceptibility (0.89-fold) to delavirdine and efavirenz (0.99-fold) and a significant loss of susceptibility (285-fold) to nevirapine compared to a wild type control RTV. The V106A-Y181C-F227L-RTV displayed a moderate loss (50-fold) of susceptibility to delavirdine and a substantial loss of susceptibility (greater than 800-fold) to nevirapine and a slight loss of susceptibility (12-fold) to efavirenz compared to a wild type control RTV.
EXAMPLE 18
Using Resistance Test Vectors and Site Directed Mutants to Correlate Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility and Resistance in HIV: Y188 and L100 and K103
[0274] Preparation of Resistance Test Vectors and Phenotypic Analysis of Patient 98-1058 HIV Samples
[0275] A resistance test vector was constructed as described in Example 1 from a patient sample designated 98-1058. This patient had been previously treated with ddI, d4T, AZT, 3TC, ddC and abacavir (NRTIs), indinavir and amprenavir (PRIs) and nevirapine (an NNRTI). Isolation of viral RNA and RT/PCR was used to generate a patient derived segment that comprised viral sequences coding for all of RP and aa 1-313 of RT. The PDS was inserted into an indicator gene viral vector to generate a resistance test vector designated RTV-1058. Individual clones of RTV-1058 were selected and were then tested in a phenotypic assay to determine accurately and quantitatively the level of susceptibility to a panel of anti-retroviral drugs. The panel of anti-retroviral drugs comprised members of the classes known as NRTIs (AZT, 3TC, d4T, ddI and ddC), NNRTIs (delavirdine and nevirapine), an PRIs (indinavir, nelfinavir, ritonavir, and saquinavir). An IC50 was determined for the resistance test vector pool for each drug tested. The pattern of susceptibility to all of the drugs tested was examined and compared to known patterns of susceptibility. A pattern of susceptibility to the NNRTIs was observed for clones 4, 5 and 10 from patient RTV-1058. Clone 4 displayed a significant loss of susceptibility (85-fold) for delavirdine and a substantial loss of susceptibility (greater than 800-fold) for nevirapine. Clone 5 displayed a substantial loss of susceptibility (250-fold) to delavirdine and a significant loss of susceptibility (120-fold) to nevirapine. Clone 10 displayed a substantial loss of susceptibility (greater than 250-fold) to delavirdine and (greater than 800-fold) to nevirapine.
[0276] Determination of Genotype of Patient HIV Samples
[0277] RTV-1058 DNA was analyzed by ABI chain terminator automated sequencing. The nucleotide sequence was compared to the consensus sequence of a wild type clade B HIV-1 (HIV sequence Database Los Almos, N. Mex.). The genotype was examined for sequences that are different from the control sequence. Mutations were noted at positions M41L, A62V, D67N, T69SST, L74V, L100I, K103N, V118I, I135T, T200S, L210W, R211K and T215Y compared to the control sequence. L74V and L100I were mixtures of wild-type and mutation. Clone 4 contained mutations at positions K103N and Y188L. Clone 5 contained mutations at positions L100I and K103N. Clone 10 contained mutations at positions L100I, K103N and Y188L. M41L, A62V, D67N, T69SST, L74V, L210W and T215Y are associated with NRTI resistance. Mutations at positions I135T, T200S and R211T are known polymorphisms in the sequence among different wild-type (drug-sensitive) variants of HIV. A mutation at L100I had previously been shown to be associated with resistance to delavirdine and nevirapine. A mutation at K103N had previously been shown to be associated with resistance to delavirdine, nevirapine and efavirenz. We examined the mutations, Y188L, L100I and K103N, using site directed mutagenesis and in vitro phenotypic susceptibility testing to correlate the observed changes in genotype with phenotype.
[0278] Site Directed Mutagenesis is Used to Confirm the Role of Specific Mutations in Phenotypic Suspectibility to Anti-restroviral Drugs in HIV
[0279] The mutations Y188L, L100I and K103N were introduced alone and in combinationn into resistance test vectors using the mega-primer method for site-directed mutagenesis (Sakar and Sommar, Ibid.). Resistance test vectors containing the Y188L mutation (Y188L-RTV), the L100I mutation (L100I-RTV), the K103N mutation (K103N-RTV), the two mutations (K103N-Y188L-RTV) and (L100I-K103N-RTV), and the three mutations (L100I-K103N-Y188L-RTV) were then tested using the phenotypic assay described earlier and the results were compared to those determined using a genetically defined resistance test vector that was wild type at positions 188, 100, and 103. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevlrapine and efavirenz, in all 6 vectors. On a wild type background (i.e. Y188L mutation alone) the Y188L-RTV displayed a slight loss of susceptibility (9-fold) to delavirdine, a substantial loss of susceptibility (greater than 800-fold) to nevirapine and a moderate loss of susceptibility (110-fold) to efavirenz compared to a wild type control RTV. On a wild type background (i.e. L100I mutation alone) the LLOOI-RTV displayed a moderate loss of susceptibility (30-fold)to delavirdine and efavirenz (10-fold) and a slight displayed moderate loss of susceptibility (10-fold) and a slight loss of susceptibility (3-fold) to nevirapine compared to a wild type control RTV. On a wild type background (i.e. K103M mutation alone) the K103N-RTV displayed moderate loss of to delavirdine susceptibility (50-fold), nevirapine (55-fold) and efavirenz (30-fold) compared to a wild type control RTV. The K103N-Y188L-RTV displayed substantial loss of susceptibility to delavirdine (greater than 250-fold), nevirapine (greater than 800-fold) and efavirenz (greater that 250-fold) compared to a wild control RTV. The L100I-K103N-RTV displayed substantial loss of susceptibility (greater that 250-fold) to delavirdine and efavirenz (greater that 250-fold) and a moderate loss of susceptibility (70-fold) to nevirapine compared to a wild type control RTV. The L100I-K103N-Y188L-RTV displayed substantial loss of susceptibility to delavirdine (greater than 250-fold), nevirapine (greater than 800-fold), and efavirenz (greater than 250-fold) compared to a wild type control RTV. Novel combinations resulted in unpredeicted resistance patterns than were different from those patterns observed for the each mutation alone.
EXAMPLE 19
Using Resistance Test Vectors to Correlate Integrase Genotypes and Phenotypes Associated with NNRTI Drug Susceptibility in HIV: T66I
[0280] Site directed-mutagenesis is used to confirm the role of specific mutations in integrase on phenotypic susceptibility to anti-retroviral drugs in HIV.
[0281] A resistance test vector containing the threonine to isoleucine mutation at position 66 of the integrase protein (T66I) was constructed and tested using the phenotypic assay described earlier. We determined the pattern of phenotypic susceptibility to the NNRTIs, delavirdine, nevirapine and efavirenz, in the T66I mutated vector. The T66I mutant displayed a reduction in susceptibility (4.7-fold) to the integrase inhibitor L-731,988, but an increase in nevirapine, delavirdine, and efavirenz susceptibility (8 to 10-fold) compared to a wild type control RTV (see FIG. 10). | This invention relates to antiviral drug susceptibility and resistance tests to be used in identifying effective drug regimens for the treatment of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) and further relates to the means and methods of monitoring the clinical progression of HIV infection and its response to antiretroviral therapy, particularly non-nucleoside reverse transcriptase inhibitor therapy using phenotypic susceptibility assays or genotypic assays. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a method and system for providing rich media content over a computer network and more particularly to a highly reliable, transparent process for displaying high-quality online advertising imagery.
2. Related Art
Computer networks, including the Internet, are a new and rapidly growing means of communication. There are currently over 300 million network users worldwide, and that number is expected to double in less than five years according to the Computer Industry Almanac (www.c-i-a.com). Because of their numbers, and because they are believed to be high-end consumers, users of the Internet and other computer networks are an attractive audience for advertising messages. According to figures from the Internet Advertising Bureau (“IAB”; www.iab.net), expenditures for Internet advertising are growing even faster than the number of network users—at almost 25 percent per quarter—and currently total over $7 billion per year.
The current standard for Internet advertising is the banner ad, a cartoon-like color image that occupies a fixed part of a web page. Banner ads usually come in one of a small number of standard sizes, and they sometimes include crude animation created by rapidly and repeatedly superposing a small number of images in the same space. Banner ads comprise the majority of Internet advertising—historically over half of total expenditures and around three-quarters of that on discrete ads (as opposed to sponsorships) according to the IAB.
The content of a banner ad image is contained in a computer file that is interpreted and displayed by a network user's web-browser program (e.g., Netscape Navigator, Microsoft Internet Explorer). Almost all banner ad files use the GIF89a format, which can be interpreted and displayed by all major web-browser programs currently on the market.
Each banner ad's file, plus the file containing the content of the host web page itself, must be transmitted to, and stored on, a network user's computer before the complete web page (ads and content) can be displayed. There may be many—sometimes dozens—of banner ads on a page, and advertisers often demand that the page be configured to display the ads first. To keep network users from waiting too long to see the content of their pages, web page owners frequently impose limits on the size of the banner ad files they will accept. These limits, in turn, sharply constrain the appearance of banner ads, e.g., by reducing the number of images per ad or the number of items per image, or by restricting the variety of colors or level of detail in an item or image.
Such limitations have combined to reduce the effectiveness of banner ads in two ways. First, they are—and because of file size limitations must remain—crude. Because banner ads are typically simple cartoons in an environment of increasingly rich and complex media, the viewing audience is becoming less responsive to the ads. The average “click-through” rate, the rate at which viewers respond to a banner ad by “clicking” on it and being transferred to the web site advertised by the banner, is falling rapidly—by almost an order of magnitude during the past five years, according to contemporary estimates in Advertising Age magazine. Secondly, despite limitations on their file sizes, banner ads often delay viewing of web page content to the point that users routinely redirect their browsers away in frustration; the very presence of the ads lowers their own viewership. Dwell-time, a measure of the time an average network user spends looking at a single page, is also declining.
In brief, banner ads, though they dominate advertising on the Internet and are so much the standard that they are directly interpretable by every major web-browser program, are an obsolete and increasingly self-defeating technology.
Advertisers, aware of the limitations of banner ads, have tried two approaches to improve upon them. The first approach is to replace the cartoon-like banner ad images with video ads, i.e., online ads that use moving, photographic-quality images rather than simple single images or series of a few simple single images. The second approach, referred to generally as interstitial ads, sometimes called pop-up ads, avoids some of the technical problems of banner ads and video ads by effectively separating the interstitial ads from their host web pages. Both approaches, though, like the banner ad approach, have run into technical and consumer-response barriers.
Video ads, unlike GIF89a-format images, cannot be displayed directly by web-browser programs. Instead, they are encoded in one of several specialized formats (e.g., MPEG, QTF, AVI) and are displayed by separate—and similarly specialized—video replay programs. Such video replay programs are separate from the web-browser programs, but they are compatible with the browsers and sometimes are referred to as plug-ins to the browsers. Some replay programs are distributed with computer operating systems, while others are available separately, either for free or at a cost. Some replay programs can interpret more than one format, although none can interpret even a large minority of the existing variety of formats, and file formats are different enough that any multi-format program is essentially a package of single-format programs. Because of the multiplicity of formats and distribution methods, and because many formats are in fairly wide use, it is unlikely that any single standard will emerge in the near future. In other words, unlike GIF image technology, the technology of computer video replay is non-standardized and is functionally complicated, and it is likely to remain so.
To view a video, a user's computer must receive at least part of the file and then activate and run a compatible replay program. This process frequently includes one or more “dialogues” between the computer and the user. For example, if the file is to be stored and then replayed, the user must specify a storage name (or approve the computer's choice) and then activate the replay. If the computer cannot determine which replay program to use, the user must specify it. And if there is no compatible replay program on the computer, the user must either cancel the replay or spend time (and possibly money) identifying, locating, and obtaining one. The complexity and time requirements of this process can be daunting even if the user actively seeks to view the video; for advertising, which needs to be entirely passive and nearly instantaneous, these are major barriers.
Another barrier to the use of video ads is imposed by the sheer size of most video files. Video images, like any other computer data, are stored and transmitted as computer files. Because of the complexity of the images (color, resolution, etc.) and the number of images in a file (usually thousands), video files typically are very large. For example, a word-processing document file may be on the order of a few dozen kilobytes (KB), and a typical web page file may be around a hundred KB, but even a thirty-second video will require a file size of thousands of KB (i.e., several megabytes, or MB). Using a standard telephone modem connection, whose transmission rate is limited by telephone technology and federal regulation, not by computer modem technology, a file of even a few megabytes can require many minutes to receive and store. For example, with a 56K modem and an effective transmission rate of over 50K, transmission requires at least three minutes per megabyte. Faster connections (e.g., via DSL or institutional intra-net) reduce this time substantially, but not so much that the file transmission does not cause a noticeable interruption. Further, those types of connections are available to only a portion of the user population. As noted above, computer users are becoming increasingly impatient with any delay, especially for the sake of advertising, and in any case most advertisers are unwilling to limit their messages to only a portion of the population.
To address the problem of file size, specialized protocols were developed that allow near-real-time playback. Sometimes called streaming, these protocols begin playback when only a portion of the file has been transmitted and stored on the user's computer (i.e., buffered). Later portions of the file are transmitted as earlier ones play back, and the parameters of the process are calibrated so that, if transmission is not interrupted, playback is continuous. The practical flaw in this approach is that transmission, particularly of large files, frequently is interrupted. Net congestion, transmission errors requiring retransmission, competing demands on the transmitting computer, and other causes, can interrupt the transmission flow long enough that the buffer is completely played out, and then playback stops until enough new data have been received. The effect on the user is that streaming video (or audio) either is occasionally interrupted by long pauses or has a jerky quality caused by frequent micro-pauses (the former with a large buffer size and the latter with a small one). These types of interruptions are unacceptable to advertisers, whose imagery requires seamless replay. Further, streaming video is subject to the same requirements as non-streaming video for identifying, obtaining, and/or activating a compatible replay program.
U.S. Pat. No. 6,029,200 to Beckerman et al. discloses a process that uses streaming video and provides a more automated approach to selecting a replay program. The “client” computer (e.g., the network user's computer) is offered a list of multiple versions of a video file, each in a different format, in a predetermined order, until a compatible format—if any—is found. This makes it more likely that the video eventually can be viewed by the user, but it requires the user's computer to know how to interpret and choose among the list of “offers,” which presumably requires specialized software. It is not clear how noticeable the process would be to the user (e.g., delay, “dialogues”), and because it applies only to streaming video, the process does not address the problem of interruptions in playback. It thus can be considered another format, albeit a somewhat generalized one, but with questionable application to advertising.
Processes developed more recently by bluestreak.com, Inc. (www.bluestreak.com) and AudioBase, Inc. (www.audiobase.com) also use streaming, and they circumvent the replay compatibility issue by transmitting their own replay programs along with the data files. These are examples of the usage of “push” technology, as used, e.g., in U.S. Pat. No. 5,740,549, issued Apr. 14, 1998 to Reilly et al. These processes are reasonably rapid—although still noticeable to the user-because neither handles full video; bluestreak offers audio, GIF-like animation, and other cartoon-like special effects, and AudioBase handles strictly audio. Both also are subject to the problems of streaming, such as “stuttering” and interruptions in playback. They thus are suitable for certain narrow, specialized forms of advertising, but their transmission delays are still non-negligible, and like other uses of streaming, their unreliable replay renders them problematic for advertising.
In summary, attempts to date to put video advertising onto Internet web pages have largely failed because of two fundamental technical characteristics of computer video—lack of standardization and very large file size—and their implications. Computer users are generally unwilling either to wait for large files to be transmitted or to take active steps to ensure a smooth replay, especially for the sake of viewing an advertisement. Advertisers are unwilling to spend money and effort on technologies that cannot reliably deliver uninterrupted imagery to a wide audience. What would satisfy both users and advertisers, but is lacking in the prior art, is a means for reliably delivering video ads without any interruption of the user's viewing experience. As a consequence, video advertising has been and remains a small and static fraction of all Internet advertising; expenditures on video have consistently been just a few percent of the total.
Interstitial advertisements—sometimes called pop-up ads—bypass some of the technical problems of on-page banner ads and video ads by effectively separating the online ads from their host web pages. The content of an interstitial ad is transmitted separately from those of its host web page. Transmission begins immediately after the host web page has been fully transmitted and while it is being displayed (i.e., during the “interstices” between other web page transmissions), and it may continue once the ad itself has begun displaying. The ad is displayed in a new “window” or other dedicated display area, either immediately after the host page is fully displayed (thus “popping up” in front of the host page) or when the user signals that he/she has finished reading the host page by closing it or activating a link to a new page. Interstitial ads can include GIF images, video, audio, or any other web page elements; they are essentially specialized web pages comprised entirely of advertising. Because they are transmitted separately, they do not delay the display of the host web page, and because the user presumably is occupied for some time reading the host web page, the ads can take much longer to transmit than on-page ads without seriously annoying the user.
Interstitial transmission of advertising is taught in U.S. Pat. No. 5,305,195, issued Apr. 19, 1994 to Murphy, for use on specialized computer terminals such as bank ATMs and school registration stations. More recent applications include U.S. Pat. No. 5,913,040, issued Jun. 15, 1999 to Rakavy et al.; U.S. Pat. No. 5,737,619, issued Apr. 7, 1998 and U.S. Pat. No. 5,572,643, issued Nov. 5, 1996, to Judson; and U.S. Pat. No. 5,604,542, issued Feb. 18, 1997 to Dedrick.
The principal problem with interstitial ads is that, as dwell time statistics show, users' patience still limits the time available for transmission. While a user is reading the host page, there typically is sufficient download time for banner ads, other GIF images, other static images, simple animations, a streaming video buffer, and usually audio and other animated elements and associated programs such as those produced by the bluestreak and AudioBase processes. However, there is not sufficient time to transmit more than one buffer worth of a video file, and there is no opportunity to create a “dialogue” with the user until the interstitial ad is displayed. Consequently, both the number and the type of elements in an interstitial ad are constrained. Additionally, interstital video ads are also subject to the same problems of non-standardization and display reliability as with on-page video ads.
A process developed by Unicast Communications Corp., disclosed in International Publication No. WO 99/60504, published Nov. 25, 1999, partially addresses these problems by installing a program on the user's computer that ensures that transmission of ads (and accompanying playback programs if any) is as “polite” as possible. The concept of “polite” transmission—i.e., file transmission minimally noticeable to the user—avoids some of the problems associated with streaming by fully storing (or caching) ads on the user's computer before displaying them. The Unicast program also checks that any necessary playback programs are available on the user's computer before the ad is displayed. However, such a process is not practically applicable to video ads, because large files take a long time to transmit no matter how politely, and video replay programs are even larger than video ads and are seldom available for transmission along with them. It is also as yet unclear whether such a powerful program will be fully compatible with most network users' operating systems and browser programs, or whether privacy concerns will limit its functionality or popularity.
Overall, while interstitial ads solve some of the problems of computer network advertising, they as yet have shown only partial success at dealing with the non-standardization and file size issues associated with video ads, or with file sizes in general. Attempts to create a “smart” solution have only added new problems. At least partially as a result, interstitials historically have accounted for less than a tenth of Internet advertising expenditures, and that share has shrunk by almost half in the last year according to the IAB.
In summary, what is needed but is missing in the prior art, is a highly reliable, entirely transparent process for displaying high-quality rich media content over a computer network.
SUMMARY OF THE INVENTION
The present invention is directed to a method, system and computer program product for providing rich media content over a computer network. In accordance with the present invention, a server on a computer network polls the software, hardware, or electronic appliance of an end user on the network, for the availability of software and/or hardware necessary for the local display of rich media content. This polling is transparent to the end user and requires no action on the part of the end user. Based on the client's response, the server sends an appropriately formatted version of the rich media file to the client. The user is not necessarily aware that this transfer is taking place, as it is taking place in the background, while the user is performing other tasks or viewing other content than that which is being transferred. Once the rich media has been transferred in its entirety and stored, or cached, in the local memory of the client, the rich media content is displayed automatically, either immediately or according to a predefined schedule or display cue, in a designated display area. The user may then be able to manipulate the rich media content without affecting the other content or tasks that were being displayed prior to the display of the rich media content.
The client may be any of a number of known electronic devices connected either physically or wirelessly to a server on the computer network. Such devices may include, but are not limited to, a desktop computer, a laptop computer, a handheld device, a telephone, a set top box, or an Internet appliance. In the preferred embodiment, the rich media comprises a short, highly compressed digital video file. For example, such rich media may be a 5–15 second long video advertisement.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1A–1E show a computer network according to the present invention at various steps during a method for providing rich media content across a computer network according to the present invention.
FIGS. 2A–2C are various embodiments of a client display area according to the present invention.
FIG. 3 is a process diagram of the method for providing rich media content across a computer network according to the present invention.
FIG. 4 is a block diagram of an example computer system useful for implementing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention is now described with reference to the figures, where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention. It will be apparent to a person skilled in the relevant art that this invention can also be employed in a variety of other devices and applications.
FIG. 1A shows a computer network 101 according to the present invention, consisting of a system of electronic devices connected either physically or wirelessly, wherein digital information is transmitted from one device to another. Such devices may include, but are not limited to, a desktop computer, a laptop computer, a handheld device, a telephone, a set top box, or an Internet appliance. FIG. 1A shows a client 102 , defined as a computer program resident on a computer system, an item of hardware, or an electronic appliance that sends and receives digital information via computer network 101 . Also shown is a server 103 , defined as a computer program resident on a computer system, an item of hardware, or an electronic appliance that sends and receives digital information via computer network 101 . The role of server 103 shown in FIG. 1A may in some cases be played by more than one actual server, as would be apparent to those skilled in the relevant art.
Server 103 also includes a memory 110 which stores digital files, including but not limited to software and data files. Specifically, memory 110 may contain one or more rich media files 105 , defined as any electronic media content that includes moving images, video with or without audio, a sequence of images captured from frames of film, frames of video, or animated shapes. “Rich”, in general, denotes electronic media information that includes more than only text or audio. Rich media files 105 are stored in the form of digital computer files. In the preferred embodiment, rich media file 105 is a 5–10 second video advertisement in the form of a highly compressed electronic file. Rich media files 105 can be stored, transmitted or displayed using a variety of proprietary and nonproprietary electronic file formats, such as QuickTime, Windows Media Player, GIF89a, Flash, AIFF, WAV, RealAudio, RealVideo, or any of a number of file formats now emerging for wireless devices, such as HDML, WML, BMP, or formats associated with WCA, and other formats known to those skilled in the relevant art appropriate to various software, hardware, and electronic appliance display systems. The particular file format does not substantially affect the content of rich media file 105 . Rich media files 105 may be previously created and stored in memory 110 , or may be created “on-the-fly” in response to the requirements of client 102 . As discussed below, the same rich media file 105 is stored in a number of different file formats ( 106 -A, 106 -B . . . 106 -X) in memory 110 to facilitate the transfer and display of rich media file 105 across computer network 101 according to the present invention.
Client 102 also includes a memory 104 , that is entirely contained within, or is entirely a part of client 102 , which stores digital files, including, but not limited to, software and data files. A subset of client memory 104 , local cache 107 , is defined as that portion of client memory 104 that is used for temporary storage of data files received over computer network 101 .
The process according to the present invention is initiated at a step 301 , as shown in FIGS. 1A and 3 , by client 102 becoming connected to server 103 , for example a desktop computer user being connected to a web site using a web browser.
