An anchor rod having at least one section provided with ribs or other raised portions or profiling and a threaded section at one or both ends, and having a variable transition section between the threaded section(s) and the profiled section; and a method of making the anchor rod.

The present invention relates to a concrete structure comprising at least two anchor rods coupled to one another, at least one of said anchor rods being provided with an external thread for that coupling. Such structures are generally known in the art. When producing large concrete structures it is frequently not possible to pour these in one piece. Therefore these are poured successively in parts. What is important here is that the reinforcement does form an essentially continuous structure. It is therefore customary in the art to fit, close to the boundary of the first part to be poured, a reinforcing rod provided with, for example, a threaded bush at the boundary surface. After pouring the casing is removed and the opening to the thread is exposed and an anchor rod, provided with an external thread, is screwed into this opening. The second part is then poured in contact with the first part and the strength of the structure is guaranteed by the connection continuing through the structure.
Stringent requirements are imposed on the anchor rods used.
In general such rods are produced by using reinforcing steel that has already been provided with raised portions or ribs as the starting material. After cutting to size, the relevant end of the reinforcing steel that has to be provided with a thread is butted. After all, insufficiency in cross-section at the location of the thread is not acceptable in a linking system. Butting of steel is carried out by heating the steel. By this means a substantial proportion of the material structure that was originally longitudinally oriented will be modified. After butting the material must be cooled under controlled conditions. It has been found that as a result of the increasingly extensive alloying of reinforcing steel, on the one hand, and the acceptance of an ever higher percentage of impurities (scrap) on the other hand, an inadmissible reduction in strength can occur if there is the slightest deviation from the norm for quenching. In particular this causes cracking. No problems have been found in the case of normal applications of reinforcing steel, that is to say where no heating and butting takes place, but the abovementioned problems are observed as soon as anchors provided with thread have to be produced.
It will be understood that cracking can ultimately lead to failure, which can have major consequences for structures in which such anchor rods can be used. Moreover, such anchor rods are used in prefabricated concrete components, as a result of which lifting slings and the like can be attached in a simple manner to the anchor rod. This gives rise to stress especially when moving the prefabricated elements concerned and failure can also have disastrous consequences here.
On the other hand, it is extremely important that anchor rods have a relatively low price for a relatively high quality.
EP 0816584A1 discloses a screw coupling for anchor rods having the features of the preamble of claim 1.
The aim is to eliminate the disadvantages known from the prior art with an improved anchor rod being placed in a concrete structure and with failure being virtually precluded.
This aim is achieved with a concrete structure as described above by the characterising measures according to claim 1.
The material structure of a metal anchor rod is understood to be, inter alia, the molecule/fibre/grain orientation of the material concerned.
It is pointed out that an anchor bolt is disclosed in U.S. Pat. No. 5,054,146. This bolt must be used in particular for anchoring the rod in boreholes, openings or the like made in rocky soils. The anchor rod concerned is introduced into such an opening and a synthetic resin material is then used to provide for adhesion between the rod and the surroundings. This anchor rod is provided with a pattern consisting of flattened sections pressed in of the material. These lobes serve as stirrers for stirring the resin by means of which the anchor rod is fixed to the structure.
Using the anchor rod according to the present invention it is possible to make concrete structures with which the risk of failure of the anchor rods is avoided as far as possible.
The pattern used according to the invention is a pattern that is customary for reinforcing steel, that is to say of shallow height and produced with a gradual transition with respect to the other part of the anchor material. This pattern is obtained with the aid of a simple rolling operation, which can be combined with the reduction in the circumference of the anchor rod.
According to an advantageous embodiment of the invention, the concrete structure comprises a first poured part with an anchor rod fitted therein, the end of which anchor rod is provided with an internal thread by means of which the one anchor rod is coupled, said one anchor rod is fitted in a second part poured in contact with said first poured part. Said internal thread can be implemented by means of a bush clamped on the anchor rod. However, it is also possible to use a rod material of relatively large diameter as the starting material, the external diameter approximately corresponding to the external diameter of the part in which the internal thread has to be made. The diameter of the other part of the rod is then reduced to a very appreciable extent in order to obtain the desired dimensions.
According to the invention such an anchor rod is preferably produced by providing a method for the production of an anchor rod comprising the provision of a length of steel rod, making a thread at one end and making a pattern on the other part of the rod, wherein the thread is preferably made by rolling a thread and wherein the pattern is made by rolling the relevant part of the rod after making the thread. Instead of rolling a thread, cutting can also be used. In such a case it is preferable to reduce the diameter of that part where there is no thread, and where the pattern has to be applied, by rolling. The strength and other mechanical properties improve as a result of this rolling operation. Pattern or relief is understood here to be any surface structure or raised portion by means of which the engagement of the anchor rod and the surrounding concrete is promoted.
According to the invention no longer a length of reinforcing steel is used as the starting material and a section of enlarged diameter is provided for the thread by butting, but that using a section of rod material the section provided with a pattern or ribs is obtained by rolling. That is to say the difference in diameter between the section provided with a thread and the section provided with a pattern is obtained not by increasing the diameter at the section provided with a thread but by reducing the diameter of the section provided with a pattern. It has been found that during such a rolling operation, which can be carried out cold, the mechanical properties of the anchor rod only improve and do not deteriorate in any way. Consequently it is possible to use a relatively low grade steel and nevertheless to achieve adequate strength as required in accordance with the standards.
Because butting now no longer takes place, the material structure of the steel in the core at the threaded section will be unchanged, that is to say will essentially match that of the original material structure of said anchor rod.
Using the method described above it is possible in a simple manner to produce anchor rods with relatively high strength from relatively low-alloy materials. Examples of such materials are types of steel which have a relatively high carbon content. Because, in contrast to the prior art, it is not necessary to carry out an annealing treatment with deformation (warm butting) in order to produce a thread, the structure of the steel material is not affected or is barely affected by the method according to the present invention.
Because it is now possible inexpensively to produce anchor rods from material of high strength, it is possible in the case of some applications to replace relatively thick anchor rods made of conventional steel by appreciably thinner anchor rods made of high-tensile material. In the case of structures subjected to heavy load, there is often the problem that anchor rods are close to one another, as a result of which it can no longer be guaranteed that concrete material, and in particular the aggregate contained therein, infiltrates between the reinforcing rods and thus provides adequate strength. By, in accordance with the invention, using reinforcing rods of high strength which have a relatively small diameter the infiltration of concrete material is guaranteed.
A further increase in the strength of the structure can be obtained by producing the thread by rolling. After all, a similar thread can be obtained with a smaller starting diameter. The diameter of the transition section will be smaller than the external diameter of the threaded section. Of course, as a result of the rolling, the material structure of steel in the thread will deviate from the initial structure of the anchor rod, but this has no effect on the material structure in the core thereof. If a thread is cut, the other section of the anchor rod can be cold-rolled in the manner described above without any problem.
According to the invention the section provided with a pattern has a very appreciable length compared with the length of the section provided with a thread.
The pattern can be any pattern known in the prior art, such as raised portions or ribs. These can be introduced simply during rolling using a profiling roller.
If the thread is used in combination with a bush, which can be either a separate coupling bush or a bush fitted on the end of another anchor rod, it can be advantageous for the transition section to have a shoulder against which such a bush bears, or to be fitted in a seating surrounding the shoulder.
The anchor rod described above can be produced from any steel material known in the state of the art, which material can be either structural steel or stainless steel. St 52.3, which is a type of steel which is relatively easy to obtain and has relatively high purity, is mentioned by way of example.
As indicated above, types of steel of relatively high strength, that is to say with tensile strengths of, for example, 1,100 N/mm2, can also be used.

