Pesticidal compositions for the control of mites in stored food products containing one or more plant essential oils. In addition, the present invention is directed to a method for controlling mites from accessing stored food products by applying a pesticidally-effective amount of the above pesticidal compositions to a locus where pest control is desired.

The present invention relates, in general, to pesticidal compositions containing plant essential oils and/or derivatives thereof against mites. In one aspect, the present invention relates to pesticidal compositions containing one or more plant essential oils and/or derivatives thereof to be used as a contact pesticide in containers or cartons where food products are stored. In another aspect, the present invention relates to pesticidal compositions containing one or more plant essential oils and/or derivatives thereof to be used as a fumigant pesticide in containers or cartons where food products are stored. In a further aspect, the present invention relates to a method for controlling stored product pests by the application of pesticidally effective amounts of the pesticidal compositions to the container or carton in which food products are stored.
Pests (invertebrates, insects, arachnids, larvae thereof, etc.) are annoying to humans for a myriad of reasons. They have annually cost humans billions of dollars in crop losses and in the expense of keeping them under control. For example, the losses caused by pests in agricultural environments include decreased crop yield, reduced crop quality, and increased harvesting costs.
Over the years, synthetic chemical pesticides have provided an effective means of pest control. For example, one approach teaches the use of complex, organic insecticides, such as disclosed in U.S. Pat. Nos. 4,376,784 and 4,308,279. Other approaches employ absorbent organic polymers for widespread dehydration of the insects. See, U.S. Pat. Nos. 4,985,251; 4,983,390; 4,818,534; and 4,983,389. Use of inorganic salts as components of pesticides has also been tried, as disclosed in U.S. Pat. Nos. 2,423,284 and 4,948,013, European Patent Application No. 462 347, Chemical Abstracts 119(5):43357q (1993) and Farm Chemicals Handbook, page c102 (1987).
However, it has become increasingly apparent that the widespread use of synthetic chemical pesticides has caused detrimental environmental effects that are harmful to humans and other animals. For instance, the public has become concerned about the amount of residual chemicals that persist in food, ground water and the environment, and that are toxic, carcinogenic or otherwise incompatible to humans, domestic animals and/or fish. Moreover, some target pests have even shown an ability to develop immunity to many commonly used synthetic chemical pesticides. In recent times, regulatory guidelines have encouraged a search for potentially less dangerous pesticidal compositions via stringent restrictions on the use of certain synthetic pesticides. As a result, elimination of effective pesticides from the market has limited economical and effective options for controlling pests. As an alternative, botanical pesticides are of great interest because they are natural pesticides, i.e., toxicants derived from plants that are safe to humans and the environment.
With respect to protecting stored food products from insects, this safety issue is even more important. Some of the major stored food products affected by mites include, but are not limited to, flour, grain, wheat, barley, corn, pasta, cereal, pet food, and others. Since the pesticides will come in contact with the stored food products to some extent, it is essential that the pesticides be safe for mammals and do not persist for very long, but rather break down very easily. Stored food products have long been suspect to mites, including mold mites, cheese mites, grain mites, and clover mites, which contaminate foodstuffs, sometimes making it unfit for consumption, causing certain reactions in mammals that may result in terrible discomfort, and in general can prove to be a terrible nuisance.
Mites can access stored food products in one of two ways. First, the mites may be in the food which is processed and packaged, then lay eggs and create problems as discussed above. Secondly, the mites may penetrate the package after the stored food products have been processed, by literally eating their way into the containers or cartons.
Accordingly, there is a great need for novel pesticidal compositions, containing no pyrethrum, synthetic pyrethroids, chlorinated hydrocarbons, organo phosphates, carbamates and the like, to be used inside the containers or cartons for stored food products as both a contact and fumigant pesticide against mites. In addition, there is a need for a method of treating the containers or cartons to kill and repel mites, thereby preserving the stored food products inside.
A primary object of the present invention is to provide novel pesticidal compositions for containers or cartons in which food products are stored.
Another object of the invention is to provide novel pesticidal compositions containing one or more plant essential oils and/or derivatives thereof, natural or synthetic, as a contact pesticide in containers or cartons against mites.
A further object of the present invention is to provide novel pesticidal compositions that contain one or more plant essential oils and/or derivatives thereof, natural or synthetic, as a fumigant pesticide in containers or cartons against mites.
It is also an object of the present invention to provide a method of treating the containers or cartons of stored food products to kill and repel mites.
It is also an object of the present invention to provide a pesticidal composition and method for mechanically, physiologically and/or neurally controlling mites.
It is a further object to provide a safe, non-toxic pesticidal composition and method that will not harm mammals or the environment.
It is still another object to provide a pesticidal composition and method that has a pleasant scent or is unscented, and that can be applied without burdensome safety precautions.
It is still another object to provide a pesticidal composition and method as described above which can be inexpensively produced or employed.
It is yet another object of the invention to provide a pesticidal composition and method to which pests cannot build immunity and/or resistance.
The above and other objects are accomplished by the present invention which is directed to pesticidal compositions comprising plant essential oils and/or derivatives thereof, natural or synthetic, in admixture with suitable carriers. In addition, the present invention is directed to a method for controlling mites by applying a pesticidally-effective amount of the above pesticidal compositions to the container or carton in which food products are stored.
Additional objects and attendant advantages of the present invention will be set forth, in part, in the description that follows, or may be learned from practicing or using the present invention. The objects and advantages may be realized and attained by means of the instrumentalities and combinations particularly recited in the appended claims. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not to be viewed as being restrictive of the invention, as claimed.
All patents, patent applications and literatures cited in this description are incorporated herein by reference in their entirety. In the case of inconsistencies, the present disclosure, including definitions, will prevail.
In one embodiment, the present invention provides a pesticidal composition comprising, in admixture with a suitable carrier and optionally with a suitable surface active agent, comprising one or more plant essential oil compounds and derivatives thereof, natural or syntetic, including racemic mixtures, enantiomers, diastereomers, hydrates, salts, solvates and metabolites, etc.
Each plant essential oil or derivative thereof, comprises a monocyclic, carbocyclic ring structure having six-members and substituted by at least one oxygenated or hydroxyl functional moiety. Examples of plant essential oils encompassed within the present invention, include, but are not limited to, members selected from the group consisting of aldehyde C16 (pure), xcex1-terpineol, amyl cinnamic aldehyde, amyl salicylate, anisic aldehyde, benzyl alcohol, benzyl acetate, cinnamaldehyde, cinnamic alcohol, carvacrol, carveol, citral, citronellal, citronellol, p-cymene, diethyl phthalate, dimethyl salicylate, dipropylene glycol, eucalyptol (cineole), eugenol, iso-eugenol, galaxolide, geraniol, guaiacol, ionone, menthol, methyl anthranilate, methyl ionone, methyl salicylate, xcex1-phellandrene, pennyroyal oil, perillaldehyde, 1- or 2-phenyl ethyl alcohol, 1- or 2-phenyl ethyl propionate, piperonal, piperonyl acetate, piperonyl alcohol, D-pulegone, terpinen-4-ol, terpinyl acetate, 4-tert butylcyclohexyl acetate, thyme oil, thymol, metabolites of trans-anethole, vanillin, ethyl vanillin, and the like. As these plant essential oil compounds are known and used for other uses, they may be prepared by a skilled artisan by employing known methods.
For example, in a preferred embodiment, the present invention is directed to a pesticidal composition for controlling mites comprising a plant essential oil selected from the group consisting of 2-phenyl ethyl alcohol, 2-phenyl ethyl propionate, benzyl alcohol, and trans-anethole, or a combination of same, with a suitable release agent. Data below shows that this embodiment is highly effective, i.e. exhibited good control against mold mites in food cartons.
It will be appreciated by the skilled artisan that the pesticidal compositions of the present invention unexpectedly exhibit excellent pesticidal activities using one or more U.S. F.D.A. approved plant essential oils, in lieu of conventional pesticides which are not safe for use in food containers or cartons. Without wishing to be bound by the following theories, it is believed that plant essential oils antagonize a pest""s nerve receptors or may act as Phase I and/or Phase II drug metabolizing enzyme inhibitors. Alternatively, plant essential oils may act via an alternative mode of action. The plant essential oils may act as agonists or antagonists against the octopamine receptors that are distinct to invertebrates. In any event, the net effect of the toxicity and action of the inventive composition disclosed herein is heretofore unknown and unexpected.
Use of pesticidal compositions of the present invention generally results in 100% mortality on contact, and provides equivalent fumigant action for extended periods of time. As such, they are advantageously employed as pesticidal agents in uses such as, without limitation, containers and cartons for stored food products such as flour, grain, wheat, barley, corn, pasta, cereal, pet food, and others.
The pesticidal compositions herein are so chemically inert that they are compatible with substantially any other constituents of stored food products, and they may be used safely in the either the preparation of food products, or the application to the container or carton after processing and/or packaging of the food products.