Next, at a step 302 , as shown in FIGS. 1B and 3 , server 103 sends a query 108 to client 102 . Query 108 is a communication wherein server 103 requests data from client 102 regarding the presence or absence of specific software and/or hardware that are required to display rich media file 105 , that has been prepared in specific file formats 106 -A, 106 -B . . . 106 -X. In one embodiment, query 108 is performed by progressing, via one or more connections with client 102 , through a set of preferred rich media content playback applications to assess the local playback capabilities of client 102 . In the preferred embodiment, this procedure is transparent to the user, meaning that the user is not required to take action to initiate this step, and the process is not noticeable to the user.
At a step 303 , as shown in FIGS. 1C and 3 , client 102 responds to query 108 with response 108 b , indicating, for example, in the example shown in FIGS. 1A–1E , that software and/or hardware required to display rich media file 105 prepared in formats 106 -C and 106 -E are available. In the preferred embodiment, this procedure is transparent to the user, such that the user is not required to take action to initiate this step, and the process is not noticeable to the user.
Determining the ability of client 102 to playback rich media file 105 may, in an alternative embodiment, be implicitly accomplished, by sending rich media file 105 via a particular computer network 101 , or in a particular file format, or toward a particular device or electronic appliance, where the ability of client 102 to playback rich media file 105 could be assumed. For example, in one embodiment, information about the technical environment of client 102 may be known by virtue of the connection established between client 102 and server 103 over computer network 101 (e.g. it may be known that client 102 is connected to server 103 from a computer, using a browser, over the internet, or that client 102 is connected to server 103 from a handheld device, such as a Palm VII device, over a wireless network.) If such information about the technical environment of client 102 is sufficient to make a determination of the appropriate file format in which to send rich media file 105 to client 102 , steps 302 and 303 may be skipped.
At a step 304 , as shown in FIGS. 1D and 3 , server 103 compares response 108 b to a predefined schedule 109 of rich media file formats 106 -A, 106 -B . . . 106 -X. Schedule 109 contains a predefined preference ranking of the various available rich media file formats 106 -A, 106 -B . . . 106 -X. The reason a preference may exist for one file format over another is that one fife format may offer the client 102 higher video quality, audio quality, speed of download, or other features, than another format. In the preferred embodiment, this procedure is transparent to the user, such that the user is not required to take action to initiate this step, and the process is not noticeable to the user. As an alternative to step 304 , an appropriate format of rich media file 105 can be created “on-the-fly” by generating a script for rich media content 105 compatible with the local playback capabilities of client 102 .
Based on the comparison at step 304 , rich media file 105 is sent to client 102 in the preferred file format at a step 305 . As shown in FIG. 1D , for example, rich media file 105 in file format 106 -C is downloaded from server 103 to client 102 . In the example shown in FIGS. 1A–1E , while both file format 106 -C and file format 106 -E were determined to be suitable for playback on client 102 , because file format 106 -C is ranked higher than file format 106 -E in schedule 109 , server 103 transfers rich media 105 in file format 106 -C from memory 110 of server 103 to memory 104 of client 102 . In the preferred embodiment, this procedure is transparent to the user, such that the user is not required to take action to initiate this step, and the process is not noticeable to the user.
In the preferred embodiment, in the event that response 108 B from client 102 did not match any of the file formats 106 -A, 106 -B . . . 106 -X available in schedule 109 , or if response 108 B from client 102 did not match any of the file formats 106 -A, 106 -B . . . 106 -X ranked above a certain preference level, server 103 will not send rich media file 105 to client 102 , as shown at a step 305 a . Since the process according to the present invention, in the preferred embodiment, is transparent to the user, the user would not be aware that the transfer of rich media file 105 was unsuccessful.
At a step 307 , as shown in FIGS. 1E and 3 , after the entirety of rich media file 105 , in preferred file format 106 -C, has been completely loaded into local cache 107 of client 102 , as shown in a step 306 , rich media file 105 may be displayed. For example, as shown in FIGS. 2A–2C , rich media file 105 may be displayed in a designated display area 202 of a physical display area 200 of client 102 .
Designated display area 202 is defined as a region, screen, or application window that is used for displaying rich media content 105 , and is distinct from content display area 201 , previously being viewed by a user in physical display area 200 . Physical display area 200 is the total area of an electronic device which is dedicated to and available for displaying information, such as a computer's monitor or a cellular phone's LCD display screen, whereas content display area 201 is defined as the part of physical display area 200 actually being used to display content at a given moment. In the case of a small handheld device, display areas 201 and 202 may occupy the same physical space (e.g. the entirety of physical display area 200 ) as shown in FIG. 2A , or all or part of a “layer” of visual content within physical display area 200 , as shown in FIGS. 2B and 2C , superimposed over a portion of a preexisting content display area 201 (e.g. a main browser window) of client 102 .
Regardless of the physical space occupied by rich media content 105 , the designated display area 202 is separate in the sense that it can be manipulated (replayed, dismissed, forwarded to another user, etc.), as described below, without affecting the remainder of the content being viewed by the user. As shown in FIGS. 2A–2C , controls 203 may be provided for manipulating rich media content 105 at a step 308 . Controls 203 may be implemented in a variety of manners, including but not limited to, mechanical buttons, onscreen representations of buttons, onscreen menus, keystrokes, pen-based input methods, voice commands, ocular movements, a menu bar, navigation bar, or toolbar. Types of manipulation that might be performed may include the ability to replay; to turn any associated sound on or off; to turn any associated video on or off; to close or dismiss rich media content 105 ; to respond to rich media content 105 by redirecting the software, hardware, or electronic appliance to another source for electronic information on computer network 101 ; to respond to rich media content 105 by acknowledging receipt; to respond to rich media content 105 by answering a question; and/or to store rich media content 105 or a reference to rich media content 105 for future viewing by user. Additionally, rich media content 105 or a reference to rich media content 105 may be forwarded to another user by entering the email address, location, address, or other contact information for such other user, either manually or through referencing a list of predetermined recipients. Forwarding may mean simply including the sending of a reference to rich media content 105 (such as a URL, an alias, a pointer, or other means of locating files on a computer network), or the actual transfer of rich media file 105 to the other user. In the context of online advertising, forwarding to additional users increases the overall exposure to the advertisement's message. Therefore, a user may be encouraged to forward rich media content 105 , for example, by the amusing or entertaining nature of rich media content 105 , or through incentives, premiums or discounts offered for forwarding. Additionally, the address or coordinates of recipients of rich media 105 may be stored on computer network 101 (e.g. in a database on server 103 ), for future use by advertisers to target specific groups of individuals.
The present invention may be implemented using hardware, software or a combination thereof and may be implemented in one or more computer systems or other processing systems. An example computer system 400 useful in implementing the present invention is shown in FIG. 4 . The computer system 400 includes one or more processors 404 . Processor 404 is connected to a communication infrastructure 406 (e.g., a communications bus, cross-over bar, or network). Various software embodiments are described in terms of this exemplary computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures.
Computer system 400 may include a display interface 402 that forwards graphics, text, and other data from the communication infrastructure 406 (or from a frame buffer, not shown) for display on a display unit 430 .
Computer system 400 also includes a main memory 408 , preferably random access memory (RAM), and may also include a secondary memory 410 . The secondary memory 410 may include, for example, a hard disk drive 412 and/or a removable storage drive 414 , representing, for example, a floppy disk drive, a magnetic tape drive, or an optical disk drive. Removable storage drive 414 reads from and/or writes to a removable storage unit 418 in a well-known manner. Removable storage unit 418 , for example a floppy disk, magnetic tape, or optical disk, is read by and written to by removable storage drive 414 . As will be appreciated, removable storage unit 418 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative embodiments, secondary memory 410 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 400 . Such means may include, for example, a removable storage unit 422 and an interface 420 . Examples of such may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 422 and interfaces 420 which allow software and data to be transferred from removable storage unit 422 to computer system 400 .
Computer system 400 may also include a communications interface 424 . Communications interface 424 allows software and data to be transferred between computer system 400 and external devices. Examples of communications interface 424 may include a modem, a network interface (such as an Ethernet card), a communications port, and a PCMCIA slot and card. Software and data transferred via communications interface 424 are in the form of signals 428 which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface 424 . These signals 428 are provided to communications interface 424 via a communications path (i.e., channel) 426 . This channel 426 carries signals 428 and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage drive 414 , a hard disk installed in hard disk drive 412 , and signals 428 . These computer program products are means for providing software to computer system 400 . The invention is directed to such computer program products.
Computer programs (also called computer control logic) are stored in main memory 408 and/or secondary memory 410 . Computer programs may also be received via communications interface 424 . Such computer programs, when executed, enable the computer system 400 to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor 404 to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system 400 .
In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 400 using removable storage drive 414 , hard drive 412 or communications interface 424 . The control logic (software), when executed by the processor 404 , causes the processor 404 to perform the functions of the invention as described herein.
In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art.
In yet another embodiment, the invention is implemented using a combination of both hardware and software.
The method according to the present invention allows for a highly reliable, entirely transparent process for displaying high-quality online advertising imagery. While a number of embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. For example, while the above embodiments have focused on the application of the method according to the present invention to the display of online advertisements, the method according to the present invention also can be used to provide other forms of rich media content to a user over a computer network, as would be apparent to those of skill in the relevant art. Thus the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | The invention presented here is a method and system for providing rich media content over a computer network. In accordance with the invention, a server on a physical or wireless computer network polls the software, hardware, or appliance of an end user on the network, for the availability of software and/or hardware necessary for the display of rich media content. This polling is transparent to the end user and requires no action on the part of the end user. Based on the client's response, the server sends an appropriately formatted version of the rich media file. The user is not necessarily aware that this transfer is taking place, as it is taking place in the background, while the user is performing other tasks or viewing content other than that which is being transferred. Once the rich media has been transferred in its entirety and stored, or cached, in the local memory of the client, the rich media content is displayed automatically in a designated display area. The user may then be able to manipulate the rich media content without affecting the other content or tasks that were being displayed prior to the display of the rich media content. | 7 |
RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 11/801,076, filed on May 7, 2007, now issued as U.S. Pat. No. 8,141,072, which is a continuation of U.S. patent application Ser. No. 11/111,292, filed on Apr. 20, 2005, now issued as U.S. Pat. No. 7,853,943, which is a continuation of U.S. patent application Ser. No. 10/869,591, filed on Jun. 15, 2004, now issued as U.S. Pat. No. 7,171,660, which is a continuation of U.S. patent application Ser. No. 09/580,931, filed on May 25, 2000, now issued as U.S. Pat. No. 6,751,794. These patent applications are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to field of remote support for computer systems. More specifically, the present invention is directed to a method and an apparatus for updating software in a plurality of computer systems.
BACKGROUND
Personal computers have become an important part of the information age. The use of the personal computers has expanded beyond the traditional university campus and large office environments. Today, many small businesses and residences have at least one personal computer running a wide range of applications sold by many different software vendors.
As the applications become easier to use, the personal computers are no longer considered the tool for only the technical users. The user community has expanded and the personal computers are being viewed more as the tools to run the applications. Most users are interested in dealing with the applications and usually have no clue when something goes wrong with their personal computers. When the user is unable to use the application on the user's personal computer, the usual action is to take the personal computer to a local personal computer repair shop.
Since there are many different brands of personal computers such as, for example, IBM, Compaq, Gateway, Dell, etc., it is usually the case that each personal computer from a different brand may have a different set up. For example, the IBM personal computer may use a different video adapter from the Dell personal computer, among others. As such, to have a problem corrected, the user usually has to bring the personal computer into the repair shop so that the technician can isolate the problem.
One of the most common problems of application failure is incompatibility. The incompatibility may be related to the hardware or to the other applications in the same personal computer system. For example, the user may have installed a new application that is incompatible with the existing application when running together. The user may have installed a new hardware adapter that is incompatible with the existing application without installing a necessary update. Often the identification of the incompatibility occurs at a most unfortunate time such as, for example, prior to the user having an opportunity to save the work in progress. This experience is frustrating, time consuming and can be costly for the user.
SUMMARY OF THE INVENTION
A client computer sends application information about software applications on the client computer to a server system. The server system performs a comparison between the application information about the software application and the most-updated upgrade package for the software application. The most-updated upgrade package for the software application is stored in a part database. The most-updated upgrade package for the software application is received by the client system automatically when the comparison indicates that the most-updated upgrade package has not been installed on the client system. A client database stores a plurality of configuration files for a plurality of client systems. A first configuration file provides the sever system with the knowledge of the software applications installed on the client system. The application information about the software application comprises version information of the software applications and is stored in a database in the client system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example in the following drawings in which like references indicate similar elements. The following drawings disclose various embodiments of the present invention for purposes of illustration only and are not intended to limit the scope of the invention.
FIG. 1 is a network diagram illustrating one embodiment of components connected in a network that can be used with the method of the present invention.
FIG. 2 is a flow diagram illustrating one embodiment of an update process.
FIG. 3 is another flow diagram illustrating one embodiment of the update process.
FIG. 4 is an exemplary tool bar that can be used with one method of the present invention.
FIG. 5 is an exemplary diagram illustrating a relationship between a server connection point, a customer data base and a part data base.
FIG. 6 is an exemplary diagram illustrating a communication protocol between a client system and the server through the Internet network.
FIG. 7 illustrates one embodiment of a computer-readable medium containing various sets of instructions, code sequences, configuration information, and other data used by a computer or other processing device.
DETAILED DESCRIPTION
A method and apparatus for remotely updating software in a plurality of computer systems is disclosed. In the following description, for purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present invention.
Some portions of the detailed descriptions that follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
The present invention also relates to apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.
The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method operations. The required structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.
In one embodiment, the method disclosed in the present invention allows for better remote support of users of client systems in the network. A server provides update information to multiple client systems connected in a network. When necessary, the updates are retrieved from a central depository, sent to the appropriate client systems and automatically update the applications. In one embodiment, the client systems are IBM-compatible personal computers running in the Window environment such as, for example, Windows 98, Windows 2000, etc. The server and the client systems are connected in a network such as, for example, the Internet. By keeping the client systems updated, remote support can be efficiently performed to minimize the down time of the client systems. Each client system comprises of multiple installed software packages. The software packages may have been previously installed on the client system prior to delivery to a user. The software may include, for example, application software, device drivers, etc.
FIG. 1 illustrates an exemplary embodiment of the update network. A server 105 maintains a client database 125 to keep track of the client systems 110 , 115 . For example, whenever a client system 110 or 115 communicates with the server 105 , the server 105 already knows about the installed software on that client system 110 , 115 . The server 105 also maintains a part database 120 containing software patches and software updates to help keeping the client systems 110 and 115 up to date. The client database 125 allows the server 105 to know about the configuration of the client systems 110 and 115 . The client database 125 and the part database 120 may be in the same database server or in separate database servers connected in the network 130 . Alternatively, the client database 125 and the part database 120 may be in the same system as the server 105 . In one embodiment, the server 105 serves as a central point for receiving update requests from the client systems 110 and 115 and for retrieving information from the databases 125 and 120 to satisfy the update requests.
FIG. 2 is a flow diagram 200 illustrating one embodiment of an update method. At block 205 , an update request is generated by the client system 110 , 115 and sent to the server 105 . The update is performed on a periodic basis, such as, for example, every 24 hours. Alternatively, the update may be performed at any time by the user sending an update request to the server 105 on the network. The server 105 knows each client system 110 , 115 by a unique identification associated with the client system 110 , 115 .
In one embodiment, the server 105 accesses a client database 125 containing information about the client system 110 , 115 . The client database 125 may include information, such as, for example, installed software packages on the client system 110 , 115 , the operating system installed on the client system 110 , 115 , etc. However, what the server 105 may not know is whether these installed software packages are up to date. For example, the user of the client system 110 , 115 may have changed the configuration parameters of the software packages, or the user may not have requested for an update for an extended length of time due to the client system 110 , 115 not being connected to the network 130 .
In one embodiment, the client system 110 , 115 may need to do a self-check and send its current software configuration to the server 105 . A self-check may be done by the server 105 directing the client system 110 , 115 specifically what to check for and the information to be collected from the client system 110 , 115 . This information is the sent to the server 105 , as shown in block 210 . Based on this information, the server 105 checks its part database 120 and determines the updates that the client system 110 , 115 needs. The updates are sent from the server 105 to the client system 110 , 115 , as shown in block 215 . The updates may be sent with instructions from the server 105 that tells the client system 110 , 115 what to do to have the updates installed, as shown in block 220 .
FIG. 3 is another flow diagram illustrating one embodiment of an update method 300 . In one embodiment, a utility program executed by the client system 110 , 115 communicates with the server 105 for information to check on the client system 110 , 115 . The execution of this utility program may be initiated by the user or it may be automatic. The utility program is herein referred to as a patch checker. The patch checker initiates the request to have the applications verified for any necessary updates. The request is sent to the server 105 along with the unique identification number of the client system 110 , 115 . The server 105 uses the client identification number to check against the client database 125 for authentication. In one embodiment, the database contains configuration information about the client system 110 , 115 . The server 105 retrieves the configuration information for the client system 110 , 115 , generates a script file and sends the script file to the client system 110 , 115 , as shown in block 305 . In one embodiment, the script file contains commands that tell the client system 110 , 115 the functions to perform. For example, the commands may direct the client system 110 , 115 to perform self-check functions. The self-check functions may have the following parameters:
‘v: filename’ get the file's version ‘m: filename’ get the file's modified date ‘d: driveletter’ get amount of free disk space ‘r: keyname’ get the value of the specified registry key ‘s: filename’ get the size of the file.
In one embodiment, the commands are executed by the client system 110 , 115 to collect information pertinent to the applications currently installed on the client system 110 , 115 .
The script file may contain a list of parts that the server 105 thinks the client system 110 , 115 has and that the server 105 wants the client system 110 , 115 to check. The parts may be the names of the applications and the server 105 may want the client system 110 , 115 to collect the current version information about the applications. In one embodiment, in order to keep the information in the client database 125 accurate, the user may not want to alter the configuration of the applications that are to be supported remotely by the server 105 . Keeping the client system 110 , 115 and the information in the client database 125 synchronized may help making the update process by the server 105 more efficient.
In block 310 , using the script information sent by the server 105 , the patch checker parses the server's commands to check the software parts on the client system 110 , 115 . The appropriate information about these software parts is collected. In one embodiment, the version of each software part is collected and sent to the server 105 , as shown in block 315 . The server 105 uses the information collected from the client system 110 , 115 and compares it with a part database 120 . For example, the server 105 may check the version number collected from the client system 110 , 115 with the version of the same software part in the part database 120 . In one embodiment, the server 105 may want to get the most updated version distributed to the client system 110 , 115 .
When the version information collected from the client system 110 , 115 is not at the same level with the version of the same software part in the part database 120 , the most updated version is retrieved from the part database 120 . When the version information from the client system 110 , 115 is already up to date, there is nothing to download. In block 320 , the patch checker asks the server 105 for the files associated with the updated versions of the software to download. The files are downloaded from the server 105 to the client system 110 , 115 in block 325 . In one embodiment, each download file is associated with an uniform resource locator (URL). The server 105 replies to the update request by sending the patch URL.
There may be one or more download files for each software to be updated, and there may be more than one software that needs to be updated, the server 105 may send several down load files to the client system 110 , 115 . The download files may be stored in a predefined directory such as, for example, the download directory. Each download file is processed individually, as shown in block 330 . In one embodiment, the download files are received from the server 105 in a compressed format, such as, the zip format, and need to be uncompressed or expanded, as shown in block 335 . Each download file is expanded into an executable program and multiple related data files. One of the data files is a text file or an instruction file containing a set of instructions or commands that can be parsed by the executable program to perform the update process, as shown in block 340 . For example, the instruction may be one of the following commands:
Delete a file ShellExecute ShellExecute with wait Registry Change Add message to a tool bar Kill a particular process Ask for reboot Force reboot Ask user to install now or later Ask user to close all programs
When all of the download files have been expanded and copied into the appropriate directories, the update process is completed. At that time, the user may be given an option of rebooting the client system 110 , 115 to activate the updated version. Alternatively, the user may continue working with the currently installed version and reboot the client system 110 , 115 at a later time.
FIG. 4 illustrates an exemplary tool bar that can be used with the present invention. In one embodiment, the tool bar is a list of dynamic link libraries (DLL) and is always running. Additional functions can be added to the tool bar by adding DLL files. For example, the patch checker can be added to the tool bar 400 by adding a patcher.dll to the tool bar 400 , and a patch checker icon can be displayed. By selecting the patch checker icon, the user can initiate the update process at any time. In one embodiment, the tool bar 400 is also used to display update related messages to the user.
FIG. 5 is an exemplary diagram illustrating a relationship between a connection point, a customer data base and a part data base. In one embodiment, the server provides a connection point 505 that connects to a customer database 510 . The customer database 510 maintains the state of every client system in the network. The state includes information concerning relevant hardware and software as currently installed on the client system. This information includes, for example, the versions of the installed software applications, the versions of the installed hardware drivers, etc. Additionally, the connection point 505 is also connected to a part database 515 . The part database 515 may contain the different versions of the application software, the DLLs, the hardware drivers, and any other software modules that may be installed on the client system. The server uses the part database 515 to keep the client system up to date. For example, when the client system is identified to have a hardware driver that is not current, the most up-to-date hardware driver is retrieved from the part database 515 .
In one embodiment, a client part database is maintained in the client system. The client part database contains the versions of the software that are installed on the client system. As additional software is installed on the client system, the client part database is updated accordingly. In one embodiment, when the server wants to know the versions of the software installed on the client system, the patch checker retrieves the version information from the client part database.
FIG. 6 is an exemplary diagram illustrating a communication protocol between a client system 600 and a server 650 through the Internet network. In one embodiment, the client system 600 has a message queue 605 to store messages that certain application 610 , such as, for example, the patch checker (patcher.dll), wants to send to the server 650 . The user selects the patch checker icon on the tool bar 400 displayed by the tool bar program 620 (dreambar.exe) to execute the patch checker 610 . The message queue 605 is processed periodically, such as, for example, every thirty minutes, while the user is connected to the Internet 690 . When the user is not connected to the Internet 690 , the messages from the patch checker (applications) 610 are stored in the message queue 605 . In one embodiment, the patch checker 610 connects to the server 650 through a message handler 615 (ConPoint.dll). The message handler 615 handles the messages generated by the patch checker 610 including, for example, the request for an update. The message handler 615 sends the message to the server 650 . In another embodiment, the message queue 605 is implemented as a text file located in a message queue directory.
In one embodiment, the server 650 is implemented with multiple java servlets. A master servlet 655 (AnnexServlet) is used to route all the messages received from the client systems 600 to the other servlets 665 , 670 on the server 650 . Each of the servlets 660 , 665 , 670 handles different type of messages. In one embodiment, as each servlet starts up, the servlet tells the master servlet which type of messages the servlet 660 , 665 , 670 handles. The master servlet 655 may be used as the connection point on the server 650 . Each of the servlets 660 , 665 , 670 may be used as a worker. For example, the servlet 660 is the patch worker handling the update messages from the patch checker 610 . The patch worker 660 sends the script file to the patch checker 610 . The script file is used by the patch checker 610 to check the client system 600 . When the patch checker 610 requests for the download, the patch worker 660 accesses the part database 665 to retrieve the necessary software versions for the client system 600 . It will be apparent to one skilled in the art that there may be other workers (servlets) on the server 650 , such as, for example, a buildworker to add a new client system to the client database, a viewworker to view contents of the client database 680 and the part database 675 , a dataworker to store data, and a messageworker to get the messages to be displayed on the tool bar 400 .