Concrete structure comprising anchor rods and anchor rod


Ectoparasites, such as fleas, ticks, mites and lice, are removed from a human or animal host after applying a composition to the affected area that causes desiccation of the organism. In one embodiment, treatment is effected by applying a substantially anhydrous composition that has a strong affinity for water. As the composition hydrates, it desiccates the pests and facilitates their mechanical removal, such as by combing.

The present invention relates generally to the removal of ectoparasites from the bodies of humans and animals, and more particularly to a topical treatment to facilitate such removal.
Ectoparasitic infestation of humans and animals is a serious health problem throughout the world. Of particular importance as a public health issue is pediculosis, or infestations with lice, which are pervasive among children and can quickly be spread in a school setting. A very common parasite is Pediculus humanus var capitis, the common head louse, although there are other important parasites, including Pthirus pubis (the pubic louse) and Pediculus humanus var corporis (the body louse). Infestations are frequently accompanied by itching and skin damage. Infections may occur when the skin is scratched in an attempt to relieve the itching. Further, lice are known to be capable of transmitting serious diseases, including trench fever, relapsing fever and typhus.
Pediculosis is most frequently treated by applying pesticidal compositions, such as lotions or shampoos, to the affected body areas, such as the hair, and then exhaustively combing with a fine-toothed comb made especially for the purpose of removing nits. Commercially available preparations may include as their active ingredients pyrethrins, piperonyl butoxide, malathion, lindane or permethrins, many of which unfortunately have neurotoxic properties, are readily absorbed through the skin and therefore can establish undesirable systemic concentrations. It is perceived that the effectiveness of pesticides has recently diminished, as the parasites appear to continually become more resistant to their action. The resistance may be aggravated by small amounts of residual pesticide on the treated areas, following the procedure. This resistance also contributes to an increased opportunity for toxic systemic exposure to the active ingredients, since the preparations must be applied repeatedly to obtain an eradication of the infestation. Further, the pesticides do not usually kill the parasite""s eggs that may be present on a host, so the tedious mechanical removal techniques must also be used.
DiNapoli et al., xe2x80x9cEradication of Head Lice with a Single Treatment,xe2x80x9d American Journal of Public Health, Vol. 78, pages 978-980, 1988, reported a study in which 7 percent of patients treated with a commercial 1 percent permethrin cream rinse, and 16 percent of patients treated with a commercial product containing 0.3 percent pyrethrins, 3 percent piperonyl butoxide, 1.2 percent petroleum distillate and 2.4 percent benzyl alcohol, experienced adverse reactions including pruritis, erythema, tingling, rash and other conditions. Further, by 14 days following treatment 38 percent of the patients treated with the pyrethrin product were found to host live lice, considered a treatment failure. Permethrin is described as having residual activity on the hair for up to two weeks.
R. J. Roberts et al., xe2x80x9cComparison of Wet Combing with Malathion for Treatment of Head Lice in the UK: a Pragmatic Randomised Controlled Trial,xe2x80x9d The Lancet, Vol. 356, pages 540-544, 2000, report that mechanical removal of lice with a commercial comb every 3-4 days for two weeks gave a xe2x80x9ccurexe2x80x9d rate of only 38 percent, while two treatments with 0.5 percent malathion lotion seven days apart gave a xe2x80x9ccurexe2x80x9d rate of 78 percent.
Published results for the various topical pesticidal treatments were compared by. R. H. Vander Stichele et al., xe2x80x9cSystematic Review of Clinical Efficacy of Topical Treatments for Head Lice,xe2x80x9d British Medical Journal, Vol. 311, pages 604-608, 1995. It was concluded that only permethrin had sufficient evidence of efficacy.
There are other approaches to treating the infestations, including the application of heavy, oily substances such as mineral oil, petrolatum, mayonnaise and the like in an attempt to suffocate the ectoparasites, but these have not been found particularly effective, esthetically pleasing or convenient. One major disadvantage of such treatments is the prolonged time (usually several hours) required to achieve suffocation, after the agent has been applied.
The suffocation technique has been refined, such as by the approach of U.S. Pat. No. 6,139,859 to Precopio which utilizes air-impermeable water-dispersible liquid compositions containing surface active agents. Another type of treatment refinement is the technique of Pearlman et al. in PCT International Publication WO 99/18800, involving the topical application of surfactant substances as xe2x80x9cpediculostatic agentsxe2x80x9d which immobilize the parasites to permit their removal by combing.
It remains desirable to have a treatment for ectoparasitic infestations which is efficacious, acts rapidly and does not generate great discomfort or require any exposure of the host to toxic agents.
The present invention is a treatment for ectoparasitic infestations, particularly those involving fleas, ticks, mites or lice, comprising establishing environmental conditions whereby systemic moisture is removed from the ectoparasites, for a time sufficient to cause immobilization or death of the ectoparasites, then removing the pests by mechanical means such as combing.
This invention involves topical applications of compositions containing active ingredients which have a strong affinity for water, such as is present in organisms such as ectoparasites. Contact of the organisms with the active agents causes desiccation which results in immobilization and/or mortality of the parasites, facilitating their mechanical removal by combing and other techniques. In many instances, the active agents also change the microenvironmental pH conditions; this can also have a significant adverse effect on mobility of the organisms and viability of their eggs.
Treatment of ectoparasites can be conducted using a composition which generates a strong hydration reaction, when contacted with water. In one embodiment, the composition is a particulate solid, a semi-solid or a fluid containing substantially no aqueous matter, or in some instances only a small amount of water, and which contains a particulate inorganic substance that undergoes a strong hydration reaction in the presence of water. Examples of suitable substances are salts of alkali metals and alkaline earth metals. The hydration reaction is not necessarily one which results in formation of any new chemical compound, but can be an absorption-type reaction, and may be exothermic, endothermic or not involve any significant temperature changes.
The invention will be described primarily as it relates to the reduction of human head lice infestations, although those skilled in the art will recognize its applicability to other ectoparasites and animal subjects, and the inventors intend that their invention will have such applicability.
In the following description and the claims, it is intended that a reference to a percentage means percent by weight, unless the context clearly indicates otherwise. Since the chemical names for certain composition ingredients are quite cumbersome, some ingredients are identified herein by their adopted names as given in standard reference works, including J. A. Wenninger et al, Eds., International Cosmetic Ingredient Dictionary and Handbook, 8th Ed., The Cosmetic, Toiletry and Fragrance Association, Washington, D.C., 1999.