The term xe2x80x9ccarrierxe2x80x9d as used herein means an inert or fluid material, which may be inorganic or organic and of synthetic or natural origin, with which the active compound is mixed or formulated to facilitate its application to the container or carton or other object to be treated, or its storage, transport and/or handling. In general, any of the materials customarily employed in formulating pesticides, herbicides, or fungicides, are suitable. The inventive pesticidal compositions of the present invention may be employed alone or in the form of mixtures with such solid and/or liquid dispersible carrier vehicles and/or other known compatible active agents such as other pesticides, or acaricides, nematicides, fungicides, bactericides, rodenticides, herbicides, fertilizers, growth-regulating agents, etc., if desired, or in the form of particular dosage preparations for specific application made therefrom, such as solutions, emulsions, suspensions, powders, pastes, and granules which are thus ready for use. The pesticidal compositions of the present invention can be formulated or mixed with, if desired, conventional inert pesticide diluents or extenders of the type usable in conventional pesticide formulations or compositions, e.g. conventional pesticide dispersible carrier vehicles such as gases, solutions, emulsions, suspensions, emulsifiable concentrates, spray powders, pastes, soluble powders, dusting agents, granules, foams, pastes, tablets, aerosols, natural and synthetic materials impregnated with active compounds, microcapsules, coating compositions for use on seeds, and formulations used with burning equipment, such as fumigating cartridges, fumigating cans and fumigating coils, as well as ULV cold mist and warm mist formulations, etc.
Formulations containing the pesticidal compositions of the present invention may be prepared in any known manner, for instance by extending the pesticidal compositions with conventional pesticide dispersible liquid diluent carriers and/or dispersible solid carriers optionally with the use of carrier vehicle assistants, e.g. conventional pesticide surface-active agents, including emulsifying agents and/or dispersing agents, whereby, for example, in the case where water is used as diluent, organic solvents may be added as auxiliary solvents. Suitable liquid diluents or carriers include water, petroleum distillates, or other liquid carriers with or without surface active agents. The choice of dispersing and emulsifying agents and the amount employed is dictated by the nature of the composition and the ability of the agent to facilitate the dispersion of the pesticidal compositions of the present invention. Non-ionic, anionic, amphoteric, or cationic dispersing and emulsifying agents may be employed, for example, the condensation products of alkylene oxides with phenol and organic acids, alkyl aryl sulfonates, complex ether alcohols, quaternary ammonium compounds, and the like.
Liquid concentrates may be prepared by dissolving a composition of the present invention with a solvent and dispersing the pesticidal compositions of the present inventions in water with the acid of suitable surface active emulsifying and dispersing agents. Examples of conventional carrier vehicles for this purpose include, but are not limited to, aerosol propellants which are gaseous at normal temperatures and pressures, such as Freon; inert dispersible liquid diluent carriers, including inert organic solvents, such as aromatic hydrocarbons (e.g. benzene, toluene, xylene, alkyl naphthalenes, etc.), halogenated especially chlorinated, aromatic hydrocarbons (e.g. chloro-benzenes, etc.), cycloalkanes, (e.g. cyclohexane, etc.). paraffins (e.g. petroleum or mineral oil fractions), chlorinated aliphatic hydrocarbons (e.g. methylene chloride, chloroethylenes, etc.), alcohols (e.g. methanol, ethanol, propanol, butanol, glycol, etc.) as well as ethers and esters thereof (e.g. glycol monomethyl ether, etc.), amines (e.g. ethanolamine, etc.), amides (e.g. dimethyl formamide etc.) sulfoxides (e.g. dimethyl sulfoxide, etc.), acetonitrile, ketones (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), and/or water; as well as inert dispersible finely divided solid carriers such as ground natural minerals (e.g. kaolins, clays, vermiculite, alumina, silica, chalk, i.e. calcium carbonate, talc, attapulgite, montmorillonite, kieselguhr, etc.) and ground synthetic minerals (e.g. highly dispersed silicic acid, silicates, e.g. alkali silicates, etc.).
Surface-active agents, i.e., conventional carrier vehicle assistants, that may be employed with the present invention include, without limitation, emulsifying agents, such as non-ionic and/or anionic emulsifying agents (e.g. polyethylene oxide esters of fatty acids, polyethylene oxide ethers of fatty alcohols, alkyl sulfates, alkyl sulfonates, aryl sulfonates, albumin hydrolyzates, etc. and especially alkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc.); and/or dispersing agents such as lignin, sulfite waste liquors, methyl cellulose, etc.
In the preparation of wettable powders, dust or granulated formulations, the active ingredient is dispersed in and on an appropriately divided carrier. In the formulation of the wettable powders the aforementioned dispersing agents as well as lignosulfonates can be included. Dusts are admixtures of the compositions with finely divided solids such as talc, attapulgite clay, kieselguhr, pyrophyllite, chalk, diatomaceous earth, vermiculite, calcium phosphates, calcium and magnesium carbonates, sulfur, flours, and other organic and inorganic solids which acts carriers for the pesticide. These finely divided solids preferably have an average particle size of less than about 50 microns. A typical dust formulation useful for controlling insects contains 1 part of pesticidal composition and 99 parts of diatomaceous earth or vermiculite. Granules may comprise porous or nonporous particles. The granule particles are relatively large, a diameter of about 400-2500 microns typically. The particles are either impregnated or coated with the inventive pesticidal compositions from solution. Granules generally contain 0.05-15%, preferably 0.5-5%, active ingredient as the pesticidally-effective amount. Thus, the contemplated are formulations with solid carriers or diluents such as bentonite, fullers earth, ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, vermiculite, and ground synthetic minerals, such as highly-dispersed silicic acid, alumina and silicates, crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, as well as synthetic granules of inorganic and organic meals, and granules of organic materials such as sawdust, coconut shells, corn cobs and tobacco stalks. Adhesives, such as carboxymethyl cellulose, natural and synthetic polymers, (such as gum arabic, polyvinyl alcohol and polyvinyl acetate), and the like, may also be used in the formulations in the form of powders, granules or emulsifiable concentrations.
If desired, colorants such as inorganic pigments, for example, iron oxide, titanium oxide and Prussian Blue, and organic dyestuffs, such as alizarin dyestuffs, azo dyestuffs or metal phthalocyanine dyestuffs, and trace elements, such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc may be used.
In commercial applications, the present invention encompasses carrier composition mixtures in which the pesticidal compositions are present in an amount substantially between about 0.01-95% by weight, and preferably 0.5-90% by weight, of the mixture, whereas carrier composition mixtures suitable for direct application or field application generally contemplate those in which the active compound is present in an amount substantially between about 0.0001-10%, preferably 0.01-1%, by weight of the mixture. Thus, the present invention contemplates over-all formulations that comprise mixtures of a conventional dispersible carrier vehicle such as (1) a dispersible inert finely divided carrier solid, and/or (2) a dispersible carrier liquid such as an inert organic solvent and/or water, preferably including a surface-active effective amount of a carrier vehicle assistant, e.g. a surface-active agent, such as an emulsifying agent and/or a dispersing agent, and an amount of the active compound which is effective for the purpose in question and which is generally between about 0.0001-95%, and preferably 0.01-95%, by weight of the mixture.
The pesticidal compositions can also be used in accordance with so-called ultra-low-volume process, i.e. by applying such compounds or by applying a liquid composition containing the same, via very effective atomizing equipment, in finely divided form, e.g. average particle diameter of from 50-100 microns, or even less, i.e. mist form, for example by airplane crop spraying techniques. In this process it is possible to use highly concentrated liquid compositions with said liquid carrier vehicles containing from about 20 to 95% by weight of the pesticidal compositions or even the 100% active substances alone, e.g. about 20-100% by weight of the pesticidal compositions. The concentration in the liquid concentrate will usually vary from about 10 to 95 percent by weight and in the solid formulations from about 0.5 to 90 percent by weight.
Furthermore, the present invention encompasses methods for killing, combating or controlling pests, which comprises applying to at least one of correspondingly (a) such pests and (b) the corresponding habitat thereof, i.e. the locus to be protected, e.g. to a container or carton for stored food products, a correspondingly combative, a pesticidally effective amount, or toxic amount of the particular pesticidal compositions of the invention alone or together with a carrier as noted above. The instant formulations or compositions may be applied in any suitable usual manner, for instance by spraying, atomizing, vaporizing, scattering, dusting, watering, squirting, sprinkling, pouring, fumigating, and the like. The method for controlling mites comprises applying the inventive composition, ordinarily in a formulation of one of the aforementioned types, to a locus or area to be protected from the insects, such as the food containers or cartons. The compound, of course, is applied in an amount sufficient to effect the desired action. This dosage is dependent upon many factors, including the targeted pest, the carrier employed, the method and conditions of the application, whether the formulation is present at the locus in the form of an aerosol, or as a film, or as discrete particles, the thickness of film or size of particles, and the like. Proper consideration and resolution of these factors to provide the necessary dosage of the active compound at the locus to be protected are within the skill of those versed in the art. In general, however, the effective dosage of the compound of this invention at the locus to be protectedxe2x80x94i.e., the dosage with which the pest comes in contactxe2x80x94is of the order of 0.001 to 5.0% based on the total weight of the formulation, though under some circumstances the effective concentration will be as little as 0.0001% or as much as 20%, on the same basis.
The pesticidal compositions and methods of the present invention are effective against a wide variety of mites and it will be understood that the mites exemplified and evaluated in the working Examples herein is representative of such a wider variety. For instance, the present invention can be used to control mites that attack plants or warm-blooded animals, stored products and fabrics. Representative stored products that can be protected from pest attack by the present invention include, without limitation, grains, flour and flour products, tobacco and tobacco products, processed foods, cereals and the like. Representative fabrics that can be protected from pest attack by the invention are wool, cotton, silk, linen and the like.
The composition and method of the present invention will be further illustrated in the following, non-limiting Examples. The Examples are illustrative of various embodiments only and do not limit the claimed invention regarding the materials, conditions, weight ratios, process parameters and the like recited herein.