In one embodiment, each client system 600 is associated with a unique identification number known to the server 650 . As a new client system 600 is inserted into the network, the client database 680 is updated with the identification number of that new client system 600 . Similarly, when the client system 600 is removed from the network, the client database 680 is updated accordingly. In one embodiment, the server 650 generates a report listing all the identification number of those client systems 600 that have not communicated with the server 650 for over a predetermined length of time. The report can then be used to investigate status of these client systems.
FIG. 7 illustrates an embodiment of a computer-readable medium 700 containing various sets of instructions, code sequences, configuration information, and other data used by a computer or other processing device. The embodiment illustrated in FIG. 7 is suitable for use with the software update method described above. The various information stored on medium 700 is used to perform various data processing operations. Computer-readable medium 700 is also referred to as a processor-readable medium. Computer-readable medium 700 can be any type of magnetic, optical, or electrical storage medium including a diskette, magnetic tape, CD-ROM, memory device, or other storage medium.
Computer-readable medium 700 includes interface code 705 that controls the flow of information between various devices or components in the computer system. Interface code 705 may control the transfer of information within a device (e.g., between the processor and a memory device), or between an input/output port and a storage device. Additionally, interface code 705 may control the transfer of information from one device to another or from one network component to another.
Computer-readable medium 700 also includes the patch checker program 710 that is used to request and receive software patches or updates from the server. Other codes stored on the computer-readable medium 700 may include the tool bar program 715 to display the patch checker icon, the message queue handler program 720 to receive the messages generated by the patch checker and send the messages to the server. The computer-readable medium 700 may also contain programs run on the server. These programs may include the patch worker 725 that communicates with the patch checker 710 from the server side, and the database access program 730 that allows the server to view the client database and the part database.
From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustration only and are not intended to limit the scope of the invention. Those of ordinary skill in the art will recognize that the invention may be embodied in other specific forms without departing from its spirit or essential characteristics. References to details of particular embodiments are not intended to limit the scope of the claims. | A client computer sends application information about a software application to a server system. The server system performs a comparison between the application information about the software application and the most-updated upgrade package for the software application. The most-updated upgrade package for the software application is stored in a part database. The most-updated upgrade package for the software application is received by the client system automatically when the comparison indicates that the most-updated upgrade package has not been installed on the client system. A client database stores a plurality of configuration files for a plurality of client systems. A first configuration file provides the sever system with the knowledge of the software applications installed on the client system. The application information about the software application comprises version information of the software applications and is stored in a database in the client system. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in cameras, and more particularly, but not by way of limitation, to a motion picture device adapted to move the film therethrough in intermittent stop-and-go motion and containing an improved film drive system for effecting such movement at exceptionally high speeds.
2. Description of the Prior Art
Heretofore, high-speed motion picture cameras in which the film is advanced intermittently, one frame at a time, have been beset by many difficulties and problems. One of the major problems with such high-speed picture cameras resides in the need for overcoming the inertia as the film and associated parts are caused to accelerate between the stop-and-go operations. This change of inertia not only causes the need for additional energy to be placed in the system, but also places a heavy strain on all of the moving parts. Accordingly, it is desirable to minimize the number of moving elements which undergo such rapid changes in velocity during the stop-and-go movement of the film through the film gate.
In addition, other operational areas of cameras of this type are constantly in need of further improvement, when possible, and these include the film drive mechanism whereby it is desirable to achieve high-speed operation with a minimum of power, and yet provide for synchronized movement of the irregular relationship between the supply reel and the take-up reel. Accordingly, it is desirable to utilize a minimum of moving parts in such drive, yet provide reliable operation, and facility of use, i.e. change of reels for use of the camera with multiple reels at one time.
Another problem that has arisen in motion picture cameras resides in the tendency of the film to bow somewhat so that a cylindrical concavity appears on the emulsion side of the film. It is therefore desirable to provide a film gate that tends to flatten out the film so as to provide a better focal plane at the film gate, yet which does not injure the emulsion or provide undue frictional drag as the film passes through the gate.
SUMMARY OF THE INVENTION
The present invention contemplates a novel motion picture camera and the like which has been particularly improved or designed and constructed for overcoming or greatly reducing the foregoing disadvantages. In accordance with the invention, an improved film drive mechanism is provided which is especially suitable for motion picture cameras, but which is also applicable to use in projectors. The film drive mechanism contains a sprocket means engaging the film travelling toward the film gate and engaging the film moving away from the film gate so as to provide a typical film loop on each side of the sprocket with the film loop going through the film gate. In this way the film can travel at a substantially constant linear speed over the sprocket means and yet move in a stop-and-go movement through the film gate by virtue of the compensating movements in the loop itself. The sprocket means may comprise a plurality of sprockets, but preferably a single sprocket is used, with the sprocket having suitable teeth for engaging the perforations provided on each side of the film strip and providing power to move the film toward and away from the film gate. Right hand and left hand film rollers are disposed in the proximity of the sprocket for bearing against the opposite or outer surface of the film passing over the sprocket in order to assure a more efficient engagement of the sprocket with the perforations of the film for assuring a more accurate registration of the film moving through the film gate.
Instead of the typical claw system moving the film in the halting stop-and-go motion, this invention utilizes an eccentric guide for the film loop on one side of the film gate cooperating with a compensating guide for the film loop on the other side of the film gate so as to control the film loop and provide conversion from a constant linear movement of the film to a stop-and-go movement at the film gate. The compensating film loop guide is of a more compact construction for reducing the accumulation of the composite error in the perforations, and the stationary register pin provided on the film gate is positioned so as to be inserted into a perforation when the eccentric crosses dead center, or is at the bottom of its travel.
The eccentric guides are two precision ball bearings mounted on the eccentric shaft and spaced to engage the film at its outer edges and dynamically balanced to provide a substantially vibration free rotation, which is not possible with the claw "pull down". The crank rollers serve the same purpose as the conventional claw pull down with the advantage of using the full strength of the film and combining with the sprocket during the pull-down time. This system makes possible the loading of the upper loop spring with a substantially frictionless film pull spring. With this construction, the rollers are simply synchronized to the sprocket means so as to provide a relatively simple mechanism containing parts rotating in a substantially constant speed, yet providing the proper conversion of the film travel for substantially constant linear movement to a stop-and-go linear movement at the film gate and back to a substantially constant linear movement. The drive connection between the sprocket and the take-up reel and the coefficient of friction variables are reduced by providing a drive roller of relatively small diameter in engagement with the outer periphery of the take-up reel, said drive roller having a relatively hard outer periphery bearing against the take-up reel with light pressure whereby relatively little friction is necessary for the driving of the take-up reel.
It is thus seen that a primary object of the present invention is to provide an improved film drive mechanism having a relatively simple construction for converting film movement from linear to the desired halting motion through the film gate and back to linear movement for rewind, said substantially constant velocity allowing for high speed movement with a minimum of strain, said high speed movement being approximately three hundred frames per second.
Another object of this invention is to provide a registration pin capable of cooperation with an eccentric drive for holding the film in a stationary position during exposure at the film gate, with the registration pin being constructed to function without movement thereof, and so positioned as to provide a pull down of approximately 100° of the shutter angle, with an exposure time substantially equal to a 180° revolution of the shutter.
A further object of the invention is to provide an improved drive for the take-up reel which is driven through a gear train in connection with the sprocket member and which includes a relatively small drive roller having a hard outer periphery in engagement with the outer periphery of the relatively large diameter take-up reel for applying relatively light driving pressure thereagainst, thus providing a low coefficient of friction, and a more efficient take-up reel operation.
Still another object of this invention is to provide a film drive mechanism of the character described which is capable of operating at relatively high speeds with a minimum of power input.
Preferably, the registration pin is mounted on the housing or main frame so as to be stationary with respect to the camera, and the film drive mechanism is constructed so that the eccentric crank not only provides the stop-and-go movement of the film, but also moves the film into and out of engagement with the registration pin. With this construction, the registration pin does not have to move back and forth in reciprocating fashion as each frame passes as in the conventional registration pins, and the extreme forces due to the high acceleration of the pin are thereby avoided.
In the preferred camera constructed according to the present invention, the camera is also constructed in easily separable parts so that the motor drive, lens system and shutter may be provided in one part of the camera, and the reel units together with their film drive mechanism may be provided in another section. This construction allows the operator to make rapid changes of film by utilizing the same main camera section with different spools of film already set up in driving relation. It is well known to facilitate reel changes, but heretofore the need of threading the film through the film guide means in the film gate has presented a problem. In accordance with the present invention, the film drive mechanism is completely provided in one portion, together with the film gate, and is particularly designed so that the change of film in no way changes the focus set by the object lens or the camera mount. The latching mechanism is particularly constructed and arranged for release by one hand of the operator of the camera for further facilitating the changing of the film.
It is therefore still another object of the invention to provide a novel two-piece camera construction in which the film drive mechanism is provided separately from the motor and shutter drive and associated parts, said two-piece construction being formed for accurate and rapid assembly with assured synchronization of the film drive mechanism and shutter mechanism, and having release means operable by one hand of the operator of the camera whereby the magazine section of the camera may be readily separated from the main section thereof.
Yet another object of the invention is the provision of a camera of the character described in which the film gate is formed with guide means providing a path having a width corresponding to the width of the film in the location of the aperture whereby the film is held in a flat configuration thereat, but without binding or excessive friction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a movie camera embodying the invention.
FIG. 2 is a perspective view of a movie camera embodying the invention and illustrated with the two sections thereof disengaged with respect to each other.
FIG. 3 is a plan view taken on line 3--3 of FIG. 2.
FIG. 4 is a side elevational view of the camera shown in FIG. 1 with the cover removed for illustration of the internal parts.
FIG. 5 is a perspective view of the film transport construction of a movie camera embodying the invention together with a diagrammatic illustration of the shutter position with respect to the film gate.
FIG. 6 is a sectional view taken on line 6--6 of FIG. 4.
FIG. 7 is an elevational view of a portion of the film drive mechanism illustrating the manner in which the film passes through the film gate.
FIG. 8 is a view taken on line 8--8 of FIG. 7.
FIG. 9 is a side elevational view of a combination spring and block for low and high speed operation, with portions shown in broken lines for purposes of illustration.
FIG. 10 is a view taken on line 10--10 of FIG. 9.
FIG. 11 is a view taken on line 11--11 of FIG. 8.
FIG. 12 is a view taken on line 12--12 of FIG. 11.
FIG. 13 is a side elevational view of a portion of a take-up reel and lower loop and eccentric member and portions of the film drive assembly for a motion picture camera embodying the invention.
FIG. 14 is a view taken on line 14--14 of FIG. 13.
FIG. 15 is a side elevational view of a drive sprocket and light shield as utilized in one embodiment of a motion picture camera embodying the invention.
FIG. 16 is a side elevational view of a modified lower loop and eccentric drive portion of the film drive assembly of a motion picture camera embodying the invention.
FIG. 17 is an elevational view, partly in section, of a bayonet lock and spring washer utilized in a camera embodying the invention.
FIG. 18 is a view taken on line 18--18 of FIG. 16.
FIG. 19 is a view taken on line 19--19 of FIG. 18.
FIG. 20 is an elevational view of a portion of the film drive assembly illustrating a modified film roller arm structure.
FIG. 21 is an elevational view of a modified film drive assembly portion as may be utilized in a motion picture camera embodying the invention.
FIG. 22 is an elevational view of a modified reel spacer as may be utilized in a motion picture camera embodying the invention.
FIG. 23 is an elevational view, partly in section, of a shutter adjustment apparatus utilized in the invention.
FIG. 24 is a side elevational view of an adjuster element utilized in the shutter adjustment apparatus shown in FIG. 23.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in detail, reference character 10 generally indicates a motion picture camera comprising two completely separable sections 12 and 14. The section 12 may be referred to as the magazine section and is provided with a suitable door 15 removably secured to one side thereof in any suitable or well known manner, such as that shown in my aforementioned U.S. Pat. No. 3,625,406, issued Dec. 7, 1971, and entitled "Motion Picture Camera and the Like:, for providing access to the interior thereof. The section 14 may be referred to as the main section and comprises a main housing 16 for supporting a suitable object lens assembly 18, shown in broken lines in FIG. 1, adapted to fit over an aperture 20 provided in the housing 16, with the housing 16 cooperating with the section 12 to provide a compact camera assembly. The section 14 also contains a suitable motor 22 (FIG. 5) for providing power to the various moving parts. The motor 22 as shown herein is preferably an electric motor supplied through a typical appliance cord (not shown). As will become more apparent hereinafter, section 14 also contains a shutter 24 synchronized to provide a speed dependent upon the speed of the motor 22, and a power-coupling means 26 for transmitting mechanical power from the section 14 to the section 12.
The section 12 comprises a housing 28 having an aperture 30 provided therein to correspond with the aperture 20 of the housing 16 whereby said apertures provide for exposure of the film at a film gate 32. The section 12 also comprises a film drive means 34 adapted to receive power from the power-coupling means 26 and drive a film strip 36 through the film gate 32 in stop-and-go fashion.
As is well known, the usual film 36 is provided with a plurality of longitudinally spaced perforations or holes 38 along at least one side or edge thereof, and preferably along with both sides thereof as particularly shown in FIGS. 5 and 7. The invention provides means for preventing lengthwise movement of the film strip 36 while a picture is being taken, said means comprising a film drive means 34 and a registration pin means 40 mounted on the housing 28 for engagement with the holes 38 of the film 36 for holding the film stationary when a hole is so engaged, said registration pin 40 cooperating with said film drive means 34. It is preferable that the registration pin means 40 include a pair of substantially identical transversely spaced pin members for simultaneously engaging the aligned holes 38 on the opposite sides of the film strip 36, but only one of the pins 40 is shown herein.
The film drive means 34 comprises an eccentrically mounted wheel means or crank means 42 positioned for contacting the film strip 36 and moving same laterally back and forth thereby causing the moving film to periodically engage and disengage the registration pin 40, substantially as set forth in my aforementioned patent. This type operation may be referred to as a beater system, and the eccentrically mounted wheel means 42 operates by engaging a loop 44 of the film 36 formed by passing the film over a guide roller 46 which is interposed between the eccentric wheel 42 and a drive sprocket 48. The wheel or roller 46 facilitates maintaining of the film strip 36 in an efficient engagement with the sprocket 48 for assuring an efficient driving of the film strip with a minimum of slack in the film and for facilitating the reduction of stretch in the film strip during the movement of the film through the drive means 34.
The wheel means 42 comprises a pair of precision ball bearings mounted on an eccentric shaft 43 in spaced relation for simultaneously engaging the opposite side edges of the film loop 44 during a pull down operation, with the bearings being dynamically balanced to provide a substantially vibration free action. The bearings cooperate with the sprocket 48 during the pull down operation, thus using the full strength of the film. When the eccentric 42 has passed its lowermost position (shown in solid lines in FIG. 8), the eccentric moves out of driving engagement with the bottom loop of the film, but the sprocket 48 continually drives the film strip in a forward direction. The eccentric 42 does not engage the loop again until the eccentric passes over the uppermost position, as shown in broken lines in FIG. 8, and begins its downward movement. At this time, the eccentric 42 engages the bottom loop and moves the loop in a direction toward the register pin means 40 for engagement of the pin means with the properly aligned perforations 38. Upon engagement of the pin means 40 with the perforations 38, the forward movement of the loop portion of the film is interrupted to provide the stop-and-go movement for the film at the film gate 32.
As shown herein, the sprocket means 48 comprises a single sprocket member having a plurality of circumferentially spaced outwardly extending teeth 50 provided around the outer periphery of each end thereof for engagement with the holes or perforations 38 of the film 36, as is well known. However, it is to be understood that the sprocket means may comprise multiple sprockets instead of a single sprocket if desired, so long as the film is fed toward the loop 44 and is taken away from the loop 44 at a substantially constant velocity. The sprocket 48 is also preferably provided with a substantially centrally disposed circumferential groove on the outer periphery thereof interposed between the two rows of teeth 50 for slidably receiving one end of a suitable stripper 51 therein, as is well known. The loop 44 is formed by moving the film 36 around a guide roller 52, a compensating guide assembly means 53, the eccentrically mounted wheel means 42, and the guide roller 46, and back to the sprocket means or member 48. Other suitable guide rollers such as rollers 54 and 56 cooperate with the roller 52 in order to direct the film 36 through a desired path and insure engagement with the sprocket 48 as set forth in my aforementioned patent. In addition, left hand and right hand film rollers 58 and 58A are carried by suitable film roller arms 60 and 61 which are pivotally secured to the housing 28 at 62 and 62A, respectively (FIG. 4). The arms 60 and 61 are yieldably urged in a direction for a pressure engagement of the rollers 58 and 58A against the outer surface of the film 36 moving over the sprocket 48 as shown in FIG. 4. This further assures an efficient engagement of the teeth 50 with the perforations 38 as the film engages the opposite sides of the sprocket 48 during movement of the film 36 through the drive apparatus 34. The arms 60 and 61 may be of substantially any desired configuration, such as shown at 60A and 61A in FIG. 20, and may be selectively pivoted in a direction for removing the rollers 58 and 58A from engagement with the film 36 when desired.
The arm 60 is provided with a spring load plunger lock device 60B at the outer end thereof for locking the arm 60 in a preselected position, and the arm 60A is similarly provided with a lock device 60C. The arm 61 is similarly provided with a plunger lock device 61B for locking the arm 61 in a preselected position. When the plunger lock devices 60B and 61B are engaged, the rollers 58 and 58A are in engagement with the film strip 36 and sprocket 48 as shown in FIG. 4. When the plunger lock devices 60B and 61B are disengaged the rollers 58 and 58A are removed from engagement with the film strip and sprocket as shown in FIG. 20.
Referring more specifically to FIG. 5, it will be apparent that a shaft 64 receives power from the coupling means 26, and the shaft 64 is part of and provides power for the film drive means 34. The shaft 64 drives a gear 66 which in turn drives a gear 68 carried by a suitable stub shaft 70 which may be secured to the housing 16 in any well known manner (not shown). The gear 68 in turn drives a gear 72 carried by a shaft 74 which also carries a gear 76 disposed in spaced relation to the gear 72. The gear 76 drives a gear 78 carried by a shaft 80 which in turn carries the sprocket 48 at the opposite end thereof. The sprocket 48 then drives the film strip 36 from a supply reel 82 and onto a take-up reel 84 in a manner as will be hereinafter set forth in detail. The sprocket 48 also feeds the film 36 into the loop 44 at a substantially constant velocity, and takes the film from the loop at the exact same velocity, the exact length of the loop being fixed by the engagement of the sprocket with the film strip 36 as set forth in my aforementioned patent.
The movement of the section of the film loop passing through the film gate 32, as shown in FIGS. 4 and 8, is regulated by the eccentrically mounted wheel means 42 and by the compensating guide means 53, which are formed to provide stop-and-go motion of the section of the loop therebetween. As shown herein, the eccentrically mounted wheel 42 is positively driven by a shaft 86 (FIG. 5) which may be keyed or otherwise secured to a gear 88 for rotation simultaneously therebetween, and the gear 88 is driven by the gear 68.
The structure of the sprocket 48, eccentrically mounted wheel 42 and guide rollers 46, 52, 54 and 56 may be of any suitable type as set forth in my aforementioned patent, but it is preferable that the outer periphery of each roller be of a slightly concave longitudinal configuration to provide an emulsion relief for all which receive the film strip 36 thereover, thus assuring an efficient handling of the film strip 36 during its movement through the drive apparatus 34. In addition, the compensating guide assembly 53 as shown in FIGS. 8 through 12 preferably comprises a housing 89 having a pair of oppositely disposed substantially straight and mutually parallel surfaces 90 and 92 for receiving the film strip 36 thereover. The lower portion of the surface 90, as viewed in FIG. 9, is preferably outwardly flaring or arcuate for gently receiving the film strip 36 thereon from the guide roller 52. A suitable half-roller or semi-cylindrical member 94 is mounted on the upper end of the housing 89 and is reciprocally secured thereto in any suitable manner. The walls or surfaces 90 and 92 are of a width substantially equal to the width of the film strip 36, and a suitable loop spring 96 is secured to the surface 90 by a screw 91, or the like. The spring 96 is of a cross-sectional contour or configuration corresponding to the outer surface 90 and lies snugly thereagainst for receiving the film strip thereon. A detent portion 93 is provided in the spring 96 for receiving the head of the screw 91 therein in order that the screw 91 will not engage the surface of the film passing over the surface of the spring 96.
One end 96A of the spring 96 is curved or arcuate corresponding to the contour of the outer surface of the element 94, and is spaced slightly therefrom in the normal relaxed position of the spring as shown in FIG. 9. It is to be noted that the spacing illustrated in FIG. 9 is exaggerated for purposes of illustration since the spacing between the element 94 and the curved portion 96A of the spring 96 is very slight for a purpose as will be hereinafter set forth. The loop spring 96 is preferably constructed from a highly polished metal, such as clock spring, and is of a width substantially equal to the width of the film strip 36 passing through the drive apparatus 34.
As the ecentric roller or wheel means 42 moves through its eccentric path, as indicated by the broken line positions therefor in FIG. 8, the film 36 is pulled outwardly and downwardly and then over the registration pin 40. As hereinbefore set forth, this action may be referred to as a beater system. The pin 40 is positioned with respect to the wheel 42 whereby the pin 40 will be inserted through a perforation 38 substantially exactly when the eccentric 42 reaches dead center at the end of its pull of the film 36. The compensating assembly 53 is provided so as to allow the film to be pulled downwardly by the eccentrically mounted wheel means 42 and otherwise compensate for the movement thereof. The pull-down on the film causes the spring 96 to move against the abutment member 94 and the spring 96 maintains the film efficiently taut during the stop portion of the stop-and-go movement at the film gate 32. It is to be understood that the eccentrically mounted wheel 42 is formed to pull the film downward, while the pin means 40 holds the film in a substantially stationary position for the period of time as the eccentric goes back toward the original pull down position, as set forth in my aforementioned patent. As the film is pulled down, the loop spring 96 of the compensating means allows for the pull down, and then takes up slack during the hold or stationary position of the film so as to get ready for the next pull down operation. With the structure shown herein it has been found that a pull down of a maximum of 100° of rotation of the shutter 24 is possible, and a frame rate of approximately 300 perforations per second. Of course, the shutter opening or aperture angle 24A must be increased with respect to the normal aperture angle whereby the overall angle of the shutter angle will be approximately 90° double shutter, equalling approximately 180° shutter time. A few degrees are allowed for the film to stabilize in the register pin 40.
FIG. 8 shows the eccentric 42 in its bottom position in solid lines, and a plurality of other positions therefor in broken lines. When the eccentric 42 has reached it bottom position and stopped pulling loop 44 through the film gate 32, the spring 96 of the compensating guide 53 is depressed, as hereinbefore set forth, and the loop 44 is displaced its maximum distance downward, as shown in solid lines in FIG. 8. It should be noted that the film 36 is pulled away from the loop to the bottom side of the sprocket 48 at the same time it is advanced toward the loop 44 by the upper portion of the sprocket 48, as viewed in the drawings , so that the length of the film in the loop 44 remains constant at all times. As hereinbefore set forth, both the crank or eccentric 42 and the sprocket 48 contribute and cooperate to advance the film during the pull down operation. It should also be noted that the pin 40 is inserted through or engaged with the perforations 38 at the moment the eccentric 42 reaches the bottom or dead center position thereof when the movement of the film 36 is stopped.