Lice egg cases (xe2x80x9cnitsxe2x80x9d) are thought to be attached to hair by means of mucopolysaccharide adhesive substances. Removal of the nits therefore requires a very thorough combing operation, and is not appreciably facilitated by many of the usual pesticide treatments. However, embodiments of the present invention provide both desiccation and a changed pH in the microenvironment of the nit, which can alter the physical and chemical nature of the egg casing itself. The provision of lubricious agents in a composition also can facilitate lice and nit removal by combing.
Suitable active agents for use in the present invention are generally those salts of alkali metals, ammonium ions, alkaline earth metals and transition metals that have a strong affinity for water. Examples of useful substances include one or more of lithium chloride, sodium chloride, sodium nitrate, sodium sulfate, potassium chloride, potassium nitrate, potassium sulfate, ammonium chloride, ammonium nitrate, magnesium chloride, magnesium nitrate, calcium chloride, calcium bromide, calcium nitrate, calcium sulfate, strontium chloride, strontium nitrate and zinc chloride. This listing is not intended to be exhaustive, as many other substances can be used. The compounds will be used in their anhydrous or substantially anhydrous forms, and mixtures of any two or more active agents can be used.
When an active ingredient is placed in contact with water, such as that contained in moistened hair, in the immediate vicinity of an ectoparasite or the egg of an ectoparasite, a desiccating microenvironment is created. Depending on the chemical nature of the active ingredient, there may also be a change in pH and/or a localized change in temperature. All of these environmental changes are detrimental to the viability of the ectoparasite and its eggs. The result will ideally be death of the ectoparasite and eggs, but in some instances inhibition of the mobility of the pest will be the primary effect. In any event, it will typically be necessary to remove the dead and immobilized organisms, and the eggs, by combing or other mechanical means.
In its least complicated embodiment, a desiccating composition for ectoparasite removal can contain only a solid particulate active ingredient or mixture of active ingredients, preferably in the form of finely divided particles. However, in many instances it will be desired to include other components, such as up to about 50 percent of inactive particulate fillers, diluents or extenders, such as talc, cornstarch and the like, to promote more uniform coverage of the area to which the composition is applied. These dry compositions can also include solid surfactants, so that the product can be easily removed following a treatment by merely adding water to form a cleansing environment (such as a shampoo) and then rinsing the treated area with additional water.
More typically, the composition will be fluid, such as in the form of a suspension or lotion containing about 1 to about 50 percent of the active ingredient or mixture of active ingredients, since such product forms are generally more easily applied.
Useful fluid desiccating compositions can be prepared by suspending, or in some instances dissolving, an active ingredient or mixture of active ingredients in a substantially anhydrous liquid vehicle such as: a hydrocarbon, including light and heavy mineral oils; a glycol such as a polyethylene glycol, propylene glycol or triethylene glycol; glycerol; and the like. Use of the glycols is presently preferred, since they can also act as desiccating agents. Typical concentrations of the vehicle range from about 1 to about 60 percent.
Optionally, a suspending agent may be present in a fluid desiccating composition to maintain a stable dispersion. Useful agents include, without limitation, fumed silica and polyvinylpyrrolidone having molecular weights from about 25,000 to about 100,000, in amounts about 0.1 to about 2 percent.
The compositions may further include other components, such as surfactants, lubricants, texture modifiers, acidifiers and/or preservatives.
Useful optional surfactants include, without limitation, sodium lauryl sulfate, sorbitan laurate, mixtures of glyceryl stearate and PEG-100 stearate, methyl gluceth-10, methyl gluceth-40, sorbitan palmitate, polysorbate 20, polysorbate 80, steareth-2 and many others. The surfactants will be present in amounts about 0.1 to about 16 percent, and can create shampoo-type products which are easily removed after the ectoparasite treatment is completed.
The lubricants that can be incorporated are represented by dimethicone, simethicone and other silicone-type materials, and act to lubricate and condition the hair, as well as facilitate passage of a comb through the hair. Useful concentrations, when this component is present, are about 0.1 to about 2 percent.
Optional texture modifiers that may be included are exemplified by stearic acid, cetyl alcohol, PEG-180, polyethylene glycol 1450 and polyethylene glycol 3350, in amounts about 0.1 percent to about 5 percent.
It may be desired to incorporate a pH-adjusting ingredient in the composition, if the hydrated active ingredient tends to establish excessively acidic or alkaline conditions (such as pH values which are less than about 4 or greater than about 9). Optional acidifiers that may be used include, without limitation, benzoic acid, citric acid and stearic acid. Useful optional alkalizers include, without limitation, calcium hydroxide, magnesium hydroxide and organic bases such as triethanolamine. The pH adjusters, when used, will generally be present in amounts about 0.1 percent to about 2 percent, as needed to obtain a desired bulk pH condition.
As an alternative to incorporating a pH adjusting ingredient, suitable bulk pH conditions can frequently be obtained by incorporating an active ingredient that yields acidic conditions together with another active ingredient which yields alkaline conditions.
Products that are intended for application to the skin frequently are protected against microbial proliferation by the inclusion of a preservative component. Suitable preservatives for use in the present compositions include, without limitation, methylparaben, propylparaben and benzethonium chloride. The preservative, when present, will typically be included in concentrations about 0.05 to about 0.2 percent.
Included within the scope of the present invention is a kit for treating an ectoparasite infestation, including a suitable container filled with a composition that can be applied to an area of the body to cause desiccation of ectoparasites, together with a mechanical device for removing ectoparasites after they are affected by the composition. For compositions that are in the form of a fluid, such as liquids, lotions and creams, the composition can be contained in a bottle or collapsible tube. Aerosol compositions can be contained in the customary dispensing canisters, fitted with a suitable valve for dispensing the product. Powdered compositions can be contained in one of the customary canisters having a perforated cap for shaking out a desired amount, or in a bottle. Many delousing combs are commercially available, being fabricated from plastic substances or metals, and any of these are suitable for inclusion in the kit. It is preferred that the kit be made suitable for a single use, including sufficient composition for one application.
The invention will be further described with reference to the following example, which is not intended to limit the scope of the claimed invention in any manner.

Schering-Plough HealthCare Products, Inc.


An object is to provide a novel anthracene derivative. Another object is to provide a light-emitting element with high luminous efficiency. Yet another object is to provide a light-emitting element with a long lifetime. Still another object is to provide a light-emitting device and an electronic device having a long lifetime by using the light-emitting elements of the present invention. The anthracene derivative represented by General Formula (1) is provided. The ability of the anthracene derivative represented by General Formula (1) to exhibit high luminous efficiency allows the production of a light-emitting element with high luminous efficiency and a long lifetime.