Pesticidal compositions containing plant essential oils against mites


The present invention relates to a filter device, especially for a fluidized bed system and particularly for use in the pharmaceutical industry, for separating particles larger than a separating grain from an amount of particles in a fluid flow. The filter device includes a housing and at least one filter portion. A part of the housing is mounted for rotational movement, and the filter portion is provided in the housing, whereby the filter portion is movable upon rotation of the housing. The present invention also relates to a method for separating particles using such a filter device.

The present invention relates to a filter device especially for a fluidised bed system, particularly for use in pharmaceutical industry, for separating particles being larger than a separating grain from an amount of particles in a fluid flow. The filter device comprises a housing and at least one filter portion. The invention also relates to a method for separating particles using such a device.
In the area of particle formation, coating and granulation it is well known to use different techniques involving a fluidised bed apparatus. Basically, fluidisation is the operation by which solids are transformed into a fluid like state through suspension in a gas or liquid. If a fluid is passed upward through a bed of fine particles at a certain velocity, the frictional force between particles and fluid will just counterbalance the weight of the particles. In this state, the vertical component of the compressive force between adjacent particles disappears, and the pressure drop through any section of the bed about equals the weight of fluid and particles in that section. At this fluid velocity, the bed is just fluidised. Higher fluid velocities might lead to states where the fluid for example forms bubbles or gives rise to a turbulent motion in the solids. At even higher velocities, the fluid will entrain solids out of the bed and bring them along in its upward motion. The term fluidised bed is used when referring to different kinds of such beds.
When the fluid in a fluidised bed entrains large amounts of solid particles, a steady state can be achieved by collecting the entrained particles and returning them to the bed. Up to a certain amount of entrainment, a cyclone that is provided inside the vessel carrying the fluidised bed can provide the necessary collection and re-entry of particles for retaining steady state conditions in the vessel. Such a system is often referred to as a fluid bed. When bigger cyclone collectors must be provided outside the bed, such a system is often called a fast fluidised bed. Both these systems are circulating fluidised beds, and they are thus useful in different processes for particle treatment, as the particles will circulate several times in the system.
Within the pharmaceutical industry, fluidised beds are often used for granulation or coating of a product. Granulation is typically performed by spraying droplets of a liquid on particles, which are kept in the fluidised state. The particles will then tend to stick together, agglomerate, either by means of a binding agent in said liquid, or by a slightly dissolving effect from said liquid. Coating is usually performed by spraying a solution of coating agents onto the particles. In both granulation and coating processes it is important that conditions, such as the temperature, are such that the agglomerates or coatings will dry quickly enough so that unwanted agglomeration will not appear. On the other hand if drying of the agglomerates or coatings happens too quickly, unwanted spray drying of the material might appear.
An application of a circulating fluidised bed is described in the document U.S. Pat. No. 4,051,603, Kern, Jr. The fluidised bed apparatus revealed comprises a container wherein a fluidised bed is arranged. The particles are disposed above a perforated plate through which the fluid, in this case hot air, is allowed to pass. The entrained particles in the resulting fluidised bed are subjected to coating by means of a nozzle extending into the container and from which coating material is sprayed. The entrained particles and the fluid are sucked into a cyclone separator. The cyclone separator is provided in connection to the container and arranged to re-enter the entrained particles to the fluidised bed, and to lead off the remaining fluid. The particles will thus circulate from the bed to the separator and back. Each time a particle passes the nozzle, it will be sprayed with coating material and thus grow in size and weight. At a certain weight, the particle will be too heavy to be entrained with the fluid. Instead, it will fall down through the fluidised bed and be collected there. The process could of course be interrupted prior to that any particles reach such a size, and the particles collected directly from the bed. This kind of apparatus may be used for granulation instead of coating of particles. A granulation liquid will then be sprayed from a nozzle instead of a coating material.
The function of a cyclone separator is based on the action of centrifugal forces. These forces are produced by accelerating the fluid with the entrained particles onto a circular track provided around a vertical cyclone axis. The centrifugal force acting on each particle will increase with increasing particle size, so that larger particles will be flung against the wall of the separator and slide downwards to an outlet, which in this case would open towards the fluidised bed. Smaller particles will follow the fluid flow all through the separator and usually leave the cyclone through an opening in the separator ceiling. The specific grain size at which the particles start to separate from the fluid is often called the separating grain. The dimensions of the cyclone as well as what kind of fluid or particles used will be some of the parameters affecting the size of the separating grain.
Cyclone separators are widely used, although showing several disadvantages. Unevenly distributed coating on the particles may appear because of the swirls that will occur in the gas flow when passing the cyclone. Furthermore, the efficiency of a cyclone separator is low when separating very small particles, such as dust of spray-dried material from the coated/granulated-particles. The dimensions of a specific cyclone offer only one separating grain, resulting in a narrow fraction of separated particles. Recycling must always be provided.
To avoid the problems related to the cyclone separators commonly used, several other devices have been proposed. In the document EP-B1-0 572 356 a fluidised bed apparatus is described provided with at least one vertical cartridge filter projecting into the fluidised bed container. The filter has a fabric filtration member, i.e. comprising a textile fabric. When such a filter has collected a certain amount of small particles, it must be cleaned unless the fluid flow through the filter will be severely restricted. In this case the filter is washed with a liquid cleaning agent. The filter is pushed upwards and out of the container in order to be washed. This is time-consuming and interrupts the operation of the fluid bed apparatus. In other documents, for example U.S. Pat. No. 5,766,281, Luy et al. and US-RE32 307, Glatt et al, different cleaning procedures are proposed, such as gas cleaning combined with wet cleaning or vibration cleaning of the filters. Filtration members made by paper or textile fabric have an additional disadvantage in that they have low strength and therefore they might be damaged when cleaned or blown out.
Particles clogging in the filter structure are a problem, which gives rise to the need of cleaning the filters. This is especially pronounced when dealing with small solid particles, such as unwanted dust of excess spray-dried material. Even if cleaning sometimes can be made during operation of the process, the fluid flows will be disturbed, and the overall efficiency will be decreased.
Other known techniques for particle separation are deflectors or fixed nets. For a fixed net, the separating grain is always decided by the mesh size, and problems with particles clogging the net do usually appear. The use of deflectors in for example a fluid passage can not be used for separating very small particles, since these will continue the travel in the passage along with the fluid. An additional end filter is therefore required for filtering off small particles.
The aim of the present invention is to provide a filter device for a fluidised bed system, especially but not exclusively for use in pharmaceutical industry, which do not have the above mentioned disadvantages. It is also an aim to provide a filter device with a separating grain that can easily be varied.
This aim is reached by a filter device, especially for a fluidised bed system and particularly for use in pharmaceutical industry, for separating particles being larger than a separating grain from an amount of particles in a fluid flow, said filter device comprising a housing and at least one filter portion, characterised in that a part of said housing is mounted for rotational movement, and that said filter portion is provided in said housing, whereby the filter portion is movable upon rotation of said housing. The fluidised bed system comprises a fluidised bed vessel for carrying out a coating, granulation or drying process, and conduits leading to and from the fluidised bed vessel containing fluid and particles to be separated.
The term xe2x80x9cseparating grainxe2x80x9d does herein refer to the size of the smallest particle that does not pass the filter device, and could be regarded as a measure of the limit of separation for said filter device. The separating grain will be determined by the mesh size of the filter portion and by the velocity of the filter portion. By varying the speed of rotation of the filter portion, the separating grain can thus be varied using only one separating system, which eliminates the need of different filters for separating particles of different sizes. Normally, the separating grain can have a range of 10-500 microns.
Typically, the separating grain will be 50 microns, i.e. particles smaller than 50 microns will pass through the filter device and thus, all particles larger than 50 microns will stay in the fluidised bed system.
The filter is kept clean and free from clogging of particles, because of the rotational motion creating centrifugal forces on the particles. Thus, no interruptions of the process for maintenance and cleaning of the filter are necessary. With the device according to the invention, satisfactory results have been achieved even when separating small particles, usually smaller than 50 microns, such as dust consisting of spray-dried material in a fluidised bed coating process.
The housing could for example be formed like a drum, which is mounted to be rotationally movable. The filter portion is then advantageously disposed at the circumference of said drum. The drum shape has the advantage that the filter device can easily be maintained at a constant rotational speed. The centrifugal forces created also contribute to keep the filter portion clean from particles. Besides, a large active area covered with the filter portion can be used.
Preferably, the filter portion comprises several filter members arranged in such a way that interstices are formed between said filter members. The filter portion is movable upon rotation of the housing in a direction intersecting at least a plurality of said filter members. The separating grain will be determined by the size of the interstices between the filter members and by the velocity of the filter portion in the rotational direction.
The probability of a particle to be stopped by the filter portion increases as the rotational velocity of the housing increases. This is due to the fact that the direction of rotation intersects at least some of the filter members of the filter portion. Further, due to the probability of a particle to be stopped by a filter member, particles that are actually smaller than the interstices could also be hindered by the filter system if an appropriate rotational velocity is chosen.
The filter portion is preferably provided inside a vessel, i.e. a fluidised bed vessel that initially contains the fluid and the particles to be separated. The housing holding the filter portion is preferably extending through the vessel, whereby a first part comprising the filter portion is mounted inside the vessel and a second part, mounted outside of the vessel is provided with at least one fluid outlet. The fluid enters through the filter portion, passes through the housing and out via the fluid outlet. Particles smaller than the separating grain will follow the fluid all the way through the housing and out via the fluid outlet. Larger particles will stay in the vessel, where they will continuously be subjected to continued coating or granulation processes. The rotating filter portion will fling the larger particles from the filter and spread them in the vessel.
The filter portion may also be provided in conduits leading to or from the vessel. By providing such conduits with the filter device clogging of the conduits can be prevented.
Advantageously, the housing carrying the filter portion is detachably arranged in a filter holder means. Such holder means can be disposed in the wall of a reaction vessel, through which the fluid with entrained particles is allowed to pass, or for example in a conduit forming a passage for said fluid. The fluid could be for example a liquid, a gas or a super-critical fluid.
Advantageously, the housing also comprises first and second body parts that are detachably interconnected. By separating the first and second body part, easy cleaning between batches or sterilising of the filter device is possible if necessary.
Preferably the filter device is provided with connector means for connection to a motor unit. Advantageously, the speed of the motor unit is variable for variation of the rotational velocity of the filter portion during operation of the filter device for obtaining the desired separating grain.
Preferably an open space is defined between the housing and the filter holder means, through which open space fluid pressure is provided, constituting a fluid seal between the housing and the filter holder means. The fluid pressure will keep the open space free from particles, and thus ensure a smooth movement of the filter device.
The invention also comprises a method for separating particles, especially for a fluidised bed system and particularly for use in pharmaceutical industry.


