The invention provides a method for fastening a polymeric label to a glass, plastic or metal container or surface by means of a water based adhesive composition by the following steps:

This invention relates to polymeric sheets or rolls particularly adapted for use as labels in the post mold labeling of plastic, glass or metal containers or surfaces. More particularly, the present invention relates to polymeric film substrates adapted for printing that also have a hydrophilic surface layer for use as labels in post mold labeling applications using conventional wet applied water based labeling equipment typically used for the application of paper labels. In another aspect the invention relates to such labels which possess the beneficial properties of the known plastic label substrates, but which are able to be applied on conventional post mold paper labeling equipment using wet applied water based solutions comprising water, water blended with a selected crosslinking catalyst, adhesives or adhesives blended with a selected crosslinking catalyst.
Plastic and glass containers or bottles are prevalent in a wide variety of shapes and sizes for holding many different types of materials such as detergents, chemicals, motor oil, beer, etc. These containers are glass or plastic (mono or multi layers) of polyethylene, polypropylene, polyester or vinyl along with other specialty blends for specific barrier and product resistance performance. Generally such containers are provided with a label which designates the trade name of the product and may contain other information as well. The early art which still is prevalent today employed the use of labels manufactured from paper substrates that were applied with a water based adhesive. Subsequently, dry pressure sensitive self adhesives and in mold labels manufactured from paper have been and continue to be used. The shortcomings of paper labels with regard to tearing, wrinkling, creasing and the like due to age and moisture, or due to a lack of deformability when applied to a deformable plastic substrate have been well documented in the labeling industry. Because of this and the need to produce recyclable plastic containers, over the years a great deal of effort has been expended to develop container decoration techniques and durable film substrates which would overcome these shortcomings.
Film facestocks for container decoration which have resulted from these efforts can be applied to glass and plastic containers as self adhesive pressure sensitive labels as described in the prior art. The use of self adhesive paper and film xe2x80x9cpressure sensitive adhesivexe2x80x9d (PSA) labels that have been preprinted and supported on a release liner is not a cost effective option because of the added cost of the release liner used to support and render processable the self adhesive face stock. The cost of this type of structure combined with the added cost of disposal of the liner does not make pressure sensitive labeling a desirable option from an economic or environmental standpoint. In addition, new capital intensive labeling equipment is required to transition from wet applied Post Mold Labels (PML) to self adhesive PSA labels plus the effect of a new process on an existing packaging line in terms of learning cure and experience.
Another film face stock labeling technique that has evolved is the use of heat activated in-mold labels as described in the prior art where a preprinted plastic label with a heat activated adhesive is placed in the mold before the molten plastic resin is injected or blown into the mold cavity at elevated temperature and pressure which activates the adhesive and fuses the label substrate to the container in-mold. The use of film based in-mold label substrates presents a more cost effective alternative then self adhesive pressure sensitive labels in terms of substrate cost but as this technology has progressed, it has been found that productivity is impacted by the label feeding step into the mold which is performed in a complex, continuous and rapid manner which results in large amounts of scrap material. Also, the initial capital investment required to tool up for a container specific in-mold label process for new molds and the complex electromechanical maintenance intensive feeding devices is significant. Another detriment for this process is the potential inventory carrying costs for varieties of labeled containers that come into play with predecorated containers such as in-mold for those who would choose to apply the label immediately pre or post filled.
Post mold decoration of glass and plastic containers in the current art can also be accomplished by direct screen printing on the container. Direct screen printing on the container is not a cost effective process and also presents the aforementioned inventory problems along with added cost for freight to and from a screen printer. The graphical possibilities for label copy are limited in terms of cost and quality with this technique. Commodity products can not support the cost of this labeling technique.
Another post mold technique that has been popular is the xe2x80x9cTherimagexe2x80x9d process. This process transfers a reverse printed image from a transfer release sheet under temperature and pressure to produce decorated containers. The xe2x80x9cTherimagexe2x80x9d technique of transferring a reverse printed image is costly because of transfer sheet costs and presents the same disposal problems and costs with the transfer sheet as occurs with the aforementioned release liner used in conjunction with self adhesive labels. Graphic design and quality is limited with this technique.
Other techniques for labeling various plastic and glass containers with preprinted paper or film label substrates include the use of hot melt adhesives which are applied to the label substrate or container in a molten state with container and substrate subsequently married while the hot melt is molten. When the hot melt adhesive cools, it sets up and bonds the label substrate to the container.
This technology requires the use of sophisticated melting and application equipment that must be operated, cleaned and maintained at elevated temperatures. This technology works well with complete 360 degree wrap around labels but has not evolved to the point to allow consistent labeling of a die cut or square cut label with less than 360 degree wrap. Affixing a cut label to an area on a container with 100% or patterned adhesive application using hot melt adhesives has not been commercially perfected. Complete wrap around hot melt applied labels where one end of the label is affixed to the container while the other end is wrapped around the container and affixed with hot melt to the label substrate is proven hot melt label application technology that works well for film and paper label substrates. This technology requires that the container be round and does not fit for individually labeled panels on a containers such a rectangular oil, contoured detergent or beer containers where a neck and front label only are applied. Another drawback is the added cost for label substrate when this technique is used since more label substrate is required because of the 100% wrap around.
Lastly, and still one of the most prevalent labeling techniques is the application of paper based labels to glass and plastic containers using natural and synthetic labeling adhesives such as BL300 produced by Henkel Adhesives or OC363-20 produced by O. C. Adhesives Corp. which are known to the art.
This is a safe (water based) proven technology that has grown and been employed for many years and consequently there are many existing machines that have been installed for this type of labeling technique such as from Krones, Neutraubling, Germany that run cut precut labels or Koyo, Japan which runs roll stock that is cut on machine to the label size. The cut label techniques and associated adhesives work well with paper based substrates applied to glass, plastic or metal containers because the wet adhesive wicks (absorbs) into the paper substrate from the applicator roll, pad or pallet which breathes and allows the moisture from the water carrier to be absorbed by and dry thru the paper base.
This technique obviously will not work with non-porous polymeric substrates as the adhesive can not wick into the polymeric substrate for initial tack and adhesive transfer to the label or drying thru the plastic. Typically, wet applied cut label machines work where glued pallets remove the label out of the label holding magazine while simultaneously gluing the back side of the label. This is accomplished by applying a thin glue film to the pallet which is then pressed in intimate contact against the first label in the stack.
After its removal, the label sticks on the entire glued area of the pallet until transferred to a xe2x80x9cgripperxe2x80x9d cylinder and removed from the pallet. The gripper cylinder than transfers the label to the container to be labeled. The various machine designs and techniques are well known within the labeling industry and to those skilled in the art. The xe2x80x9cKrones Manual Of Labeling Technologyxe2x80x9d by Hermann Kronseder dated December 1978, is hereby incorporated by reference.
Attempts have been made to use polymeric substrates with high moisture vapor transmission rates (MVTR) and tacky or pressure sensitive adhesive on conventional labeling equipment with little success. The tacky adhesive required to stick to the water impervious polymeric substrate causes machining problems by gumming up the adhesive application system and creates cleanup issues. The high MVTR substrates also did not have good wet tack with existing commercially available adhesives that would machine without problems and did not dry rapidly enough making the labels prone to xe2x80x9cswimmingxe2x80x9d or moving from the desired application area during down stream processing. In addition, the adhesives do not wet out and apply uniformly to non hydrophilic surfaces with the crude adhesive metering and application systems currently in use on existing paper labeling machinery. Without uniform application, wet out and wet tack, it will be impossible to apply a clear label that has the no label look because of adhesive and application imperfections.