When the eccentric 42 leaves the bottomost position, the film 36 is once against advanced through the free upper loop until the eccentric 42 has once again made contact with the bottom loop to begin the next pull down to repeat the cycle. It will thus be seen that the portion of the loop 44 passing through the film gate is moved in alternate stop-and-go motion. Reciprocating motion of the registration pin is completely eliminated as set forth in my aforementioned patent, and the registration pin is active during the halting period to positively hold the film during the entire exposure thereof. The compact structure of the loop compensating spring assembly 53 reduces the accumulation of the composite error in the perforations of the film strip, and the right hand and left hand rollers 58 keep the film tight against the sprocket 48 for a more accurate registration of the film. The large contact area of the spring 96 with the film 36 reduces the pressure per square inch on the film 36 thereby reducing stretching of the film and other adverse effects normally present with the relatively high pressures acting on the film. The movement of the spring 96, as is compresses or depresses, follows the movement of the film, thus reducing resistance to the movement of the film through the drive assembly 34. It is also to be noted that the distance between the sprocket 48 and the registration pin 40 is relatively short, thereby reducing the composite error between the perforations 38 of the film 36.
Referring to FIGS. 4, 5 and 13, it will be seen that the present invention also provides an apparatus for moving the film 36 longitudinally from the supply reel 82, through the film gate 32, and to the take-up reel 84. A gear-train drive system generally indicated at 100 is operably engaged with the gear 76 for actuation thereby to rotate a shaft 102 about its own longitudinal axis. A friction roller 104 is carried at one end of the shaft 102 and the outer periphery of the roller 104 is in constant engagement with the outer periphery of the take-up reel 84 for transmitting rotation to the reel 84. The friction roller 104 is preferably constructed of a hard metal, or the like, for reducing the friction between the reel 84 and the roller 104, and the diametric size of the wheel or roller 104 is particularly selected in order that the core of the take-up reel 84 rotates through one revolution during the advance of one wrap of the film around the core of the reel 82, see particularly FIG. 4. The wheel 104 is suitably connected with a helical spring 105 whereby the roller is constantly urged against the outer periphery of the reel 84 and whereby the pressure of the roller 104 against the reel 84 is determined by the tension of the spring 105, which is preferably very light. Of course, suitable release means (not shown) is provided for holding the roller 104 out of engagement with the reel 84 during removal of the reel, or the like, as is well known.
The film strip 36 is directed from the supply reel around a plurality of rollers 106, 108, 110 and 112 and around the roller 54 to the drive sprocket 48 as particularly shown in FIG. 5. The forward rotation of the sprocket 48 pulls the film from the reel 82 and causes the reel 82 to rotate in the direction indicated by the arrow 114. The reel 82 is preferably freely journalled on a suitable shaft 116 in any suitable manner for facilitating the rotation of the reel 82. The reel 84 is also journalled on a similar shaft 116A, and is disposed in spaced relation to the reel 82. The reel 84 rotates in the direction indicated by the arrow 118.
A suitable film counting mechanism, generally indicated at 120 is preferably provided in the section 12 and includes a finger 121 which rides on or is in engagement with the outer periphery of the film wound on the core of the reel 82, as particularly shown in FIG. 5, and actuates a suitable visual counter (not shown) for indicating the quantity of unexposed film remaining in the camera 10 to be exposed, or for indicating the quantity of film remaining in the camera which has not been exposed, as desired and as is well known.
The register pin means 40 as shown herein is preferably carried by or is integral with a plate member 40A having an aperture 40B provided therein corresponding to the apertures 20 and 30. The plate 40A may be secured to the inner periphery of the housing 28 in any suitable manner, such as by screws 40C, and properly orientated so as to align the aperture 40B with the aperture 20. In this manner, the register pin means 40 is secured to the housing 28, as hereinbefore set forth.
The film gate comprises a guide means generally indicated at 122 (FIGS. 7 and 8) formed with a width corresponding to the width of the film in the location of the aperture 30 and for holding the film in a flat configuration at the aperture 30. A first post abuttment or film edge guide member 123 extends along one side of the guide 122, and the semicylindrical abutment member 94 is secured thereto by a suitable fastening screw 126, or the like, in such a manner that the member 94 extends substantially perpendicular from the abuttment member 123, thus securing the compensating guide 53 to the abuttment 123 with the surface 92 thereof being disposed in the proximity of the plate 40A. The film strip 36 passes along the surface 92 and is held in a firm flat position in the stationary position of the film during exposure thereof. A film guide spring 124 is secured to the inner periphery of the housing 28 by suitable screws 128, and is oppositely disposed from the abutment 124, as particularly shown in FIG. 7. A film guide 130 is supported by the spring 124 and extends longitudinally along the length of the film strip portion disposed in the guide 122 throughout a relatively long distance for reducing the pressure per square inch applied along the side edge of the film strip. When the film strip 36 is stopped at the film gate, a single frame 132 of the film 36 will be positioned in alignment with the apertures 20, 30 and 40B for exposure, as is well known.
The guide 122 is secured in position within the housing 28 by a bayonet type locking device generally indicated at 134 (FIG. 17). The device 134 comprises a first connection element 135 extending into the interior of the housing 28 and having the usual L-shaped bayonet slot 135A provided therein for receiving a second connection element 135B for cooperation therewith. The second connection element 135B is rotatably secured between the abuttment member 123 and the first connection element 135 and is provided with an axially extending stem member 135C extending rotatably through the abuttment 123 for connection with a suitable knob member 136. A suitable spring washer 138 is interposed between the outer periphery of the abuttment 123 and the inner face of the knob 136, and a suitable handle or operator element 139 extends radially outwardly from the knob 136 for manual rotation of the knob 136 in order to actuate the bayonet connection members 135 and 135B. It has been found that threaded-type connection members frequently are subject to the vibrations of the operation of the camera and tend to loosen, whereas the bayonet type connection as shown herein securely retains the elements in the desired operational position during operation of the camera 10.
Referring to FIG. 6, a built-in space 140 is provided between the reels 82 and 84, and a plurality of radially extending spring members 141 and 142 are disposed in the space 140 for bearing against each reel to retain the reels securely in the selected spaced position. The width of the space 140 is determined by the distance between the reels 82 and 84 on the shafts 116 and 116A, and the springs 141 and 142 are pivotally or hingedly secured at 141A and 142A, respectively, to a neck member 144 of a stud member 146 which extends slidably in the hollow shafts 116 and 116A. The inner end of the neck 144 is suitably engaged with one end of a suitable helical spring 148 which is anchored in the shaft 116 in any well known manner, and the outer end of the stud 146 is provided with a knurled knob 150. When the spacer springs 141 and 142 are in the radially outwardly extending position shown in FIG. 6, the reels 82 and 84 are held securely in the spaced relation. When it is desired to load or remove a reel, or the like, the knob 150 may be manually grasped for pulling the stud 146 against the force of the spring 148, whereupon the springs 141 and 142 will be pivoted to a position against the outer periphery of the neck 144 and to a position within the interior of the shaft 116A. When the knob 150 is released, the spring 148 will return the stud 146 and springs 141 and 142 to the position shown in FIG. 6.
A modified spacer device for the reels 82 and 84 is generally indicated at 152 in FIG. 22. The device 152 comprises a stud member 154 reciprocally disposed within the shaft 116 and movable between the positions shown in solid lines and broken lines. A plurality of radially outwardly extending spacer fingers 151 and 151A are pivotally or hingedly secured to the stud 154 and 153. A knurled knob 155 is provided on the outer end of the stud 154 for the same purpose as the knob 150. In the radially extended position of the fingers 151 and 151A shown in solid lines in FIG. 22, the reels 82 and 84 are securely retained in spaced relation. When the knob 155 is manually pulled in a direction away from the outer wall of the housing 28, the fingres 151 and 151A are pivoted to the position shown in broken lines for disposition within the shaft 116. The reels may then be removed, loaded, or the like. When the knob is returned to the position shown in solid lines, the fingers 151 and 151A are returned to the spacing position.
Also shown in FIGS. 6 and 22 is a release apparatus 156 operable by one hand of the user of the camera for readily releasing the engagement between the two sections 12 and 14. This feature is particularly useful when the camera is utilized under conditions requiring rapid film changing, but when one hand of the operator is otherwise engaged, such as in military aircraft, or the like. The latch mechanism as shown herein preferably comprises a fixed latch member 158 mounted on one section, such as the section 14, and a yieldable retractable release element 160 mounted on the other section. A latch engaging member 162 is pivotally mounted at 162A on a block 163 secured to the housing 28, and a release lever 164 is pivotally secured at 164A and 164B to the latch engaging member 162 whereby manual movement of the lever 164 is a direction indicated by the arrow 164C will cause the member 162 to pivot about the point 162A in a direction against the force of the latch member 160 for disengagement from the latch member 158, thus releasing the engagement between the sections 12 and 14. The retractable release element 160 normally bears against the outer edge of the side of the latch engaging member 162 for maintaining the latch members 162 and 158 in mutual engagement for securely locking the sections 12 and 14 together. The release lever member 164 may be readily depressed with one hand for release of the engagement between the latch members 162 and 158 while maintaining a firm grip on the magazine section 12.
As is well known, the shutter 24 is rotated about its central axis in synchronization with the movement of the film loop 44 through the film gate 32 whereby the shutter apparatus 24A is always in alignment with the apertures 20, 30 and 40B when the film has been stopped in the film gate. The shutter 24 as shown herein is driven by a suitable gear train generally indicated at 165 in FIG. 5 and which is operably connected between the motor 22 and a shutter drive gear 24B. A sleeve 166 is suitably secured to the inwardly directed face of the shutter 24 and extends axially outwardly therefrom and is suitably supported by bearings 168 for rotation about its longitudinal axis. A gear 166A is riveted or otherwise rigidly secured to the inwardly directed face of the shutter 24 for simultaneous rotation therebetween and is in constant driving engagement with the gear 24B. A second gear 166B is disposed on the shaft 168 and the hub 166C thereof is secured to the shaft 168 by a pin 166D. The gear is independent of the gear 166A for a purpose as will be hereinafter set forth. A slotted adjustment pin 170 is slidably disposed within the sleeve 168 and is movable in reverse directions as indicated by the arrow 172. A plurality of circumferentially spaced bores 168A (preferably two diametrically opposed holes) are provided in the sidewall of the sleeve 168 for receiving one end of a detent spring 170A therein, said spring 170A being carried by the pin 170. The pin 166C extends through the bifurcated inner end of the pin 170, thus securing the gear 166B to the pin 170. The pin 166C extends through diametrically opposed slots (not shown) provided in the sleeves 168, for permitting movement of the gear 166B between the position shown in solid lines in FIG. 24 to the position shown in broken lines. When the pin 170 is pulled with sufficient force for overcoming the force of the spring 170A, the pin may be moved to the position shown in broken lines, whereupon the gear 166B is simultaneously moved to the broken line position shown in FIG. 22. In this position the gear 166B is out of driving engagement with the gear 24B, and the shutter 24 may be manually angularly adjusted for positioning the shutter aperture 24A at the desired location. When the proper adjustment has been made, the pin 170 may be returned to the position shown in solid lines, whereupon the detent spring will engage one of the apertures 168A for locking the pin in position in order to retain the gear 166B in the position shown in solid lines. The gear 166B is then in driving engagement with the gear 24B, and the actuation of the gear train 165 efficiently rotates the shutter 24 in the proper synchronization, as is well known.
Referring now to FIGS. 16 through 19, a modified film gate is generally indicated at 172 which comprises a plate 174 generally similar to the plate 40A for supporting the register pins 40. The plate 174 may be secured to the housing 28 in the same manner as hereinbefore set forth whereby the aperture 176 provided in the plate 174 will be in alignment with the apertures 20 and 30 for permitting proper exposure of the film frame 132. A film guide or abuttment member 178 is secured along one side edge of the plate 174 for engagement with one side edge of the film strip 36, and a film guide spring 180 is suitably secured to the plate for yieldable engagement with the opposite side edge of the film strip. A pair of spaced rollers 182 and 184 are secured in the section 12 for receiving the film 36 thereover and are preferably provided with film engaging flanges 186 and 188 at the opposite ends thereof for engaging the opposite edges of the film strip during movement of the film through the gate 172.
As particularly shown in FIG. 15, in the event the compensating spring 96 is not utilized, it is desirable to provide a light shield 190, which may be suitably secured in the proximity of the film gate for protecting the oncoming portion 192 of the film strip 36 from exposure when the shutter 24 is actuated for exposing the film frame 132 at the shutter aperture.
A modified release mechanism for the sections 12 and 14 is generally indicated at 200 as shown in FIG. 22, and comprises a latch member 202 pivotally secured to the block 163 at 204 for engaging the release element 160 in the same manner as the latch member 162. A release lever 206 generally similar to the lever 164 is pivotally secured to the housing 28 at 208 and is provided with a latch engaging member 210 on the inner end thereof. When the latch 206 is depressed against the outer periphery of the housing 28, or moved in the direction indicated by the arrow 212, the latch engaging member 210 pivots the latch 202 in a direction against the force of the release latch member 160 for releasing the engagement between the latches 158 and 202, thus releasing the section 12 from the section 14.
It will be apparent that suitable mounting holes 214 may be provided in the housing 16, if desired, and as shown in FIG. 1. The holes 214 are preferably tapped or provided with internal threads for receiving suitable screws (not shown) therein for facilitating mounting of the camera 10 on a suitable structure, such as a tripod (not shown) or other suitable stable element, as is well known.
From the foregoing it will be apparent that the present invention provides a motion picture camera having an improved film handling means wherein the film strip is moved through the camera at high speed in an efficient manner, with a stop-and-go motion, and so arranged and constructed as to provide a substantially vibration free, exceptionally high speed operation, and without the previously inherent disadvantages associated with high speed motion picture camera operation.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein may be made within the spirit and scope of this invention. | A motion picture camera of the type which advances the film through a film gate in a stop-and-go motion and particularly designed for high speed operation, and comprising a film drive mechanism having a sprocket and two guide assemblies for forming and guiding a loop of film through the film gate, one of the guide assemblies being mounted on an eccentric for continuous rotation while moving the loop of film against a stationary registration pin in intermittent fashion, the registration pin being disposed for insertion through a perforation of the film when the eccentric crosses dead center, and the other guide assembly being a compact structure for cooperating with the first guide assembly to reduce any accumulation of the composite error in the perforations of the film; the camera is also constructed in two sections which are removably secured together by a release mechanism which is readily separable by one hand of the operator of the camera, one section of the camera containing a film supply reel and take-up reel having a self-contained reel spacer interposed therebetween and the film guide apparatus, and the other section of the camera containing power devices and an adjustable shutter arranged for producing a greater shutter time during exposure of each frame of the film, and an appropriate lens system, the film gate including a film channel along the wall of the magazine and being characterized by having a zero clearance construction and remaining in substantially fixed relation to the lens mounting, and the film drive mechanism also being formed to drive through the sprocket and the film and including a novel take-up friction drive in constant engagement with the take-up reel. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of, and claims priority from, U.S. patent application Ser. No. 11/123,773, filed on May 5, 2005, which application claimed priority from U.S. Provisional Patent Application No. 60/571,604, filed May 13, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to linings and liners made of graphite and other refractory materials for the production of aluminum by carbothermic reduction of alumina.
[0004] 2. Description of the Related Art
[0005] For a century the aluminum industry has relied on the Hall-Heroult process for aluminum smelting. In comparison with processes used to produce competing materials, such as steel and plastics, the process is energy-intensive and costly. Hence, alternative aluminum production processes have been sought.
[0006] One such alternative is the process referred to as direct carbothermic reduction of alumina. As described in U.S. Pat. No. 2,974,032 (Grunert et al.) the process, which can be summarized with the overall reaction
[0000] Al 2 O 3 +3C=2Al+3CO (1)
[0007] takes place, or can be made to take place, in two steps:
[0000] 2Al 2 O 3 +9C=Al 4 C 3 +6CO (2)
[0000] Al 4 C 3 +Al 2 O 3 =6Al+3CO (3).
[0008] Reaction (2) takes place at temperatures between 1900 and 2000° C. The actual aluminum producing reaction (3) takes place at temperatures of 2200° C. and above; the reaction rate increases with increasing temperature. In addition to the species stated in reactions (2) and (3), volatile Al species including Al 2 O are formed in reactions (2) and (3) and are carried away with the off gas. Unless recovered, these volatile species represent a loss in the yield of aluminum. Both reactions (2) and (3) are endothermic.
[0009] Various attempts have been made to develop efficient production technology for the direct carbothermic reduction of alumina (cf. Marshall Bruno, Light Metals 2003, TMS (The Minerals, Metals & Materials Society) 2003 ). U.S. Pat. No. 3,607,221 (Kibby) describes a process in which all products quickly vaporize to essentially only gaseous aluminum and CO, containing the vaporous mixture with a layer of liquid aluminum at a temperature sufficiently low that the vapor pressure of the liquid aluminum is less than the partial pressure of the aluminum vapor in contact with it and sufficiently high to prevent the reaction of carbon monoxide and aluminum and recovering the substantially pure aluminum.
[0010] Other patents relating to carbothermic reduction to produce aluminum include U.S. Pat. Nos. 4,486,229 (Troup et al.) and 4,491,472 (Stevenson et al.). Dual reaction zones are described in U.S. Pat. No. 4,099,959 (Dewing et al.). More recent efforts by Alcoa and Elkem led to a novel two-compartment reactor design as described in U.S. Pat. No. 6,440,193 (Johansen et al.).
[0011] In the two-compartment reactor, reaction (2) is substantially confined to a low-temperature compartment. The molten bath of Al 4 C 3 and Al 2 O 3 flows under an underflow partition wall into a high-temperature compartment, where reaction (3) takes place. The thus generated aluminum forms a layer on the top of a molten slag layer and is tapped from the high-temperature compartment. The off-gases from the low-temperature compartment and from the high-temperature compartment, which contain Al vapor and volatile Al 2 O are reacted in a separate vapor recovery units to form Al 4 C 3 , which is re-injected into the low-temperature compartment. The energy necessary to maintain the temperature in the low-temperature compartment can be provided by way of high intensity resistance heating such as through graphite electrodes submerged into the molten bath. Similarly, the energy necessary to maintain the temperature in the high-temperature compartment can be provided by a plurality of pairs of electrodes substantially horizontally arranged in the sidewalls of that compartment of the reaction vessel.
[0012] U.S. Pat. No. 4,099,959 (Dewing et al.) proposed using a steel shell without any inner lining for the reaction vessel. During furnace operation, a lining of frozen slag would form on the steel, thus protecting it from the harsh environment inside the reaction chamber and furthermore preventing electrical short-circuiting. Nonetheless, in order to ensure the safety of the system and to avoid the possibility of breakthrough of molten slag, it was suggested to provide features such as two duplicate and completely independent water cooling systems, infra-red radiation detectors or other temperature sensors which monitor the steel shell, as well as current detectors in the electrical grounding connection to the steel shell. When the detectors detect any malfunctioning of the system, power is automatically turned off and the redundant water cooling system is turned on.
[0013] Besides the complexities is that operations safety system, the frozen slag layer is only formed after some initial start-up procedures during which the steel shell would be heavily attacked by the molten slag. In addition, the melt furnace atmosphere is under pressure and contains substantial amounts of CO gas which easily diffuses through the frozen slag and then attacks the steel surface. Furthermore, it is very difficult to maintain a uniform layer of the frozen slag under real operational conditions. Hence, the above-described safety system would regularly cause power shut-offs making it difficult to run an efficient and continuous production process. Finally, once the extremely hot molten slag reaches the steel shell it is a difficult task to cool the system down by the mere use of water spraying devices.
SUMMARY OF THE INVENTION
[0014] It is accordingly an object of the invention to provide a liner for a carbothermic reduction furnace which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type. Specifically, the object is to provide inner linings to the steel shell of carbothermic reduction furnaces for the production of alumina, in particular linings made of refractory material and graphite, which provide protection against the molten slag, which do not contaminate the melt, which are not attacked by the CO-rich melt furnace atmosphere, and which provide an effective heat dissipation system in case of a power shut-off.
[0015] With the foregoing and other objects in view there is provided, in accordance with the invention, a reactor vessel for a carbothermic reduction furnace, in particular for the carbothermic reduction of alumina. The vessel comprises:
[0016] an outer shell having an inner wall surface; and
[0017] a lining structure disposed on the inner wall surface and protecting the outer shell against attack from molten slag inside the reactor vessel, the lining having a relatively thick base layer of graphite disposed on the inner wall surface and a relatively thin refractory material layer on the base layer of graphite and in intimate contact therewith.
[0018] The lining structure has a thermal conductivity of at least 35 W/m·K and, preferably, within the range of between 120 W/m·K and 200 W/m·K.
[0019] The lining structure is specifically configured for carbothermic reduction of alumina. The outer shell is a steel shell and the lining structure is formed to protect the molten slag of alumina against iron contamination from the steel shell and the steel shell against CO attack. The lining structure is preferably configured to be substantially resistant to CO attack and to have a low Fe content of less than 0.1% by weight.
[0020] In accordance with an added feature of the invention, the refractory material layer is a corundum layer. Preferably, the corundum layer is formed of corundum and approximately 25% by weight Sialon.
[0021] The corundum layer may be formed as a coating layer or it may be formed of a plurality of thin corundum tiles attached to the base layer of graphite with a high-temperature glue based on graphite particles dispersed in a resin (e.g., phenolic resin, furanic, epoxy).
[0022] With the above and other objects in view there is also provided, in accordance with the invention, a method of producing a lining structure for a carbothermic reduction furnace. The method comprises:
[0023] mixing a major proportion of calcined low-iron coke with a minor proportion of pitch at a temperature above a softening point of the pitch and forming (e.g., extruding) the mixture into one or more blocks;
[0024] calcining the blocks to form calcined blocks;
[0025] impregnating the calcined blocks with impregnation pitch, rebaking the impregnated blocks, calcining the blocks, and machining the calcined blocks;
[0026] coating at least one surface of each of the blocks with a slurry comprising ground corundum, and heat treating the slurry to form a refractory coating on and in intimate contact with the at least one surface of the graphite blocks; and joining the blocks to form a solid lining of a carbothermic reduction furnace, with the surface having the refractory coating facing an interior of the furnace.
[0027] In accordance with an additional feature of the invention, the mixing step comprises providing approximately 82 parts of anode grade coke and approximately 18 parts pitch and mixing at a temperature of approximately 150° C.
[0028] In accordance with another feature of the invention, the coating step comprises coating with a slurry of approximately 75% finely ground corundum and approximately 25% Sialon particles, and heat treating the slurry at a temperature of approximately 2500° C.
[0029] In accordance with a further feature of the invention, the graphite block is calcined at a calcining temperature above 2800° C.
[0030] In sum, the invention provided for linings made of graphite and other refractory material for the production of aluminum by carbothermic reduction of alumina. The graphite linings are in direct contact with an outer steel shell and the refractory material linings are in intimate contact with the graphite lining.
[0031] It is important for the lining structure to exhibit superior heat transfer, i.e., to have good thermal conductivity numbers, in order to effectively cool the edge regions of the molten bath so that a frozen slag layer is formed and maintained. The thermal conductivity should be at least 35 W/m·K and it is preferably in the range 120 W/m·K and 200 W/m·K.
[0032] It is also quite important, especially in the context of the carbothermic reduction of alumina that the graphite linings be substantially resistant to CO attacks and that they have a low Fe content of less than 0.1%. The novel refractory material linings are chemically and physically resistant against the molten slag. The preferred lining is thus formed with corundum (aluminum oxide), and more preferably with corundum bonded by 25% Sialon.