An organic compound can take various structures compared with an inorganic compound, and it is possible to synthesize a material having various functions by appropriate molecular-design of an organic compound. Owing to these advantages, photo electronics and electronics, which employ a functional organic material, have been attracting attention in recent years.
A solar cell, a light-emitting element, an organic transistor, and the like can be exemplified as an electronic device using an organic compound as a functional organic material. These devices take advantage of electrical properties and optical properties of the organic compound. Among them, in particular, a light-emitting element has been making remarkable progress.
It is considered that the light emission mechanism of a light-emitting element is as follows: when a voltage is applied between a pair of electrodes which interpose a light-emitting layer, electrons injected from a cathode and holes injected from an anode are recombined in the light-emitting layer to form a molecular exciton, and energy is released to emit light when the molecular exciton relaxes to the ground state. As excited states, a singlet excited state and a triplet excited state are known, and light emission is considered to be possible through either of these excited states.
In an attempt to improve the performances of such a light-emitting element, there are many problems which depend on the material, and in order to solve these problems, improvement of the element structure and development of a material have been carried out.
For example, in Patent Document 1: United States Patent Application Laid-Open No. 2005-0260442, an anthracene derivative exhibiting green light emission is disclosed. However, in Patent Document 1, only the PL spectrum of the anthracene derivative is described, and the device performance is not disclosed when the anthracene derivative was applied to a light-emitting element.
Also, in Patent Document 2: Japanese Published Patent Application No. 2004-91334, a light-emitting element using an anthracene derivative as a charge transporting layer is mentioned. However, in Patent Document 2, there is no description on the lifetime of the light-emitting element.
If commercialization is considered, extending the lifetime is an important issue. Further, the development of light-emitting elements with much higher performances is desired.

This patent is subject to a terminal disclaimer.

Anthracene derivative, and light-emitting element, light-emitting device, electronic device using anthracene derivative

Semiconductor Energy Laboratory Co., Ltd.


Method and apparatus for secure transmissions. Each user is provided a registration key. A long-time updated broadcast key is encrypted using the registration key and provided periodically to a user. A short-time updated key is encrypted using the broadcast key. The short-time key is available with each broadcast message, wherein sufficient information to calculate the short-time key is provided in an Internet protocol header preceding the broadcast content. Broadcasts are then encrypted using the short-time key, wherein the user decrypts the broadcast message using the short-time key.

1. Field
The present invention relates to data processing systems generally and specifically, to methods and apparatus for security in a data processing system.
2. Background
Security in data processing and information systems, including communications systems, contributes to accountability, fairness, accuracy, confidentiality, operability, as well as a plethora of other desired criteria. Encryption, or the general field of cryptography, is used in electronic commerce, wireless communications, broadcasting, and has an unlimited range of applications. In electronic commerce, encryption is used to prevent fraud in and to verify financial transactions. In data processing systems, encryption is used to verify a participant's identity. Encryption is also used to prevent hacking, protect Web pages, and prevent access to confidential documents, as well as a variety of other security measures.
Systems employing cryptography, often referred to as cryptosystems, can be partitioned into symmetric cryptosystems and asymmetric cryptosystems. A symmetric encryption system uses a same key (i.e., the secret key) to encrypt and decrypt a message. Whereas an asymmetric encryption system uses a first key (i.e., the public key) to encrypt a message and uses a second, different key (i.e., the private key) to decrypt it. Asymmetric cryptosystems are also called public key cryptosystems. A problem exists in symmetric cryptosystems in the secure provision of the secret key from a sender to a recipient. Further, a problem exists when keys or other encryption mechanisms are updated frequently. In a data processing system, methods of securely updating keys incur additional processing time, memory storage and other processing overhead. In a wireless communication system, updating keys uses valuable bandwidth otherwise available for transmission.
The prior art does not provide a method for updating keys to a large group of mobile stations in order that they may access an encrypted broadcast. There is a need, therefore, for a secure and efficient method of updating keys in a data processing system. Further, there is a need for a secure and efficient method of updating keys in a wireless communication system.

Method and apparatus for security in a data processing system


A stack of laminated transparent lenses consists of two alternating optically clear materials in intimate contact. The materials are a plastic lens and clear adhesive. The adhesive is uninterrupted. The lens and the adhesive have refraction mismatch of less than 0.2. A tab portion is part of each lens and acts as an aid in peeling away the outermost lens after contamination of the lens layer during racing conditions. The lens stack can be mounted to the posts on the face shield of a racing helmet or laminated directly to a windshield.

none
1. Field of the Invention
The present invention pertains to the following areas of technology: Apparelxe2x80x94Guards and Protectors; for wearer""s head and face; eye shields such as goggles having a lens-cover plate; and windshield covers.
2. Description of the Prior Art
Face shields are employed in environments where contamination of the eyes may occur. It is well known in the art that flexible transparent lenses affixed by numerous methods are overlaid on the face shield for protection. The lenses are easily removed and discarded when visibility is reduced from the accumulation of dirt or other contaminants. In motor sports for instance, multiple layers of transparent lenses are overlaid on the face shield, each being sequentially removed as they become contaminated, because they reduce the visibility of the operator. The drawback of the lenses in the prior art is that each transparent lens applied over the face shield is itself a hindrance to good visibility due to its optical index of refraction. Most common materials used as plastics have optical indexes of refraction ranging from 1.47 to 1.498. The index mismatch between the removable lens and air (air has an optical index of 1.00) causes a reflection of 4% of the light that would normally come to the operator""s eyes. This reflection effect is additive for each additional surface to air interface. Then for each removable lens having two surfaces, the reflections are 8%. Thus a stack of seven lenses would reflect 42% of the light away from the operator thereby reducing the brightness of the objects viewed. A second optical phenomenon occurs simultaneously that also reduces visibility. The reflections are bi-directional and thus make the lens stack appear as a semi-permeable mirror to the operator. This mirror effect further reduces visibility, because the light that passes through the lens stack reflects off of the operator""s face and then reflects off of the lens stack into the operator""s eyes. The effect to the operator is that he sees his own image on the inside of the stack nearly as brightly as the objects viewed on the outside. This significantly reduces visibility.
Another drawback to this stacking arrangement is that moisture exhaled by the operator""s breath can cloud or fog-up the lenses also reducing visibility. The air spaces between each lens allows the moisture to enter this area.
An object of the present invention is to provide a series of easily removable optically clear lens stacks that do not cause reflection to the operator""s eyes. The prior art discloses reflective lens stacks that do cause reflections to the operator""s eyes. An example of this type of prior art of reflective lens stacks is disclosed in U.S. Pat. No. 5,592,698 issued on Jan. 14, 1997 to Woods.
Refraction is the change in the direction in which waves travel when they pass from one kind of matter into another. Waves are refracted (bent) when they pass at an angle from one medium into another in which the velocity of light is different. The amount that a ray of a certain wavelength bends in passing from one medium to another is indicated by the index of refraction between the two mediums for that wavelength. The index of refraction indicates the amount that a light ray bends as it passes out of one substance and into another. When light passes from air to a denser substance, such as Mylar film, it slows down. If the light ray enters the Mylar film at any angle except a right angle, the slowing down causes the light ray to bend at the point of entry. This bending is called refraction. The ratio of the speed of light in air to its speed in the Mylar film is the Mylar film""s index of refraction.
The present invention includes a series of alternating optically clear films whose indexes of refraction are matched to within 0.2 and which will nearly eliminate all reflections to the operator""s eyes. The layers of film are adhesively laminated to one another and are compliant so there is no air between the layers. The film layers can be large and generally rectangular in shape with a tab extending from each of the film layers. The tabs can be staggered so that the user can remove the top most layer and then the next succeeding layer. This embodiment of the present invention can be applied to race car windshields, windows, visors or direct view displays such as ATM machines that are subject to contaminating environments. Accordingly, the present invention is an adhesively laminated multi-layered clear film adapted to be used on a racer""s face shield, or on the windshield of a race car to keep the viewing area clean during the course of a race.