Accordingly, it is an object of the invention to provide a polymeric label particularly adapted for use in post mold wet applied labeling of polymeric, glass and metal containers that would readily feed from the label magazine or gripper, adhere with sufficient tack without moving through post labeling handling and processing including but not limited to conveying, filling, case packing and pelletizing.
It is also an object of the invention to provide a polymeric label particularly adapted for use in post mold wet applied labeling of polymeric and glass containers that would have sufficient wet tack and affinity for water, a water based solution or adhesive used to allow for transfer of the water, water based solution or water based adhesive to the polymeric label substrate from the applicator roll(s), pad(s) or pallet(s) of the labeling machine.
It is also an object of the invention to provide a polymeric label for use in post mold wet applied labeling of polymeric and glass containers that would have a coefficient of expansion or contraction under the conditions which the container sees which is the same or compatible with that of the polymeric resin, glass or metal from which the container is made so that expansion and contraction of the container will not wrinkle or otherwise affect the integrity of the label.
It is also an object of the invention to provide a polymeric label for use in wet applied post mold labeling which would combine suitable properties of modulus of elasticity and flexibility and would not be degraded by handling and flexing of the subsequent container. Finally, it would be desirable to provide a label for use in wet applied post mold labeling of polymeric containers which does not have to be removed from such containers in order to recycle or regrind defective or post consumer polymeric containers.
In considering the performance or economic shortcomings of prior art materials, I have discovered a process by which a polymeric label may be applied to a glass, plastic or metal container or surface by means of a water based adhesive composition, said method comprising:
(a) applying a layer of a hydrophilic solid material to a polymeric label to form a hydrophilic layer on said polymeric label;
(b) applying water, water containing a cross-linking agent or a water based adhesive over said hydrophilic layer to form a fastenable polymeric label; (c) fastening said fastenable polymeric label to a glass, plastic or metal container or surface; and
(d) curing said polymeric label on said glass, plastic or metal surface or container.
Hydrophilic materials are selected so that their coefficients of expansion or contraction, thickness and modulus of elasticity when applied to a polymer film will result in a polymeric film facestock that will have hydrophilicity, absorbtivity, wet tack and drying properties that will permit the polymer film to be applied to polymeric, glass or metal containers via water based wet labeling techniques on standard paper labeling equipment. The apparatus which is used to apply paper labels is well known to those in the art. The polymeric label substrate with the hydrophilic coating will demonstrate sufficient xe2x80x9cwet tackxe2x80x9d during the label application period and the label drying period to permit containers to be handled and processed. The polymeric film based facestock will provide a label with printability, chemical and dimensional stability, resistance to cracking, tearing, creasing, wrinkling or any other degradation of the sort experienced by paper labels due to physical or environmental extremes.
The invention also permits the use of a water based adhesive to fasten a clear or contact clear polymeric film substrate which is reverse printed and then overcoated with the hydrophilic layer to glass or plastic containers using a water base adhesive. As used herein the reference to a xe2x80x9ccontainerxe2x80x9d includes a surface of an objects made of glass, plastic or metals such as dishes, bottles, cans, toys and building materials.
Optionally, if a metalized coating of a thin metal film is deposited on the polymeric sheets or rolls, premium quality decorative labels with all of the advantages set forth above will be provided.
The hydrophilic component or blends containing the hydrophilic component will be applied in the present invention to the selected polymeric sheet in a continuous or patterned layer to provide the absorptive, wet tack and drying properties that are necessary to enable polymeric sheets to be successfully used as label substrates on polymeric or glass containers when applied with water based wet labeling techniques. The hydrophilic layer, which may be applied by either a coating or an extrusion technique, has the function of absorbing a major portion of moisture to activate the layer as an adhesive thus causing selected hydrophilic layers to function as an adhesive without any applied adhesive or to absorb the moisture from an adhesive if used, to cause the polymer film to adhere to the glass, plastic or metal container and to set up rapidly and positively.
It is also possible to coestrude the hydrophilic layer with the polymer film layer.
The choice of polymeric substrate for the label film will determine the rigidity, deformability or conformability, regrindability, printability and expansion or contraction characteristics required for application to the selected container without the problems associated with paper labels.
In addition, the polymeric film substrate for the substantially label will be selected so that it will expand or contract to the same degree as the container so that when ambient conditions change, the label will not pucker or blister.
The term xe2x80x9cfilm facestockxe2x80x9d or xe2x80x9cpolymeric label substratexe2x80x9d as used herein should be taken for purposes of the present invention to refer to a material compatible in terms of rigidity, deformability or conformability, regrindability if a plastic container and expansion or contraction characteristics with the plastic or glass container to be labeled. Similarly, the xe2x80x9chydrophilic layerxe2x80x9d previously mentioned has the properties of wet tack, absorbtivity, drying, sufficient adhesion to the polymeric label substrate and affinity and adhesion to the labeling adhesive if used in the wet or dry form.
It is contemplated that selected hydrophilic layers can be wet or remoistened without adhesive for use on a glass, plastic or metal container or a water based adhesive can be used to affix the polymeric label substrate with the hydrophilic layer to the glass, plastic or metal container. For deformable containers, the adhesive if used, can be selected from those commercially available that are characterized by the ability to form a bond with the container and a hydrophilic layer such that when dry, the strength of the container wall-adhesive interface and the hydrophiliic layer-adhesive interface and the cohesive strength of the adhesive itself are all greater than the forces required for deformation of the label.
As used herein and in the appended claims, the term xe2x80x9chydrophilicxe2x80x9d is used to describe materials or mixtures of materials which bind or absorb water. The preferred xe2x80x9chydrophilicxe2x80x9d materials are those acrylic polymers which bind or absorb water. The especially preferred xe2x80x9chydrophilicxe2x80x9d material is DP6-6006, a sodium polyacrylate from Allied Colloids.
It is also an aspect of the present invention to use crosslinkable (reactive) components in the hydrophilic layer that can cure with a catalyst supplied in the rewetting water or adhesive (if used) that will promote adhesion to the labeled container along with chemical and moisture resistance. Examples of cross-linkable materials are those which contain carboxyl groups, hydroxyl groups or other functional group which will react with a cross-linking agent. The catalyst can also be added to the adhesive which may or may not have reactive components which would cure the adhesive and hydrophilic layer together or the catalyst may only cross-link the hydrophilic layer. When water and a cross-linking catalyst are combined, the composition will comprise 0.25-10% by wt. of cross-linking catalyst.
The coated, extruded or coextruded hydrophilic layer functions in effect as an adhesive layer which is defined as a substance capable of combining two surfaces by the formation of a bond whether it is a moist hydrophilic layer to glass or polymer or a dry hydrophilic layer to a wet labeling adhesive which is an intermediate layer that bonds to both the hydrophilic layer and glass or polymer of the container when dry.
The use of the proper hydrophilic layer for a given polymeric labeling substrate and container to be labeled will have a direct effect on the speed which the labeling line can be run.
When considering the choice of the material which forms the hydrophilic layer, which may be applied by coating, coextrusion or extrusion, one must consider the label substrate, container to be labeled, labeling machinery, water or adhesive application technique and down stream processing requirements such as filling, conveying and packing. In addition the final appearance of the label such as the clear no label look or a plain opaque label must be considered in the choice of the components of the hydrophilic layer. Generally, a deposit of from 0.25 to 8 lbs./3000 FT2 of the hydrophilic layer, when dried, may be employed on the polymeric film layer, depending on the particular hydrophilic material that is selected.
It is critical to the successful application of a hydrophilic polymeric film label to control how the water or water based adhesive is applied to the hydrophilic layer, how deposition (weight or thickness) is controlled and how the resultant combination with the container is pressed together. Generally, from 0.25 to 1.5 g./sq. ft. of water or water based adhesive is applied to the hydrophilic layer with 100% coverage of the label. If a grid or other pattern of adhesive is employed, then the amount of adhesive may be reduced. If a grid pattern is employed, the hydrophilic layer may be applied to be substantially in register with the adhesive layer. It will generally be possible to reduce the typical amount of adhesive applied to a label when using the hydrophilic layer of the invention to an amount which is 20-80% of the amount that is typically employed for affixing paper labels to a surface. The choice of the hydrophilic layer and the type of label substrate and container to be adhered together, as discussed above, the plant processing conditions after labeling, storage requirements and the end use requirements that must be met such as high temperature resistance or ice proofness and the choice of an intermediate adhesive layer are important considerations. There are many more specific variables within these considerations all of which influence the formulation of the proper hydrophilic layer and adhesive (if used) for a specific application.
The bonding of the hydrophilic layer with or without an intermediate adhesive layer can be accomplished with mechanical (non smooth surfaces) and specific adhesion when the hydrophilic layer is wet with water or a water based solution that could contain a cross-linking agent or a water based adhesive that could contain a cross-linking component. Examples of cross-linking agents include zirconium salts of mineral acids, such as Bacote 20 from Magnesium Elektron, Inc., Polyfunctional Aziridine such as Xama-2 from EIT, Inc., water soluble polyamide-epichlorohydrin material such as Polycup 172 and the like which may be used at a level of 0.2-8% by weight of the adhesive composition.
Mechanical adhesion is defined as the bonding between surfaces in which the adhesive holds the parts together by inter-locking action and actual physical penetration. Specific adhesion is the bonding between surfaces which are held together by molecular forces wherein the surfaces are non porous and no penetration is possible.
These forces are related to the polarity and size of the molecules and the initial action in obtaining a bond when the hydrophilic surface is wet and a bond develops through molecular forces.
In mechanical as well as specific adhesion, the hydrophilic layer with optional intermediate adhesive layer must xe2x80x9cwetxe2x80x9d both surfaces completely or weak bonded areas will develop as it dries or xe2x80x9csetsxe2x80x9d resulting in a poor bond. Not only is wetting of the surfaces critical, penetration is also important. Penetration is important since most combinations of surfaces to be adhered together involve at least one porous or absorptive surface which controls the xe2x80x9csettingxe2x80x9d characteristics. To facilitate wetting of the surface and penetration, the hydrophilic layer or hydrophilic layer with intermediate adhesive must be in a fluid state which for purposes of this invention is accomplished by applying water or water based adhesive to the selected hydrophilic layer which when applied to the container to be labeled brings the hydrophilic layer and container wall into intimate molecular contact. By using a wet hydrophilic layer or intermediate adhesive which also wets and penetrates the hydrophilic layer as well as the container surface, a fluid region is created that flows to cover the surface as completely as possible. This is critical to the invention where even an apparently smooth surface in reality is composed of a random network of hills and valleys. When the hydrophilic layer is in the wet condition, with or without adhesive, it serves as a wetting bridge to promote adhesion.
Various commercially available adhesives can be matched with hydrophilic layers to provide good adhesion of polymeric film layers to a plastic or glass surface. These material include starch based adhesives or casein based adhesives now predominantly used for glass applications since they do not bond well to plastic or metal. Specific adhesives hat may be employed include EVA based materials which have free carboxyl groups, converted starch solutions, PVA based adhesives, casein based adhesives, synthetic resin dispersions for metal or plastic containers or blends of synthetic and starch based products and the like.
It is clear that one specific hydrophilic layer may not fit all applications but hydrophilic layers can be tailored to particular applications based on the conditions and requirements for wet PML labeling of polymeric substrates.
For a coextruded product, if a adhesion promoting tie layer is employed, materials such as maleic anhydride, ethyl acrylic acid and the like may be employed at levels up to 5% by weight of the hydrophilic composition. For a coated product, if a primer is employed, materials such as chlorinated polypropylene, polyethylene imine (PEI) and the like may be employed at levels of 0.05-1.0 #/3000 sq. ft.
Plasticizers such as n-di-octylphthalate may be employed at a level of 0.5-3% by weight of the adhesive composition to prevent the polymeric film label from losing flexibility.
The slip aids and anti-blocking compounds prevent excessive friction between the hydrophilic layer and the printed label face and also control the effect of ambient moisture levels which may tend to cause label blocking and interfere with the operation of high speed automated machinery which is used to apply labels. These materials may be used at a level of 0.5-3% by weight of the hydrophilic layer composition and include materials such as microcrystalline wax emulsions, erucamide dispersions, polytetrafluoroethylene compositions, silicone beads, modified silicone solutions, parafin wax emulsions, high melting polypropylene emulsions, carnauba wax emulsions, oxidized ethylene/EVA compositions, micronized polyethylene wax/PTFE emulsions, micronized polypropylene, micronized fluorocarbons such as PTFE (Teflon), micronized polyethylene, silica and talc.
If an antistatic agent is employed, it may be present at a level of 0.5-3% by weight of the hydrophilic formulation. These materials include quaternary ammonium salts such as Ethaquad C12, sulfonated styrene maleic anhydride, sulfonated polystyrene, sulfonated vinyl toluene maleic anhydride, conductive polymers and organo modified silicones such as Silwet L77.
Protective coatings may be used to protect the exposed polymer film of the label when applied at a level of 0.25-4 lbs./3000 sq. ft. using conventional application techniques. These materials include styrenated acrylics such as OC1043 from O. C. Adhesives Inc., urethanes such as AS455 from Adhesion Systems Inc., Flexcon Release Varnish from Mandersxe2x80x94Premier.
If desired, a humectant may be added to the adhesive at a level of 0.5-3% to provide curl resistance and to impart layflat properties to the polymeric film labels. These humectants include urea, polyethylene glycols such as PEG400, polyvinyl alcohol, glycerine and the like.

Techniques for labeling of plastic, glass or metal containers or surfaces with polymeric labels

Abstract: (a) applying a layer of a hydrophilic solid material to a polymeric label to form a hydrophilic layer;

Abstract: (b) applying water or a water based adhesive to the hydrophilic layer to form a fastenable polymeric label;

Abstract: (c) fastening the fastenable polymeric label to a glass, plastic or metal container or surface; and

Abstract: (d) allowing said the polymeric label to dry on the glass, plastic or metal container or surface.


An electric tool for applying a pressing force has a tool housing and a drive arranged in the tool housing. The drive has an electric motor and a drive element configured to be driven by the electric motor. The drive element is located externally to the tool housing. A pressing unit is connected to the drive element remote from the tool housing and has two pressing parts. The drive element acts on at least one of the two pressing parts for moving the at least one pressing part relative to the other one of the two pressing parts. The drive element is preferably a hydraulically actuated piston, and the electric motor operates a pump element that supplies hydraulic medium to the piston.

1. Field of the Invention
The invention relates to a device for applying a pressing force, comprising a housing in which a drive is arranged that has a motor and a drive element driven by the motor, and further comprising a pressing unit with two pressing parts wherein at least one of the two pressing parts is moved relative to the other pressing part during the pressing action.
2. Description of the Related Art
It is, for example, known to connect pipes fixedly to one another by pressing them together. In this context, radial as well as axial pressing techniques are employed. According to the radial pressing technique, a press fitting with inner or outer positioned sealing ring is manually inserted into the pipe or placed onto the pipe. The press fitting is then radially pressed by means of a device in the form of pressing pliers.
According to the axial pressing technique it is known to employ a press fitting comprised of a support sleeve and a pressure sleeve. In order to connect pipes to one another, one pipe is first widened before the press fitting can be inserted into the widened pipe end. This additional widening process is complex and requires an additional working step. The pressing sleeve is pressed by means of the device axially against the stop on the fitting. In another axial pressing technique, a pressing ring and a squeeze ring are slipped over the pipe. A support sleeve (fitting) is inserted into the pipe and the pressing ring is pressed by means of the device axially across the squeeze ring until it reaches the stop on the support ring. In this technique a prior widening of the pipe is not needed.
Devices are known which have two arms projecting from the base member and having at their free ends each a pressing part. The free ends of the arms are connected to one another by a spindle which can be rotated by means of a ratchet spanner. In this context, one arm is pivoted relative to the other arm. Because of this pivot movement, one pressing part moves along a circular arc which may result in problems during the pressing action on a straight pipe.
Moreover, a manually operated pressing device is known which operates similar to a pair of pliers. It has actuating arms which during the axial pressing process are pivoted back an forth relative to one another wherein a chain or a ratchet moves one of the pressing parts in the direction toward the other pressing part. This device has large dimensions and its use is cumbersome.
Moreover, a device is known in which one pressing part is provided on a sliding sleeve which can be moved by a hydraulic medium on the pipe piece in the direction toward the other pressing part. From one end of the pipe piece a further pipe piece projects perpendicularly via which the hydraulic medium is supplied. A hydraulic hose is connected to the free end of this further pipe piece which is connected to a hydraulic device arranged in the room. A grip projects perpendicularly from this further pipe piece and the device is held by this grip. Due to the described configuration, the device can be carried only with difficulty because the grip is arranged at the one end and the pipe piece support for the pressing parts is arranged at the other end of the pipe. Accordingly, a considerable force expenditure is required in order to hold the device during the pressing process.
Further pressing devices are configured as sliding pliers in which the pressing parts also perform a pivot movement which results in problems for straight pipes.
It is also known to convert such a pivot movement by an additional lever mechanism into a straight movement of the pressing parts. However, the constructive expenditure of such a device is high. Especially, the weight of such a pressing device, because of the additional lever mechanism, is greatly increased so that the manipulation during the pressing process is made much more difficult.
It is an object of the present invention to configure the device of the aforementioned kind such that it has a simple design and provides a simple manipulation while ensuring a flawless pressing result.
In accordance with the present invention, this is achieved in that the device is an electric tool and that first the drive element and then the pressing unit are connected to the tool housing of the electric tool in series.
The device according to the invention is embodied as an electric tool in which the housing, the drive element for at least one of the pressing parts, and the pressing unit are arranged in series to one another. This results in a constructively simple configuration. Because of the position of the individual. parts, the device according to the invention can be of a compact configuration. Moreover, with this configuration an optimal weight distribution of the device is provided so that it can be held effortlessly during the pressing action.

REMS -WERK Christian Fxc3x6ll und Sxc3x6hne GmbH and Co.


An examination or surgical glove having an inner coating of a compound which prevents the degranulation of mast cells which releases medicators of inflammation. The coating includes anti-mast cell and anti-inflammatory agents such cromolyn compounds and human type protease inhibitors.

The present invention relates to surgical or examination gloves having a quick release interior. More particularly, there is provided a powdered coating for inhibiting skin irritations of users who become allergic to latex and for the prevention of accidental infections. The invention uses antiviral protease inhibitors and cromolyn compounds alone or in combination.
Surgical and examination gloves perform a barrier function providing separation between a patient and a health care worker. In fulfilling this function, the gloves act to block the introduction of infectious agents, particularly bacteria and fungi, from the hands of the healthcare worker into a surgical incision or wound of the patient. In this regard, it has been recognized that bacteria present in pores of a healthcare workers hands frequently survive antibacterial scrubbing to be released with perspiration into the interior of the glove. These bacteria pose a significant risk for infection if a tear or hole in the glove allows their release. Thus, antimicrobial gloves have been proposed with the intention of killing these released bacteria within the glove. As disclosed in U.S. Pat. No. 4,853,978 to Stockum, which is herein incorporated by reference.
The barrier function of the gloves also serves as to protect the health care worker from pathogenic agents, particularly those present in blood or other body fluids of the patient. Of particular significance in this regard are viruses, such as HIV, the virus causing Acquired Immunodeficiency Syndrome (AIDS), and Hepatitis B virus (HBV) which may even penetrate through a glove that is not actually perforated but merely stretched. Agents which are effective against these pathogenic agents, however, are less common than those that will provide an effect against simple skin bacteria or fungi and must frequently be present at much higher levels to be efficacious. This can cause difficulties for the wearer whose skin is in contact with high levels of antiinfective agent sometimes for hours at a time. It would therefore be highly advantageous to provide gloves in which an effective virucidal agent were maintained in a xe2x80x9creadyxe2x80x9d state, available for quick or even instant release as needed to counter the effects of possible viral contamination.
The Stockum patent cited above provides a partial but incomplete solution to this problem. Stockum discloses gloves havng an interior coating of polyurethane, starch, and chlorhexideine. Chlorhexidine has the ability to kill the AIDS virus and HBV as shown in prior commonly assigned U.S. patent application Ser. No. 07/385,290, which is incorporated herein by reference. The release rates reported by Stockum, i.e., release from the coating over several hours, are not quick enough, however, to provide meaningful protection from viral pathogens. Moreover, we have found that gloves made by dipping cured gloves in an antimicrobial preparation suffer from significant activity loss on storage, and thus from poor reliability.
Still another problem associated with rubber latex gloves pertains to the latex proteins inherently found therein. Latex proteins, which exist naturally in natural rubber latex, are essential as an emulsifier to the polyisoprene for maintaining the latex state. Unfortunately, the proteins have caused allergic reactions and other serious health problems in humans, and the latex proteins appear to have a relatively progressive effect on humans such that the undesirable reactions increase in severity with increased exposure to the proteins. For example, conventional latex gloves include a powder or donning agent such as corn starch on the surfaces thereof which facilitates removal of the gloves from a mold and facilitates placing the gloves on (donning) and removing the gloves from the users hands. Although that powder acts as a layer between the latex gloves and the hand wearing the glove, the latex proteins readily pass through the powder to the skin. In light of the health problems associated with exposure to the latex proteins, two alternative treatments for the gloves have been conventionally utilized to significantly reduce or eliminate the possibility that persons wearing the latex covered gloves will contact the latex proteins therein. Gloves treated according to such additional treatments are known as xe2x80x9cpowder-freexe2x80x9d. The first of such additional treatments is chlorination or chlorine leaching of the glove, which removes some of the proteins from the globes. Such chlorination treatment actually weakens the gloves because it initiates a deterioration process, but conventional sulfur-cure gloves remain sufficiently strong even after chlorination. The second of such additional processes involves application of a wax coating, whereby the surfaces of the conventional powdered gloves are coated with an ingestible, biodegradable wax material. The wax material may be carnauba wax, which is the same wax that is used on the candy shells of certain candy products such as MandMs(copyright). Although such wax coating does not degrade the desired characteristics of the latex glove, it does tend to melt to some extent after being maintained at body temperature over a period of time, and this is undesirable because the melted wax leaves a residue on the users"" hands after the gloves are removed, which residue is often subsequently transferred to instruments or other articles handled by the user.
U.S. Pat. No. 5,376,633 to Lezdey et al discloses that certain protease inhibitors have anti-viral characteristics.
U.S. Pat No. 5,376,917 to Lezdey et al, which is herein incorporated by reference discloses that certain protease inhibitors are also anti-inflammatory, particularly alphal-antitrypsin.
Co-pending application Ser. No. 09/758,593 of Lezdey et al (now abandoned) which is herein incorporated by reference discloses that cromolyn compounds prevent the degradation of mast cells which occur during allergic reactions but also anti-PAR (Protease Activation Receptor).
U.S. Pat. No. 5,618,710 to Navia et al, which is herein incorporated by reference discloses a method for stabilizes proteins by crosslinking, which can be used to stabilize the protease of the invention.
The present invention relates to surgical and examination gloves, which are commonly made from polyvinyl chloride, polyurethane, and rubber. Natural rubber latex is the preferred material. The invention provides an inner coating of at least one compound, which will prevent or inhibit an allergic reaction from use of the gloves and/or provides for anti-infection in the event of accidental seepage of body fluids, accordingly, a cromolyn compound and/or an antiviral protease inhibitor.
The cromolyn compound is one, which can prevent degranulation of mast cells, such compounds include for example, cromolyn, cromolyn sodium, and disodium cromolyn.
The protease inhibitor preferably is a serine protease inhibitor selected from the group consisting of alpha-1 antitrypsin, secretory leucocyte protease inhibitor, alpha-2 macroglobulin, the derivatives, complexes and conjugates thereof. Some cystein protease inhibitors, which are anti-viral can be used.
The cromolyn compounds and/or the protease inhibitors can be used alone or in combination with conventional lubricating agents.
It is therefore an object of the invention to provide an inner coating to surgical and examination gloves, which will prevent irritation.
It is another object of the invention to provide a latex glove, which is non-allergenic.
It is still another object of the invention to provide a latex glove with an inner coating, which is antiviral.
It is yet another object for the invention to provide a latex glove which can be easily donned.
These and other objects and advantages will become more apparent from a reading of the Description of the Preferred Embodiments and the claims.
The present invention resides in an elastomeric glove, which, is used for examination or in surgery have an inner coating of a compound, which will prevent irritation and/or can prevent infection because of seepage of body fluids. The elastomeric body may be formed from any variety of materials known in the art for the manufacture of surgical or examination gloves including polyvinylchloride, polyurethane, and silicone rubbers. Natural rubber latex is the preferred material, however, because of the flexibility and durability of this material.
The elastomeric body is formed in accordance with known procedures for the formation of gloves. Basically, these procedures involve preparing a fluid containing the elastomer, dipping a hand-shaped mandrel into the fluid to obtain a glove shaped coating, and coagulating, drying, and curing the coating. The inner coating can be incorporated on outside of the coated mandrel, after the curing step, because the glove is inverted in the process of removing it form the mandrel.
The inner coating can comprise a cromolyn compound, which can prevent the degranulation of mast cells, for example cromolyn, cromolyn sodium, and dissodium cromolyn.
The inner coating can also comprise of a protease inhibitor which is anti-viral and which binds with any of the mediators of inflammation. Preferred are the serine protease inhibitor and alpha-2 macroglobulin. The protease inhibitors are known to posses anti-inflammatory activity as well as being anti-viral agents.
Since the protease inhibitors are subject to degradation and have a short shelf life, they can be added to the gloves prior to use. Preferably, the stable form of the protease inhibitors are, used as the conjugates with polyethylene glycol, detran, cyclodextrin, and the like. The protease inhibitors can be crosslinked as disclosed in U.S. Pat. No. 5,618,710 are also useful.
For many uses, the cromolyn compounds are sufficient since they can prevent the onset of any allergic reaction of the user to the glove.
In surgical and examination procedures wherein the patient has an infectious disease, the protease inhibitors are preferred because they not only will prevent an allergic reaction but are antiviral agents for use in the event of seepage.
The cromolyn compounds can also be used in combination with the protease inhibitors. The inner coating can comprise about 3 to 10 mg. of the compounds depending upon the particular use of the glove.
The active ingredients used for the inner coating may be combined with conventional coating agents which provide improved donning properties to the gloves such as silicone, fumed silica, silicon dioxide, and the like. About 3.0 to 6.0 mg. of the conventional coating material can be utilized.
The protease inhibitors can be used in an amount of about 1.0 to 10 mg. alone or in combination with cromolyn compounds. In the case of surgery, when inorganic additives such as talc and silcon dioxide should not be utilized, the conjugates, especially the polyethylene glucol conjugates of alphal-antitrypsin provide suitable donning characteristics.
The use of plasma derived protease inhibitors, which are anti-viral and anti-inflammatory in advantageous for surgical gloves since the donning of the gloves at times causes spillage of the donning agent. Inorganic material, if released, could cause an allergic reaction in the patient.


A prime mover for extracting power from moving water is described comprising a body which is caused to oscillate in water by reversing the direction of thrust generated by at least one submerged control member e.g. a hydroplane or rotating cylinder protruding from a side of the body.

This invention relates to a prime mover, an apparatus and method for extracting power from moving water such as tidal flows and river currents.
Hitherto, this has generally been proposed or achieved by means of turbines analogous to underwater windmills. The blades of these windmills rotate as a result of the water flow about a horizontal or vertical axis at low speeds of the order of 10 to 30 revolutions per minute and at high torque. Gearboxes are required to transfer rotation at such speeds to the high speeds required for electrical generators. The gearboxes are large, complex and expensive with high power losses. The gearboxes also suffer from reliability problems and are difficult to maintain, particularly when located under water.
GB 1604372 discloses a device for utilising tidal energy which comprises two cylindrical tank members fitting slidably inside one another. The device is supported on a tripod resting on the seabed. A flotation collar renders the outer tank buoyant so that it rises and falls with the water level as a result of which air within the tanks is compressed by their relative movement.
Connections provided in the cover of the inner tank allow the compressed air to be used to drive an air turbine situated at a remote location.
The current invention aims to provide a prime mover (for converting natural energy into mechanical power), an apparatus and a method for transferring kinetic energy from slow moving water. The prime mover can be used with any suitable energy removal scheme. For example it can be used to produce electrical energy directly or to provide a useful form of mechanical movement. In a further aspect of the invention, kinetic energy from slow moving water is transferred into kinetic energy of a fluid travelling at high speed. Preferably the fluid is air.
According to a first aspect of the invention there is provided a prime mover for extracting power from moving water comprising a body which is caused to oscillate relative to the water by reversing the direction of thrust generated by at least one submerged control member protruding from a side of the body.
Whilst this prime mover is ideally suited for extracting energy from flowing water, extraction from other flowing fluids is possible and the term "water" should be interpreted as covering other flowing liquids and gases throughout this document.
Preferably, at least one control member protrudes from each side of the body.
Preferably, the shape of the body is such that water is caused to travel faster over a portion of the surface of the body and in which one or more protruding control members are positioned at that portion of the surface of the body.
Preferably, the body comprises curved sides which orientate the body with respect to a flow of water so that the control member or members are substantially perpendicular to the direction of flow of the moving water.
Preferably, the control member (s) is generally planar.
Preferably, the shape of the sides is symmetrical.
Preferably, the sides of the body are convex.
Preferably, at least one second protruding control member is provided fixed with respect to the body and arranged so that when the direction of thrust of a first reversible protruding control member is reversed, the angle of the second fixed control member with respect to the flow of water is altered so that the action of the water on that second fixed member. Thus the control member acts like a tail plane of an aircraft.
Preferably, the fixed second control member is positioned at a point on the body at which the velocity of the water flowing past the body is at or near a maximum.
Preferably, the first reversible control member is spaced laterally from it in the direction of the water flow.
Preferably, the reversible control member is downstream of the fixed control member. This is much like a tail plane on an aircraft.
Preferably, one or more control members comprise hydroplanes whereby the direction of thrust is reversed by reversing the angle of inclination of at least one hydroplane.
Preferably, the distribution of control members on opposing sides of the body is symmetrical.
Preferably, the body is elongate and tends to orientate itself so that it is elongate in the direction of flow of the current.
Preferably, the body oscillates in a vertical direction.
Preferably, one or more reversible controls members are pivotable in its entirety.
Preferably, one or more reversible control member are pivotable about an edge protruding from the body.
Preferably, one or more reversible control members are pivotable about a central axis protruding from the body.
Preferably, one or more of the reversible control members are formed by a pivotable flap mounted to a control member or other mounting means fixed with respect to the body.
Preferably, one or more reversible control members have an aerofoil shape.
In a further embodiment, one or more control members comprise a rotatable cylindrical structure whose direction of rotation can be reversed to generate a change in direction of thrust. As an example, the cylindrical structure may form a continuous cylinder or may have spaced vanes.
Preferably, more than one control member is provided on opposing sides of the body.
Preferably, the control members are spaced along the body in a direction substantially perpendicular to the direction of flow of the water when the body is orientated so that its control members protrude from the body in a direction substantially perpendicular to the direction of flow of water.
Preferably, the body is arranged to oscillate vertically and two or more control members are provided on opposing sides of the body spaced in a substantially vertical line.
Preferably, three or more control members are provided on each side and the separation of the control members is substantially equal.
According to a further aspect there is provided, apparatus for extracting power from moving water comprising a prime mover as described herein.
Preferably, the prime mover is connected to mooring means secured or securable under water.
Preferably, the prime mover is connected to mooring cable.
Preferably, the prime mover is axially slidably mounted or mountable to a column secured or securable under water in an upright position.
Preferably, the prime mover comprises a downwardly extending tube which surrounds the column.
Preferably, power conversion means are provided for converting the oscillations of the prime mover into another form of power such as electrical power.
Preferably, the prime mover is submerged when generating power.
Preferably, power conversion means are provided comprising one or more hydraulic pumps, a crank for generating mechanical rotation or means for generating electricity such as an electric coil and magnet.
Preferably, power conversion means are provided comprising a fluid pump for pumping fluid to a higher level.
Preferably, the apparatus is moored to or mounted on a structure such as column on which apparatus for extracting power from wind or wave is mounted. Thus, the prime mover extracts power from tidal or river current flow, and power is also extracted from wind or waves.
Whilst the prime mover is ideally suited to extracting power from tidal and river currents, it is also adaptable to be used for extracting power from waves as will be explained below in connection with a preferred embodiment.
Preferably, the prime mover is buoyant. Typically, it will float on the surface with part of its structure below the surface.
Preferably, the prime mover comprises an open bottomed tank which when it oscillates alternately compresses and decompresses a fluid inside it between a closed top of the tank and the water surface.
It will be understood by those skilled in the art from the information disclosed herein that the inventions in this preferred embodiment can operate in two modes.
In the first mode, power is extracted from tidal and river flows in the following way. As water flows past the control member, upward and downward thrust is produced causing the prime mover to move in a plane which crosses the flow direction (typically it is roughly perpendicular). Reversing the control member causes the direction of thrust to be reversed and when this is repeated the prime mover reciprocates generally in the plane.
This reciprocating movement can be converted into a more useful form of energy by an appropriate energy removal arrangement. In this preferred embodiment the prime mover is a tank which alternately compresses and decompresses a fluid.
In the second mode, power is extracted from waves. As waves impinge on the tank, the water level inside it rises and falls relative to the top of the collector.
Vertical movement of the tank is damped by the drag of the hydroplanes. This drag can be supplemented, though this is not always necessary, by reversing the control member or members to produce thrust in a direction opposite to the rise and fall of water in the waves.
Thus the tank tends to remain stationary relative to a fixed point, the shore or sea bed say, but the fluid inside the tank is alternately compressed and decompressed by the action of the waves.
Preferably, at least one duct in the top of the tank permits the fluid alternately to flow out of and into the tank.
Preferably, the fluid flowing through one or more ducts drives a turbine. Preferably, the turbine is mounted on the tank. Thus, the turbine operates in air when the fluid chosen is air. Preferably, the turbine is directly drivably connected to an electrical generator.
Preferably, the number and/or size of ducts open at any time, or selected to drive a selected turbine at a particular time, can be varied so that the flow of air can be optimised to the efficiency requirements of the turbine.
Preferably, a turbine is housed in a duct. Preferably, a generator, or combined turbine and generator is housed in the duct.
Preferably, the turbine rotates in the same direction irrespective of the flow of fluid out of or into the tank.
Preferably, valve means are provided so that fluid passes through the turbine in the same direction irrespective of the flow of fluid out of or into the tank.
Preferably, the fluid is air.
In a further aspect there is provided a method of extracting power from moving water comprising repeatedly reversing the direction of thrust generated by a submerged control member protruding from a body in a prime mover as described herein.
In FIG. 1, a large buoyant or floating open bottomed tank 10 contains air as a working fluid (see 17 in FIG. 3). Tank 10 has a substantially flat top 12 and is canoe shaped in plan view. The convex sides 14 of tank 10 meet to provide a pointed edge. The sides serve to orientate the tank so that the pointed edge points into the flow so that water passes over convex sides 14. Thus, water travels over sides 14 between points P, Q and R. At point Q the flow of water is generally homogenous and is typically faster than the flow of water at points P and R because of the constriction produced by the widening of the tank at that point. This is a suitable point at which to place hydroplanes 22 protruding from sides 14, the kinetic of the water energy available to be extracted being proportional to the cube of the velocity of the flow. Therefore the hydroplanes are advantageously located at this point of maximum velocity.
Tank 10 typically comprises a downwardly extending tube (not shown) which slidably surrounds a support column 16 secured underwater, usually to the sea of river bed 18, in an upright position. Typically, a large diameter plane bearing 20 is secured in the top of the tube and a similar bearing (not shown) is secured in the bottom of the tube so that the two bearings are widely spaced apart. Thus, said bearings are slidable axially and rotateably relative to the column 16. Further bearing strips 20 may be provided as an alternative or in addition to the circular bearings as shown in FIG. 1.
Hydroplanes 22 are submerged and pivotable in their entirety, typically about a lower edge 23, about an axis generally perpendicular to sides 14 of the tank. The two upper hydroplanes 22 on opposite sides 14 of the tank are interconnected by a shaft (not shown) and the two lower hydroplanes are likewise interconnected. The inclination of the hydroplanes 22 is reversible in unison by partially rotating the associated shafts, for example by hydraulic or mechanical means. Such change in the inclination of the hydroplanes is typically under computerised control and in response to several parameters. These parameters include motion of the tank, water flow direction, forces on the hydroplanes and/or air pressure in the tank. As will be explained below, the optimum arrangement is such that air is virtually always flowing into or out of the tank. The energy within the tank at a given time is equivalent to the air pressure times the air volume. The energy available to be collected is equivalent to the volume change over a given time period times the pressure differential over the same period.
The maximum angle of inclination of the hydroplanes 22 is also adjustable. Whilst hydroplanes 22 typically act as hydroplanes causing lift by the action of water flowing over their upper and lower surfaces, control members 22 can be caused to act as water deflectors much in the same way that a kite deflects air. This is shown in FIG. 12 and will be described in further detail later.
Two ducts 25 are formed in the top 12 of tank 10. These ducts house high speed air turbines and, optionally, also generators which are directly drivable by the flow of air into and out of the tank and can supply rotation directly to the electrical generators (not shown) wherever these are located. Turbines 24, and the generators, need not therefore be located underwater but are working in air enhancing reliability and ease of maintenance. Valve means (not shown) can be provided in each duct so that air passes through each turbine 24 in the same direction irrespective of the flow of air into or out of the tank.
Alternatively, a special turbine such a Wells turbine is used, such turbines always turn in the same direction irrespective of the direction of air flow.
In operation, the shape and in particular the convex sides 14 of tank 10 automatically orientate it like a weather vane so that control members 22 are kept substantially at right angles to the water current indicated by arrow 26. This orientation reduces drag on the tank and increases the velocity of the current passing along particularly the widest most portion of the sides and therefore over hydroplanes 22.
The action of water current 26 on hydroplanes 22 causes the tank to move upwards and downwards on column 16 depending upon the inclination, for the time being, of the hydroplanes. Thus, the tank is caused to oscillate as indicated by arrow 32 so as to alternately compress (as it moves downwards) and decompress (as it moves upwards) the air contained inside it between top 12 and water surface 28.
As tank 10 moves downwards the pressure differential causes air to be expelled through the ducts. During the downward part of the cycle, the downward force from hydroplanes 22 and the weight of the tank opposes the buoyancy forces, ie upthrust of the water on the tank.
This can be seen in steps a and b of FIG. 3. The air pressure inside the tank is greater than atmospheric pressure outside and causes a small change h in the level of water inside the tank compared to the level of water outside the tank. This head of water coupled with further downward movement of the tank by virtue of the angle of inclination of the hydroplanes causes the continued pressure differential inside and outside the tank. Air 30 is expelled from the tank via ducts 25. As can be seen in FIGS. 4 and 5, at T=T1 air commences to be expelled from the tank. This continues until T=T3 when the downward forces on the tank are balanced by the upward forces of water, head h of water is lost and the pressure inside the tank equals atmospheric pressure. At this point flow 30 ceases. It is desirable that the length of time spent at this point is kept to a minimum.
Therefore, towards the bottom of the movement and preferably before too long is spent at the bottom of the movement, the inclination of the hydroplanes 22 is caused to reverse so that these exert a vertical upward force.
Tank 10 is accelerated upwards by a combination of this force and its buoyancy (see step E in FIG. 3).
As the tank moves upwards, the pressure within it falls below atmospheric and a small head of water h is developed compared to the level of water outside the tank. Air is drawn in through the ducts (see step F).
At the top of the movement the head of water h disappears and the pressure inside the tank again reaches atmospheric.
Thus, if the distance of the tank above water surface 28 at rest is X1 and below water surface 28 is X2 then at step G, the top of the motion, X1 has increased in relation to X2.
In the measurements shown in FIG. 4 there is no peak in the pressure measurement to indicate air flowing in to the tank because of the limitation of the measuring equipment. Nevertheless, air was observed to flow into the tank during the period indicated.
The cycle is repeated beginning again with hydroplanes 22 being inclined in the other direction with respect to current 26.
The velocity of the air passing through the turbines can be varied by changing the size and/or the number of ducts. Thus, in FIG. 6, of the six ducts shown, one or more of these may be closed off or otherwise removed from the flow of air so that the velocity of air passing through the remaining ducts is increased. Thus the size and/or number of the ducts can be varied so customising a particular apparatus for a particular location (since current flows vary from location to location) or for particular conditions. Indeed, several ducts can be diverted through a single turbine, so that it operates in its most effective range for power generation, when water flow is slow, and rediverted to several ducts (and hence several turbines) when water flow is fast. Typically, the air turbines also comprise a generator located in the ducts. The velocity of air passing through the turbines can also be varied by changing the number and/or size of the hydroplanes. This ability to customise the tank to location and the prevailing conditions allows it to operate at optimum or near optimum efficiency in given circumstances.
Since the tank 10 floats and is slidable relative to column 16 it is self-adjusting to changes in the height of water surface 28. Furthermore, since it can rotate on monopile 16 it is self-adjusting to changes in the direction of water flow. This can be particularly important for tidal flows where inward and outward tidal flows are not at approximately 180 degrees to each other.
This is shown in detail in FIGS. 13A and 13B in which cables 33 can be used to moor tank 10 on monopiles 25 when inward and outward flow are in substantially opposite directions or in river flows. A limited amount of rotation can be possible when using mooring cables if the attachment points of the cables are designed for this. However, a central monopile 16 is typically used to mount tank 10 when inward and outward flows are at angle β with respect to one another. This allows rotation of tank 10 by angle β to align itself with the prevailing tidal flow.
The angle of inclination of the hydroplanes relative to the direction and speed of the water current governs the magnitude of lift and drag forces on the tank. Thus, typically control members 22 function as hydroplanes acting as hydroplanes generating lift but little drag.
In FIG. 12, water flow 26 is redirected downwards by control member 22d causing tank 10 to move in the direction of arrow 32. This is similar to the way that a kite maintains it height. Control member 22D is rotated through a vertical plane about a horizontal axis to cause the tank 10 to reverse its direction of motion. Control members 22D can however cause drag so their use may be limited to particular circumstances where drag is not a problem, such as when firm cable moorings are available.
Adjustment of the angle of hydroplanes or control members 22d such as those in FIG. 12 can allow for maximum power output over a wide range of current speeds. Thus there are several variables as described above which can be optimised to increase the efficiency and power output of the apparatus. Furthermore, the apparatus can be connected to shore by a power cable and can be submersible during storms thereby reducing the risk of damage.
FIG. 6 shows control members 22C and 22B which typically function as hydroplanes operating over an angular range of 5 to 30 degrees, for example, 2α equals around 60 degrees. The frequency with which the planes are reversed is typically 5 to 20 seconds, but may be less than or more than this. The angular orientation of the hydroplanes in a working position is selected from a range of angular working positions. Hydroplanes 22a are located on the widest portion of tank 10. Alternative or further hydroplanes 22B and 22C can be located at other points though this is less preferred.
Hydroplanes 22B are equally spaced whereas hydroplanes 22c are not equally spaced. By locating hydroplanes in a vertical direction, one above the other, roughly perpendicular to the water flow the turbulence flow produced downstream does not interfere with its neighbours. Thus, typically one of the series 22A and 22B and 22C, is selected rather than having hydroplanes spaced along the tank in the direction of flow of the water. The hydroplanes may be staggered, i.e. spaced vertically but overlapping in a horizontal direction such as hydroplanes 22E in FIG. 8.
FIGS. 8A and 8B also show a tank similar to that in FIGS. 6 and 7 but moored by cables 33 to a suitable mooring point either above or below water level. FIG. 9A shows two symmetrical cross-sections, one more aerodynamic than the other, for use as hydroplanes and one aerofoil cross-section for use as hydroplane. Typically, symmetrical shapes are preferred and aerodynamic shapes are preferred most of all.
FIG. 10 shows fixed hydroplanes 22 which do not rotate with respect to member 10. Rotatable tail hydroplanes 34 cause the tank to rise or fall. Once this rise has begun, it slightly tilts the tank so that hydroplanes 22 are now at an angle with respect to water flow 26 thus adding to the forces causing the tank to rise or fall. Other hydroplanes, or mounting structures, fixed with respect to the tank on which reversible hydroplanes are mounted may be used. These resemble pivotal flaps on aeroplane wings. A further type of hydroplane suitable for use with the invention is shown in FIG. 9B. Here, hydroplane 22F shown in cross section is flexible and can be flexed so that its curvature is inverted (reversed) causing lift 32A or downward thrust 32B as appropriate.
FIGS. 14A to 18 show the use of a prime mover 40 mounted about a monopile 16 or moored via cables 33 and provided with hydroplanes 22 causing prime mover 40 to rise or fall on the reverse of these hydroplanes. Several different kinds of power conversion means are provided for converting the oscillating motion of prime mover 40 into usable forms of power, whether this is water stored at a higher level, mechanical rotation, electrical power, hydraulic power and so on. Whist tank 10 is typically buoyant, prime mover 40 is typically partially buoyant so that it is submerged when at rest. Prime mover 40 rises and falls in exactly the same way as tank 10 by reversing the inclination of hydroplanes 22 or control members 22D as previously described. Thus, prime mover 40 oscillates up and down in the direction of arrow 32.
In FIGS. 14A and 14B, a hydraulic piston pumps fluid within a control chamber 40 to generate power or connects to a crank.
In FIGS. 15A and 15B a similar hydraulic pump 42 is used though in this case control chamber 44 is located beneath the surface and is moored to the sea bed by cables 33. Thus, the prime mover 40 here floats above the sea bed.
Typically column 16A, about which prime mover 40 is located, comprises slots through which members mounted on prime mover 40 project to drive pump 42 so causing the piston in hydraulic apparatus 42 to rise and fall. Also column 16A is open to the surface to permit access to the control and generating chamber 44 and so that power can be extracted for example by cables.
In FIGS. 16A and 16B shaft 42a rises and falls causing a crank system 43 to generate mechanical rotation which can be converted into electrical power or caused to drive a turbine.
In FIG. 17 struts 46 carry a coil 48 and move up and down in the direction of arrow 32 along with prime mover 40. Coil 48 is positioned about a magnet 50 to provide directly an ac current directly.
In FIG. 18, water is pumped by hydraulic apparatus 42 and pipe 52 into an elevated storage chamber 54. The water falls back via pipe 56 and can be used to generate electrical power in water turbine 58.
In FIG. 19, an alternative embodiment uses rotating cylinders to generate upward and downward thrust.
Cylinders 61 rotate in the direction of arrow 62 with respect to current 26. The cylinders produce drag 62 but also a downward force 60, or an upward force when rotation is reversed. Whilst rotation may be produced by driving connecting rod 64 using electricity, current 26 may be used to provide the necessary rotation via rotating wheel 70 which via connecting means 68 and gear box 66 causes rod 64 to rotate. A windmill type wheel rotating about a horizontal axis (not shown) could also be used. The gear box could be used to produce the reversal in rotation 63 without changing the direction of motion of rotating wheel 70.
Thus, the invention provides not only an apparatus for converting slow moving water or other suitable fluids (both gases and liquids) into fast moving air so that rotational speeds of 1,000 to 3,000 revolutions per minute in turbines can be generated, but also prime movers which can be combined with any appropriate energy removal system. Suitable liquids or other gases can be used in place of air. The fast moving fluid is typically lighter than the fluid from which power is extracted. The tank can be non-buoyant or of neutral buoyancy. The tank or prime mover can be orientated by power driven means instead of like a weather vane. One or more rudders or other vertical control surfaces may be provided to aid the orientation of the tank. These may be power driven but could be manually set for example on each tide change. The tank and the prime mover can be located permanently under water. The tank can have a shape different from that shown. A single tank or several tanks may be used.
The apparatus can be used to provide power for an associated desalination plant. One further arrangement is for a combined apparatus responsive to tidal flows, waves and windpower is provide. For example, a wind turbine mounted on top of a support column could be used.
Thus power generation is derivable from the action of wave energy on the prime mover, especially when the prime mover is a tank, tidal flows on the prime mover and wind power from the wind turbine mounted on top of the support column. Power generation is possible from the action of waves on one of the control surfaces providing resistance to the bobbing motion of the tank under the influence of the waves. Power generation from waves incident on the semi buoyant collector cause the water inside the collector level to rise and fall relative to the top of the collector. Vertical movement of the collector is damped by the drag of the hydroplanes. The force of the moving water in the wave cycle pushing against the hydroplanes can cause the collector to move in opposite phase to the water inside the collector so causing the fluid in it to be alternately compressed and decompressed. The angle of the hydroplanes can be altered to increase this effect of the waves passing into the collector. The apparatus can incorporate means for storage of energy or can be used to provide power for an autonomous device such as a buoy. A further embodiment may include two prime movers such as tanks 10 with one or more hydroplanes extending between the prime movers.
This offers stability to the hydroplanes since both ends of each hydroplane are supported by the tanks.
Control members in the form of hydroplanes and rotating cylindrical structures (whether hollow, solid or vanes spaces about roughly cylindrical periphery and so on) can be used in combination on a prime mover of the invention.
The prime mover may be arranged to oscillate horizontally. The angle of inclination, need not be the same for the upward and downward parts of this cycle (eg to take account of the weight of the prime mover).