A test device is described for testing an electromagnetic quantity, such as a voltage or a magnetic field. The test device includes a housing, a sensor arranged in the housing and sensing the electromagnetic quantity, a processing circuit for processing to signals received from the sensor, display elements for displaying the signals processed by the processing unit, a galvanic element for supplying power to the test device, an illuminator for illuminating an area to be tested, and a switch for activating the illuminator. The test device has a small footprint and does not require an external light source even under difficult lighting conditions.

1. Field of the Invention
This application relates to the field of electric test devices and more particularly to the field of electric test devices having an illumination unit.
2. Description of Related Art
Test devices for measuring electrical voltages are known in the art. Such devices are frequently pen-shaped, with an electrical circuit arranged inside a handle portion which can be held by an operator. A pin which is connected to the electrical circuit, extends away from the front end of the handle portion and can be brought into electrical contact with a wire to be tested. Examples of such voltage testers are described, for example, in the U.S. Pat. Nos. 5,293,113 and 5,448,162 commonly assigned to the Applicant.
Test devices are frequently used under poor viewing conditions, in particular when the wires to be tested are difficult to access. In particular under unfavorable lighting conditions, the operator may have difficulty finding the correct wire. To illuminate the area of interest, the operator may have to use a separate flashlight or a lamp connected with an extension cord which may be difficult to implement.
It is therefore desirable to provide a test device for electrical voltages which takes up little space and which does not require an external light source even under difficult lighting conditions.
According to an aspect of the invention, a test device for electrical voltages is integrated with an illumination device in a common housing which can be used both as a voltage sensor and as a flashlight. The test device further includes a processing circuit for processing the measured voltage signals, display elements for displaying these signals, and a galvanic element for supplying power to the device. With these features, the test device is simple, has a small footprint and can be easily carried. Moreover, the test device is adapted for testing electrical voltages under difficult lighting conditions and can also be used as a stand-alone flashlight.
The housing is preferably elongated and shaped like a pen. The housing may also be provided with a clip so that the test device can be easily carried, much like a writing utensil. With the elongated pen-shaped arrangement, the voltage sensor can be advantageously arranged in one end of the housing, while an illumination device is arranged in the other end of the housing, so that the sensor and the illumination device can be used independently. The elongated housing may also be adapted to receive cylindrical galvanic elements, for example, a primary galvanic cell or a rechargeable battery.
The processing circuit may be arranged on a narrow elongated printed circuit board to be received in the elongated pen-shaped housing. The elongated printed circuit board is preferably oriented parallel to the galvanic element(s) and may be inserted into a guide rail or channel provided in the housing.
The voltage sensor may be implemented as an electrically conducting pin or strip operating as an antenna, wherein the pin or strip terminates in a extended tip of the housing. With this arrangement, a voltage can be measured contactless with high sensitivity.
According to another advantageous embodiment, a magnetic sensor can be integrated into the housing. The magnetic sensor is preferably a Reed contact. A test device equipped with such a magnetic sensor can readily detect magnetic fields, thereby obviating the need for a separate test device.
The housing may be provided with a removable end cap to facilitate replacement of the galvanic element(s) and/or device maintenance and repair. The end cap may include a lamp of the illumination device. A plug connection between the end cap and the housing is provided with electrical contacts, thereby providing a reliable mechanical seat of the end cap on the housing as well as an electrically conducting connection between the lamp and a corresponding switch located in the housing of the test device.
The switch for switching the lamp power on and off can be implemented in several ways. For example, the switch may be a slide switch. The switch may also be a rotary switch and advantageously actuated by rotating the end cap relative to the housing. For example, the end cap may be rotated clockwise to turn the lamp on and rotated counter-clockwise to turn the lamp off, or vice versa. The switch for activating the lamp function may also be a simple push-button switch or toggle switch disposed on the housing.
According to another advantageous embodiment, the switch can be in the form of a clip disposed on the housing. The test device can thereby be attached with the clip to, for example, a shirt pocket and the like. The clip may also operate as a switch.
Display elements for displaying the voltage are preferably light emitting diodes (LEDs), wherein the housing is transparent to light at least in the region of the LED""s. The LED""s and the light-transmissive region of the housing, respectively, can have different colors to make it easier to differentiate between displayed voltages and displayed magnetic fields.
In addition to the visual display, the housing may incorporate an acoustic indicator, for example, a buzzer.
Further features and advantages of the present invention will be apparent from the following description of preferred embodiments and from the claims.

Test device for electrical voltages with integrated illumination unit


A method of establishing a radio link between subscribers of a telecommunications network, in particular in a decentralized mobile radio network with mobile radio sets serving both as terminals and as transmitters, wherein at least one virtual transmitter for switching the radio signals can be defined for each subscriber, and wherein one or more subscribers can assume the work of the virtual transmitter or transmitters, and a telecommunications network, in particular a decentralized mobile radio network with mobile radio sets serving both as terminals and as transmitters, and in particular for carrying out the method, wherein at least one virtual transmitter for switching the radio signals can be defined for each subscriber, and wherein the work of the virtual transmitter or transmitters can be assumed by one or more subscribers.