Optical stack of laminated removable lenses for face shields windows and displays


An apparatus for producing, bagging and dispensing ice has an ice supply station, an ice collection station, a film supply, a bag forming station, and an ice transport device to transport ice from the collection station to the bag forming station. A controller controls supply of two superimposed film layers to the bag forming station, bag forming, and ice supply to the bags. A bag is partially formed from the superimposed film layers by a sealing device at the bag forming station, and ice is transported from the ice collector into the partially formed bag. The remaining open portions of the bag are sealed when sufficient ice has been supplied to the bag, which is then separated from the film supply for discharge into a storage and freezer compartment. The preceding steps are repeated until the storage and freezer compartment is filled to a predetermined level with bags of ice.

1. Field of the Invention
The present invention relates generally to ice making and dispensing machines, and is particularly concerned with a method and apparatus for producing, bagging and dispensing ice in bags.
2. Introduction
Machines have been developed for making ice in various forms (cubes or other shapes, crushed ice, and the like) packaging the ice loosely in bags, and delivering the bags of ice into a storage compartment accessible by customers in supermarkets. Such machines are designed with a top part with an ice cube making unit, a central packing machine which packs the ice loosely in bags, and a lower part with a storage compartment into which the bags are dropped from the packing machine. The storage compartment has an access door which can be opened by a customer to retrieve a desired number of ice bags.
In prior ice dispensing or distributing machines, the bagging process involved dispensing ice into pre-made bags which are stored in a magazine in the bagging unit. This is relatively expensive and requires frequent changing of magazines as the bags are used up. Another problem is variation in weight of ice supplied to each bag. Also, the ice can potentially start to melt as it is distributed into bags.
One example of an ice bagging apparatus is disclosed in U.S. Pat. No. 4,368,608. This apparatus comprise an ice maker which is placed above an ice collecting and bagging zone. The ice maker dispenses ice directly into a bag. This causes condensate to enter some of the ice bags during filling when the ice maker has completed a defrost cycle. This has the disadvantage that the water freezes the ice cubes together into bigger solid blocks, which are hard to separate.

Method and apparatus for producing, bagging and dispensing ice


A method of producing alkylene glycol esters of unbranched aliphatic dicarboxylic acids with limited homolog distribution, and the use of the esters produced as monomer structural units for producing polymers are disclosed.