[0033] The use of graphite furnace linings is well known in blast furnaces. In the case of the carbothermic reduction of alumina, however, graphite, which is a highly structured type of carbon, would be consumed according to reaction (1), albeit not nearly as fast as the low-structured carbon species added to the melt. The graphite therefore needs to be protected by a thin layer of a refractory material that is chemically and physically resistant against the molten slag. This protection is especially important during the furnace start-up phase and to ensure that it does not contaminate the melt.
[0034] The material can be corundum, which is a special form of aluminum oxide (Al 2 O 3 ). During the critical start-up phase it can resist the molten slag and, because it is chemically identical, it does not leach any contaminants into the melt. According to reaction (1) it is, however, consumed to slight extent during start-up before a frozen slag layer finally forms and protects its surface from further consumption. A further improvement of chemical stability can be provided by using Sialon-bonded corundum. Sialon is commercially available, by way of example, from Saint-Gobain Ceramics, which provides such materials for use as ceramic cups in blast furnaces.
[0035] Sialon is a silicon nitride ceramic with a small percentage of aluminum oxide added. The chemical formula of Sialon is Si (6-x) Al x O x N (8-x) , with x<4.2. The benefit of Sialon, in this context, is a dramatic improvement in thermal stability and overall corrosion resistance that are conferred by high x values.
[0036] In case of a production accident, the melt may overheat, thus melting the frozen slag layer on the inner corundum lining which is then being gradually consumed. During that period, the adjacent graphite lining, exhibiting very good thermal conductivity, would quickly dissipate the heat in the axial as well as in the radial direction to the outer parts of the furnace. By the time, the graphite gets attacked by the melt eventually broken through the thin corundum lining, the melt temperature will have already significantly dropped to a point where it will start forming a frozen slag layer. Even if this effect is locally somewhat delayed, at temperatures below about 1000° C. the graphite material provides an effective barrier against further chemical attack by the melt.
[0037] Graphite linings commonly used for blast furnaces and other applications contain more than 0.1% Fe. Since the pressurized hot carbothermic reduction furnace atmosphere is saturated with CO gas, it will leak through the inner corundum lining and preferably react with the Fe-containing domains of the graphite lining. To ensure longevity of the graphite lining, it should contain only traces of Fe of less than 0.1%. In a further embodiment of this invention, a low-iron coke, more preferably anode coke, is used as the raw material to reach the required purity level of the final graphite lining. Anode grade coke is a very pure coke with a minimal iron content.
[0038] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0039] Although the invention is illustrated and described herein as embodied in a liner for a carbothermic reduction furnace, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0040] The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of an exemplary implementation of the invention, including specific examples and embodiments of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0041] FIG. 1 is a partial perspective view of a graphite lining block with a protective refractory layer on one surface of the block;
[0042] FIG. 2A is a partial sectional view taken through a lining block with a corundum coating formed on one surface of the block;
[0043] FIG. 2B is a similar section taken through a furnace lining with the protective refractory layer formed of corundum tile glued to the block; and
[0044] FIG. 3 is a partial section taken through the wall of a reactor vessel with a steel shell and a lining structure according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown diagrammatic view of a graphite block 1 forming a building block for the lining according to the invention. The graphite block 1 carries a thin protective refractory layer 2 on one of its surfaces. In a preferred embodiment of the invention, the protective layer 2 is a corundum layer in the form of a coating layer or a tile layer. The protective layer 2 is very thin relative to the graphite block 1 . The thickness of the layer 2 is more than two orders of magnitude, and typically nearly three orders of magnitude, less than the thickness of the block 1 . For example, the corundum coating is about 3 mm thick and the corundum tile layer is about 0.5 to 2 mm thick. The graphite block, in one preferred embodiment, is about 1.2 m (1200 mm) thick.
[0046] As shown in FIG. 2A , the protective layer 2 is a coating layer 2 that forms an intimate bond with the graphite block 1 . In a preferred embodiment, a slurry of approx. 75% fine powder of corundum and approx. 25% Sialon is deposited on the block 1 and then baked at a temperature of approx. 2500° C. The resulting coating coating layer 3 has a thickness of approx. 3 mm.
[0047] In an alternative embodiment, which is illustrated in FIG. 2B , the protective layer 2 may also be formed by gluing corundum tiles 4 on the graphite block 1 . The corundum tiles 4 have a thickness of 0.5-1 mm. They are rather thin, because the protective layer 2 is primarily important for protecting the furnace shell and, more specifically, the graphite block 1 , during the initial start-up. The tiles 4 may have a flat dimension of 75 mm×75 mm or 100 mm×100 mm.
[0048] The tiles 4 are glued to the block 1 with a high-temperature cement 5 . The high-temperature cement, or high-temp glue, consists of about 50% (w/w) finely ground graphite particles and resin which, upon complete processing, becomes carbonized. The resin may be a phenolic-based resin, or furanic resin, or epoxy resin.
[0049] Referring now to FIG. 3 , there is illustrated a partial section of a steel shell 6 of a carbothermic reduction furnace. The lining on the inner wall surface of the shell is formed of a plurality of graphite blocks 1 that are glued to the steel shell 6 and to one another with a high-temperature cement or glue 7 . The protective layer 2 on the tightly placed blocks 1 forms a contiguous protective layer with narrow grout lines of high-temperature glue 7 . The same cement 7 may be used to glue the blocks to the steel shell 6 and to glue the blocks 1 together. It is important, thereby, to assure that the glue is high-temperature resistant, and does not impair the high thermal conductivity of the liner structure. In other words, the cement 7 has to exhibit good thermal conductivity.
[0050] Upon furnace start-up, the graphite linings expand slightly and this pressure as well as the heat achieve curing of the cement 7 . This assures sufficient tightness in between the blocks 1 and good thermal contact also to the steel shell.
[0051] As shown in FIG. 3 , the furnace is used for carbothermic reduction of alumina. The hot melt 9 contains a mixture of carbon (C), aluminum oxide (Al 2 O 3 ), and aluminum carbide (Al 4 C 3 ). The illustration also includes a frozen slag layer 8 that forms during regular operation of the furnace.
[0052] The following examples are presented to further illustrate and explain the present invention. They should not be viewed as limiting in any regard. Unless otherwise indicated, all parts and percentages are by weight.
EXAMPLE 1
[0053] 82 parts calcined low-iron coke and 18 parts of pitch having a softening point of 110° C. (Mettler) are mixed at 150° C., in an intense mixer with high energy input for 15 min. The mixture was extruded at 115° C. The extruded block was calcined for 3 to 4 weeks in a Riedhammer-type ring furnace with a final firing temperature of 900° C.
[0054] The thus obtained blocks were impregnated with impregnation pitch in autoclaves at 250° C. and pressures up to 25 bar. Afterwards they were rebaked within 1-3 weeks in rebaking furnaces at 1000° C. followed by graphitization in Castner type furnaces in firing rates up to 20 h at final temperatures surpassing 2800° C. The thus obtained graphite blocks were finally machined to the required dimensions.
COMPARATIVE EXAMPLE 1
[0055] The same procedure was carried out using, instead of the low-iron anode grade coke, conventional needle coke with a high iron content as raw material for the graphite lining.
EXAMPLE 2
[0056] A graphite block obtained according to example 1 was machined to blocks of 1 m×1 m (height×width) and 1.2 m depth. One of the 1 m×1 m surfaces was coated with a slurry of 75% finely ground corundum and 25% Sialon particles which was heat treated to final temperatures above 2500° C. The thus obtained coating had a thickness of 3 mm.
[0057] The coated graphite lining was joined by high-temperature glue with other graphite linings manufactured in the same manner to a solid lining wall inside a carbothermic reduction furnace steel shell.
[0000]
Graphite
(low Fe
Graphite/
Graphite
Lining type
content)
Sialon
(conventional)
Bulk Density
(g/cm 3 )
1.65
1.65
1.63
Open Porosity
(%)
20
21
24
Coefficient of
(μm/K · m)
2.5
2.4
1.1
linear thermal
expansion
(20 to 200° C.)
Thermal
(W/m · K)
150
122
150
Conductivity
Iron content
(%)
0.005
0.005
0.2
[0058] The above description is intended to enable the person skilled in the art to practice the invention. It is not intended to detail all of the possible variations and modifications that will become apparent to the skilled worker upon reading the description. It is intended, however, that all such modifications and variations be included within the scope of the invention that is defined by the following claims. The claims are intended to cover the indicated elements and steps in any arrangement or sequence that is effective to meet the objectives intended for the invention, unless the context specifically indicates the contrary. | An inner lining for the steel shell of a carbothermic reduction furnace for the production of alumina has a base layer of graphite and a coating layer of refractory material. The refractory material is corundum (Al 2 O 3 ) bound by Sialon (Si.Al.O.N). The lining structure provides protection against the molten slag and it is not attacked by the CO-rich melt furnace atmosphere. Further, the lining does not contaminate the melt and it provides an effective heat dissipation system in case of a power shut-off. | 2 |
FIELD OF THE INVENTION
The present invention relates to explosives in general, and in particular to modified forms of high shock explosives used in rock blasting situations. The modified explosives are so called low shock energy explosives (LSEE). More particularly, the present invention relates to low shock energy explosives for use in rock or mineral blasting situations and to methods of mining using such explosives. Even more particularly, though not exclusively, the present invention relates to the manufacture and use of chemically modified forms of Ammonium Nitrate Fuel Oil (ANFO) explosives which have been modified, preferably by the incorporation of a slower reacting solid fuel material, for delaying the time taken for the development of the maximum amount of energy of the explosive.
Although the present invention will be described with particular reference to the use of modified ANFO explosives in rock blasting, it is to be noted that the present invention is not limited to the production and use of this type of explosive, but rather the scope of the present invention is more extensive so as to also include materials, modifications and uses other than those specifically described. For example, the present invention is equally applicable to the so called heavy or high-density ANFO/EMULSION high shock energy explosive. The modification of heavy ANFO/EMULSION explosive by the incorporation of a solid fuel material can produce a similar shift in the energy balance to create a LSEE.
BACKGROUND TO THE INVENTION
Explosives currently being used in rock blasting situations are generally high shock energy explosives in which all of the explosive energy and the attendant high-pressure gases are generated more or less instantaneously. A typical example of such an explosive which is currently used is ANFO which is a mixture of ammonium nitrate (AN) and vegetable and mineral oils with flash point greater than 140° F., typically diesel oil No.2 (FO). The use of ANFO explosives in many blasting situations results in a number of disadvantages which include the following:
(i) The explosive releases energy in two main forms--shock, and heave energy. At detonation there is a sudden increase of pressure that displaces the blasthole wall, generating a strain, or shock, wave that produces cracks in the rock. The energy in this wave is the shock energy. After the shock wave has propagated through the rock, the hot pressurised gas which is left in the blasthole is able to extend the cracks as well as to heave the burden. The gas has an energy content called the heave energy. Before blasting, rock generally contains sufficient fractures that can be propagated by the heave energy alone. Thus the shock energy serves little or no useful purpose in fractured rock. For ANFO 94/6 (94% Ammonium Nitrate/6% Fuel Oil), the total energy theoretically available is 3727 J/g, which comprises 1241 J/g shock energy, 2255 J/g heave energy and 231 J/g of residual energy, where the residual energy is the internal energy of the gas itself and cannot be utilised.
(ii) Due to the high shock energy generated by the explosion a greater proportion of fine rock particles (fines) are produced by the shock wave crushing the rock located in close proximity to the borehole more than is desirable or is required, such as for example, for use in further processing steps.
(iii) Minerals, or other materials of economic value, such as for example, diamonds which are to be extracted from the rock are sometimes damaged by the crushing of diamond bearing rock caused by the shock wave, particularly in locations close to the blasthole.
It is thought that the development of a low shock energy explosive in which more of the energy of the explosive is generated as heave energy and less as shock energy, and where the energy is more gradually released, may alleviate at least some of the problems associated with the use of conventional high shock energy explosives. Therefore, it is an aim of the present invention to provide a modified explosive, particularly a modified high shock energy explosive which is useful in blasting, in which the production of shock energy is reduced somewhat when compared to conventional blasting explosives.
Previous attempts to produce a LSEE involved dilution of the explosive mixture to produce a lower bulk energy for a given mass of explosive mixture. In general, previous attempts have resulted in low shock, low bulk energy explosives which necessitates the drilling of more blastholes. For example, ANFORGAN is a known form of LSEE that consists of a mixture of ANFO and sawdust, typically in the ratio of about 2:1. The sawdust acts as a diluent for the ANFO which reduces the density of the explosive mixture. It is well known that the shock energy of an explosive decreases as its density decreases. The problem with reducing the density of the explosive is that in a blasthole the amount of explosive is limited by the volume of the hole. A low density explosive will not have as much mass in a given volume as a high density explosive. Since the effects of the explosive are related to the amount of explosive in the hole, a low density explosive will not break the rock as effectively as a high density explosive. It is an object of the present invention to lower the shock energy but to keep the total energy at a level comparable to a conventional explosive, such as ANFO.
SUMMARY OF THE INVENTION
According to the present invention there is provided an explosive composition comprising an oxidizing agent in solid particle form and a fuel material, wherein said fuel material includes a non-absorbent solid fuel material incorporated into the composition in particulate form, the weight ratio of the oxidizing agent to the fuel material being in the range of 85:15 to 99:1, and the percentage by weight of the solid fuel material is set between 1 to 15% of the total weight of the composition, the balance, if any, of the fuel material comprising a liquid hydrocarbon component, and wherein at least one of the dimensions of the solid fuel material particles is of a similar size to or larger than the oxidizing agent particles so that a significant proportion of the oxidizing agent particles are not in contact with any solid fuel material particles whereby, in use, the solid fuel material is effective in substantially reducing the shock energy whilst increasing the heave energy so that the total energy per unit volume released remains comparable to a conventional high shock energy explosive of similar density.
It has been found that by substituting some or all of the liquid fuel oil with a slower burning solid fuel, the time during which the pressure builds up is lengthened, as much as fivefold, which significantly reduces the amount of shock energy produced.
Typically, the oxidizing agent is selected from ammonium nitrate, sodium nitrate, calcium nitrate, ammonium perchlorate or the like. The preferred oxidizing agent is ammonium nitrate.
Typically, the fuel material includes a fuel oil component, more typically, a diesel oil and may include mixtures of different oils. It is to be noted that fuel oils having a higher boiling point than diesel oil may be employed either in place of or in combination with the diesel oil. The preferred fuel oils should all be hydrocarbon fuels with very little or no nitrogen or oxygen being present.
In one preferred embodiment no fuel oil is employed, the fuel material being comprised entirely of solid fuel.
Typically the solid fuel is selected from the group comprising rubber, gilsonite, unexpanded polystyrene in solid form, acrylonitrile-butadiene-styrene (ABS), waxed wood meal, rosin and other suitable non-absorbent carbonaceous materials. Preferred solid fuels are rubber or unexpanded polystyrene, with rubber being the most preferred. The rubber may be selected from natural rubbers, synthetic rubbers, or combinations thereof.
Typically, the rubber is in the form of particles which are obtained from previously made rubber products, including natural or synthetic rubbers. Typically the buff produced in the process of retreading vehicle tires is used as the source of rubber particles. The buff could also be subjected to cryogenic freezing and then ground into particles. The particles are then screened to a desired predetermined size or particle size range. A preferred size range is from about 1-5 mm. It is desirable to avoid a bi-modal grist. Preferably one of the dimensions of the rubber particles should be comparable to the size of the ammonium nitrate prills. It is also preferred that the particles be all more or less uniform in size.
As an alternative to the rubber particles or in addition thereto, gilsonite may be used as the solid fuel. It is preferred that the gilsonite be of a -30 mesh size.
Other materials which may optionally be added to the composition include binders, retardants, inert materials, fillers, or the like. One example of an inert material added to the composition of the present invention is silicon dioxide in the form of sand particles. It is thought that the sand particles act as heat sinks which delay the time taken for the explosive to reach its maximum energy.
Preferably, when making the explosive composition of the present invention, all components are typically added simultaneously to a single large mix tank from separate smaller holding and/or weighing tanks.
It is preferred that the combined amounts of fuel oil and rubber be from 6 to 9% by weight of the total weight of the explosive composition, more preferably 6 to 7% with the amount of fuel oil being from as low as 0% to 5% of the total weight.
It is further preferred in one embodiment that the low shock explosive composition of the present invention have a composition in which the AN:FO:solid fuel ratio is within the range from 94:2:4 to 96:11/2:21/2. It is thought that in said one embodiment the changes in the oil to solid ratio help to slow down the production of maximum energy by the explosive to a more controlled release by having excess oil present in the composition.
The viscosity of the oil added to the explosive mixture in one form of the present invention is thought to be important since the added oil will not only penetrate internally into the prilled particles of the oxidising agent but will also remain in contact with the outside surface of the prilled particles.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawing in which:
FIG. 1 is a plot of borehole pressure in Kilobar as a function of time in microseconds for a conventional explosive as represented by the curve OABCD as compared to that from one form of the explosive of the present invention as represented by the curve OBCD.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
During blasting, an explosive located in a borehole is suddenly converted from its pre-blast state, such as for example, from a solid or liquid material existing at normal atmospheric pressure into a high pressure gas. On detonation of the explosive the massive instantaneous increase of pressure causes the borehole or blast hole to increase in size. The increase in size of the blast hole is caused by movement of the walls of the blast hole which movement in turn decreases the explosive gas pressure inside the blast hole. As the borehole diameter increases, restraining forces develop in the surrounding rock mass, and When the gas pressure has fallen to about one half of its initial value immediately after detonation further expansion of the borehole ceases. By this time, however, significant crushing and radial cracking have occurred in the rock structure in the vicinity of the borehole. As further time proceeds, the stress and crack fields developed in the rock structure extend outwardly from the bore hole until such time as large scale damage has occurred in the surrounding rock mass and the residual gas pressure is able to heave the rock burden forward to complete the effects of the blast. This sequence of events is illustrated in curve OABCD of FIG. 1, together with representative time intervals, where the curve portion OA corresponds to the instantaneous development of maximum energy or pressure, curve portion AB corresponds to the borehole expansion immediately after detonation and attendant reduction in pressure, curve portion BC corresponds to the crack extension and pressurisation stage as the pressure within the borehole reduces even further, and curve portion CD corresponds to the heave. Therefore, the sudden application of pressure and the development of maximum energy is represented by the line OA, and the subsequent borehole expansion and decrease in pressure is represented by curve ABCD.
Curve OBCD, on the other hand, illustrates the behaviour of one form of the low shock energy explosive of the present invention in which the development of maximum energy corresponding to detonation of the explosive and expansion of the borehole is controlled to be more gradual as can be seen by the relatively gentler slope of curve OB as compared to that of OA. The behaviour of the low shock energy explosive within the borehole after point B on the curve is reached is similar to that of conventional high shock energy explosives.
In FIG. 1, the shaded area OABO represents the energy which is propagated as a shock wave into the rock mass surrounding the borehole and is the amount of energy which is to be saved by using the explosive of the present invention as compared to conventional explosives since this energy is substantially wasted and furthermore damages the minerals being won from the rocks. For open pit mines, the insitu rock mass is often heavily jointed which leads to strong attenuation of the shock wave by frictional and other dissipative mechanisms. Thus, the shock energy is largely wasted energy, and does little else than lead to slope instability and other vibration caused problems.
Several exemplary embodiments of LSEE explosive compositions in the form of modified ANFO explosives will now be described with reference to the results of experimental tests performed on each composition.
EXAMPLE 1--ANRUB
It was originally believed that to ensure detonation when using a modified ANFO explosive some of the ammonium nitrate prills had to absorb fuel oil, or that they had to be intimately mixed at least. However, it has been found that it is not necessary to have any fuel in the prills. In this preferred embodiment, called ANRUB (Ammonium Nitrate/Rubber), no fuel oil is employed at all, the fuel for the reaction coming from the rubber itself acting as a solid fuel. In each of the following examples, commercially available explosive grade, porous AN prills were used having a mean prill diameter of between 1.0 to 2.0 mm.
Underwater Testing
Underwater testing of various compositions of ANRUB was performed in order to measure changes in the shock energy as well as in the heave energy. When an explosion takes place underwater, a shock wave is propagated through the water from the detonating explosive and in addition a gas bubble, which contains the gases evolved during the explosion, is formed. The internal energy of the gas in the bubble, or the bubble energy, is equivalent to the heave energy of the explosion in rock.
In the underwater testing three different sizes of rubber particle were employed in the explosive composition by sieving into the following sizes:
______________________________________COARSE 100% passed 2.36 mm and 100% retained on 1.18 mmMEDIUM 100% passed 1.18 mm and 100% retained on 850 μmFINE 100% passed 850 μm.______________________________________
In addition, the underwater explosion was confined to simulate charge confinement in rock using two different types of confinement
Light confinement--4 liter paint tins, weight 350 g.
Heavy confinement--101.7 mm i.d. steel tubes
500 mm long
6.3 mm wall thickness, weight 9200 g.
All charges were primed with HDP-3 boosters (approximately 140 g Pentolite) which was initiated with a No.8 AI detonator. The results of the underwater testing for ANRUB are summarised in Table 1. All compositions except where otherwise noted were oxygen balanced. The energy figures in brackets are the standard deviations.
TABLE 1__________________________________________________________________________ Paint Tin Steel Tube CONFINEMENT: Shock Energy Bubble Energy Shock Energy Bubble EnergyEXPLOSIVE: SE j/g BE j/g SE j/g BE j/g__________________________________________________________________________ANFO (94/6) 693 (87) 2217 (50) 810 (19) 2044 (27)ANRUB COARSE 440 (48) 1659 (114) 634 (6) 1713 (39)(93/7)ANRUB MEDIUM 484 (31) 1757 (84) 739 (48) 1828 (32)(93/7)ANRUB FINE 587 (51) 1965 (102) 732 (29) 1914 (43)(93/7)ANRUB COARSE 454 (60) 1477 (231)(96.5/3.5)ANRUB COARSE 1713 (115) 734 (23) 1788 (32)(89.5/10.5)ANRUB COARSE 589 (70) 1975 (187) 734 (21) 1780 (42)(86/14)ANRUB MEDIUM 374 (15) 1545 (86)(96.5/3.5)ANRUB MEDIUM 477 (84) 1841 (190)(89.5/10.5)ANRUB MEDIUM 570 (11) 2063 (23)(86/14)__________________________________________________________________________
Even with heavy confinement it appears the underwater explosive reactions were incomplete due to the explosive not being held at a high enough density and pressure to react completely as the bubble of explosive gases expand. Hence, although the shock energy is lower in each case than for ANFO, the bubble energy is also lower as the full bubble energy was not developed. Subsequent testing in rock, where the gaseous explosive products are contained and confined for much longer so that the reactions go to completion, confirmed that ANRUB acts as a true LSEE. In rock where the explosive gases cannot expand as freely as they do in water the slower reacting solid fuel mixtures have more time to react completely, thus increasing the effective bubble or heave energy. However, the shock energy would not be expected to change significantly as it is a function of the initial detonation velocity and pressure at the detonation front--not the subsequent expansion of the gases.
The size of the rubber particles affects the rate at which the explosive reacts, suggesting that it is the intimacy between the solid fuel and the ammonium nitrate prills that controls the rate at which the explosive mixture reacts. Fine rubber reacts faster than the coarse rubber, as would be expected from a surface to mass ratio for the two grades of rubber particles. However, the smaller the fuel size, the higher the shock energy, and therefore a compromise may need to be found to obtain an optimum, by which all the fuel has time to react but at a rate slow enough to give decreased shock energy.
A problem with using rubber particles is that of segregation. Any fine rubber particles tend to segregate to the bottom of the mixture and affect the reaction. Rubber particles that are too coarse tend to float on top of the mixture. Coarse rubber particles were found to mix more uniformly with the ammonium nitrate prills. The addition of water or saturated AN solution during mixing of the AN/RUB was also found to significantly enhance the uniformity of the mixture, particularly with finer rubber particles.
Rock Testing
A shock wave is necessary for the initiation of detonation within a column of explosive. The intensity of the required shock wave is dependent upon the sensitivity of the explosive. Once the detonation process commences, a shock front propagates along the length of the charge. The speed with which this shock front moves through the explosive is known as the velocity of detonation (VOD) of the explosive. The theory of the LSEE according to the invention is based upon slowing the rate of reaction for a detonating explosive. The faster an explosive reacts, the larger the amount of shock energy produced. The shock energy is proportional to the square of the VOD. Hence a decrease in the VOD indicates a decrease in the shock energy. Both single hole and multiple hole firings in rock were conducted in order to confirm that ANRUB is characterised by both a reduction in the shock energy (reduced VOD) and an increase in the heave energy.
The detonation velocities were all found by the technique of measuring the time for the detonation front to short out pairs of wires at half meter intervals along the explosive charge. They are listed for various hole sizes, rock types and for both ANFO and ANRUB in Table 2.
TABLE 2______________________________________ Explosive ANFO ANRUB HoleRock Diameter (mm) Detonation Velocities (m/s)______________________________________Iron Ore 381 4370 3960 4380 3900 150 3300Soft Iron Ore 381 4350 3910Granite 89 3550 2600______________________________________
The figures in Table 2 indicate that ANRUB produces a consistently lower VOD compared to ANFO. However, a reduction in the VOD of an explosive is only partial confirmation that the explosive has the desired low shock energy characteristics. The vibrations produced by detonating ANRUB must also be reduced with respect to ANFO. Vibration measurement were made both at a Mt. Tom Price mine site and at a local quarry facility.
QUARRY
Vibration measurements were taken with two triaxial geophone assemblies, placed 10 and 20 meters back from the face, and perpendicular to the face, halfway between the two 89 mm blast holes. The rock type was granite.
TABLE 3______________________________________ Explosive ANFO ANFO ANRUB ANRUBDistance (m) Peak Particle Velocity (mm/s)______________________________________10 756 426 1.7720 127 73 1.75______________________________________
TOM PRICE
Three geophone assemblies were positioned 15 meters behind the blast, parallel to the face. One geophone was placed one quarter of the way along the blast. The second behind the centre of the blast, and the third, three quarters of the way along the blast. One half of the blast was charged with ANFO and the other with ANRUB.
The first test was in soft iron ore using 381 mm diameter holes, 15 m high bench and 2 m subgrade. The blasthole to geophone distances ranged from 15 to 60 meters. The average burden was 7.8 meters and the average spacing was 9.0 meters, with a stemming depth of 9 meters. The blast consisted of 12 holes along the face, and was two rows deep.
Correlation of measurements of the vector sum of the radial and transverse particle velocities show: ##EQU1## where R is the distance from the blasthole to the geophone assembly,
b is the blasthole radius and,
ppv is the peak particle velocity,
96.24 and 76.00 are the ppv at the blasthole wall for ANFO and ANRUB respectively, and
0.0052 and 0.00488 are the attenuation coefficients for ANFO and ANRUB respectively.
The ratio of the ppv between ANFO and ANRUB is: ##EQU2## The second test was in iron ore using 381 mm diameter holes. The geophone arrays were the same as above. The average burden was 8.8 meters and the average spacing was 10.2 meters, with a stemming depth of 8 meters. The blast consisted of 14 holes along the face, and was two rows deep. ##EQU3## The ratio of the ppv between ANFO and ANRUB is: ##EQU4##
The vibration measurements indicate that ANRUB displays a consistently lower vibration characteristic than comparable ANFO, thus confirming that ANRUB has the desired low shock energy characteristics.
In order to determine whether ANRUB has a comparable total energy to ANFO, it is also necessary to measure the heave energy. If the shock energy of ANRUB is reduced With respect to ANFO, for the total energy to be preserved, the heave energy must consequently increase. Although heave energy can not be measured directly, it is directly related to the burden velocity. In order to measure heave velocities, high speed photography was taken at 500 fps, which is suitable for back analysis to determine heave velocities. There are two main components of heave velocity--face and crest.
The initial vertical heave velocities were calculated by analysing high speed 16 mm film of the blast. Markers (witches hats and paint cans) were placed on the crest. Their subsequent motion reflects the velocity of the crest caused by the explosive.
TABLE 4______________________________________Explosive Velocities (m/s) Average (m/s)______________________________________ANFO 4.00 3.97 3.37 4.00 3.84ANRUB 4.89 6.27 4.54 5.23______________________________________
The ratio of average heave velocities ##EQU5##
Explosive Classification of ANRUB
Explosive regulations restrict the mixing of explosives, such as ANFO, to being prepared at the top-of-the-hole. That is, the fuel oil is added to the ammonium nitrate prills just prior to the mixture being pumped down the hole. The time required to obtain a uniform mix of ANRUB does not permit mixing the produce at the top-of-the-hole. These same regulations prohibit the transport of bulk explosives, which means that ANRUB cannot be pre-mixed and transported to the hole under the current explosive classification.
To overcome this problem, it was decided to attempt to classify ANRUB in Hazard Division 1.5. Only "very insensitive" explosive substances can be classified as 1.5D. In order to evaluate whether an explosive composition is "very insensitive" it must pass the Series 5 tests outlined below. The Series 5 tests consist of four different types of tests:
Type 5(a): Cap Sensitivity Test--a shock test which determines the sensitivity to detonation by a standard detonator.
Type 5(b): Deflagration to Detonation Tests--thermal tests which determine the tendency of transition from deflagration to detonation.
Type 5(c): External Fire Test--essentially a test to determine if a substance, when in large quantities, explodes when subjected to a large fire.
Type 5 (d): Princess Incendiary Spark Test--to determine if a substance ignites when subjected to a incendiary spark.
ANRUB passed all four tests and has been authorised as ANRUB, UN No. 0082 classification 1.5D, Category (ZZ). This means it can be pre-mixed and transported in bulk, thus providing much greater flexibility to the mixing and transportation of ANRUB.
EXAMPLE 2--ANFORB
An alternate embodiment of the present invention which is known as ANFORB (Ammonium Nitrate/Fuel Oil/Rubber) simulates semi-gelatinous explosives which consist of about 10% of a thin reactive layer of nitroglycerine spread over crystals of ammonium nitrate (AN) and a solid fuel. Detonation of the nitroglycerine initiates a reaction between the AN and fuel which in turn provides the energy for rock breakage. ANFORB simulates semi-gelatinous explosives in the sense that it uses ANFO to initiate a reaction between AN and rubber particles as solid fuel. In this embodiment 30% of 94:6 ANFO explosive is selected and combined with 70% of a 93:7 AN/Rubber material to form a slow burn explosive. The 30% of ANFO is used as the initiator for the combination whereas the 93:7 AN/Rubber material is used to provide for the controlled development of maximum energy. This represents 93% AN, 2% fuel oil and 5% rubber in the ANFORB. The AN/FO/RUB ratio can be altered to obtain the optimum composition.
Underwater testing indicates that ANFORB has similar explosive properties to ANRUB, producing an average bubble energy of 1957±147 J/g. As a slight deviation from the initial ANFORB in which the solid and liquid fuels are added separately to the Drills, ROIL was tested. ROIL consists of pre-mixing the solid and liquid fuels prior to their addition to the AN prills. Underwater tests on ROIL also produced results comparable to ANRUB, with an average shock energy of 593±62 J/g and a bubble energy of 1898±117 J/g.
EXAMPLE 3--ANPS
Two different forms of unexpanded polystyrene were tested as solid fuels for a LSEE called ANPS (AmmoniumNitrate/Polystyrene). The first comes in the form of cylindrical polystyrene beads, a few millimeters long with a diameter of about 2 mm. Experiments on this mixture underwater resulted in an average shock energy of 314±88 J/g and a bubble energy of 1268±149 J/g. The beads tend to segregate from the prills to form a non-uniform mixture. In addition, the energies released are quite low, indicating a very slow rate of reaction. It is probable, however, that under the confinement of a steel tube these energies would increase significantly.
The second form is that of polystyrene flakes. These have a larger surface area per unit mass than the beads and therefore they should react faster. The measured underwater shock energy for the ANPS flake is 330±79 J/g with a corresponding bubble energy of 1299±181 J/g. A problem lies in the sizes of the flakes; those that are too small settle to the bottom of the mix and those that are too large float on top of the mixture. By sieving the flakes into definite size distributions, the fraction that mixes well can be used to provide a uniform explosive mix.
ANPS flakes have been experimented upon underwater, with confinement being provided by a steel tube. As expected, the shock and bubble energies rose to the values of 545±33 J/g and 1616±75 J/g respectively. Confinement of the charge has resulted in an increase in the combined bubble and shock energies of over 500 J/g, which is significant. There is still uncertainty as to whether the explosive has reacted completely. If the explosive reactions are incomplete, then it is likely that when confined in rock the bubble/heave energy will increase, giving ANPS the properties of a true LSEE in accordance with the invention.
EXAMPLE 4--ANPW
ANPW is a mixture of ammonium nitrate, sawdust and paraffin wax. Two different sized sawdust samples were taken, denoted fine and coarse. The sawdust and liquid paraffin wax are mixed together to form paraffin wax coated, sawdust particles. Upon cooling the mixtures down, they formed a cake in the bottom of the mixing container; this was difficult to break up. Mixing the solid fuel paraffin wax coated sawdust particles and ammonium nitrate together was not too difficult and the underwater testing gave shock energies of 540±29 J/g and 474±53 J/g for the fine and coarse samples respectively. The heave energies for the fine and coarse samples are 1915±38 J/g and 1862±38 J/g respectively.
EXAMPLE 5--HANRUB
Heavy ANFO's are high energy, high density explosives. Their main advantages are their higher density and subsequent higher bulk strength. Another advantage is that Heavy ANFO's are water resistant, depending upon their composition. This is ideal for sites where water intersects the blastholes and hence some of the holes are partially filled with water. In addition, rainwater does not dissolve or deteriorate the product once it is loaded.
Heavy ANFO's consist of an oxygen balanced mixture of Ammonium Nitrate, Fuel Oil and emulsion e.g. High Energy Fuel (HEF) or (ENERGAN). The HEF or ENERGAN phase has a high density and coats the surface of the AN prills, filling up the interstices between the prills with a resultant increase in the density of the product.
HANRUB is a Heavy Explosive which consists of an oxygen balanced mixture of Ammonium Nitrate, Rubber and an Emulsion phase. The aim is to produce an explosive with the following properties:
High density
High gas energy
Low shock energy
The explosive also has a degree of water resistance, depending upon the amount of emulsion in the mixture. When the emulsion completely fills the voids between the prills and the rubber, a degree of water resistance is obtained.
HEF 001 is 75% Ammonium Nitrate, 3.1% Fuel Oil and 21.9% HEF. It loads down a 381 mm hole at 121 kgm -1 , a density of 1.06 gcm -3 . The HANRUB equivalent, 75% Ammonium Nitrate, 3.1% Rubber and 21.9% emulsion, has a loading density of 0.88 gcm -3 , or 100 kgm -1 in a 381 mmhole.
Two holes of HEF 001 and two for HANRUB were detonated during the field trials at Tom Price. High speed photography of the blasts was analysed and the following results obtained.
TABLE 5______________________________________ Heave VelocityExplosive (m/s)______________________________________HEF 001 6.19HANRUB 7.71______________________________________ ##STR1##
The above figures indicate that the heave velocity and hence the heave energy for HANRUB is indeed increased compared to HEF001, by a similar factor as ANRUB when compared to ANFO.
Higher density, Heavy Explosives can be produced by increasing the percentage of emulsion in the mixture. A 60/40 ANFO/emulsion mixture has a density around 1.2 gcm -3 . Increasing the HEF content of HANRUB, will consequently increase the density of the product. There is a limit to the maximum density possible with Heavy Explosives, that is, when all the voids between the prills are filled with emulsion, of approximately 1.3 gcm -3 .
Now that several examples of the explosive composition according to the invention have been described in detail, it will be apparent that the use of a solid fuel in accordance with the invention can produce the desired LSEE. In a conventional ANFO explosive composition, the liquid fuel is absorbed by the porous grade ammonium nitrate (AN) prills. In a preferred form of the invention, in which all of the liquid fuel is replaced with a solid fuel, less porous or even crystalline AN, which is less expensive than Porous AN prills, can be used. This has the advantage of lowering the cost of the explosive.
Other advantages of the preferred LSEE of the present invention include the following:
1. A relative increase in the heave energy with respect to the shock energy will lead to a more efficient rock blasting explosive.
2. This increase in efficiency will result in a reduction in the amount of explosive needed per hole to produce similar explosive results, which will produce a cost saving.
3. There is an increase in the stability of the slopes and a reduction in ground vibration thus making the LSEE more "environmentally friendly".
4. There is a decrease in the amount of fines produced.
5. There is a reduction in the amount of damage done to the minerals being mined, particularly diamonds.
6. Due to the relative insensitivity to inadvertent explosion of the LSEE it can be pre-mixed and transported in bulk to the mine site and around the mine site.
The described Examples have been advanced by way explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features herein disclosed.
Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications, other than those specifically described, without departing from the basic principles of the invention. All such variations and modifications are considered to be within the scope of the present invention, the nature of which is to be determined from the foregoing description and the appended claims. | An explosive composition comprising an oxidising agent such as ammonium nitrate (AN), and a fuel material which may include a fuel oil (FO) and which also comprises a solid fuel such as rubber particles or polystyrene beads or flakes. The solid fuel is incorporated into the composition to provide for the controlled release of energy upon detonation of the explosive composition. It has been found that by substituting some or all of the liquid fuel oil with a slower burning solid fuel, the time during which the pressure builds up during detonation is lengthened. Thus a low shock energy explosive (LSEE) can be produced having reduced shock energy and increased heave energy compared to convention explosives, such as ANFO. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present Utility patent application claims priority benefit of the U.S. provisional application for patent Ser. No. 60/851,712, entitled “A Device for Containment and Protection of a Liquid Handling System” and filed on Oct. 14, 2006 under 35 U.S.C. 119(c).
FIELD OF THE INVENTION
[0002] The present invention relates generally to water systems. More particularly, the invention relates to a device for the containment and protection of a liquid handling system enabling easy installation and removal.
BACKGROUND OF THE INVENTION
[0003] Several issues have been identified with liquid handling systems. One of these problems is that fluid pumping devices installed in homes or other buildings leave room for extensive damage by defective or worn out devices. Defects such as, but not limited to, failed and leaking pressure tanks and bad pressure switches may cause pressure relief valves to release water into the building and can cause water damage and mold issues inside the building. Another issue is that valuable building space is occupied by liquid handling systems. Other problems include, without limitation, limited access to the device due to physical building limitations, and hazards caused by the proximity of electrical devices. These issues may be avoided by housing the liquid handling system in a containment device outside of the building.
[0004] The current art provides some methods for housing liquid handling systems. For example, without limitation, separate “pump houses” may be built to house liquid handling systems. However, pump houses are expensive to construct and may not be appealing in a yard. In cold climates, pump houses must be heated to prevent freezing. In warm climates, pump houses tend to cause the liquid to warm up, and if this is a drinking water system, it may not to pleasing or refreshing to drink warm water. Also, pump houses tend to be confining and tend to collect everything else around the house or facility including, without limitation, toxic items such as, but not limited to, herbicides, and pesticides that should not be stored near water systems. This collection of objects also creates problems and safety issues with servicing the equipment of the liquid handling system. Pump houses are often dirty and filled with insects. Pump houses can become homes for pests such as, but not limited to, rodents, poisonous spiders, snakes, etc., creating additional health hazards. Also, pump houses require maintenance themselves including, without limitation, regular painting, cleaning, and roof maintenance.
[0005] Another solution is to house liquid handling systems in concrete “well rings” buried in ground. Concrete rings allow for the placement of a liquid handling system in-ground and protect the liquid handling system from freezing and resist vandalism, although less expensive than pump houses. However, concrete rings are still costly. Concrete rings are very heavy and may require a boom truck or truck-trailer to deliver and may require a crane, backhoe or similar device to set in-ground. Use of concrete rings requires entering a confined space to work on the water system device. Confined space issues include, without limitation, hazardous gasses, and electrical safety issues that actually may not meet electrical codes. Also, these concrete rings are not very tight, allowing nuisances such as, but not limited to, bugs, snakes, water, etc. to enter the concrete ring. It is also difficult to get plumbing through the concrete ring. The lids of these concrete rings are often very heavy and may require hoisting equipment to remove. The use of concrete rings does eliminate or minimize potential water damage in structures from leaking devices, and provide some protection from weather. Use of concrete rings in ground may be more aesthetically pleasing than a building, but is still somewhat of an eyesore. Furthermore, with the advent of new variable speed pumping systems and computerized pumping systems, it is necessary to have devices as big as concrete rings to house these smaller components.
[0006] In view of the foregoing, there is a need for an improved containment device for a liquid handling system that protects the liquid handling system from the elements and pests, is simpler to install than current containment devices, and provides easy access to the liquid handling system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0008] FIGS. 1 , 2 , and 3 illustrate an exemplary vault assembly for a liquid handling system containment device, in accordance with an embodiment of the present invention. FIG. 1 shows a front view; FIG. 2 shows a side perspective view, and FIG. 3 shows an exploded view;
[0009] FIG. 4 illustrates a side perspective view of an exemplary quick connect adapter from a liquid handling system containment device, in accordance with an embodiment of the present invention;
[0010] FIG. 5 illustrates a side perspective view of an exemplary quick connector assembly from a liquid handling system containment device, in accordance with an embodiment of the present invention; and
[0011] FIG. 6 illustrates a side perspective view and an exploded view of an exemplary optional quick connect assembly for a regulating device, in accordance with an embodiment of the present invention.
[0012] FIG. 7 illustrates a side view of vault 8 with cutaway showing Quick connect 6 and 11 mounted on sidwall of vault.
[0013] Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.
SUMMARY OF THE INVENTION
[0014] To achieve the forgoing and other objects and in accordance with the purpose of the invention, a device for containment and protection of a liquid handling system is presented.
[0015] In one embodiment, a containment device for a liquid handling system is presented. The devise comprises a vault comprising a cavity of sufficient dimensions to contain at least the liquid handling system, a closed bottom and an open top. A supporting device comprising a first half of a quick connect system connected to external plumbing is positioned in a lower portion of the cavity and secured to the vault in a manner to provide support for a weight of the liquid handling system. A bracket comprising a second half of a quick connect system connected to internal plumbing for the liquid handling system is configured to retain the liquid handling system, contact the supporting device when the bracket and liquid handling system is lowered into the cavity and mate the first second halves of the quick connect system allowing liquid to flow from the external plumbing to the internal plumbing. A lid is secured to the top for minimizing the intrusion of environmental elements into the vault. In another embodiment, the device further comprises an alignment feature for guiding the bracket to property contact the base. In another embodiment, the device further comprises an additional quick connect system for plumbing of regulation devices for the liquid handling system such that the regulation devices can be removed from the vault without removing the liquid handling system. In an embodiment, the regulation device is a gauge. In a further embodiment, the device further comprises a means for lowering and lifting the bracket and liquid handling system in the cavity. In an embodiment, the means for lowering and lifting is a lifting pipe attached to the bracket. In another embodiment, the external plumbing is attached to mainlines outside the vault. In a further embodiment, the vault is fabricated in a manner suitable for being buried below ground. The device is further fabricated to minimize distortions from soil pressure. In another embodiment, the device further comprises fasteners for securing the lid to the top. In yet another embodiment, the bracket retains the liquid handling system by fastener means. In another embodiment, the vault is constructed of a plastic material or galvanized steel. In another embodiment, the lid is constructed of molded plastic or fabricated metal.
[0016] In another embodiment, a containment device for a liquid handling system is presented. The device comprises a means for housing the liquid handling system, a means for quick connecting and disconnecting the liquid handling system from external plumbing, and a means for protecting contents of the housing. In a further embodiment, the device further comprises a means for lowering and lifting the liquid handling system in the housing. In yet another embodiment, the device further comprises a means for guiding the lowering of the liquid handling system. In still another embodiment, the device further comprises a means for minimizing distortions to the housing when the device is buried under ground.
[0017] In another embodiment, a quick connect device for use with a containment device for a liquid handling system is presented. The device comprises a connector shoe comprising a flat area with a plurality of openings for accepting a plurality of plumbing connectors on a first side of the connector shoe, the connector shoe retaining a plurality of O-ring type sealers in groves on a second side and placed circumferentially about the openings, and a connector base comprising a flat area with a plurality of openings for accepting a plurality of plumbing connectors on a first side, a slotted perpendicular boss along two edges of a second side, the boss dimensioned and positioned to hold in place the connector shoe, when the connector shoe is inserted between the bosses, and align the plurality of openings of the connector shoe and the connector base such that fluids can pass between the connector shoe and the connector base and the sealers prevent leaking. In another embodiment, the connector shoe comprises a regulation device connected to at least one opening. In another embodiment, the regulation device is a gauge.
[0018] Other features, advantages, and object of the present invention will become more apparent and be more readily understood from the following detailed description, which should be read in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given here with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, without limitation, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending on the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive.
[0020] The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.
[0021] Embodiments of the present invention provide liquid handling system containment devices that reduce cost of installation, simplify service and replacement of liquid handling systems, create protected space for liquid handling systems, and protect liquid handling systems from the elements such as, but not limited to, rain, snow, freezing, and heat. These embodiments also minimize vandalism by being out of site and having a secure lid. The lid in these embodiments may also be colored to minimize visibility of the containment device.
[0022] The preferred embodiment of the present invention is designed to hold a liquid handling system by the use of quick connect devices, enabling easy removal of the liquid handling system for service and replacement. No entrance into the vault is required. By servicing the liquid handling system components above ground, the need to enter the containment device is eliminated. Therefore, confined space is not an issue with the preferred embodiment, and not having to enter the vault eliminates hazardous gasses issues. Not entering the containment device also generally climinates clear area issues for electrical appliances needed, for example, without limitation, pressure switches, disconnects, junction boxes, breaker panels, etc.
[0023] FIGS. 1 , 2 , and 3 illustrate an exemplary vault assembly 20 for a liquid handling system containment device, in accordance with an embodiment of the present invention. FIG. 1 shows a front view; FIG. 2 shows a side perspective view, and FIG. 3 shows an exploded view. The present embodiment comprises vault assembly 20 that houses liquid handling system devices such as, but not limited to, pressure tanks, pumps, filters, etc., in a clean, safe place that is weather resistant, for example, without limitation, resistant to heat, freezing, rain, snow, etc. The present embodiment enables easy initial installation and easy future repair and maintenance.
[0024] In the present embodiment, vault assembly 20 is comprised of a molded or fabricated vault 8 of adequate construction to withstand soil pressures to prevent distortion or collapsing when buried underground up to a lid 1 . Vault 8 is preferably constructed of a plastic or galvanized steel, but may be constructed of various alternate materials such as, but not limited to, aluminum or other metals. Vault 8 houses a quick connect system and a liquid handling device 4 connected to the quick connect system. The top of vault 8 has a ridge that enables lid 1 to seal to vault 8 and areas adequate to fasten lid 1 to vault 8 with fasteners 2 for security and safety. Fasteners 2 are designed to make removal of lid 1 difficult, adding to security. Fasteners 2 may be, for example, without limitation, latches, hooks, or bolts passing through lid 1 and threaded into vault 8 , to secure lid 1 to vault 8 . Lid 1 may be constructed of molded plastic or fabricated metal dependant on traffic, security, and aesthetic needs.
[0025] Vault 8 comprises a bottom to prevent pests from entering and provisions for drainage that may be needed. A quick connect base 11 , the first half of the quick connect system, is attached to a supporting device 10 that is also attached to other areas of vault 8 to support the weight of the liquid handling system being installed in vault 8 . Quick connect base 11 is bolted or welded to vault 8 to hold quick connect base 11 square. Liquid handling device 4 connects to bracket 5 by means such as, but not limited to clamps or bolts. Bracket 5 holds the second half of the quick connect system, a quick connect shoe 6 , and holds quick connect shoe 6 inline with quick connect base 11 , assuring proper alignment and support of liquid handling device 4 . Liquid handling device 4 is installed or removed by a lifting pipe 3 that is installed on bracket 5 . In alternate embodiments a handle on liquid handling device 4 may be used for lifting liquid handling device 4 out of vault 8 . Liquid handling device 4 may be any device connected to a pumping system such as, but not limited to, a pump, tank, meter, filter, valving, etc.
[0026] In the present embodiment, when lifting liquid handling device 4 out of vault 8 , typical plumbing 7 is disconnected by quick connect shoe 6 and quick connect base 11 separating in a vertical direction. To install quick connect assembly with pumping device 4 into vault 8 , the user slides quick connect assembly with liquid handling device 4 into the cavity of vault 8 in a vertical direction and aligns alignment feature 17 which guides quick connect shoe 6 into quick connect base 11 , thereby enabling quick connect shoe 6 to enter quick connect base 11 and pressing down until bracket 5 and a base supporting bracket 10 touch. At this point, plumbing 7 is connected, allowing fluid to pass from liquid handling device 4 through plumbing 7 to quick connect through shoe 6 and base 11 and on to external plumbing 9 .
[0027] External plumbing 9 enables items inside of vault 8 to be connected to mainlines outside of vault 8 . In some embodiments, plumbing 7 may be modified to accept a miniature quick connector 7 a, as shown by way of example in FIG. 6 , which enables pressure regulation devices such as, but not limited to, gauges to be easily removed without removing liquid handling device 4 from vault 8 . In other embodiments these regulation devices may be plumbed in direct without a quick connect when the servicing of the item is not an issue for example without limitation, with a pressure release valve. Items such as, but not limited to, pressure regulating valves, gate valves, ball valves, pressure relief valves and similar devices may be installed in plumbing 7 and external plumbing 9 as needed. These items can be installed at manufacture, in shop, or in the field as needed.
[0028] FIG. 4 illustrates a side perspective view of an exemplary quick connect adapter from a liquid handling system containment device, in accordance with an embodiment of the present invention. In the present embodiment, the quick connect adapter comprises quick connect base 11 and quick connect shoe 6 . Quick connect base 11 is a device that accepts quick connect shoe 6 . Quick connect base 11 has a flat area that has on each edge a slotted perpendicular boss that holds and aligns holes in quick connect shoe 6 and holes in quick connect base 11 when properly installed. O-rings 6 a in quick connect shoe 6 provide sealing to allow fluid to pass from quick connect base 11 to quick connect shoe 6 without leaking. O-rings 6 a are set in a groove machined in quick connect shoe 6 . Connection to quick connect shoe 6 and quick connect base 11 is accomplished with connectors 12 allowing pipe connection for controlled flow. Connectors 12 connect quick connect shoe 6 to plumbing 7 and quick connect base 11 to external plumbing 9 , shown by way of example in FIGS. 1 , 2 , and 3 . Connectors 12 may be threaded or plain end to be soldered or welded. Plumbing 7 and external plumbing 9 are fitted with conventional plumbing fittings such as, but not limited to, copper, galvanized steel, or plastic, to accommodate various apparatuses as liquid handling device 4 . This plumbing may be done at the factory, on site, or in a shop.
[0029] FIG. 5 illustrates a side perspective view of an exemplary quick connector assembly from a liquid handling system containment device, in accordance with an embodiment of the present invention. In the present embodiment, quick connect shoe 6 and quick connect base 11 may be installed anywhere on bracket 5 and base supporting bracket 10 to accommodate various liquid handling devices. In alternate embodiments, more than one quick connect adapter may be installed if needed or desired. In some embodiments portions of the outer ring of bracket 5 may be cut away to facilitate clearance for items mounted on the wall of vault 8 during removal, for example, without limitation, controllers, switches, disconnects, J-boxes, etc.
[0030] FIG. 6 illustrates a side perspective view and an exploded view of an exemplary optional quick connect assembly for a regulating device, in accordance with an embodiment of the present invention. Some embodiments of the present invention may have a small quick connector 7 a, as shown by way of examples in FIG. 1 and 2 . Quick connector 7 a can be used to adapt pressure-regulating devices to plumbing 7 and external plumbing 9 , shown by way of example in FIGS. 1 , 2 , and 3 . These pressure-regulating devices may include, without limitation, pressure switches, gauges, transducers etc. Quick connector 7 a enables these accessory devices to be removed and serviced without removal of the main device.
[0031] In some embodiments these accessory devices may also be connected by a small quick connect adapter similar to the quick connect adapter, shown by way of example in FIG. 6 , connecting liquid handling device 4 to the plumbing of the vault assembly. This small quick connect adapter comprises a quick connect base 23 and a quick connect shoe 24 . Quick connect base 23 and quick connect shoe 24 slide together to allow fluid to flow through to the accessory devices. O-rings 25 seal the connections between quick connect base 23 and quick connect shoe 24 to prevent leaking. O-rings 25 set in a grooves machined in quick connect shoe 24 . Pipe nipples 26 adapt the plumbing from quick connect shoe 24 to the accessory device.
[0032] By constructing vault 8 from plastics or thin gauge metals, vault 8 can be delivered in a pickup truck or trailer and set into an existing ditch by one person, without lifting equipment or with minimal lifting equipment. Installation is very quick. The only water connections that require attention at installation are external plumbing 9 positioned outside of vault 8 below the freezing level. Vault 8 is designed to control fluids by minimizing or eliminating rainwater and groundwater from entering. However, caution must be used when installing vault 8 in high water tables. In these situations water removal means such as, but not limited to, drains, sump pumps, or holes may be used to drain or remove any fluids that enter vault 8 . Vault 8 is installed in the ground after a waterline ditch has been dug, and water lines are connected to plumbing 9 at this time. A typical installation of vault assembly 20 , according to the present embodiment, is as follows.
[0033] After the excavator digs ditches for vault 8 and lines, vault 8 is placed in the ditch. The ditch must be of adequate width and depth to enable vault 8 to be buried to the level of lid 1 at the point of installation. Water lines are then connected to external plumbing 9 at vault 8 . Liquid handling device 4 can be in vault 8 at this time or may be installed into vault 8 after backfilling. If liquid handling device 4 is to be installed after backfilling, the excavator then backfills the ditch. Liquid handling device 4 along with bracket 4 is lowered into vault 8 . Alignment feature 17 guides quick connect shoe 6 into quick connect base 11 , and quick connect shoe 6 and quick connect base 11 are aligned. Bracket 4 with Liquid handling device 4 is then pushed into place. If electrical is needed, the electrical system is wired at this point. Lid 1 and fasteners 2 are then installed. If liquid handling device 4 requires service, fasteners 2 and lid 1 are removed and bracket 5 with liquid handling device 4 is lifted out of vault 8 . Liquid handling device 4 may be serviced and then reinstalled into vault 8 as described above.
[0034] Liquid handling device 4 that is housed in vault 8 may be assembled at a factory, in a shop, or in the field by service personnel. In the present embodiment, all other components are comprised in vault 8 . Electrical connections are preferably performed by an electrician. Controllers and other items such as, but not limited to switches, disconnects, J boxes, etc. may be installed on a post, inside vault 8 , or inside other structures as preferred. Vault 8 has a plastic or metallic lid 1 that seals to vault 8 attached with fasteners 2 to supply security and safety. This design enables many different components to be installed in vault 8 , for example, without limitation, pumps, meters, filters, pressure tanks, etc. The physical size of vault 8 , quick connect shoe 6 , and quick connect base 11 , bracket 5 and base support bracket 10 can be changed to facilitate equipment of different sizes, for example, without limitation, larger tanks, pumps, filters, meters, etc. Special ordered systems can be built individually as needed.
[0035] Being able to install the vault assembly outside, according to the present embodiment, provides space saving in buildings where the liquid handling system is needed. However, in alternate embodiments, this vault assembly may be installed in the floor of structures if needed.
[0036] An embodiment of the invention may be configured to enable the component parts of the foregoing liquid handling device to be removable from the housing using the quick connect shoe 6 and base 11 mounted to the sidewall of Vault 8 without using brackets 5 an 10 as shown in FIG. 7 page 7 of 7. This solution functions best for small lighter system devices. A drawback of this solution is Quick connect shoe 6 and base 11 is not intended to suspend excessive weight of large devices. Also, the flex in the sidewall of the vault at mounting point can cause problems with the removal of the heavy devices. A support 21 has been added to minimize flexing issues in this configuration. Support 21 is attached to the plumbing 7 . Support 21 rests on bottom of vault 8 to help support weight of device 4 .
[0037] Having fully described at least one embodiment of the present invention, other equivalent or alternative means for implementing a containment device for a liquid handling system according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims. | A containment device for a liquid handling system is presented. The devise has a vault having a cavity, a closed bottom and an open top. A supporting device having a first half of a quick connect system connected to external plumbing is positioned in a lower portion of the cavity and secured to the vault to provide support for a weight of the liquid handling system. A bracket having a second half of a quick connect system connected to internal plumbing for the liquid handling system is configured to retain the liquid handling system, contact the supporting device when the bracket and liquid handling system is lowered into the cavity and mate the first second halves of the quick connect system allowing liquid to flow from the external plumbing to the internal plumbing. A lid is secured to the top for minimizing the intrusion of environmental elements into the vault. | 4 |
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to the digital reconstruction of a three-dimensional tomosynthesis image and a graphics processing unit (GPU) which is used to execute a reconstruction process based on a more accurate model of the acquisition process.
[0002] Given the fact that breast cancer is one of the most common cancers among women today, early detection of the cancer or other anomalies indicative of cancer, like microcalcifications, so that these may be treated prior to metastatic spread, is an important objective. Accordingly, it is a major task to improve imaging techniques and related systems, as well as methods for reconstruction of tomographical images.
[0003] Conventional mammography techniques are based on 2-dimensional imaging and generally suffer from the limitation that 3-dimensional anatomical information (for example masses or other anatomical structures to be detected) is projected onto a 2-dimensional image and therefore overlapping breast tissue often makes it difficult to perceive and characterize subtle lesions. In other cases the superposition of normal tissue structures can resemble suspicious lesions and lead to further, unnecessary medical procedures.
[0004] In order to overcome these limitations a 3-dimensional imaging approach has been introduced. This approach analyses direct projections by computer software in order to construct or reconstruct a 3-dimensional volume of the breast, the reconstructed volume. In these systems x-rays are sent by an x-ray source to an x-ray detector. Between the source and the detector the medical volume (for example the breast) is arranged and preferably compressed. The x-ray beam, sent by the x-ray source is attenuated by the volume, so that attenuated signals may be received at the detector or by a set of detector elements, which produce signals, representing the attenuation of the incident x-rays and which are processed in order to reconstruct the 3-dimensional image. Normally the breast is exposed to radiation from a plurality of different angles. For example, a digital breast tomosynthesis system may acquire 25 direct projection images in which the source may move, such that the imaging angle may change within about 50 degrees. Alternate to the moving x-ray source there may be provided several x-ray sources in order to acquire signals from different angles. This 3-dimensional tomosynthesis technique provides spatial differentiation of overlapping tissues while losing some spatial differentiation between in plane adjacent structures, compared to the above-mentioned 2D imaging technique (in the direction perpendicular to the detector).
[0005] However, digital breast tomosynthesis suffers from incomplete data (only a range of about 50 degrees is sampled out of the 180 degrees necessary for a complete data set are measured) which causes artifacts and creates the problem that there will be an infinite number of possible reconstruction volumes that can be described by the measured data. Another source of artifacts is introduced when the mathematical acquisition model used in the reconstruction deviates from the physical reality of the acquisition. In addition, a desire to minimize patient exposure to ionizing radiation leads to high noise in the measured data (poor quantum statistics) which is then propagated through the reconstructed volume.
[0006] In order to overcome these problems and improve the reconstruction result, several reconstruction algorithms have been suggested in state of the art systems.
[0007] Popular filtered backprojection (FBP) reconstruction methods provide high contrast and acceptable detail level in reconstructed images but those methods lose the information about relative tissue density (see for example: Mertelmeier T., Orman J., Haerer W., Kumar M. K., “Optimizing filtered backprojection reconstruction for a breast tomosynthesis proto-type device”, Proc. SPIE 6141, 2006). This happens due to removal of low frequency components with some filter kernels. Although these algorithms assume complete and noiseless data, some corrections can be applied to reduce the resuiting problems.
[0008] So-called iterative reconstruction techniques do not make any assumptions on the measured data. Instead, a mathematical model of the acquisition process is used to define a cost function that needs to be maximized. For example, maximum likelihood methods use the Poisson distribution of the measured data to calculate the statistical likelihood of the projections and use it as a cost function. In the case of perfect data, the reconstructed volume with maximized cost function would be identical to the original image.
[0009] Iterative reconstruction techniques repeatedly or iteratively apply an update to the reconstruction volume to generate an image that maximizes the defined cost function. This cost function depends on the model of the measurement (data acquisition), which includes the forward projection. Iterative reconstruction algorithms help to improve image quality, reduce artifacts in reconstructed images and allow reduction of x-ray dose. However, iterative reconstruction algorithms require significantly more computation time than conventional (for example FBP) reconstruction methods, because they have to execute a lot of iterations to generate each image, i.e. to “converge” to a solution. Further, these algorithms typically become computationally intensive and therefore are often impractical for clinical applications, due to the fact that images should be available to the radiologist within a reasonable amount of time.
[0010] Iterative reconstruction offer possibilities for improving image quality and reducing artifacts as compared to analytical methods. Artifacts are mostly caused by a discrepancy between the real physical acquisition process and the model of the acquisition process used for reconstruction. Consequently, artifacts may be reduced and thus image quality enhanced by using a better (more accurate) model for image acquisition. Generally, more accurate models will be more complex and will require more processing time and memory.
[0011] With respect to the problem of incomplete data and high image noise, application of an iterative reconstruction approach could be beneficial due to the possibility to include prior functions. Generally, these prior functions put additional constraints on the reconstructed volume (for example limiting variance between adjacent voxels in order to reduce noise), thus reducing the number of possible solutions in the case of incomplete data. However, one of the disadvantages of this approach is that it requires empirical determination of the optimal parameters of the prior function which usually involves a grid search over a range of values. The latter is not practical for high resolution breast imaging especially when multiple prior functions are evaluated. Another significant limitation is that iterative reconstruction methods with priors require to keep the multiple versions of the whole volume in memory. The precondition mentioned before (to keep a lot of data in memory) is required for the update step and prior function computation. The latter limits the maximum size of the reconstructed volume to the amount of GPU (graphics processing unit) memory.
OBJECT OF THE INVENTION
[0012] Based on the above-mentioned approaches in state of the art it is therefore an object of present invention to provide an iterative reconstruction for digital breast tomosynthesis, which has a faster convergent speed and an efficient memory usage as known algorithms, while using a more accurate (and complex) acquisition model and while assuring efficient noise control and which may be implemented in the graphical processing unit. Moreover, it should be possible to overcome the drawbacks of the present reconstruction algorithms, mentioned above.
SUMMARY OF THE INVENTION
[0013] In one aspect the method for digitally and iteratively reconstructing a 3-dimensional tomosynthesis image of a 3-dimensional volume, particularly of an organ and/or a body part/structure, comprises:
Receiving signals of the tomosynthesis image system, wherein x-ray radiation is sent by an x-ray source to be received at a detector and is attenuated by anatomical structures of the 3-dimensional volume Providing a model for image-acquisition, wherein this model can include parameters based on the physical movement of the x-ray source during x-ray emission/radiation and wherein the model could be different for each patch Creating a cost function which includes the provided acquisition model. For complete, noiseless data, the cost function should be maximal for the true volume that has been measured on the system. An example is the Poisson likelihood of the acquired data. Reconstructing the 3D volume by iteratively updating (changing) the volume so that the cost function is optimized. For example, the update step to maximize the likelihood can be calculated with the MLTR algorithm or the ML-convex algorithm or the ML-gradient algorithm or a grouped coordinate ascent algorithm (wherein the grouped coordinate ascent algorithm is not applied for each patch, it is applied to the entire volume and the patches (groups) are the result) or another algorithm.
[0018] A short explanation of terms used within this application is given below.
[0019] The x-ray source or tube is adapted to emit x-ray radiation, which is generally directed towards the detector. Typically the x-ray source is rotatable about an axis of rotation in order to image a compressed breast from a plurality of angles. Typically the source may be moved within an interval of 50° on an arc above breast in preconfigurable angular steps (typically: 2° steps between −25° to 25°). During x-ray exposure breast and detector remain stationary or static, respectively. Alternatively, it is also possible to provide not one single x-ray source, but a plurality of x-ray sources positioned at different locations, which may be arranged on an arc and/or which may be activated according to a preconfigurable (time) pattern:
[0020] The detector usually is a flat panel detector. The detector may consist of a plurality of detector fields. The detector is a digital detector. The detector might also be combined with at least one plate of the compression system or with a compression paddle.
[0021] The 3-dimensional volume mainly refers to a medical volume to be examined. According to a preferred embodiment the invention is applied for tomosynthesis mammography. However, the invention might also be applied for a variety of 3-dimensional imaging situations, such as heart imaging, bone imaging or generally examinations of soft tissues. Other embodiments do not refer to report generation or diagnosis, but refer to surgical applications like implantations, also comprising orthopedic implants, heart implants etc.
[0022] The 3-dimensional volume, for example the breast, consists of a plurality of different tissue structures with a different density, for example fat tissue, glandular tissue, muscle, ligaments, blood vessels or other tissues, which also differ in their attenuation factors. Therefore, microcalcifications, lesions or other anatomical modifications or anatomical structures superimposing other structures are also detectable in the reconstructed image.
[0023] “Reconstructing” refers to an iterative method where the 3D volume is modified in several steps in order to maximize a cost function. In one aspect of the invention parts of the volume (a patch, or a plane in the volume to be reconstructed) are updated sequentially within one update iteration of the entire volume. After a patch has been updated, its new values will be used when updating the other patches. Therefore, the'order of updating matters and the logic of the algorithm is based on a sequential updating scheme. Thus, update steps are calculated for one patch and then applied to the reconstruction volume. After this update (and taking into account the changes that are introduced by this update) the update step for the next patch is calculated and applied to the image patch-by-patch. Reconstructing may comprise displaying the reconstructed volume on a monitor or output device.
[0024] The term “iterative” refers to the fact that the algorithm starts from an initial image for which the cost function is calculated. In each following step, the update algorithm determines the necessary change to the volume (the update step) which will increase the cost function. Because of the complex mathematical form of the cost function, it is impossible to find an update step which maximizes the cost function in one step. The algorithm is thus repeated until a certain stopping condition is met (for example after a fixed number of iterations, or after a certain noise level has been reached in the volume). After each step the cost function calculated from the current volume will be higher than in the previous iteration, and thus closer to its maximum value.
[0025] According to one aspect, the invention provides a method that enables to the use of a digital tomosynthesis to efficiently provide accurate 3-dimensional imaging of a target object, like a breast. Particularly, the method allows including a more accurate model of the acquisition process into the cost function of a maximum-likelihood for transmission algorithm (MLTR), in addition, the convergence speed of the algorithm is increased by applying a grouped coordinate ascent algorithm, where groups of voxels (as volume segments) are updated sequentially instead of simultaneously. This allows an efficient implementation on a graphical processing unit by reducing memory requirements.
[0026] The “model” is a mathematical abstraction of the physical image acquisition process which is used during image calculation and reconstruction. Accordingly, the model is based on positional data relevant to the physical acquisition process and/or relates to real physical acquisition parameters, like image acquisition geometry, movement of x-ray source and/or x-ray detector during exposure, acquisition angles, radiation dose, detector properties, and image-related parameters, like spatial resolution and contrast resolution etc. A model may be formatted in a mathematical or abstract denomination or language. Based on the model there are deducible instructions relating to image reconstruction, which also might be implemented in hardware or software. The model is a representation of the physical acquisition process and serves as input data or basis for the reconstruction process, implemented on a system or on a reconstructor.
[0027] The model processed and used within an embodiment of this invention is based on the main acquisition assumptions as in regular MLTR. It is assumed that the transmission data are Poisson-distributed. In contrast to a regular MLTR algorithm (see below) it is assumed that the x-ray tube moves during exposure: the acquisition model is changed from a “step and shoot model” to a model where the focus of the x-ray tube is moving during x-ray exposure. That is to say in original state of the art systems a model for the acquisition process has been based on the fact that the focus of the x-ray tube was stationary during each detector exposure and then moved to the next acquisition angle. In contrast to this in the model of the present invention the focus of the x-ray tube is also moving during x-ray exposure, and thus is better (more accurate) adapted to the real physical acquisition situation. This fact can be modeled as a smoothing of the transmission data provided that the volume has been split in patches parallel to the detector surface.
[0028] In the most simple case the acquisition model can be written as ŷ i =b i exp(−Σ i l ij μ j ) with ŷ i the result of the modelled measurement, μ the attenuation distribution (the 3D volume to be reconstructed, b i the blank value for projection line i (the theoretical measurement value in the case where there is no attenuation measured) and l ij the intersection length between projection line i and voxel j.
[0029] An example for including tube motion in the data acquisition model is shown here. The physical reality is closely described by the following formula:
[0000]
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=
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-
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[0030] With Ŷi the measured data with pixel index i, with x defining the tube positions within a single x-ray exposure, with p enumerating the planes in the reconstruction volume, with \mu_j the attenuation value in voxel j of the reconstruction volume, with b_x the number of x-ray photons emitted by the x-ray tube at position x, with l_ixj the intersection length for the x-ray passing between the x-ray tube at position x, voxel j and pixel i and S_i the scatter in pixel i.
[0031] Although this is a good description of reality, this model result in a cost function for which the derived update step is too complex for practical implementation. To this end, we simplify this model to the following model:
[0000] ŷ i =b i ψ i ÷S i
[0000] ψ i =Π p ψ i p
[0000] ψ i p =Σ n PSP in p ·ψ i p
[0000] ψ i p =exp(−Σ jep l ij μ j ),
[0032] With PSF in the above mentioned formula referring to a point spread function which is the mathematical description of the image blurring caused by the tube motion.
[0033] These two models are mathematically different, but result in similar results. The second model however results in a cost function for which the calculated update step is simple enough for easy implementation.
[0034] Starting from the model for the data acquisition, on can define a cost function. This cost function should be defined in such way that the attenuation μ (which enters the cost function through the acquisition model) which maximizes the cost function (or in other embodiments minimizes it, but this is a trivial change of sign) is the “true” attenuation distribution of the volume in the case of complete (180° angular sampling) and noiseless data.
[0035] In maximum likelihood algorithms, the log-likelihood L (usually named likelihood instead of log-likelihood) is chosen as cost function. It can be written as L=Σ i y i ln(ŷ i )−ŷ i , where it both includes the measured data (y i ) and the data acquisition model (ŷ i ).
[0036] From the previous section one can see that the image is reconstructed based on information from both the acquisition model and the acquired data. However, in some situations there might be additional information and/or constraints that should be included in the reconstruction. In this situation one can include this information/restraint in the form of a prior function which is added to the cost function discussed in the previous paragraphs.
[0037] These prior functions can for example include information on the expected attenuation values in the reconstructed volume, or put a limitation on the maximum variance between neighboring voxels in the reconstruction volume. Starting from the likelihood cost function mentioned above, the new cost function F then becomes F=L−βP, with P the prior function and β the relative weight that is attributed to the prior function relative to the likelihood. In the case of a noise reducing prior, higher β will result in a smoother (less noisy image). When β=0, the additional information/constraints from the prior are not taken into account for the reconstruction. The prior function can contain numerous other parameters that describe its exact mathematical behavior in the reconstruction algorithm.
[0038] An additional useful effect of the'prior function in the specific case of tomosynthesis is the fact that usually the cost function for tomosynthesis is not convex, and the following maximization algorithms will only converge to the local maximum and not the maximum of the entire function. Adding a convex prior can limit the total number of local maxima so that the following algorithms are more likely to find the global maximum.
[0039] The actual reconstruction of the 3D volume occurs when maximizing the cost function by iteratively updating the volume.
[0040] Because of the mathematical complexity of the cost functions it is not possible to calculate the volume for which the cost function is maximized in one step. To this end several iterative algorithms exist that update the volume in several steps in order to maximize the cost function. The key is to step sufficiently fast (otherwise too many iterations are needed to reach the top), but not too fast (otherwise one may step over the top so that the next step has to undo part of the current step). The simplest example is the gradient ascent algorithm, where in each iteration a step is taken in the direction of the largest gradient. This algorithm is inefficient and thus not often used.
[0041] Another approach is Newton's method, where a quadratic approximation of the cost function is calculated, and this quadratic function is maximized. The quadratic approximation is then repeated for the updated value of the cost function until a certain stop condition.
[0042] For example in the MLTR algorithm, log-likelihood L is maximized by changing the attenuation distribution μ . The likelihood can be written as L=Σ i y i ln(ŷ i )−ŷ i , with y i the measured transmission scan and ŷ i the estimated transmission scan. In the most simple case the acquisition process can be written as ŷ i =b i exp(−ρ i l ij μ j ) with b i the blank value for projection line i and l ij the intersection length between projection line i and voxel j. With this information, one can construct a gradient ascent algorithm. In a more general form, including an additional weighting factor α and prior P( μ ) with weight β, the update step derived with Newton's method can be written as:
[0000]
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.
[0043] It is assumed that the prior P( μ ) is convex and can be written as P( μ )=Σ fk P(μ j , μ k ). Choosing α j =1 in the equation above gives the update step for the MLTR algorithm.
[0044] The MLTR-algorithm is described in more detail in Nuyts J., Man B. De, Dupont P. et al.; “Iterative reconstruction for helical CT: A simulation study”, Physics in Medicine and Biology, 1998; 43(4): 729-737. A similar update step can be derived for different cost functions.
[0045] Another approach is to construct a surrogate function of the cost function. In this situation the surrogate function is an approximation of the cost function that is mathematically easier to maximize. An example is Lange's ML convex algorithm (Lange K, Fessler J A., “Globally convergent algorithms for maximum a posteriori transmission tomography”, IEEE Transactions on Image Processing. 1995; 4(10):1430-1438.)
[0046] By choosing α j =μ j ÷ε with ε>0 in the update step above, an algorithm with characteristics from both the MLTR and Convex algorithm is obtained.
[0047] The approaches mentioned above will update the entire volume in one step in one iteration. This general approach limits the convergence speed of the algorithm: generally the more voxels are updated in one iteration, the smaller the update steps can be.
[0048] An alternative approach is to update only a subset of all voxels during one subiteration, with several subiterations for which all voxels are updates are considered one full iteration. This approach is a grouped coordinate ascent algorithm originally described by Fessler J. A. (see: Fessler, E. P. Ficaro, N. H. Clinthorne, and K. Lange, “Grouped-coordinate ascent algorithms for penalized-likelihood transmission image reconstruction.,” IEEE Transactions on Medical Imaging , vol. 16, no. 2, pp. 166-175, April 1997).
[0049] The grouped coordinate ascent algorithm essentially “splits” the volume in a plurality of subvolumes, the ‘groups’ in the algorithm, here referred to as patches. A patch, therefore, comprises a plurality of voxels and refers to a subvolume. The exact choice of these patches has a definite influence on the size of the update steps and is dependent on the geometry of the image acquisition.
[0050] According to the invention the peculiar geometry of the tomosynthesis acquisition makes that one specific choice of groups/patches (the patches being parallel to the detector surface) are nearly optimal in a mathematical sense. Based on the specific segmentation or partialization of the volume it is possible to optimize the sequential updating strategy for tomosynthesis.
[0051] For the tomosynthesis geometry one method of splitting the reconstruction volume is close to optimal with respect to the resulting update steps in the maximization of the cost function. This optimal choice is selecting each slice parallel to the detector as a single patch. The number of slices in a single patch is preconfigured and might be configurable before reconstruction. Thus, splitting refers to dividing the image into regions, called patches, the patches being updated separately and sequentially. According to an aspect of present invention a patch refers to one layer or plane within the volume. Generally, the following rule holds: the thinner the patches (less volume slices in one patch), the larger the step size can be, and the faster the convergence. Therefore, the slice-by-slice patches are close to optimal for this kind of approach.
[0052] In iteration N of the volume, after the attenuation values of the voxels in a x th patch P are updated to new values, these values are immediately applied to the full volume, so that this now consists of patches P that have been updates N−1 times, and patches P that have been updated N times. Iteration N+1 of the algorithm starts when each patch P has received its N th update.
[0053] Since each patch is now updated separately, it is much easier to apply different reconstruction models for each of the patches P. For example patch P k may be reconstructed with other reconstruction model than patch P n . This is theoretically possible while updating the entire volume in one step, but this will results in a very complex and inefficient update step. Van Slambrouck (see: K. Van Slambrouck and J. Nuyts, “A patchwork (back)projector to accelerate artifact reduction in CT reconstruction,” in IEEE Nuclear Science Symposium Conference Record, 2010, no. 60819) used the patches to introduce different (spectral) acquisition models in different parts of the reconstruction volume.
[0054] In this case the specific choice of the patches as groups in the grouped coordinate ascent algorithm enables an efficient implementation of the acquisition model which takes into account the tube motion as a patch dependent model and will result in less blurring due to the motion of the x-ray tube in the final reconstructed image.
[0055] In addition to allowing different acquisition models in different patches, the size of the update steps calculated for this specific choice of the patches as groups in the grouped coordinate ascent algorithm are mathematically close to maximal. Part of this increased convergence comes from the sequential updates but most of the increased convergence is due to an increased step size in the update. This can be seen by considering the update formula shown above (page 14). In this formula, a patch update can be considered as an update with α j =0 everywhere except in the current patch.
[0056] Therefore the sum Σ h l th α h in the denominator will be smaller and the step size for updates will be larger for smaller patches. Choosing patches as slices parallel to the detector will cause this sum to be as small as possible for as many of the detector positions i as possible.
[0057] Given the fact that the proposed process or method does not require the entire reconstruction volume to be in memory, a significant advantage of present invention is therefore to be seen in that implementation of this method is possible on graphics processing unit (GPU), where memory is the main restraint. This also is a major advantage over present prior art systems.
[0058] Given the fact that the basic concept of the present invention is based on providing patches parallel to the detector for the volume to be reconstructed the method may also be named patchwork reconstruction. Since using the patchwork reconstruction changes the denominator in the update formula substantially, using the same β value will result in a different amount of smoothing, when compared to a non-patched reconstruction. Therefore, β is adjusted so that resulting images look similar after a preselected or pre-configurable number of iterations.
[0059] When using different acquisition models for the different patches, noise will be different for each patch, therefore β will need to be different for each patch so that the resulting noise will be the same in each patch.
[0060] The number of iterations and prior function parameters could be computed or calculated, or adjusted respectively with an interactive adjustment, by an automatic adjustment or by calculating noise, which will be described below in more detail. In the following delta refers to a parameter in one embodiment of the prior where it defines the border between voxel variations which can be considered noise and voxel variations which describe real differences in attenuation.
Interactive Adjustment:
[0061] The number of iterations could be preselected by a user (radiologist) on a training set of patient images such that all clinical significant features (micro-calcifications, lesions, Cooper's ligaments, etc.) are imaged with sufficient contrast. The parameters of the prior function, like beta, are then calculated such that at the faintest visible clinically significant edges and microcalcifications with gradient G are preserved. The gradient below the determined value G would be considered as noise and smoothed out. That gives the “upper limit” estimate for the delta which determines the gradient range on which the prior works. The prior function parameters delta and the strength of the prior β could be adjusted to the preferences of the user in a second, interactive step. Such a method allows a better prediction at early iterations without requiring the full convergence.
Automatic Adjustment:
[0062] According to another aspect for adjusting the parameters the prior function parameters are adjusted by maximizing the contrast and edge sharpness in a set of reconstructed clinical features such as micro-calcifications masses and mass speculations. A reference reconstruction method (for example filtered backprojection or an iterative reconstruction method with a large number of iterations to ensure visualization of all clinically relevant feature) is used to reconstruct a set of patient images. A user could manually outline or segment clinically significant features in each reconstructed patient image. The number of iterations is then chosen such that the contrast of the faintest clinical features is sufficiently high for human observer (reference values could be obtained by experiments with phantoms in experiments) or such that the change of clinical feature contrast in each subsequent iteration is lower than a predefined threshold. Then the “upper limit” estimate for the delta and beta is computed such that the faintest edges in the training set of manually outlined clinical features are preserved. An interactive final step could be used for the fine adjustment of prior function parameters to the preferences of the user.
Noise Calculation:
[0063] In a further alternative embodiment it is possible to calculate noise at each iteration in function of beta and delta, by using the method described by Qi (J. Qi, “A unified noise analysis for iterative image estimation.,” Physics in Medicine and Biology , vol. 48, no. 21, pp. 3505-19, November 2003.).
[0064] This formula can then be reversed to determine the required beta and delta to attain the desired noise level in the reconstruction.
[0065] Generally, the patchwork algorithm tends to accumulate all low frequency information in the first patch P 1 . To ensure that low frequency information will be uniformly distributed over all patches P, the volume is initialized with an estimate of the mean attenuation and weighted updates are used during the first few iterations.
[0066] For example: The updates are weighted by 1/N with N the remaining number of patches P including the current one. Thus, the first update in a case with 10 patches P will have a weight of 1/10, the second update has a weight of 1/9 down to the last update with a weight of 1. In addition, in iteration 2 the patches P are updated from plane (patch) N down to plane 1 , while in all other iterations, the updates go up from plane 1 to plane N. Using two iterations with weighted updates provides some robustness against suboptimal initializations and is probably necessary when initializing clinical images with a constant attenuation.
[0067] According to another embodiment of present invention a backprojection or a filtered backprojection (FBP) is used as initialization. The weighted updates might or might not be used in this case.
[0068] According to a preferred embodiment of present invention reconstructing comprises displaying the reconstructed 3-dimensional image. Obviously, the reconstructed image may be transferred to other computational processing units or workstations in order to be processed or displayed. Preferably the reconstructed image will be stored in a memory or buffer.
[0069] Another solution of the above-mentioned object is to be seen in a system according to the claims. The system or reconstructor preferably is part of an embedded system, which could be implemented as a hardware unit, for example in an embedded processor or in a microprocessing unit. This processing unit may be part of the graphics processing unit and preferably consists of a receiver, a model generator, a reconstructor, a storage unit (and an assembler). Other embodiments of the for inputting and outputting image data.
[0070] Another solution is to be seen in a computer program product. The product is loaded or may be loaded into a memory or into the graphics processing unit of a computer, with computer readable instructions for execution of a method mentioned above, if the instructions are executed on the computer or directly in the graphics processing unit. Another solution relates to the computer program. The computer program may be stored on a storage medium or may be transferred over a network, such as the internet or other wide or local area networks.
[0071] The present invention generally leads to a number of major advantages over prior art systems. Results show, that the convergence speed is faster. Further, memory requirements are lower compared to prior art systems. Moreover, efficient noise control is possible, while boundaries and edges are preserved.
[0072] In the following the invention is described with respect to the Figures, showing exemplary embodiments of present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings:
[0074] FIG. 1 a schematic overview of our tomosynthesis reconstruction of a medical volume to be displayed on a monitor.
[0075] FIG. 2 a schematic overview of components of a reconstruction system according to the invention.
[0076] FIG. 3 a workflow for a reconstruction process of present invention according to a preferred embodiment of the same and
[0077] FIG. 4 a schematic overview of a graphics processing unit with an embedded system according to an embodiment of present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0078] FIG. 1 illustrates a radiographic imaging system in accordance with some embodiments of present invention. The system comprises an x-ray source arrangement. This x-ray source arrangement may itself comprise a plurality of x-ray tubes 100 which are adapted to emit x-ray radiation. Further, the system comprises an x-ray detector 101 , which may be implemented as a digital flat panel detector. The medical volume to be reconstructed is depicted in FIG. 1 as a schematic representation, shown as an oval. During computed tomography the x-ray source or tube generates and directs an x-ray beam towards the patient, while the detector measures the x-ray absorbtion at a plurality of transmission paths defined by the x-ray beam during the acquisition process. The detector 101 produces a voltage proportional to the intensity of incident x-rays. The voltage is read and digitized for subsequent processing in a computer 200 . During image acquisition huge amounts of data are thus accumulated. For the purpose of image reconstruction the accumulated data are later on analyzed and processed for image reconstruction.
[0079] According to one aspect of present invention the volume to be reconstructed is divided or split into a plurality of patches or slices, which in FIG. 1 are referenced by the reference numeral P. The patches P are parallel to a surface of the detector 101 .
[0080] In the algorithm to maximize the cost function (the reconstruction algorithm), within one iteration of this algorithm, the calculated update step for each patch P of the plurality of patches is applied to the patch before calculating the update step for the next patch. All the patches P of the plurality of patches are thus updated separately and sequentially within each iteration of the reconstruction algorithm. The reconstruction process is executed by performing a plurality of different algorithms, which may be implemented in software and/or in hardware by means of a system S. The system S may be implemented on a microprocessor unit, for example in the graphics processing unit GPU of the computer 200 . After having reconstructed all patches P of the volume a 3-dimensional image of the volume to be reconstructed may be calculated and displayed on a monitor 900 .
[0081] According to the invention a more accurate model of the acquisition process is included in the cost function, for example the likelihood for a maximum-likelihood for transmission (MLTR) algorithm. A possible embodiment of this more accurate model takes into account that the x-ray tube 100 is moving during the x-ray exposure. The convergence speed of the algorithm used for reconstruction is accelerated by applying a grouped coordinate ascent (GCA) algorithm. The groups in the grouped coordinate ascent algorithm are defined by the patches P in which the volume to be reconstructed has been split. These patches (or groups of Voxels) are updated sequentially (instead of simultaneously as known from state of the art algorithms).
[0082] FIG. 2 shows a microprocessor implementation of the reconstruction algorithm by means of a system S in a schematic overview. The image acquisition system is depicted in inner rectangle shown the upper right-hand side of FIG. 2 , comprising x-ray tube 100 and x-ray-detector 101 . The acquisition system is in data exchange with the computer 200 , used for image reconstruction. The computek 200 communicates with the monitor 900 , in order to display the reconstructed 3-dimensional image. The computer 200 may also communicate with a printer 910 , a further workstation 920 and a separate memory unit 220 . The image acquisition system is in data exchange with a controller 800 or a controlling unit 800 . The controller 800 itself comprises a source/tube controller 801 , a detector controller 802 and an acquisition controller 803 .
[0083] For a person skilled in the art the image acquisition system may comprise further models or elements, like a collimator, which may configure or define the size and shape of the x-ray beam that emerges from the x-ray tube 100 .
[0084] The models or instances of the reconstruction system S, mentioned above with respect to the description of the embodiment, depicted in FIG. 2 may communicate over a protocol or a bus system of a signal processing circuitry, which typically is based on a general purpose or an application specific digital computer. The computer may execute routines and instructions, mentioned with respect of the reconstruction process of present invention. The source controller 801 may be adapted to position the x-ray source 100 relative to a patient or a patient's body part and/or relative to the detector 101 . The detector controller 802 is adapted to control the detection process of the signals received by the detector unit 101 . The detector controller 802 may execute various signal processing and filtration functions, for example initial adjustments of dynamic ranges of detection parameters or for interleaving of digital image data etc.
[0085] Typically, the controller 800 is coupled to the computer 200 (not shown in FIG. 2 ). The acquisition controller 803 usually comprises a converter, in order to receive and sample analogue signals, detected from the detector and converse the data to digital signals for subsequent processing by the computer 200 (particularly for the reconstruction process). The data, being collected during x-ray exposure may be transmitted to the computer 200 and forwarded to memory 220 . Alternatively, memory 220 may also be directly implemented on the computer 200 .
[0086] The monitor 900 or display unit 900 is also coupled to the computer 200 and is adapted to display the reconstructed 3-dimensional image and to control the displaying process. In this respect it should be noted that the computer 200 may also be coupled to other devices or processing circuitries.
[0087] With respect to FIG. 4 a more detailed explanation of the reconstruction system S is given, which is implemented on the graphics processing unit GPU.
[0088] The system S comprises:
a receiver 20 , a model generator 21 , a reconstuctor 22 , a storage unit 23 .
[0093] According to a preferred embodiment the graphics processing unit GPU may also consist of a compressor 30 , of a rendering unit 32 and/or of a control unit 33 .
[0094] The receiver 20 of the system S is adapted for receiving digital signals of the tomosynthesis image system, wherein x-ray radiation is sent by an x-ray source 100 to be received at a detector 101 and which is attenuated by structures of the 3-dimensional volume (patient body part). As already mentioned above, the receiver 200 may also comprise a converter and additional components (e.g. filter components).
[0095] The model generator 21 is adapted to provide the modified model for image acquisition, wherein the modified model is based on a physical movement of the x-ray source 100 during x-ray exposure. In contrast to this, state of the art systems are based on the fact that the x-ray tube is stationary during each detector exposure and then moves to the next acquisition angle.
[0096] The reconstructor 22 is adapted to perform the algorithm workflow shown in FIG. 3 and explained below and in the description (summary) of the invention. Particularly, it is adapted for iteratively performing an update step for predetermined number of iterations or until convergence is reached.
[0097] The storage unit 23 is adapted for storing a data set. The data set may represent a patch P to be reconstructed and may additionally be adapted to also store the reconstructed patch after application of the reconstruction algorithms. The reconstructed patch is generated by reconstructor 22 .
[0098] FIG. 3 shows a typical workflow for image reconstruction according to a preferred embodiment of the present invention is shown and explained in more detail below.
[0099] Step A: Input of acquired data and all acquisition parameters (compressed breast thickness, tube current, exposure time, or other parameters)
[0100] Step B: Initialization of the reconstruction volume. For example: volume with homogeneous attenuation, backprojection of the acquired data, a scaled filtered backprojection of the acquired date or another initialization.
[0101] Step C: Start the algorithm with iteration 1 .
[0102] Step D: Loop of the iterations, stop when a stop condition has been met, for example after a fixed number of iterations is reached or when a certain noise level is reached in the reconstructed volume.
[0103] Step E: Determine the order in which the patches will be updated in this iteration. For example: from top to bottom in the 2 nd iteration, from bottom to top in other iterations.
[0104] Step F: Execute the following steps once for each patch.
[0105] Step G: Calculate the update step for the current patch. The calculation of this update step can depend on, among other factors:
The data acquisition model that is used to create the cost function. The parameters of this model are read in step A. The model and/or parameters can be different for each patch. The algorithm that is used to maximize the cost function. For example: gradient ascent algorithm The selected prior function, prior function parameters and prior function weight β
[0109] Step H: Determine the fraction of the update step that is applied to the patch in this instance refers to the fact that additional weights are applied in the first few iterations to properly distribute low frequency information in the direction perpendicular to the detector surface. For example weight 1/(P+1−p) in iterations 1 and 2.
[0110] Step I: Update the current patch in the reconstruction volume
[0111] Step J: Go to the next patch in the order that was determined in step E.
[0112] Step K: Calculate the stopping criterion of the algorithm, for example the current iteration number, or the current noise level in the reconstruction so that it can be tested in step D
[0113] Step L: End of the algorithm. The current volume is considered the result of the reconstruction algorithm.
[0114] Generally, the system S is adapted to execute the patchwork reconstruction algorithm as described above. The patchwork reconstruction is based on patches/groups/planes, wherein each patch is parallel to the detector surface. The patchwork reconstruction algorithm is iterative. Generally, the scope of the invention is not limited by a specific ordering (including an ordering of the method steps).
[0115] Generally, the reconstruction suggested in this application is characterized by an adapted optimization strategy (in sequential updating) and by a more precise acquisition model that is included in the cost function. The optimization algorithm might be a gradient ascent algorithm, ML convex algorithm or MLTR algorithm.
[0116] While the techniques for reconstruction have been discussed in the context of mammography, other fields of medical imaging may also be relevant, like bone or heart examinations. Indeed, the described reconstruction process may be applicable in any situation where the goal is to reconstruct 3-dimensional image information from projection data.
[0117] The invention may be susceptible to various modifications and alternative embodiments. Specific embodiments have been shown by way of example in the above detailed description of the drawings. However, it should be understood that the invention is not intended to be limited to these particular forms disclosed herein. Rather, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
[0118] The following is a list of reference numerals and symbols used in the specification above:
100 x-ray source 101 detector 200 computer 220 memory 800 controller 801 source controller 802 detector controller 803 acquisition controller 900 monitor 910 printer 920 workstation S reconstructor 20 receiver 21 model generator 22 reconstructor 23 storage unit 30 co-processor 32 rendering unit 33 control unit GPU graphics processing unit P patch A data acquisition B initial guess for reconstruction volume C set iteration nr=1 D last iteration finished? E Determine the order in which the patches will be updated in this iteration (set patch nr=1 if it=/=2, if it=2, set patch nr to last patch F all patches finished? G calculate update for current patch H weight for update step if iteration nr<x. I update current guess for reconstruction volume J Go to the next patch in the order that was determined in step E (patch nr+=1 for it=/=2, patch nr−=1 for it=2) K create stop criterion iteration nr+=1 L current reconstruction volume is the result | A method for digitally reconstructing a 3-dimensional tomosynthesis image by iterative reconstruction, a reconstructor, and a computer program product method are capable of plane-by-plane iterative reconstruction for digital breast tomosynthesis. The reconstruction process is based on a grouped coordinate ascent algorithm where the volume is split into a plurality of patches, wherein all patches are parallel to a surface of a detector. Splitting the volume allows implementing a modified model for image acquisition where the physical movement of the x-ray source is taken into account because each of the patches is updated separately and sequentially. In addition the splitting allows an efficient implementation on a graphical processing unit by reducing memory requirements. | 6 |
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