The invention relates to a method of establishing a radio link between subscribers of a telecommunications network, in particular in a decentralized mobile radio network with mobile radio sets serving both as terminals and as transmitters.
Furthermore, the invention relates to a telecommunications network, in particular a decentralized mobile radio network with mobile radio sets serving both as terminals and as transmitters.
Methods of the kind under discussion are known in connection with radio networks, such as, for example, the mobile radio networks known as C-, D1-, D2, and E-plus networks. Furthermore, telecommunications networks of the kind under discussion are known from practice. For establishing a radio link, the known telecommunications networks comprise stationary radio equipment in the form of stationary transmitters. The establishment of a radio link occurs by means of external switching methods within the scope of an external radio network management. The localization of the network subscribers and the establishment of a link between the network subscribers occurs in these mobile radio networks by means of the central switching equipment.
In the establishment of a radio link, the central transmitters play the fundamental part, since they are in a constant, reciprocal contact with the network subscribers via a division of the radio network into individual network cells. Thus, the respective transmitter always knows the location of the network subscriber by its response to the transmitter and furthermore to the network control center.
When a radio link is established between two network subscribers, the network subscribers are first localized by means of the central switching method. Subsequently, the radio link between the network subscribers is computed or determined, and then offered. In this connection, the preliminary computation or determination of the communication path via possible relay links is named xe2x80x9crouting.xe2x80x9d
The known methods operate between the mobile radio sets and the stationary transmitters of the respective network cells of the known radio networks. In the case of the known radio networks of this kind, it is thus essential that external and centrally controlled methods be applied, which are operated mainly from an external operator stationxe2x80x94for example, a central operating computerxe2x80x94outside of the individual mobile radio sets or radio terminals.
Besides these known methods and telecommunications networks with stationary transmitters, it is also known to use methods and telecommunications networks, which are totally decentralized, and which use mobile radio sets both as terminals and as transmitters. In this instance, stationary transmitters, which are centrally controlled, are omitted. Note, in particular Applicant""s Application No. 195 35 021.9 filed in Germany, which describes a radio network that employs mobile radio sets both as terminals and as transmitters. The described radio network is designed as a neural network, which is totally selfmanaging and selfcontrolling.
Without limitation to this type of network, the present invention is described by way of the aforesaid neural network, wherein the mobile radio sets serve both as terminals and as transmitters. In this system, stationary network cells are no longer formed. While it is thus no cellular system, it comprises identical, dynamic neighborhood areas of each subscriber. The size of such a substantially circular neighborhood area around an observed subscriber is dimensioned by that distance from the observed subscriber, in which the radio communication of the observed subscriber can still be monitored by another, neighboring subscriber. In the case of an unimpeded radio wave propagation, this distance is the radius of the neighborhood area. In the case of radio interferences or radio obstructions, the neighborhood area may also assume a shape that deviates from a circle.
The size of a neighborhood area continues to be dependent on the radio coverage. During a movement of the observed subscriber, the neighborhood area moves along with the subscriber. Therefore, the telecommunications network under discussion, is a real, totally mobile network. Mobile networks can otherwise be realized only by investment-cost-intensive mobile satellite network systems. This radio network is a distribution network without a centralized switching service. Switching is automatically and collectively performed by one or more subscribers after calling a destination subscriber.
An active subscriberxe2x80x94the source subscriberxe2x80x94forms a network relay link with one of its next neighbors, with which it establishes a direct radio contact. Unless they are the called destination subscribers, these neighbors serve as transmitters. Between the source subscriber and the destination subscriber, the radio link may occur via a plurality of transmitters. In this instance, the network link will consist of a plurality of network relay links between the individual transmitters.
To localize and address the subscribers, the subscribers receive a position identification, which can be actualized after certain time intervals. The position identification is known to each subscriber via an address directory, or it is stored in the mobile radio set. This position identification is useful in a destination-directed establishment of a radio link, since it makes it possible to prevent a radio call from propagating like an avalanche for purposes of establishing a radio link. Instead, it can be approximately predetermined in the direction toward the destination receiver. Such a method of establishing a radio link has already been disclosed in Applicant""s German Application 197 26 956.7.
In the stage of development of the above described neural telecommunications network until now in part quasi stationary transmitters are provided, which are formed by a functional part of a mobile radio set. Each user has a mobile radio set, which consists of a terminal element and a spatially separable transmitter element. This transmitter element is stationarily installed at the user as a quasi stationary base transmitter with a fixed position identification. With that, not only all radio links of the user, but also any radio links of other subscribers can occur via the user-associated transmitter element or via transmitter elements of other subscribers.
Besides the position identification, a subscriber also disposes of a subscriber-specific identification. This could be, for example, the name of the user.
In the case of constantly stationary subscribers, it possible to establish a radio link exclusively by way of the position identification. As soon as the subscriber moves with its terminal element, this will no longer be possible at first sight, since the subscriber has left the position known to the other subscribers, and since the other subscribers then do not yet know the new position of the destination subscriber. However, a movement of the destination subscriber within the neighborhood area of the transmitter nearest to it in the radio chain is noncritical, since the destination subscriber can hear the radio call of this nearest transmitter, and identify itself as destination subscriber via the subscriber-specific identification. With that, it is possible to establish the radio link in full.
In such a telecommunications network, an establishment of a radio link or an offered radio link remains likewise unaffected by a movement of the subscriber, as long as the neighborhood areas of the subscribers of a radio link chain or the transmitters overlap in part. In other words, a radio link or an establishment of a radio link remains possible as long as the destination subscriber is located with its terminal element within the neighborhood area of any transmitter of the radio link chain. This can be explained by the fact that during its transmission work, each transmitter also transmits the complete address of the destination subscriberxe2x80x94position identification and subscriber-specific identificationxe2x80x94and the destination subscriber monitors the transmission operations of the transmitters and, if need be, is then able to identify itself as destination subscriber. This spatial region of the composite neighborhood areas of all transmitters, which is noncritical with respect to the establishment of the radio link and the radio link during the movement of a destination subscriber, is named radio hose. In other words, the radio hose is that regional surface, which is covered by the neighborhood area surfaces of the chain subscribers of a radio link.
However, if a destination subscriber moves out of the foregoing neighborhood areas of the intended transmitters, a different localization mechanism with respect to the observed subscriber will be operative, in which it is necessary to newly identify the subscriber in its new position. This new position identification is transmitted, for example, to its stationary base transmitter, which is then in a position to retransmit radio calls made via same to the observed subscriber.
In conclusion, it remains to be stated that the respective base transmitter of a destination subscriber is in essence permanently stationary, and that its position identification is recorded in the subscriber directory or address directory of the telecommunications network. Moving network subscribers can then be addressed via their associated base transmitter. Same retransmits as a transmitter the radio link to the moving terminal of the network subscriber.
However, in the known telecommunications network it is problematic that a quasi stationary structure exists in the form of the base transmitters. Such a structure is normally named xe2x80x9cbackbone.xe2x80x9d Such a stationary structure restricts the flexibility of the telecommunications network and subscribers considerably, since it is always necessary to position a base transmitter and to permanently handle two components of the equipment, namely the terminal element and the transmitter element.
It is therefore the object of the present invention to describe a method of establishing a radio link as well as a telecommunications network of the kind under discussion, which allows to attain a greater flexibility and convenience when in use.
In accordance with the invention, the foregoing object is accomplished by defining for each subscriber at least one virtual transmitter for switching the radio signals, and that one or more subscribers are able to assume the work of each virtual transmitter. Also, for establishing a radio link between a signal transmitter and a signal receiver, a virtual transmitter is assigned to the signal receiver, and the assigned virtual transmitter is allocated the position identification of a previous location of the signal receiver or a position identification that is freely selectable and not taken by another subscriber.
To begin with, it has been recognized according to the invention that it is basically possible to realize a telecommunications network and a method of establishing a radio link within the telecommunications network, wherein solid structures in the meaning of a xe2x80x9cbackbonexe2x80x9d are omitted. To this end, the invention further provides that for each subscriber, at least one virtual transmitter is defined for switching the radio signals. The definition of such a virtual transmitter makes it possible to do without the known, stationary and real base transmitters. Since such a virtual transmitter does not physically exist, the invention further provides that one or more subscribers assume the work of the virtual transmitter or transmitters. The subscribers, which assume the work of the virtual transmitter or transmitters, are preferably stationary at times. A number of stationary subscribers, which is adequate for the operation of the network, always exists in the telecommunications network under discussion from a statistic viewpoint, since it is unlikely that all subscribers of the telecommunications network are constantly in motion.
Consequently, the method of establishing a radio link according to the present invention realizes a method, which allows to attain a greater flexibility and ease when in use, and thus enables a greater portion of movement of the network subscribers.
In a particularly advantageous manner, it would be possible that the subscriber or subscribers, which assume the work of the virtual transmitter or transmitters, realize individually or collectively the virtual transmitter or transmitters by assuming the work. This would make it possible to attain a particularly simple realization of virtual transmitters.
Furthermore, it would be possible to associate to the signal receiver the virtual transmitter for establishing a radio link between a signal transmitter and a signal receiver. This would make it possible to realize quasi a virtual base transmitter for the signal receiver through the virtual transmitter.
To this end, it would be possible to allocate to the virtual transmitter in a particularly direct manner, the position identification of a previous location of the signal receiver. As a result of allocating such a position identification, a definition of the virtual transmitter would then involve that a radio call to the signal receiver is transmitted to its known, previous location. There, it would basically not be possible to reach it, since it has already moved away from this location. When the virtual transmitter is defined, which occurs by a radio call to the desired position of the virtual transmitter being defined, the transmitters in the neighborhood area of the desired position of the virtual transmitter are however informed via a special coding of the radio call that it is only a virtual transmitter at the particular location. Consequently, the neighboring transmitters are able to retransmit the radio call, if need be, by dividing their work, to the destination subscriber, whose new position has been reported during the definition of the virtual transmitter to the transmitters of the neighborhood area of the desired position of the virtual transmitter. As a result, it would be possible to retransmit the radio signals, via the virtual transmitter, to the signal receiver or destination subscriber.
As an alternative to such a retransmission, it would be possible that the virtual transmitter transmits to a previous transmitter and/or to the signal transmitter the new, changed position identification of the signal receiver or destination subscriber. With that, there exist two possibilities of switching the radio signals via the virtual transmitters.
The determination of the position identification may occur in a fast and automatic way in that the moving signal receiver computes in its actual neighborhood area, its new position identification from the monitored position identifications of its neighboring subscribers. More specifically, the observed signal receiver localizes itself in its xe2x80x9cnewxe2x80x9d neighborhood area with the aid of at least temporarily stationary transmitters. This occurs in that as a potential transmitter of other radio links, the observed subscriber monitors the radio communication of its neighborhood area, and receives and stores the position identifications of the neighboring subscribers in its neighborhood area. It may use these data to compute its own actual position. To this end, the usual interpolation methods are available. In the case that the position identification is computed from, for example, absolute, satellite-assisted data, it will be possible to generate even exact, own position identifications.
Besides allocating the position identification of a previous location of the signal receiver to the virtual transmitter, it would also be possible, for purposes of increasing flexibility, to allocate to the virtual transmitter a freely selectable position identification and/or a position identification not taken by another subscriber. With that, a virtual base transmitter would be defined in locations, in which the signal receiver has never been.
In a flexible manner, it would be possible to define the virtual transmitter, through the signal receiver, actively with respect to its user action, or automatically as a function of fulfilling a predeterminable condition. In this connection, the user could make the frequency of the definition of a virtual transmitter dependent on how reliably it wants to be reachable within the telecommunications network. The more often it defines virtual transmitters through a radio call, or the more often it notifies possibly already existing virtual transmitters of its possibly changed position identification, the better and more reliably it can be reached. The definition of a virtual transmitter as a function of fulfilling a predeterminable condition could be a temporal condition, i.e., the definition of a virtual transmitter automatically occurs at predeterminable time intervals.
In a particularly comfortable manner, the automatic definition could occur, after the signal receiver has left its original neighborhood area, or after one or more predeterminable subscribers in the original neighborhood area have left same or their original neighborhood area, or after the signal receiver has left the neighborhood area of one or more predeterminable subscribers. The first alternative describes the instance, wherein the signal receiver has clearly reduced the probability that it can be reliably reached because of leaving its original neighborhood area. The second alternative considers the instance, wherein defined transmitters are no longer available, and that thus the transmitter density is possibly reduced such that a reliable availability of the signal receiver is no longer guaranteed. The third alternative considers the instance similar to the second alternative, wherein defined transmitters, even including transmitters having originally been outside of the original neighborhood area of the signal receiver, are no longer available. However, these transmitters are no longer available, because this time the signal receiver has moved and not the transmitters. An automatic definition of one or more virtual transmitters could however occur, even when one or more predeterminable subscribers have removed themselves from their neighborhood area. In this instance, the observed subscribers need not have originally been in the neighborhood area of the signal receiver.
Depending on the addressing or position identification system, it would be possible to allocate to the subscribers a location-related and/or a subscriber-related identification. The definition of virtual transmitters occurs in accordance with the selected identification system.
For a better understanding of the foregoing method of establishing a radio link, same is summarized one more time as follows:
In the case that the observed destination subscriber removes itself from its original location, it will report at certain time intervals to the subscribers of its original neighborhood area for purposes of transmitting its new position identification. In this instance, it addresses its future, virtual base transmitter, which is allocated the position identification of its original location. This radio call serving to define the virtual base transmitter is retransmitted to the original location, where it is monitored and stored by potential transmitters and neighbors of this location, which have a similar position identification. In the case of this radio call, a corresponding radio code sequence parameter is put on the mode xe2x80x9cbase transmitter responsexe2x80x9d and transmitted. This effects that the potential transmitters in the original neighborhood area are informed about the definition procedure, and discontinue to be active after a preferably discontinued search for the virtual base transmitter. Thus, the establishment of the radio link is discontinued at these transmitters, since the destination subscriber or the virtual base transmitter is not found. However, all nearest neighbors of this location will then know the new address of the observed destination subscriber.
That transmitter, which is within a deliberate attempt of establishing a radio link with the observed subscriber, the last member in the radio link chain, and which receives no further positive signal for taking over or no signal of the destination subscriber, will then search its memory for the specified destination address of the network subscriber being searched. When it becomes successful, i.e., when radio call code sequences with the destination address of the searched subscriber and parameters put on xe2x80x9cbase transmitter responsexe2x80x9d exist, this transmitter will assume the part of the searched virtual base transmitter. It will identify itself as such and then transmit the new position identification of the searched destination subscriber in accordance with the base transmitter function, or it connects directly to same.
In the described method, it is essential that in a certain local area, network subscribers be available, which do not all move out of this area at the same time, or which do not all move within this area at the same time. However, this condition is nearly always met for statistical reasons.
The introduction of virtual transmitters makes it possible to realize a radio relay network without hardware, i.e., without a xe2x80x9cbackbone.xe2x80x9d Instead of using a xe2x80x9cbackbonexe2x80x9d to assist the telecommunications network, an information pattern, for example, a routing information pattern is put in the network. By addressing virtual storage locations, which represent the virtual transmitters or the neighborhood areas, routing information can be stored decentralized and used everywhere in the network.
The definition of a plurality of virtual transmitters makes it possible to generate in many ways radio link structures that are realized as tree structures, star structures, ring structures, or mixed topological structures. If need be, this would permit predetermining in a purposeful manner even complicated information transmission links with nodal and switching points, to circulate, for example, media information, which is intended for an entire group of receivers.
It would also be possible to include useful-content-dependent, thematic priority parameters in the radio call code sequence, which is essential for establishing a radio link, and contains, for example, the destination subscriber identification, the transmitter identification of the previously transmitting subscriber, the time of the transmission by the signal transmitter, the position identification of the signal transmitter, a parameter of identifying a base transmitter response, and parameters with respect to the transmitting power priority. This means, depending on the identification of useful contents, the transmission occurs with a greater or lesser priority. Besides determining the priority of such transmissions, such an identification also provides a distinction between different thematic transmissions. Thematic transmissions of information may be media applications that are to be unidirectionally transmitted, with one source and different destination subscribers. These may be data transmissions between a plurality of sources and a plurality of destination subscribers, conference or broker circuits.
The transmission of such information flows may be determined in the radio link takeup procedure, preferably via transmitters, which have previously transmitted this subject matter during a certain elapsed period of time. The destination transmitter with a thematic priority automatically retransmits thematic radio calls, which are intended for any defined destination subscriber, to all other destination subscribers known to it with identical signal transmitter identification and identical, thematic priority number. As a result, identical information flows, which proceed from the same source subscriber to a plurality of destination subscribers, reach the destination subscribers no longer via many different radio paths that are to be individually offered and maintained, but via common relay radio paths or chains of relay radio links with the same transmitters, which simultaneously operate as distributors at the nodes.
A thematic transmitter selection allows thematically selected transmitter radio paths to build up among one another. In this instance, thematically defined radio paths or thematic subnetworks are realized besides the address-defined radio paths. By reducing a thematic transmission to thematically selected transmitters, a thematic subnetwork automatically results after the procedure with a minimum number of transmitters in the radio paths, or relay radio paths, or chains of relay radio paths, which superpose preferably congruently, or form star-shaped, ring-shaped, or branched tree structures of the transmission paths.
These thematic radio paths correspond up to the nodes to the different receivers. At the nodes, the respective transmitter directly addresses, if need, a plurality of additional destination transmitters. As a result of the thematic selection, distributors or distributor nodes automatically form from previous, simple transmitters.
Thematic radio transmissions automatically minimize the radio activity of the radio network. On the one hand, it is possible to transmit data from the source of information, via common relay radio paths with a minimal number of common transmitters to different end subscribers. On the other hand, individual end subscribers, which request thematic radio transmissions from a source, possibly need no longer establish a radio contact up to the source subscriber. Instead, they need to find only any transmitter already included in the thematic transmission for purposes of engaging in the thematic radio network.
In the ideal case only a single end subscriber needs to establish a radio contact to the terminal source subscriber. Yet, the end subscribers will not lose the possibility of transmitting, if need be, interactive data to the terminal source. In the case that the thematic data transmissions are time information programs, the source subscriber needs to transmit each time only one information packet for all thematic end subscribers.
At this point, it should be noted that because of realizing virtual transmitters, the greater mobility of the subscribers makes it possible to reach and link moving transmitters for connecting different networks of this kind via traffic routes of the transmitters, for example, interstate highways, waterways, and railroads.

Method for establishing a radio communication and telecommunication network


A method and an apparatus for a dynamic mudcap drilling and well control assembly is provided. In one embodiment, the apparatus comprises of a tubular body disposable in a well casing forming an outer annulus there between and an inner annulus formable between the body and a drill string disposed therein. The apparatus further includes a sealing member to seal the inner annulus at a location above a lower end of the tubular body and a pressure control member disposable in the inner annulus at a location above the lower end of the tubular body. In another embodiment, the assembly uses two rotating control heads, one at the top of the wellhead assembly in a conventional manner and a specially designed downhole unit. Finally, the assembly provides a method for allowing the well to produce hydrocarbons while tripping the drill string.

1. Field of the Invention
The present invention relates to a method and an apparatus for drilling a well. More particularly, the invention relates to a method and an apparatus for drilling a well in an underbalanced condition. More particularly still, the invention relates to a method and an apparatus enhancing safety of the personnel and equipment during drilling a well in an underbalanced condition using a dynamic column of heavy fluid.
2. Description of the Related Art
Historically, wells have been drilled with a column of fluid in the wellbore designed to overcome any formation pressure encountered as the wellbore is formed. In additional to control, the column of fluid is effective in carrying away cuttings as it is injected at the lower end of drill string and is then circulated to the surface of the well. While this approach is effective in well control, the drilling fluid can enter and be lost in the formation. Additionally, the weight of the fluid in the wellbore can damage the formation, preventing an adequate migration of hydrocarbons into the wellbore after the well is completed. Also, additives placed in the drilling fluid to improve viscosity can cake at the formation and impede production.
More recently, underbalanced drilling has been used to avoid the shortcomings of the forgoing method. Underbalanced drilling is a method wherein the pressure of drilling fluid in a borehole is intentionally maintained below the formation pressure in wellbore.
In underbalanced drilling operations, a rotating control head (RCH) is an essential piece of wellhead equipment in order to provide some barrier between wellbore pressure and the surface of the well. A RCH is located at the top of the well bore to act as barrier and prevent leakage of return fluid to the top of the wellhead so that personnel on the rig floor are not exposed to produced liquid and hazardous gases. An RCH operates with a rotating seal that fits around the drill string. The rotating seal is housed in a bearing assembly in the RCH. Because it operates as a barrier, the RCH is often subjected to high-pressure differential from below. In order for the RCH to work properly, stripper rubber elements designed to seal the drill pipe must fit around the drill pipe closely. These rubber elements are frequently changed on the job with new elements to ensure proper functioning of the RCH. However, even with frequent change of these elements, operators are often concerned about the safety on the high-pressure wells, especially where hazardous gases are expected with the return fluid. Additionally, in relatively high-pressure gas wells the use of drilling fluid density for controlling return flow pressure lowers production from the well and requires the produced gas be recompressed before it is fed into a service line or used for re-injection.
In another form of underbalanced drilling, two concentric casing strings are disposed down the wellbore. Drilling fluid is pumped into the drill string disposed inside the inner casing. A surface RCH is connected to the drill string at the wellbore. Another fluid is pumped into an annulus formed between the two casing strings. Thereafter, both of the injected fluids return to the surface through an annulus formed between the drill string and inner casing. Gas rather then fluid may be pumped into the outer annulus when drilling a low-pressure well to urge return fluid up the annulus. Conversely, when drilling a high pressure well, fluid is preferred because the hydrostatic head of the fluid can control a wide range of downhole pressure. The operator can regulate the downhole pressure by varying the flow rate of the second fluid. This method has a positive effect on the rotating control head (RCH) in high-pressure wells because the pressure of returning fluid at the wellhead is reduced to the extent that there is added friction loss. However, the RCH is not isolated from produced fluids therefore imposes a safety risk on rig operators from leakage of produced fluid due to a failure in the RCH.
A mudcap drilling system is yet another method of underbalanced drilling. This drilling method is effective where the drilling operator is faced with high annular pressure. FIG. 1 is a section view showing a traditional mud cap drilling system. After a borehole is drilled, a casing 30 is disposed therein and cemented in the wellbore 15. A drill string 35 is disposed in the wellbore 15 creating an annulus 10 between the casing 30 and the drill string 35. The drill operator loads the annulus 10 by pumping a predetermined amount of heavy density fluid in an inlet port 60. This fluid is designed to minimize gas migration up the annulus 10. After the fluid reaches the predetermined hydrostatic pressure, the drill operator shuts in an inlet port 60.
As illustrated on FIG. 1, the system includes a rotating control head (RCH) 50 at the surface of the wellhead 15. The RCH 50 includes a seal that rotates with the drill string 35. The heavy density fluid applies an upward pressure on the downward facing RCH 50, thereby sealing off the outer diameter of the drill string 35. The purpose of the RCH 50 is to form a barrier between the heavy density fluid mudcap and the rig floor. At this point, the shut in surface pressure on the annulus plus the hydrostatic pressure resulting from the heavy density fluid equals the formation pressure. This annular column of heavy density fluid is held in place by a pressure barrier 45 created between hydrostatic fluid column pressure and the downhole pressure. To offset any annular loses of fluid into to the formations 25, it may be necessary to add fluid to the mudcap in the same sequence as it was initially introduced. Additionally, the system also includes a blow out preventor 55 (BOP) disposed at the surface of the well for use in an emergency. Thereafter the mudcap is established, the drilling operation may continue pumping clean fluid that is compatible with the formation fluids down a drill string 30 exiting out nozzles in a drill bit 40. A permeable formation fracture 25 receives the drilling fluid as it pumped down the drill string 30. A term used in the oil and gas industry called xe2x80x9cbullheadingxe2x80x9d results due to the formation of the barrier 45 at the bottom of the annular column 10 between the heavy density fluid and hydrocarbon formation pressure. The barrier 45 prevents drilling fluid returning to the surface, thereby urging the fluid into the formations 25. Although this process requires specialized well control and well circulation equipment during the mudcap drilling operation, there is no need for extensive fluid separation system since the formation fluids are kept downhole.
There are several problems that exist with the traditional mudcap drilling system. For example, as with other forms of well control the surface rotating control head (RCH) is the only barrier between the high-pressure return fluid and personnel on the rig floor. The operators are often concerned about safety on high-pressure wells since there is no early warning system in place. In another example, the RCH stripper rubbers wear out rapidly due to the high differential pressure. These stripper rubbers need to be changed periodically on the job to ensure proper functioning of the RCH. This is a costly operation in terms of rig time and cost of the rubber elements. In a further example, this drilling method can only operate if a permeable fracture or formation exists because all the drilling fluids are not returned to the surface but are being pumped into a permeable fracture. This drilling fluid loss is also a costly investment. In yet a further example, reservoir damage can occur due to the lack of control of a true underbalanced state between the fluid column pressure and the formation pressure, thereby reducing the productivity of the well. In the final example, the well does not produce hydrocarbons while tripping the drill string in a traditional mudcap drilling operation.
In view of the deficiencies of the traditional mudcap drilling system and other well control methods, a need exists to ensure the safety of the rig operators by providing an early warning system to tell the operators that a potential catastrophic problem exists. There is a further need to extend the life of the RCH due to the high cost of non-productive rig time as a result of replacing the rubber part. There is yet a further need to save operational costs and prevent formation damage by allowing the drilling fluid to return to the surface of the wellhead while maintaining the benefits of a traditional mudcap system. There is yet even a further need for a mudcap assembly, which allows the well to produce hydrocarbons while tripping the drill string.
The present invention provides a method and an apparatus for a dynamic mudcap drilling and well control assembly. In one embodiment, the apparatus comprises of a tubular body disposable in a well casing forming an outer annulus there between and an inner annulus formable between the body and a drill string disposed therein. The apparatus further includes a sealing member to seal the inner annulus at a location above a lower end of the tubular body and a pressure control member disposable in the inner annulus at a location above the lower end of the tubular body.
In another embodiment, the assembly uses two rotating control heads, one at the top of the wellhead assembly in a conventional manner and a specially designed downhole unit. Thus, creating dual barriers preventing any potential leak of produced gases or liquid hydrocarbon on to the rig floor, thereby ensuring the safety of the rig operators. Furthermore, the assembly provides an early warning method for detecting catastrophic failure in any of the two rotating control heads. Additionally, the assembly provides a practical method for reducing wear on the RCH stripper rubbers by ensuring the pressure differential across both the surface and downhole RCH is small, thereby extending the life of the RCH and reducing the non-productive time of the rig due to periodic replacement of the rubber part in the RCH. Further, the assembly provides for a way of circulating the return flow to the top of the wellbore thereby reducing cost of drilling by utilizing the return drilling fluid. Further yet, the assembly provides a practical method for containing and controlling wellhead pressure of return fluids by use of a high-density fluid column. Additionally, the assembly using a WEATHERFORD(copyright) deployment valve allows the well to continue to produce hydrocarbons without any drill string in the well bore. Finally, the assembly provides a method for allowing the well to produce hydrocarbons while tripping the drill string.

Dynamic mudcap drilling and well control system


The present invention relates to a belt buckle caddy which stores a set of telescopic pens or pencils which include blinking light reminders when in use to remind the user to place the pens or pencils back in the caddy after use. The caddy also includes a front interchangeable ornament lighted by a glowing or blinking light useful as a safety feature during night walks and to match the users attire. Left and right grooves on the front of the buckle caddy serve to guide the ornament onto the front of the caddy and tubes extending from a top opening on the caddy serve to store the pens or pencils when not in use. Two small holes are formed through the caddy to facilitate holding fixed ornaments or LED electrical contacts which are connected to lithium batteries located on the rear of the caddy.

The present invention relates to a belt buckle caddy which stores a set of telescopic pens or pencils in tubes self contained within the belt buckle. The pens or pencils include blinking light reminders when in use to remind the user to replace the pens or pencils within the belt buckle caddy when not in use. The telescopic pens or pencils are handy for brief writing of a phone number, addresses, etc. and the belt buckle avoids staining of the user's shirt by providing a storage area for the pens or pencils other than a shirt pocket. Also, the blinking light reminder functions as an alarm to prevent loss of the pens or pencils after use.
The invention also relates to a belt buckle caddy which includes an interchangeable front ornament lighted by a glowing or blinking light serving as a safety feature during night walks. The lighted interchangeable ornament allows one to view the ornament night or day and to match a desired ornament to a selected attire. The ornament is mounted using right and left grooves formed on the front of the belt buckle which guide the ornament into position over two small holes in the front of the buckle. The two small holes serve to hold LED electrical contacts connected to lithium batteries on the rear of the buckle. The two small holes can also serve to hold a fixed ornament. A wide variety of belt buckle shapes such as rectangular, oval, round, square, large or small can be used. Also, the belt buckle can be made using plastic or metal.
The combination is useful and desirable. The device serves to enhance the safety of the user at night and provides an aestetically pleasing appearance. The device is also a novelty for disco dancing.


An exhaust system for exhausting gases and molten debris caused by an electric arc within a switchgear. The exhaust system includes a switchgear having lower and upper compartments and an exhaust unit externally mounted to the switchgear. A wall panel of the switchgear includes blow out panels coinciding with openings in the lower compartment and corresponding ventilation flaps in a top surface of the exhaust unit to exhaust gas from the lower compartment out the blow out panels in a vertical direction, exiting through the flaps. The upper compartment includes ventilation flaps for exhausting gas in a vertical direction directly through the flaps and optionally through side-mounted blow out panels that communicate with the vertical vent path to the flaps in the top of the exhaust unit. A bus compartment in the exhaust unit includes a vent path to flaps in the top of the exhaust unit for exhausting gas produced by bus arcing.

Medium voltage (MV) switchgear can include an exhaust system for venting gas and debris particles generated by an electric arc under arc-fault conditions. During an arc fault explosion, temperature and pressure inside the switchgear increase very rapidly, and the rapid pressure build-up can damage the switchgear and its components. In certain environments, vertically stacked breakers, such as 2-high breaker units are commonly employed. These vertically stacked units have an upper and a lower compartment, each for receiving a circuit breaker or current/voltage transformer. Prior solutions have proposed internal arc chambers located within the switchgear for venting gas and debris from the lower compartment through the roof or top of the switchgear enclosure. The sudden, high temperature and pressure created by an exploding arc can damage numerous internal components of the switchgear as the gas and debris escape through the top vents of the switchgear enclosure. Moreover, the internal arc chambers in some prior exhaust systems have a horizontal internal chamber that communicates with a vertical internal chamber, such that if the sudden pressure created by an electric arc is not immediately relieved by the top vents, one or both of the sides of the switchgear enclosure terminating the horizontal internal chamber can blow out, venting hot gases and debris out the side of the switchgear enclosure and endangering a human standing nearby. An arc fault can also occur on the busbar conductors that run inside of a switchgear unit. Attempts have been made to exhaust gas caused by arcs on the busbars, but such designs are complicated and expensive to implement.
What is needed is a vertical exhaust system for an arc-resistant switchgear. Aspects and embodiments disclosed herein are directed to addressing/solving these and other needs.

Arc resistant switchgear vertical exhaust system


An improved implantable hearing aid microphone comprises a housing having an internal chamber with an aperture thereto and a first diaphragm sealably positioned across the aperture. A microphone having a second diaphragm is positioned within the chamber to define an enclosed volume between the first and second diaphragms for mechanically amplifying acoustic signals received by the first diaphragm. A peripheral rim may define the aperture of the housing, wherein the first diaphragm may be recessed between about 0.5 mm and 1.0 mm relative to the peripheral rim across the lateral extent of the first diaphragm. The internal chamber may be defined to include a first portion having a first cross-sectional area adjacent to the first diaphragm, and a second portion having a second cross-sectional area adjacent to the second diaphragm that is smaller than the first cross-sectional area. The second portion may be disposed to extend away from the first portion about an axis that is transverse to the first diaphragm. In turn, the first diaphragm may be provided to have an effective cross-sectional area that is at least about 100 times greater than the effective cross-sectional area of the second diaphragm. In one arrangement, the second internal chamber portion may be of an L-shaped configuration with a first leg being coaxially aligned with a center axis of the first diaphragm and a second leg disposed substantially perpendicular thereto with the second diaphragm disposed therein. The first diaphragm may comprise a biocompatible material, such titanium or a titanium alloy. The first diaphragm may be provided to have a cross-width of between about 8 to 15 millimeters and a thickness of between about 10 and 20 microns.

The present invention related to the field of implantable hearing aid devices, and in particular, to implantable hearing aid microphones employable in fully- and semi-implantable hearing aid systems.
Traditional hearing aids are placed in a user""s ear canal. The devices function to receive and amplify acoustic signals within the ear canal to yield enhanced hearing. In some devices, xe2x80x9cbehind-the-earxe2x80x9d units have been utilized which comprise a microphone to transduce the acoustic input into an electrical signal, some type of signal processing circuitry to modify the signal appropriate to the individual hearing loss, an output transducer (commonly referred to in the field as a xe2x80x9creceiverxe2x80x9d) to transduce the processed electrical signal back into acoustic energy, and a battery to supply power to the electrical components.
More recently, a number of different types of fully- or semi-implantable hearing aid devices have been proposed. By way of primary example, implantable devices include those which employ implanted electromechanical transducers for stimulation of the ossicular chain and/or oval window (see e.g., U.S. Pat. No. 5,702,342), and those which utilize implanted exciter coils to electromagnetically stimulate magnets fixed within the middle ear (see e.g., U.S. Pat. No. 5,897,486). In these as well as other implanted devices, acoustic signals are received by an implantable microphone, wherein the acoustic signal is converted to an electrical signal that is employed to drive an actuator that stimulates the ossicular chain and/or oval window.
As may be appreciated, such implantable hearing aid microphones must necessarily be positioned at a location that facilitates the receipt of acoustic signals and effective signal conversion/transmission to an implanted actuator. For such purposes, implantable hearing aid microphones are most typically positioned in a surgical procedure between a patient""s skull and skin, at a location rearward and upward of a patient""s ear (e.g., in the mastoid region).
Given such positioning, the size and ease of installation of implantable hearing aid microphones are primary considerations in the further development and acceptance of implantable hearing aid systems. Further, due to the subcutaneous location of implantable hearing aid microphones, it is important that effective and efficient amplification be provided to yield a high fidelity signal. Relatedly, the componentry cost of providing such amplification is of importance to achieving widespread use of implantable system. Finally, it is important that the overall design of implantable microphones mitigate servicing/replacement needs.
In view of the foregoing, a primary objective of the present invention is to provide an implantable hearing aid microphone having a relatively small profile, particularly in the lateral extent.
Another objective of the present invention is to provide an implantable hearing aid microphone that reduces the extent of exposed surfaces for tissue attachment/infiltration, thereby reducing the potential need/periodicity of microphone servicing/replacement.
An additional objective of the present invention is to provide an implantable hearing aid microphone that is reliable and cost effective.
Yet further objectives of the present invention are to provide an implantable hearing aid microphone that is relatively robust and that provides for effective and efficient acoustic signal conversion to yield a high fidelity signal for middle ear stimulation.
One or more of the above objectives and additional advantages are realized in the implantable hearing aid microphone apparatus comprising the present invention. Such apparatus includes a housing having an internal chamber with an aperture thereto defined by a peripheral rim surrounding the aperture. A first diaphragm is sealably positioned across the aperture. Additionally, a microphone having a second diaphragm is disposed within the internal chamber to define an enclosed volume between the first and second diaphragms for mechanically amplifying acoustic signals received by the first diaphragm.
In one aspect of the present invention, the first diaphragm is recessed relative to the peripheral rim surrounding the aperture. More particularly, the first diaphragm may be preferably recessed between about 0.5 mm and 1.0 mm relative to the peripheral rim of the housing and across the lateral extent of the first diaphragm. Further, the outer edge of the peripheral rim may be disposed in a first plane and at least an outer face of the first diaphragm may be flat and disposed in parallel relation to the first plane.
In another aspect of the present invention, the internal chamber may be defined to comprise at least a first portion having a first cross-sectional area adjacent to the first diaphragm, and a second portion extending away from the first portion about an axis transfer to the aperture and/or first diaphragm and having a second cross-sectional area adjacent to the second diaphragm. Preferably, the first cross-sectional area is greater than the second-sectional area. Relatedly, it is preferable that the first diaphragm having an effective cross-sectional area (i.e., the area exposed for receipt of acoustic signals) that is at least about 100 times greater than the effective cross-sectional area of the second diaphragm.
The second portion of the internal chamber may adjoin the first portion internal chamber at a reduced opening therebetween, wherein the opening is smaller than and is positioned in opposing relation to the aperture. Further, the aperture and the opening may be coaxially aligned and may each be of circular configuration.
In one arrangement, the second portion of the internal chamber may be of an L-shaped configuration, wherein an opening between the first and second portions of the internal chamber is located at an end of a first leg of the second portion. In turn, the second diaphragm is positioned in a second leg of the second portion. Preferably, both the first and second legs of the second internal chamber portion, as well as the first internal chamber portion may, each be of a cylindrical configuration. Further, the first and second legs of the L-shaped second internal chamber portion may adjoin an internally rounded elbow.
In yet another aspect of the present invention, the first diaphragm may comprise a biocompatible material. By way of primary example, the first diaphragm may comprise a material selected from a group consisting of titanium and titanium-alloys. Further, it is preferable that the maximum cross-width of the first diaphragm (i.e., as measured across the area exposed for receipt of acoustic signals) established between about 8 and 15 millimeters, and most preferably between about 10-12 millimeters. Further, it is preferable that the first diaphragm thickness be established at between about 10 and 20 microns across the lateral extent thereof, and most preferably between about 12 and 15 microns.
By virtue of the above-noted features, an implantable microphone may be provided to reduce exposed surfaces for tissue infiltration. Further, a microphone may be constructed to reduce lateral space requirements upon surgical installation. Additionally, a microphone may be readily fabricated and assembled in a cost effective manner, while also yielding effective, high-quality signal amplification capabilities.
Additional aspects and advantages of the present invention will be apparent to those skilled in the art upon review of the further description that follows.