This invention relates to a process for the production of so-called narrow-range alkylene glycol esters of unbranched aliphatic dicarboxylic acids and to their use as a monomer unit for the production of polymers.
The addition of alkylene oxides onto CH-acid compounds such as, for example, fatty alcohols, alkyl phenols, fatty amines or even fatty acids is one of the industrially established processes for the production of nonionic surfactants. These reactions are normally carried out in the presence of homogeneous basic catalysts such as, for example, sodium hydroxide or sodium methylate. Unfortunately, alkoxylation lacks selectivity as a reaction with the result that, in practice, it is found that the maximum of the resulting homolog distribution does not correspond with the average degree of alkoxylation, particularly with low alkoxylation ratios.
Attempts have been made to counteract this unwanted effect by using catalysts which have greater selectivity and which, overall, lead to alkoxylates, particularly ethoxylates, with a narrow homolog distribution. These products are often also referred to in the literature as xe2x80x9cnarrow-range ethoxylatesxe2x80x9d. Preferred homogeneous catalysts for this purpose are alkaline earth metal salts, for example barium phosphate or strontium ether carboxylates. Heterogeneous catalysts, for example calcined hydrotalcites, ay also be used for this purpose.
However, known processes for ethoxylating fatty acids have failed to produce satisfactory results. In particular, attempts to produce fatty acids with low degrees of ethoxylation, particularly fatty acid+1EO adducts, which are of interest as intermediates for the synthesis of ether sulfate surfactants with an isethionate-like structure, have revealed unsatisfactory selectivities. Besides the unwanted presence of homologs with relatively high degrees of ethoxylation, significant amounts of polyethylene glycol and diesters in particular are also formed. The process according to U.S. Pat. No. 3,884,946 (Henkel), which recommends using amines as catalysts for this purpose, also provides the xe2x80x9clow-ethoxylatedxe2x80x9d fatty acids in yields well below 90% of the theoretical.
According to EP-A-178 913, not only straight-chain fatty acids, but also branched neocarboxylic acids with a tertiary carbon atom adjacent the carboxyl group can be alkoxylated with high selectivity in the presence of amines, such as diethanolamine and triethanolamine. However, if high yields are to be obtained by this process, relatively high temperatures of 140 to 185xc2x0 C. have to be applied.
According to the cited prior art, the problem of the selectivity of the alkoxylation process has only been investigated for monomeric carboxylic acids. However, the problem of selective alkoxylation has not hitherto been addressed or, according to EP-A-178 913, has only been tentatively addressed for oligomeric carboxylic acids, more particularly unbranched aliphatic dicarboxylic acids. Accordingly, there is a need to find a selective process for the alkoxylation of unbranched aliphatic dicarboxylic acids.
Accordingly, the problem addressed by the present invention was to provide an improved process for the production of alkylene glycol esters of unbranched aliphatic dicarboxylic acids, more particularly unbranched aliphatic dicarboxylic acids with low degrees of alkoxylation, using a homogeneous catalyst which would be distinguished by improved selectivity.
Surprisingly, the problem stated above has been solved by the use of alkanolamines, particularly triethanolamine, as catalyst in the addition of alkylene oxides onto the unbranched aliphatic dicarboxylic acids. This process is particularly suitable for the production of unbranched aliphatic dicarboxylic acids with low degrees of alkoxylation.
Accordingly, the present invention relates to a process for the production of alkylene glycol esters of unbranched aliphatic dicarboxylic acids by addition of alkylene oxides onto unbranched aliphatic dicarboxylic acids in the presence of basic catalysts, characterized in that alkanol-amines are used as the basic catalysts.
In the context of the present invention, the expressions xe2x80x9calkoxylated unbranched aliphatic dicarboxylic acidsxe2x80x9d and xe2x80x9calkylene glycol esters of unbranched aliphatic dicarboxylic acidsxe2x80x9d are used synonymously. The expressions xe2x80x9caddition of alkylene oxidesxe2x80x9d and xe2x80x9calkoxylationxe2x80x9d are also used synonymously.
Dicarboxylic Acids
In the context of the present invention, unbranched aliphatic dicarboxylic acids are those which have no branches in the hydrocarbon group. Unbranched aliphatic xcex1,xcfx89-dicarboxylic acids corresponding to formula (I):
HOOCxe2x80x94Rxe2x80x94COOHxe2x80x83xe2x80x83(I)
in which R is a difunctional, unbranched, aliphatic, saturated and/or unsaturated hydrocarbon group, are preferred. The substituent R is preferably a hydrocarbon group of the described type containing 1 to 20 carbon atoms. Suitable dicarboxylic acids for the purposes of the invention are malonic acid, succinic acid, adipic acid and azelaic acid, which are commercially obtainable, and the unbranched aliphatic xcex1, xcfx89-dicarboxylic acids which can be obtained by fermentative or microbial processes from alkanes, alkenes, alcohols or esters thereof in the presence of a microorganism of the genus Candida tropicalis in the presence of nutrients and optionally co-substrates in accordance with DE-A-37 21 119 or DE-A-37 38 812. Unbranched xcex1,xcfx89-aliphatic dicarboxylic acids containing 10 to 20 hydrocarbon groups (R in formula (I)), which may even unsaturated, can be obtained particularly easily by this process.
According to the invention, unbranched aliphatic xcex1,xcfx89-dicarboxylic acids selected from the group consisting of malonic acid, succinic acid, adipic acid and azelaic acid are preferred.
Alkanolamines
Typical examples of alkanolamines, which may be used as homogeneous basic catalysts, are monoethanolamine, diethanolamine and preferably triethanolamine. The alkanolamines are normally used in quantities of 0.05 to 5% by weight and preferably in quantities of 0.1 to 1.5% by weight, based on the dicarboxylic acids.
Alkoxylation
The alkoxylation may be carried out by methods known per se and is described in the following with reference by way of example to ethoxylation.
Normally, the unbranched aliphatic dicarboxylic acid and the catalyst are first introduced into a stirred autoclave which is freed from traces of water before the reaction by alternate evacuation, preferably at temperatures of 80 to 120xc2x0 C., and purging with nitrogen. The unbranched aliphatic dicarboxylic acid is then reacted with the ethylene oxide which may be introduced into the autoclave in portions via a siphon after heating.
The molar reaction ratio of unbranched aliphatic dicarboxylic acid to ethylene oxide is preferably in the range from 1:0.5 to 1:6.0 and preferably in the range from 1:1 to 1:3.0. The process shows particular advantages in regard to selectivity where about 2 moles of ethylene oxide are reacted per mole of dicarboxylic acid (molar ratio 2:1).
The ethoxylation may be carried out at temperatures of 90xc2x0 C. to 130xc2x0 C., but is preferably carried out at a temperature of 100 to 120xc2x0 C. If reaction temperatures above 140xc2x0 C. are selected for the process as a whole, the selectivity of the-addition of ethylene oxide diminishes. Autogenous pressures of 1 to 5 bar and preferably 3 to 5 bar are recommended for the ethoxylation reaction. At the end of the reaction, it is advisable to stir the reaction mixture for a certain time (15 to 90 mins.) at the reaction temperature and under the autogenous pressures in order to complete the reaction. The autoclave is then cooled, vented and, if desired, acids such as, for example, lactic acid or phosphoric acid are added to the product in order to neutralize the basic catalyst.
The foregoing observations on the pure ethoxylation reaction also apply accordingly to the pure propoxylation and to the mixed ethoxylation and propoxylation reaction. For the mixed ethoxylation and propoxylation reaction, either a mixture of ethylene oxide and propylene oxide or first ethylene oxide and then propylene oxide or vice versa may be reacted with the unbranched aliphatic dicarboxylic acids, the molar ratios of unbranched aliphatic dicarboxylic acids to alkylene oxide, i.e. ethylene oxide and propylene oxide in the mixed ethoxylation and propoxylation reaction, being in the above-mentioned range of 1:0.5 to 1:6, preferably in the range from 1:1 to 1:3 and more preferably of the order of 1:2.
In principle, the process according to the invention is also suitable for alkoxylation with butylene oxide, although the alkoxylation reaction is preferably carried out with ethylene oxide and/or propylene oxide and, more particularly, with ethylene oxide only.
The addition of the alkylene oxides onto the two carboxyl groups of the dicarboxylic acid is a statistical process, i.e. alkylene oxide units are added onto both carboxyl groups with a very high degree of probability.
The process according to the invention gives product mixtures, alkylene glycol monoesters of the branched aliphatic dicarboxylic acids which correspond to formula (II):
H (O Alk)nOOCR COO(AlkO)mHxe2x80x83xe2x80x83(II)
in which R is as defined for formula (I), Alk is an alkylene oxide unit, more particularly a CH2CH2, CHCH3CH2 and/or CH2CHCH3 unit, and n and m are each a number of 0 to 6.0, the sum of n+m being a number of 0.5 to 6, being formed in quantities of preferably more than 85% by weight and, more preferably, more than 90% by weight. In one particular embodiment, n and m in formula (II) stand for the number 1.
As can be seen from formula (II), by far the majority of the product mixtures obtained in accordance with the invention are monoesters of alkylene glycols, i.e. the alkylene glycols added on still have one free hydroxyl group and are esterified at the other hydroxyl group with a carboxyl group of the unbranched aliphatic dicarboxylic acid. If the free hydroxyl group of the alkylene glycols is esterified with another carboxyl group of another unbranched aliphatic dicarboxylic acid, higher molecular diesters of alkylene glycols are formed. Another advantage of the process according to the invention is that the percentage content of such diesters, which is particularly problematical in the case of the higher molecular unbranched aliphatic dicarboxylic acids, can be reduced. Thus, the products obtained by the process according to the invention preferably have a monoester content of more than 85% by weight and, in particular, more than 90% by weight and a diester content below 7% by weight and preferably below 5% by weight, based on the end product. The balance to 100% by weight consists of unreacted residual acid.
The selectivity of the process according to the invention is reflected in the fact that at least 90% by weight and preferably at least 95% by weight of the compounds corresponding to formula (II) have substantially the same number as the degree of alkoxylation n or m, the sum of n and m corresponding to the reaction ratios of alkylene oxide per mole of unbranched aliphatic dicarboxylic acid. In other words, compounds of formula (II) of which at least 90% have substantially the same value (i.e. 1) for n and m are formed in the addition of 2 moles of ethylene oxide onto 1 mole of unbranched aliphatic dicarboxylic acids.
The addition products obtained by the process according to the invention may be regarded in the broadest sense as diols with an ester function which may be used, for example, in the production of polyesters. Accordingly, the present invention also relates to the use of the addition products of alkylene oxides with unbranched aliphatic dicarboxylic acids produced in accordance with claim 1 as a monomer unit for polymers, more particularly for polyesters.

Method for producing alkylene glycol esters with limited homologue distribution


A housing of a switchgear cabinet for a printing machine, with housing elements formed of electrically conductive material having an electrically insulating surface layer, includes at least one door, one body and one electrically conductive elastic seal disposed therebetween, respective mutually allocated elements of the housing elements having corresponding electrically conductive contact locations at electrically conductive strip material connected to the conductive material of the housing elements; each of the contact locations being covered by a protective layer which is removable during assembly of the cabinet, for the purpose of electrically conductively connecting the housing elements and the seal.

The invention relates to a housing of a switchgear cabinet for a printing machine, with housing elements formed of electrically conductive material, which have an electrically insulating surface layer, and which include at least one door, one body and one electrically conductive elastic seal disposed therebetween.
The cabinet includes a body, at least one door and at least one electrically conductive seal that is disposed therebetween for the purpose of sealing and shielding the housing elements. The body is formed of various housing elements, such as ceilings, floors, walls, and detachable accessories or insertion parts for receiving the components or subassemblies of the electronic control.
The housing elements are produced from electrically conductive material. Steel or steel plate are preferably utilized for this purpose. They are protected against corrosion by an appropriate surface treatment such as varnishing, coating or surface tempering. In this process, the housing elements are individually surface-treated and then assembled into the switchgear cabinet.
To ensure undisturbed operation, it is necessary to satisfy electromagnetic compatibility (EMC) requirements, whereby electromagnetic fields must be shielded. On one hand, the interior of the switchgear cabinet must be kept free of electromagnetic fields, and on the other hand, the environment must be protected from electromagnetic fields which arise in the interior of the cabinet. It is also possible to provide separate electromagnetic shielding for individual compartments in the interior of the cabinet.
It is particularly important that the surface of the cabinet or of the individual compartments be completely electrically conductive. An electrical field acts upon the conductive surface to the effect that charge displacements are generated in the conductive housing material, which produces a charging of the surface. These charges of the cabinet, known as surface charges, generate a field which precisely counteracts the field acting upon the surface. The interior of the cabinet is then ideally entirely free of fields. The functional principle that is used therein is based on what is known as the Faraday effect, with the cabinet forming a so-called Faraday cage.
To achieve complete shielding, the cabinet must be produced with an optimally uniformly conductive surface, so that disturbances stemming from various properties or thicknesses of the materials or other instabilities in the surface can be avoided. Particularly in moving parts such as the door, all edges must be conductively connected to the body, because unstable points of the surface will emerge there otherwise, at which a transfer of electromagnetic fields could occur.
In addition, the housing of the switchgear cabinet must be sealed against dust, oil vapors, and moisture (IP) and against other environmental influences in the vicinity of the machine operation.
German Patent 196 10 045 thus proposes the disposing of an EMC seal between the body and the door. The EMC seal is electrically conductive and elastic, and connects the housing elements which are allocated to one another. To this end, seals made of conductive plastic material, plastic-material seals having electrically conductive coverings, or electrically conductive metal nettings and braidings (for example, sheet covers having contact locations or points at the adjoining housing element) are proposed. Additional EMC seals which serve various functions such as sealing a window or a mountable coverplate are known from German Patents 9107917 and 296 09 873.
A disadvantage of these seals is that the insulating surface treatment renders the connections between the mounted housing elements, i.e., between the seal and the body or the door, insufficiently conductive. As a result, the housing of the cabinet has the required thorough and stable electrical conductivity only accidentally, if at all.
In addition, so-called two-chamber systems have become known, which have an inner housing made of conductive material, e.g., hot-galvanized sheet and state-of-the-art EMC seals, and an outer housing wherein the inner housing is disposed. The outer housing is produced from varnished sheetmetal or plastic material with corresponding seals against dust and moisture. A disadvantage of this arrangement is in the production outlay and the associated cost disadvantages, as well as poor accessibility, because the various housings impede access to the electronic components or subassemblies in the interior of the cabinet.
An additional measure is to provide a varnished housing having two seals, one of which is provided against dust and moisture (IP), and the other of which is provided as an EMC shield. What poses the biggest problem here is obtaining good and reliable conductivity over the course of several years, as well as the high outlay in production.
The published German Patent Document DE 42 07 308 C2 teaches a method for producing a sheetmetal housing from a housing body having at least one sealing part wherein the housing body and an opening can be connected to one another in an electrically and magnetically conductive manner. To this end, the housing body is greased, and a contact surface is then placed on the housing body in a flame injection procedure and covered with a cover strip. Next, the housing body is cleaned and varnished, and the cover strip is removed. The sealing part is either chromated or is formed of rustproof material, or it is provided with a contact surface in the same manner. Next, the housing body and the sealing part are connected to an elastic HF sealing element. This method is disadvantageous due to the great outlay and the associated costs.
It is accordingly an object of the invention to overcome the above mentioned disadvantages by providing a shielded switchgear cabinet housing with surface-treated housing elements with which it is possible to obtain an optimal shielding against electromagnetic fields, in particular by producing considerably uniform conductivity of the overall switchgear cabinet.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a housing of a switchgear cabinet for a printing machine, with housing elements formed of electrically conductive material having an electrically insulating surface layer, comprising at least one door, one body and one electrically conductive elastic seal disposed therebetween, respective mutually allocated elements of the housing elements having corresponding electrically conductive contact locations at electrically conductive strip material connected to the conductive material of the housing elements; each of the contact locations being covered by a protective layer which is removable during assembly of the cabinet, for the purpose of electrically conductively connecting the housing elements and the seal.
In accordance with another feature of the invention, the protective layer is formed of at least one material selected from the group consisting of paper, plastic material, metal and a composite material.
In accordance with a further feature of the invention, the contact locations are elevations which are embossed and/or stamped in the conductive material of the respective housing element.
In accordance with an added feature of the invention, the contact locations form a contact surface.
In accordance with an additional feature of the invention, the strip material is covered with a removable film.
In accordance with yet another feature of the invention, mutually corresponding contact locations are constructed at the housing elements, which are to be connected as a borehole into which a self-cutting conductive screw with a cutting thread is screwable, the self-cutting screw, when tightened, serving for cutting into the conductive material and for gas-tightly sealing the borehole.
In accordance with yet a further feature of the invention, the self-cutting screw has at least one cutting element on an inner surface of a screw head thereof, and when the screw is tightened, the cutting element serves for cutting through the insulating surface coating into the conductive material of a respective adjoining housing element.
In accordance with yet an added feature of the invention, the cutting element is an annular or ring cutter.
In accordance with yet an additional feature of the invention, the self-cutting screw has a surface with low contact resistance.
In accordance with still another feature of the invention, the surface of the self-cutting screw is selected from the group consisting of zinc-plated, nickel-plated, chromated and blue-chromated surfaces.
In accordance with still a further feature of the invention, the seal is electrically conductively secured via a contact surface to at least one of the door and the body and, assuming that the door is closed, contacts corresponding contact locations on an allocated opposing surface for assuring a conductive connection.
In accordance with a concomitant feature of the invention, the strip material is flexible.
Thus, provided in accordance with the invention is that the joint surfaces of the housing elements are kept electrically conductive. To this end, contact locations are produced at the joint surfaces of the conductive materials of the housing elements and provided with a protective layer prior to the varnishing or surface coating. The contact locations are covered by the protective layer when they are varnished or coated with an insulating material. The protective layer is not removed until the cabinet is assembled, so that after assembly a permanently electrically conductive connection emerges between the individual housing parts by way of the direct contact of the conductive housing elements at the contact locations. The protective layer is applied to the conductive material of the housing elements prior to the varnishing or coating of the conductive housing elements, so that a residue-free conductive surface is available for the conductive assembly process.
Advantageously provided for is that the protective layer is formed of paper, plastic material, metal and/or a composite material. Simplicity is served in that conventional film or foil-type cover materials can be utilized, for example, materials which are provided with an adhesive layer on one side that can easily be removed from the electrically conductive material of the housing elements. Materials made of composites having a stable, torsionally resistant carrier layer including an absorbent layer have proven to be particularly well suited. The absorbent layer can, in accordance with the invention, consist of paper or a similar material, and the torsionally resistant carrier layer can be produced from plastic material or metal.
An advantageous embodiment of the invention is realized in that the contact locations are elevations which are embossed or stamped into the conductive material of the housing element. In order to be able to produce a conductive connection between the housing elements, the contact locations must be constructed so that the material thickness of the varnish or coating of the two adjacent housing elements is overcome, because the contact locations would otherwise be spaced a corresponding distance from one another. To this end, provision is made for this equalization to be produced by slight elevations which are preferably embossed or stamped. The elevations should be constructed so that the housing does not become leaky. This is preferably achieved in that the elevation exclusively compensates for the material thickness of the surface coating at the contact surfaces, so that the housing elements abut one another on flat surfaces.
Another embodiment is achieved by the fact that the contact locations form a contact surface. To achieve an optimal seal and shielding of the housing, there is provided, in accordance with the invention, that the contact locations be produced as contact surfaces. This is achieved in, accordance with the invention, by the fact that the contact locations are at an electrically conductive, preferably flexible strip material, which is connected to the conductive material of the housing element. The strip material can thus be applied to the blank conductive housing element prior to the treatment of the surface. So that the strip has a conductive contact surface subsequent to the surface treatment, it is further provided that the strip material be covered with a removable film. The film is preferably heat-resistant and can be removed following the surface treatment.
This preferably self-adhesive strip is constructed, according to the invention, as fabric tape. It includes a conductive glue on one side and is formed of conductive material. The fabric tape is covered by a protective film that is removable. The fabric tape is particularly well suited to remaining free of deformations and maintaining electrical conductivity in the subsequent combustion process for burning-in the varnish.
Furthermore, the film over the self-adhesive fabric tape is approximately 1 mm narrower than the actual fabric tape in the marginal region. Thus, in the varnishing process, the varnish is also applied to the fabric tape, at least at the margins, which imparts an additional holding effect to the fastening action. The conductive adhesive is insensitive to various solvents of the pretreatment agents which are required in order to pretreat the cabinet prior to varnishing, and also to varnishing and or coating materials. Also, the removable film has a corresponding resistance. The tape material and the film are also stable especially at the high temperatures which are needed to burn-in the varnish. When the film is removed following the cleaning, varnishing, and burn-in processes, the film does not leave behind any adhesive or other residues on the conductive fabric tape. This embodiment thus represents a simple and economical possibility for producing a conductive connection.
The housing elements can be connected by clamps or clips, in a conventional manner. An inventive alternative for fixing the housing elements is realized in that mutually corresponding contact locations are constructed as boreholes at the housing elements that are to be connected, into which a conductive self-cutting screw having a cutting thread can be inserted; and the self-cutting screw cuts into the conductive material when the screw is tightened. The housing elements can thus be fixed to one another by screw connections and, at the same time, a conductive connection is produced, whereby the self-cutting thread cuts into the conductive material of the housing elements when tightened. Boreholes wherein the screws are inserted are provided at the housing elements for this purpose.
Another embodiment is prepared by providing that the self-cutting screw has at least one cutting element located at the inner screw head thereof, preferably an annular blade, and that the cutting element cuts through the insulating surface coating into the conductive material of the adjoining housing element when the screw is tightened. This enhancement of the screw produces an improved conductivity of the screw and the screw head with the adjoining housing element. Provided in accordance with the invention is that the screw cut the self-cutting thread thereof into a borehole at the other housing element. The adjoining housing element is simply pressed to the other housing element by the pressing force of the screw head. So that the screw head produces a conductive connection to the adjoining housing element, the cutting element is provided so as to cut through the insulating surface coating into the conductive material of the housing element. According to the invention, an annular or ring blade is advantageous in this regard.
In principle, any conductive screw with a self-cutting thread which is made of sufficiently hard material is suitable. It has proven particularly advantageous when the self-cutting screw has a surface with low contact resistance, which is preferably zinc- or nickel-plated, chromated or blue-chromated. An improved conductivity can be achieved advantageously by the surface treatment of the screw. Furthermore, a low contact resistance is achieved with the surface-treated screw, which makes possible an optimal conductivity, i.e., an optimal shielding.
The contact locations produced in accordance with the invention can be used to achieve an electrically conductive connection between the EMC seal and the door and/or the body by way of a contact surface. When the door is closed, it contacts corresponding contact locations on an allocated opposing surface and ensures a conductive connection. This produces an optimal shielding of the housing, because the seal connects the contact surfaces at both housing elements. The seal thus creates a conductive connection between two mutually allocated housing elements which are not connected to one another directly.
In another advantageous embodiment, provision is made for the seal to be electrically conductively fastened to the door and/or the body by way of a contact surface, and for it to contact corresponding contact locations on an allocated opposing surface when the door is closed, thereby ensuring a conductive connection. The seal may be fastened to the door or the body. For this purpose, the door has a number of contact locations, or a contact surface. These encompass the entire fastening surface of the seal at the door. The opposing surface is then disposed at the body and likewise includes a number of contact locations for producing the electrical connection between the two housing elements. On the other hand, the seal can be fastened at the body, which then has the corresponding contact surface, while the opposing surface that is provided with corresponding contact locations is disposed at the door. The seal is advantageously constructed as a plug seal that is insertable in separately provided fastening openings in order to fasten the strip material, and that clamps the strip material between the seal and the housing element.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a shielded switchgear cabinet housing, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: