A weight plate having rotatable handles is disclosed. By rotating, the handles provide a sure grip to the user, while allowing the user to perform various exercises without adjusting his or her grip on the device. The handles also facilitate the safe loading and unloading of the device on plate-loaded exercise equipment. The weight plate may thus be used as a stand-alone exercise device, as a weight plate loaded onto a barbell or dumbbell bar, or as a weight plate used on plate-loaded exercise equipment.

The present invention relates to exercise devices, and in particular relates to weightlifting plates.
Gymnasiums weight rooms, fitness centers, sports training centers, and other areas where weight training equipment is used have traditionally maintained one or both of two broad categories of weight-training equipment. Free weights, the first category of equipment, includes such well-known devices as dumbbells and barbells. Free weights are preferred by many athletes and weight-training enthusiasts because such devices allow full, natural movement during exercise. Since the movement of such devices are fully controlled by the user, these movements are dictated by the natural, curving movements of the human body. For example, a user performing a curl with a dumbbell may begin from a position with the dumbbell held directly below the shoulder with the arm extended downward. From this position, the user bends his or her arm at the elbow, which brings the dumbbell upward in a natural, curving movement. Finally, the dumbbell may be brought to rest against the user""s chest and upper arm. During such a movement, the user need not adjust his or her grip on the dumbbell, because the bar does not rotate relative to the user""s hand. In addition, the user""s wrist is allowed full movement, providing for a graceful, curved, natural motion during exercise.
Although free weights allow a full range of movement during exercise, they do possess certain disadvantages. The primary disadvantage is a lack of convenience. Most dumbbells are constructed to have a certain amount of weight, and thus when a user wants to change the amount of weight, the user must switch dumbbells. This usually requires the user to return the dumbbell being used to an equipment rack, select another dumbbell, and then return to the exercise area. Other dumbbells are constructed so that the user may adjust the weight by either substituting weighted plates of different sizes, or by attaching additional plates. With these dumbbells, the user must remove the locking mechanisms (typically a collar) on each end of the bar, remove the already attached weighted plates if required, attach the desired weighted plates, then reattach the locking mechanisms. With either type of dumbbell, the process of changing the amount of weight used is time-consuming and laborious. This is particularly a problem when a number of users are taking turns using a single piece of equipment, since each user""s natural abilities and skill level may require a different amount of weight for a given exercise. A common example of this problem is a football team; an appropriate amount of weight for a particular exercise may vary considerably between the large, strong linemen and the more nimble but less muscular receivers.
To provide greater convenience for multiple users, a second category of weight training equipment developed, known as xe2x80x9cstack-loadedxe2x80x9d or xe2x80x9cselectorizedxe2x80x9d equipment. Such equipment employs a stack of weighted plates that are connected by cables and pulleys to handles that the user may grip. By moving the position of a pin within the stack of weighted plates, the user may easily and quickly manipulate the amount of weight employed for a particular exercise. This is particularly convenient when a number of users are taking turns at a single piece of equipment, since each user needs simply to move the pin to the amount of weight desired for the particular exercise. Such equipment largely solves the problem of inconvenience created by multiple users of varying skill and strength taking turns with a particular piece of equipment. The disadvantage of selectorized equipment, however, is that the movements employed in the use of such equipment are rigid and unnatural, and make it difficult for the user to isolate particular muscles or muscle groups for development. For example, performing a bench press exercise on a selectorized bench press or xe2x80x9cuniversalxe2x80x9d machine would require the user to push up on a bar while gripping the bench press bar with both hands. The bar may be connected through a cable and a series of pulleys to a stack of plates. If, as is often the case, the user has one arm that is stronger than the other, the user""s weaker arm will be allowed to simply follow the stronger arm, and perform little of the work during the exercise. Thus such equipment does not allow the user to easily isolate particular muscles or muscle groups during exercise. Selectorized equipment also tends to force movement along straight lines, rather than along natural curves that mimic the natural movements of the human body. These straight lines simplify the design and construction of selectorized weight equipment, but also serve to reduce the user""s ability to efficiently target particular muscle groups for development.
Another disadvantage experienced by the user exercising with selectorized equipment is that the user often must readjust his or her grip as the bar moves during each repetition of an exercise. This problem results from the fact that the bar typically does not turn with the user""s hand as the exercise is performed. A dumbbell bar, on the other hand, naturally turns as the user""s hand turns, and thus a firm grip may be maintained through the entire movement. This limitation of selectorized equipment also contributes to the sensation that exercise with such equipment feels less natural.
To partially address these limitations, selectorized equipment has in part been replaced in recent years with plate-loaded equipment. Instead of using stacked plates that are manipulated through cables and pulleys, plate-loaded equipment uses weighted plates with holes in the middle that are individually added or removed to the equipment using spindles. These plates may be similar to or identical to the plates used on some dumbbells and barbells. This approach allows greater flexibility in equipment design, and improves the ability of the equipment to isolate particular muscle groups during exercise. While not as convenient as selectorized equipment, plate-loaded equipment may be constructed to more closely follow the natural movements of the human body, and produce more comfortable and natural exercise routines. By adding or removing weight plates, the user can vary the amount of weight on a piece of plate-loaded equipment in much the same way as the user changes the amount of weight on a barbell or dumbbell.
Traditional weightlifting plates, or xe2x80x9cweight plates,xe2x80x9d that are used on barbells, dumbbells, and plate-loaded equipment, are shaped as large, flat discs with a hole in the middle. Weight plates are generally designed primarily for attachment to a dumbbell or barbell bar. The plates slide onto one end of the bar through the hole, possibly in addition to other plates added on that end of the bar, and then are fastened into position by a bolt, collar, or some other locking means. By adding or removing weight plates of different sizes, the user may control the amount of weight on the bar. In this way, the user is offered greater flexibility in the type of barbell or dumbbell exercises performed, and may tailor the weight chosen to the user""s relative strength and weight-training goals without owning a multitude of dumbbells or barbells of different sizes. In gymnasiums and other facilities having both free weights and plate-loaded equipment, weight plates may be used on either type of equipment, since they may easily be removed from a barbell bar, for example, and then mounted onto the spindle of a piece of plate-loaded equipment. This allows the gym owner to avoid the purchase of expensive but duplicative equipment.
A third method of using weight plates is as a stand-alone training or exercise device. In particular, the xe2x80x9cOlympicxe2x80x9d style weight plates, which are typically quite large and constructed of iron, have been somewhat popular in years past for this purpose. These devices offer the user certain flexibility in the choice of training regimen that may not be available if only barbells and dumbbells are used. For example, a user may hold an Olympic plate against the user""s abdomen during sit-up exercises to more quickly build muscle mass in the user""s abdominal area. A dumbbell having similar weight would be far more bulky and unwieldy for this particular exercise. The prior art contains examples of weight plates that are designed to be particularly suited to stand-alone use; U.S. Pat. No. 5,692,996, to Widerman, discloses one such example.
Using a traditional weight plate as a stand-alone exercise device may create significant safety concerns. The only practical way for the user to grip such plates is for the user to hold the plate at the edges. This type of grip may be quite difficult or unsteady, depending upon the weight of the plate, the thickness of the plate, whether a thicker rim extends around the edge of the plate, the strength of the user""s grip, and the size of the user""s hands. In addition, as the user moves through various exercises, the user may need to change his or her grip position on the plate, which is especially difficult because the user is only holding the edge of a heavy plate. The risk of dropping such a plate during exercise increases each time the user is required to change grip positions. Also, the iron surface of an Olympic weight plate is relatively slick, which is only exacerbated when the user perspires through the course of an exercise routine. These same problems occur when the user is changing plates on a dumbbell or barbell bar, or even when the user is changing weight plates on plate-loaded equipment. In each case, maintaining a firm grip on the plate is a significant safety concern.
One proposed solution to the problem of securely gripping a weight plate is to add elongated holes through the surface of the plate. The user may then place his or her hands through the holes to grip the weight plate. U.S. Pat. No. 5,137,502 to Anastasi, and design pat. nos. 355,007 and 409,695, both to Rojas et al., disclose several such weight plates. In addition, commercial examples of such plates are now produced by the Irongrip Barbell Company of Fountain Valley, Calif. These plates have two or three holes through which the user may place his or her fingers, with the user""s thumbs remaining on the side of the plate facing the user. If the plate is small enough, the user may place his or her fingers through one hole, and his or her thumb through another hole. Utilizing either of these gripping techniques, the plate may be held more securely because the user""s hands actually extend through the plate. These designs reduce the risk of the user""s hands slipping from the plate, since the fingers are xe2x80x9ccapturedxe2x80x9d to some degree within the holes passing through the plate.
Plates having elongated holes to receive the user""s fingers may also facilitate certain types of exercises not possible with traditional weight plates. For example, the user wishing to perform a one-handed curl with a traditional plate would find it difficult to grip the plate in such a manner as to make this exercise possible. If the user gripped the plate along the edge, which is the only practical means of gripping a traditional weight plate, the user""s grip would necessarily be somewhat precarious as the plate is raised. By contrast, a weight plate with elongated holes to receive fingers would allow the user to keep a more secure grip on the plate while bending the elbow and raising the plate toward the user""s armpit. While this type of exercise is not a traditional curl, and would not follow the natural movements of the human body as a dumbbell curl would, the grip of the user would be more secure than that held along the edge of a traditional weight plate during such an exercise.
It would be difficult if not impossible to perform a full, traditional curl using such a weight plate, since as the user raises his or her hand toward the chest, and the wrist rolls inward, the plate would begin to extend horizontally outward, and away from the user. This problem results from the fact that the back of the user""s hand and forearm would press against the plate. Because the user would have little leverage on the plate when it reaches this horizontally extended position, the user may not have sufficient strength to pull the plate up sufficiently to complete a traditional curl repetition. At best, this maneuver would be difficult and uncomfortable for the user. Other exercises would be similarly difficult or impossible because of the inherent limitations of the method of gripping such plates.
These plates with elongated holes also do not provide the user with a solution to the problem of changing his or her grip during each repetition of an exercise. For example, a user performing a traditional one-handed curl with one of these plates would be required to shift his or her grip on the plate as the plate is raised. In effect, the portion of the plate between the hole through which the user""s hand is inserted and the rim of the plate must xe2x80x9crollxe2x80x9d in the user""s palm during this exercise. In fact, these plates may actually increase the severity of the grip-adjustment problem for certain exercises, since it may be more difficult for the user to change his or her grip while the hand is xe2x80x9ccapturedxe2x80x9d within a hole in the weight plate than when the grip is simply at the outer edge of a traditional Olympic plate. The user must necessarily release his or her grip on the weight plate somewhat in order to adjust his or her grip position, and thus the risk that the user will drop the plate increases. Also, constantly adjusting one""s grip during repetitions of a particular exercise is uncomfortable for the user, reducing the user""s willingness to continue the exercise and thereby reach the user""s weight-training goals. This same problem is encountered as the user lifts such a weight plate to place it on the spindle of a piece of plate-loaded equipment. Thus a weight plate that both provides a more secure grip and does not require that the user shift his or her grip position during each repetition of an exercise or loading is desired.
The present invention overcomes the limitations of the prior art by providing a weight plate with rotatable handles. The rotatable handles give the user a sure grip that automatically turns in response to the user""s movements so that the user need not adjust his or her grip on the device during exercise. The handles are attached to the weight plate in such a manner that the user has room around the handles to insert his or her hands. In one form, the present invention incorporates hollow shafts that are coaxially mounted around a rod to provide free rotation during exercise. When the user grips the present invention at one of these handles, the user can move through an exercise (for example, a traditional, one-handed curl) without releasing his or her grip with respect to the handle. The bar simply rotates during each repetition due to the force of gravity on the weight plate, so that the weight plate is always suspended directly below the bar.
An object of the present invention is, therefore, to provide a weight plate that provides a handle.
A further object of the present invention is to provide a weight plate that allows the user to perform various exercises without adjusting his or her grip position.
A further object of the invention is to provide a weight plate with handles that rotate during exercise.
Further objects and advantages of the present invention will be apparent from a consideration of the following detailed description of the preferred embodiments in conjunction with the appended drawings as briefly described following.


A filter substrate impregnated with an emulsion polymer, the emulsion polymer being substantially devoid of phenolics and stabilized using a protective colloid.

The present invention relates to colloidally stabilized emulsions, and particularly colloidally stabilized emulsions having reduced or no phenolics.
Phenolics (e.g., phenol-formaldehyde resins), have been used as adhesives, laminates, molding materials, paints and the like. Of particular interest is the use of phenolics as adhesives or binders in non-woven substrates and papers. More specifically, phenolics are used in bonding of refractory shapes; fiber bonding such as in filters; felt bonding; binding of friction products such as brake pads; in papermaking; in insulation; in roofing products; and in the binding of foundry sands such as abrasives. Of particular interest is the use of phenolics in filters. Typically, the filter is provided by impregnating a continuous roll of paper with a phenolic resole in the form of an alcohol solution of a condensate of phenol with formaldehyde. The impregnated and saturated paper is heated to remove the solvent (alcohol) and corrugated to increase surface area. The resin is then cured in an oven and the paper is rolled again. The rolls of the impregnated paper are provided to the filter manufacturer for completion of the process which includes pleating and final curing. Such filters are used in the both air and oil filtering systems in stationary and mobile internal combustion engines.
Phenolics, however, have disadvantages such as high phenol and formaldehyde levels, brittleness when fully cured, slow curing characteristics, instability and poor shelf life. Moreover, phenolics, particularly water-based phenolics, are difficult to use to impregnate fiber substrates. In such impregnation, co-solvents such as alcohols, must be used and then removed.
To this end, it would be desirable to substantially eliminate, or in the alternative, substantially reduce the amount of phenolics used in products and with substrates wherein phenolics have traditionally been used as binders or adhesives.
The present invention provides compositions wherein phenolics are substantially eliminated, substantially reduced or replaced by the use of a colloidally stabilized emulsion polymer. By using the colloidally stabilized polymer of the invention and eliminating or replacing the use of phenolics, a wide variety of polymers having crosslinkable functionality such as provided by crosslinkers such as epoxies, polyisocyanates, polyurethanes, N-methylol acrylamide, melaminelformaldehyde and the like, can be used or blended together while providing properties comparable to those of polymers having phenolics or of phenolics alone.
Alternatively, the colloidally stabilized emulsion polymers, when blended with phenolics, are more stable and compatible with phenolics as compared to surfactant stabilized emulsions. By compatibility, it is meant that the emulsion polymers, when blended with phenolics, remain stable without coagulating or gelling or becoming a paste over longer periods of time. Thus, the blended product can be used over extended periods of time without concern for instability or degradation of performance. Moreover, the need to use undesirable solvents is eliminated.
The present invention will now be described more fully hereinafter, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It is believed that a wide variety of polymers in emulsion form can be colloidally stabilized, particularly with polyvinyl alcohol, and optionally blended with phenolics. Specific polymers in emulsion form include polyvinylacetate, vinylacetate-ethylene(VAE), vinyl acrylics, epoxies, urethanes, acrylics, styrene acrylics, butadiene copolymers, and hybrid emulsions of combinations of the foregoing. The present invention can be used in systems to replace phenolics wherein phenolics are used alone, or can be used in systems wherein phenolics are used with other polymers. In the latter, the phenolics can be substantially eliminated or can be substantially reduced.
Of particular interest are emulsion polymers that have high levels (i.e., greater than about 15 percent by weight) of nitrogen-containing monomers such as acrylonitrile. By being able to increase the level of acrylonitrile, properties such as oil and grease resistance can be improved without adversely affecting the physical properties contributed to by the phenolics.
As stated above, it is desirable to substantially eliminate the use of phenolics; however, phenolics may still be used at a reduced level. The phenols employed in the formation of the phenolic resins generally include any phenol which as heretofore been employed in the formation of phenolic resins and which are not substituted at either the two ortho positions or at the one ortho and the para position. Such unsubstituted positions are necessary for the polymerization reaction to occur. Substituted phenols employed in the formation of the phenolic resins include: alkyl substituted phenols, aryl-substituted phenols, cycloalkyl-substituted phenols, alkenyl-substituted phenols, alkoxy substituted phenols, aryloxy substituted phenols, and halogen-substituted phenols. Specific examples of suitable phenols include: phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, 3-4-xylenol, 3,4,5-trimethylphenol, 3-ethyl phenol, 3,5-diethyl phenol, p-butyl phenol, 3,5-dibutyl phenol, p-amyl phenol, p-cyclohexyl phenol, p-octyl phenol, 3,5-dicyclohexyl phenol, p-phenyl phenol, p-crotyl phenol, 3,5-dimethoxy phenol, 3,4,5-trimethoxy phenol, p-ethoxy phenol, p-butoxy phenol, 3-methyl-4-methyoxy phenol, and p-phenoxy phenol.
The aldehydes reacted with the phenol component can include any of the aldehydes heretofore employed in the formation of phenolic resins and include, for example, formaldehyde, and benzaldehyde. In general, the aldehydes employed have the formula Rxe2x80x2CHO wherein Rxe2x80x2 is a hydrogen or hydrocarbon radical of 1-8 carbon atoms. A particularly preferred phenolic is Resafen 8121 available from Resana, Sao Paulo, Brazil.
With respect to the polymers, of particular interest are the ones with aliphatic conjugated dienes. Suitable aliphatic conjugated dienes are C4 to C9 dienes and include, for example, butadiene monomers such as 1,3-butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, and the like, such as described in U.S. Pat. No. 5,900,451 to Krishnan et al., the disclosure of which is incorporated herein by reference in its entirety. Blends or copolymers of the diene monomers can also be used. The aliphatic conjugated diene is used in an amount, based on total weight of the starting monomers, from about to 1 to about 99 percent by weight, preferably from about 5 to about 30 percent by weight, and most preferably from about 5 to about 15 percent by weight. A particularly preferred aliphatic conjugated diene is 1,3-butadiene.
Suitable non-aromatic unsaturated monocarboxylic ester monomers include acrylates and methacrylates. The acrylates and methacrylates may include functional groups such as amino groups, hydroxy groups, epoxy groups and the like. Exemplary acrylates and methacrylates include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, isobutyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxybutyl methacrylate, n-propyl methacrylate and the like. Exemplary amino-functional methacrylates include t-butylamino ethyl methacrylate and dimethylamino ethyl methacrylate. Suitable non-aromatic dicarboxylic ester monomers are dialkyl fumarates, itaconates and maleates, with the alkyl group having two to eight carbons, with or without functional groups. Specific monomers include diethyl and dimethyl fumarates, itaconates and maleates. Other suitable non-aromatic dicarboxylic ester monomers include di(ethylene glycol) maleate, di(ethylene glycol) itaconate, bis(2-hydroxyethyl) maleate, 2-hydroxyethyl methyl fumarate, and the like.
The non-aromatic unsaturated mono- or dicarboxylic ester monomer is used in an amount, based on total weight of the starting monomers, preferably from about 5 to about 95 percent by weight, and most preferably from about 20 to about 80 percent by weight. A particularly preferred non-aromatic unsaturated monocarboxylic ester monomer is methyl methacrylate.
Various aromatic unsaturated monomers may be used and include, but are not limited to, styrene and styrene derivatives such as alphamethylstyrene, p-methyl styrene, vinyltoluene, ethylstyrene, tert-butyl styrene, monochlorostyrene, dichlorostyrene, vinyl benzyl chloride, fluorostyrene, alkoxystyrenes (e.g., paramethoxystyrene) and the like. Mixtures of the above may be used. Preferably, styrene is employed. The aromatic unsaturated monomer is preferably used from about 5 to about 95 percent based on the total monomer weight, and more preferably from about 20 to about 80 percent by weight.
Exemplary nitrogen-containing monomers which may be used include, for example, acrylonitrile, methacrylonitrile, acrylamide, and methacrylamide. Acrylonitrile is preferred. Mixtures of the above may be used. The nitrogen-containing monomer is preferably used, for example, in an amount ranging from about 5 to about 95 percent based on the total weight of the monomers, and more preferably from about 15 to about 80 percent by weight.
Known and conventional protective colloids may be employed in the emulsion polymer such as partially and fully hydrolyzed polyvinyl alcohols; cellulose, ethers, e.g., hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, starch ad start derivatives, carboxymethyl cellulose (CMC); the natural and synthetic gums, e.g., gum tragacanth and gum Arabic, polyacrylic acid; acrylates; poly(vinyl alcohol)co(vinyl amine) copolymers and the like. Partially and fully hydrolyzed polyvinyl alcohols such as those available from Air Products, sold under the trademark Airvol(trademark) are preferred and are preferably employed from about 0.1 to about 10 percent based on the weight of the total monomer, more preferably from about 0.5 to 5 percent, and most preferably from about 1 to about 4 percent.
In accordance with the invention, a polymerizable surfactant which contains ethylenic unsaturation is used and is copolymerized with the other monomers during emulsion polymerization. As a result, the surfactant is incorporated in to the backbone of the polymer and serves to stabilize the latex. Examples of suitable surfactants containing ethylenic unsaturation are provided in U.S. Pat. No. 5,296,627 to Tang et al., the disclosure of which is incorporated by reference herein in its entirety.
Various polymerizable surfactants are also described in U.S. Pat. No. 5,900,451 to Krishnan et al. A preferred polymerizable surfactant is SAM 186N(trademark) sold by PPG Industries, Inc. of Pittsburgh, Pa. The polymerizable surfactant may be used in various amounts. Specifically, the stabilized emulsion polymer may include between about 0.1 and about 5 percent polymerizable surfactant based on the monomer weight, more preferably from about 1 to about 4 weight percent, and most preferably from about 2 to about 3 weight percent.
Conventional surfactants may be used in conjunction with the surfactant having ethylenic unsaturation described herein. Such surfactants are preferably of the anionic and nonionic type. The selection of these surfactants is apparent to one skilled in the art. Preferred nonionic surfactants are selected from the family of alkylphenoxypoly(ethyleneoxy) ethanols where the alkyl group typically various from C7-C18 and the ethylene oxide units vary from 4-100 moles. Various preferred surfactants in this class include the ethoxylated octyl and nonyl phenols, and in particular ethoxylated nonyl phenols with a hydrophobic/lipophilic balance (HLB) of 15-19. Non-APE (alkylphenol ethoxylate) surfactants such as ethoxylated alcohols, for example, Abex 2525, are also preferred. Anionic surfactants can be selected from the broad class of sulfonates, sulfates, ethersulfates, sulfosuccinates, diphenyloxide disulfonates, and the like, and are readily apparent to anyone skilled in the art.
An unsaturated mono- or dicarboxylic acid monomer may also be included in the stabilized emulsion polymer. These monomers include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid. Derivatives, blends, and mixtures of the above may also be used. The unsaturated mono- or discarboxylic acid monomer may be used in an amount ranging from about 0 to about 15 percent based on the total monomer weight, and more preferably from about 0 to about 5 weight percent.
Additional comonomers can be added to the stabilized emulsion polymer. Included among such additional comonomers are monoethylenically unsaturated substituted aliphatic hydrocarbons such as vinyl chloride, and vinylidene chloride; aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl butyrate, vinyl versatate and vinyl neodecanoate.
The stabilized emulsion polymer can include additives to enhance its various physical and mechanical properties; the selection of which is readily apparent to one skilled in the art. For example, crosslinking agents can be included such as vinylic compounds (e.g., divinyl benzene); allyllic compounds (e.g., allyl methacrylate, diallyl maleate); multifunctional acrylates (e.g., di, tri and tetra (meth)acrylates); self-crosslinking monomers such as N-methylol acrylamide, N-methylol methacrylamide and C1 to C4 ethers of these monomers respectively (e.g., N-iso[butoxymethoxy] methacrylamide), acrylamido glycolic acid and its esters, and alkyl acrylamido glycolate alkyl ethers (e.g., methylacrylamido glycolate methyl ether). The crosslinking agents can be included in amounts of up to about 15 percent by weight, and preferably from about 3 to about 8 percent by weight. Additional monomers such as silanes can be included to improve specific properties such as latex stability, solvent resistance, as well as adhesion and strength and are described, for example, in U.S. Pat. No. 5,830,934 to Krishnan, the disclosure of which is incorporated herein by reference in its entirety.
Initiators which facilitate polymerization are typically used and include, for example, materials such as persulfates, organic peroxides, peresters, and azo compounds such as azobis(isobutyronitrile) (AIBN). Persulfate initiators are preferred and include, for example, potassium persulfate and ammonium persulfate.
Reductants may be employed in the polymerization, and are typically employed in combination with the initiator as part of a redox system. Suitable reductants include sodium bisulfite, erythorbic acid, ascorbic acid, sodium thiosulfate, sodium formaldehyde sulfoxylate (SFS), and the like.
Other additives which may be used include other natural and synthetic binders, fixing agents, wetting agents, plasticizers (e.g., diisodecyl phthalate), softeners, foam-inhibiting agents, froth aids, other crosslinking agents (e.g., melamine formaldehyde resin, epoxies, polyisocyanates, etc.), flame retardants, dispersing agents (e.g., tetrasodium pyrophosphate), pH adjusting components (e.g., ammonium hydroxide), sequestering or chelating agents (e.g., ethylene diaminetetraacetic acid (EDTA)) and other components. The selection of any of these additives is readily apparent to one skilled in the art.
One use of the reduced phenolic/butadiene blend is, for example, the fabrication of filters (e.g., oil filters). In the first or treating step, a continuous roll of paper is conventionally impregnated with the binder in the form of an alcohol solution. When a phenolic is used, the saturated paper is heated to remove the alcohol (solvent). In the present invention, the alcohol solution is not needed and this step is eliminated. The treated paper is then corrugated for the purpose of increasing surface area. The corrugated sheet is subsequently conveyed through an oven in order to advance the cure of the resinous impregnate to a fusible intermediate or B stage, and then the corrugated sheet is made into a filter.


A slide for use with swimming pools has at least one flow fitting in a side rail of the slide and directs fluid flow from the side rail onto the slide bed, thereby providing a film of water over substantially all of the bed.

Presently known means of wetting swimming pool slides employ relatively low volumetric flow rates, the flow rate typically being characterized as a trickle. Such a flow rate is typically adequate to wet the entire bed of the slide only after a person has gone down the slide and disbursed the water thereacross. Subsequent users can move down the slide in relative comfort. However, the first person down the slide may experience some discomfort from contact with nonwetted portions of the slide. Known means of wetting slides are ineffective at providing a film of water over the entire bed of the slide.
One type of known slide wetting means employs a tube extending across a top of the slide with a plurality of holes therein. The holes are too small to provide the desired wetting effect given the typically available water pressure. Water resultantly trickles from the holes and down the slide. Additionally, flow to the tube is commonly limited by the diameter of the hose supplying the tube being no larger than the tube.
It is desired to provide a slide having wetting means which maintains a film of water over substantially the entire bed of the slide. It is also desired to provide a slide with a wetting means which induce minimal back pressure at a high volumetric rate of flow, thereby accommodating a high rate of flow therethrough at relatively low outlet pressures typically associated with swimming pool filter pumps having multiple flow outlets in parallel with one another. It is also desired to be able to easily convert a slide with no wetting means or inadequate wetting means to one having wetting means able to maintain a film of water over the slide bed.

High volume flow water slide for swimming pools


The invention relates to a method and a device for the production of NADCl4 in which D is aluminium or iron, where, in a first reaction step, a melt of aluminium or iron is reacted with chlorine gas to give gaseous metal halide, and this is subsequently reacted, in a second reaction step, with solid sodium chloride to give the corresponding compound and is separated off as a melt.

The invention relates to a method and a device for the production of NaDCl4, in which D is aluminium or iron, where, in a first reaction step, a melt of aluminium or iron is reacted with chlorine gas to give gaseous metal halide, and this is subsequently reacted, in a second reaction step, with solid sodium chloride to give the corresponding compound and is separated off as a melt
Melts of salts, such as, for example, NaAlCl4 have various areas of application. Salt melts can be employed as storage medium in heat storage systems, as heat transfer media, for example in heating baths, for covering and cleaning molten metals, for the electrocoating of high-melting materials or as melt electrolytes in primary batteries, as described in GB 2046506. A further potential application of these salts is in rechargeable sodium batteries. The salts are employed in batteries which have operating temperatures of between 130xc2x0 C. and 200xc2x0 C. (Abraham. J. Electrochem. Soc., Vol. 137, 1189-1190, (1990)).
DE 3419279 describes an electrochemical cell in which the cathode matrix is impregnated with a sodium aluminium halide salt melt electrolyte.
A relatively new area of application is the xe2x80x9cZEBRA batteryxe2x80x9d. This high-temperature cell consists of an electrode of liquid sodium, a beta aluminium electrolyte and an electrode of transition-metal chloride in an NaAlCl4 melt (Cleaver, J. Electrochem. Soc., Vol. 142, 3409-3413, (1995)).
DE 3718920 describes the production of salt melts by the addition of a pure metal and an alkali metal halide to the melt The reaction cell is operated at above the melting point of the salt melt. The alkali metal halide in the working example is NaCl, the molten alkali metal is sodium, and the separator is beta-aluminium oxide. Owing to the use of pure sodium, special safety precautions, such as working under a protective-gas atmosphere, have to be taken. The reactions must take place in separate cells, since poisoning of the separator by the by-product AlHal3 formed must be prevented.
All the methods known hitherto for the production of salt melts work batchwise. A batch procedure has some severe disadvantages compared with a continuous production method. In the case of a batch change, the apparatus has to be opened. The product may then be contaminated by the oxygen from the ambient air, water and dust The batch change results in down times of the plant and thus in a reduced space-time yield. For an effective discontinuous method, large apparatuses have to be used. The start-up process requires correspondingly more energy and time. It has been found that impurities are entrained into the process, in particular during start-up of plants. FR 2168912 describes a complex purification method for alkali metal aluminium halides. The two-step purification process is composed of an oxygen treatment for degradation of the organic impurities and an aluminium treatment for precipitation of iron and heavy metals. The aluminium treatment must be carried out under a nitrogen or argon atmosphere.
For the production of the alkali metal aluminium halides, the reaction of corresponding aluminium halides and alkali metal halides in a closed tube is described (Friedmann, J. Am. Chem. Soc., 72, 2236-2243, (1950)). A pressure increase to 6-7 atmospheres has been observed in this method, which results in problems (FR 2168912). The apparatuses have to be fitted with the appropriate safety precautions.
The object of the invention is to provide a continuous method for the production of pure salt melts which excludes disadvantageous ambient influences, minimises the energy demand and facilitates an optimum space-time yield.
A further object is to make large quantities of salt melts available in the shortest possible time.
The object according to the invention is achieved by a method for the production of salt melts, and mixtures thereof, of the general formula
NaDCl4 xe2x80x83xe2x80x83(1)
in which
D is Al or Fe,
which, in a first reaction step (i), a melt of aluminium or iron is reacted with chlorine gas to give gaseous metal halide (DCl3), and this is subsequently, in a second reaction step (ii), reacted with solid sodium chloride to give the corresponding compound of the formula (I) and is separated off as a melt.
The invention furthermore relates to a device for carrying out the method, essentially consisting of a reaction vessel (1) containing the melt of the metal D, with a feed device for chlorine gas (2), a collection device for gaseous metal chloride (4) above the reaction vessel (1), and a further reactor vessel (5) which contains sodium chloride in solid form and is connected to the said collection device.
The products from the method are suitable for use as melt electrolyte in electrochemical cells, as storage medium in heat storage systems, as heat transfer medium, for example in heating baths, for covering and cleaning molten metals, for the electrocoating of high-melting materials or as melt electrolytes in rechargeable sodium batteries and primary batteries.
In the alternative methods, the solids, for example NaCl and AlCl3, are mixed and warmed to the melting point. The amount of heat necessary for this purpose has to be supplied from the outside.
Surprisingly, it has been found that the exothermicity of the reaction of aluminium or iron (D) with Cl2 to give aluminium chloride or iron chloride (DCl3) can be utilised for the further process for the production of NaDCl4.
In the process according to the invention, DCl3 (where D=Al or Fe) is formed at temperatures between 700xc2x0 C. and 1200xc2x0 C. In contrast to conventional methods, this DCl3 is fed in gaseous form to an alkali metal salt bed of NaCl.
It has been found that the accompanying heat of the gas (DCl3) is sufficient to warm the alkali metal salt (NaCl) to the melting point of the salt melt NaDCl4 (I).
An essential advantage of the method is the use of cheaper raw materials and the utilisation of the heat of reaction being liberated for controlling the temperature of the method. Method steps, such as the condensation of the metal halide (DCl3), can thereby be saved and the energy demand for carrying out the process reduced.
It has been found that the continuous performance of the method enables interfering environmental influences to be excluded. This enables a constantly high quality of the product to be established after the start-up phase.
All continuously operating reaction vessels which appear suitable to the person skilled in the art can be used for the method. For the reaction with chlorine gas, a feed device with gas inlet is necessary. The reaction vessel is provided with a refractory lining. A ceramic lining which is insensitive to the materials employed and the high temperatures is advisable.
The metal D in powder or granule form is provided for the process via a solids metering unit (3).
For collecting the reaction product (DCl3), a collection device (4), provided with a feed line to the downstream reaction vessel (5), is installed above the reaction vessel (1) for the melt
The feed of the reaction product takes place between the upper quarter and the lower quarter of the reactor vessel (5), which contains a mixture of metal D and sodium chloride in solid form. Complete conversion of the reactants into the reaction products can thus be ensured.
The salt melt formed runs off in a downward direction through the alkali metal salt bed (NaCl), which is supported by a support grille or a coarse filter plate.
A mixture of solid sodium chloride and metal D in powder or granule form is fed continuously, corresponding to the amount of end product formed and separated off, to the reaction vessel (5) via a solids metering unit (6).
Due to water entrained by the raw materials, undesired HCl gas forms. This can react away to give the metal halide (DCl3) due to amounts of the corresponding metal granules or powder (D) present in the alkali metal salt bed.
It is advisable for a further reactor vessel (7) with alkali metal salt bed to be installed downstream of the reactor vessel (5) in the flow direction for purification of the melt in order to allow the metal halide (DCl3) formed in turn to react away to give NaDCl4.
A temperature control device is merely necessary for heating up once in the start phase and, where appropriate, for cooling. The energy necessary for melting the metal granules (D) is also provided by the heat of reaction.
The method can be carried out continuously or discontinuously as required.
A general example of the invention, which is shown in the drawing, is explained in greater detail below. FIG. 1 shows a reaction vessel containing metal melt 1 having a feed device for chlorine gas 2 and solids metering device 3, collection device for gaseous metal chloride DCl3 4 and reactor vessel 5 containing metal granule or metal powder and alkali metal salt bed, and solids metering device 6, as well as a downstream reactor vessel 7.
Reaction Step i:
For the production of salts conforming to the formula (1) and mixtures thereof, the raw materials can be fed to the reaction vessel (1) in premixed form via the solids metering device (3). The filling can be carried out under inert gas.
The heatable reaction vessel (1) contains liquid metal melt. Suitable metals (D) are iron and aluminium. Chlorine gas is fed into the reaction apparatus via the feed device (2). The volume of the melt and the volume flow of the gas is determined as a function of the requisite residence time and the desired throughput. A temperature above the melting point of the metal (D) is set in the reaction vessel (1).
The gaseous metal halide (DCl3) is fed to the reaction vessel (5) via the collection device (4) for the reaction product formed.
Reaction Step ii:
The metal halide is fed to the metal granule or metal powder and alkali metal salt bed between the upper and lower quarter of the reactor vessel (5), preferably between the upper quarter and the centre. A mixture of metal granules or powder (D) and alkali metal salt (NaCl) is fed constantly to the reactor vessel via a solids metering device (6) in accordance with consumption.
The metal halide (DCl3) is reacted with the alkali metal salt in the reactor vessel (5) to give NaDCl4.
Reaction Step iii:
The melt maybe contaminated due to contact with water or atmospheric moisture. The hydrogen halide formed can react away with the metal granules (D) added to the salt bed in the reactor vessel (5) to give the metal halide (DCl3).
Reaction Step iv:
For further processing, the metal halide is passed through the reactor vessel (7). Row takes place from bottom to top through the purification unit charged with alkali metal salt NaCl. In the process, the metal halide DCl3 is reacted with the alkali metal salt NaCl to give the desired salt NaDCl4.
The flow from bottom to top through the reactor vessel (7) is not absolutely necessary. However, it has the advantage that the particles becoming smaller due to the reaction are not forced onto the sieve plate by the flow, blocking it. Nevertheless, homogeneous through-flow (plug flow) in the column is ensured in this way. Homogeneous through-flow is an essential prerequisite for complete reaction in the purification unit.

Method and device for the continuous production of NaAlCl4 or NaFeCl4


A vehicle monitoring system includes a communication subsystem configured to provide two-way wireless communication, and a controller mounted in a vehicle and configured to receive data indicative of a location of the vehicle and to control the communication subsystem to transmit the data indicative of the vehicle location toward a remote communication center and receive operational information transmitted from the remote communication center. The controller receives a mode change command included in the operational information and in response changes operating mode between an authorization mode, in which the controller transmits an alert signal to the remote communication center, and a tracking mode, in which the controller transmits the data indicative of vehicle location continuously at predetermined intervals regardless of the authorization signal.

This disclosure relates in general to vehicle security systems and, but not by way of limitation, to vehicle security systems for theft detection and vehicle location awareness and monitoring.
Many types of vehicle anti-theft devices having various features and combinations of features are available. One early type of vehicle anti-theft system includes a noise and light alarm that is triggered by vibration or tampering of the vehicle without a key in the lock or ignition switch of the vehicle. While this type of system is effective, perhaps, against casual thieves, it can be circumvented and does not prevent unauthorized movement of a vehicle.
Another type of anti-theft system is oriented toward theft recovery of a vehicle after it has been stolen. Equipment hidden in the vehicle transmits a signal upon a theft event and usually the signal can be received to locate the vehicle. Such systems are typically not designed to identify unexpected but authorized movement of a vehicle. Other drawbacks include limitations with respect to the accurate location of unauthorized movement. Also, the consumer who owns the vehicle must discover that the vehicle is missing and must notify law enforcement authorities before action is taken.
Finally, there exist various types of GPS (Global Positioning System) locating devices that may be used in vehicles. These products allow for tracking of fleet vehicles, for instance, in the nature of location, speed, vehicle service situations, etc. A GPS locating system can be useful, but there are limitations with respect to vehicle theft and recovery applications. Vehicle recovery systems would be useful if they provide improved theft detection and vehicle location awareness and monitoring so as to identify unauthorized movement and assist in recovery.
Accordingly, there is a need to overcome the foregoing limitations and drawbacks and provide an effective vehicle security and location system.


The present invention provides a stable foodstuffs which contain a cholesterol lowering amount of a sterol or stanol ester, crystal fat inhibitors and emulsifiers. The foodstuffs, including salad dressings are stable even when refrigerated.

This invention relates to stable salad dressings containing a sterol ester and methods of producing the same.
It has been shown that the addition of plant sterols, such as xcex2-sitosterol, to diets will reduce serum cholesterol levels. The sterols reduce serum cholesterol through the disruption of intestinal absorption of dietary cholesterol by displacing it from bile acid micelli. More recently, xcex2-sitosterol""s saturated derivative, xcex2-sitostanol, has been shown to be more effective in the reduction of intestinal cholesterol absorption. The sitostanol itself is virtually unabsorbed, so it does not contribute at all to in vivo serum sterol concentration upon consumption. Unfortunately, typical sterols and stanols are insoluble in the micelli phase of the alimentary canal and have only limited solubility in oils and/or fats or water. Hence, free sterols or stanols themselves are not optimum candidates for use in typical pharmaceutical or dietary dosage forms as cholesterol reducing agents.
The incorporation of these materials into foods are also difficult due to the limited solubility of the stanol or sterol in foods such as margarine and salad dressings. Salad dressings are particularly difficult in that they are frequently sold at room temperature, but require refrigeration after opening. Formulating a stable composition is particularly difficult when changes in temperature occur.
The present invention is directed to a stable food containing a cholesterol reducing amount of a sterol ester; an effective amount of a fat crystal inhibitor, and an effective amount of a hydrocolloid stabilizer or emulsifier. In a particularly preferred embodiment the present invention is a salad dressing which remains stable even when refrigerated.
As disclosed in U.S. Pat. Nos. 5,502,045, 5,578,334 and 5,244,877, the contents of which are incorporated herein by reference, it is known that consumption of xcex2-sitosterol is known to reduce cholesterol levels in the blood stream. In order to be effective it is necessary to consume from about 0.5 to about 1.5 grams, and more preferably about 1 gram of xcex2-sitosterol per serving size. The word sterol ester as used in the present invention is understood to include any cholesterol lowering agent including stanols, stanol esters, sterol esters and the like.
In order to incorporate an effective amount of xcex2-sitosterol in a salad dressing, in which an average serving size of about 30 grams, it is necessary to incorporate less than about 10 percent by weight, typically less than about 8 percent and most preferably about 6 percent by weight of the xcex2-sitosterol in a salad dressing serving.
At this relatively high level of xcex2-sitosterol, it is difficult to formulate a stable product, especially after the product has been opened and requires refrigeration. Refrigeration as used herein, is understood to be temperatures below room temperature, which includes about 60 F but the term also includes temperatures of 40 F and below. These lower temperatures are commonly found in commercial and residential refrigerators.
As used throughout this application, stable is understood to mean that the product does not separate into different phases. Instead the food, most preferably the salad dressing, will be relatively uniform and not separate into distinct layers. An example of a stable system is a salad dressing which remains creamy after a period of time. An example of an unstable system is an Italian salad dressing which after the passage of some time will separate into two distinct regions, an oil phase and an aqueous phase.
The present invention requires the incorporation of an effective amount of fat crystal inhibitors which include polyglycerol esters of fatty acids, sorbitan esters of fatty acids such as sorbitan tristearate; polysorbates made from the reaction product of monoglycerides or sorbitan esters with ethylene oxides, mixtures of these materials and the like. Examples of useful polysorbates include polyoxyethylene 20 mono- and diglycerides of saturated fatty acids, polyoxyethylene 4 sorbitan monostearate, polyoxyethylene 20 sorbitan tristearate, polyoxyethylene 20 sorbitan monooleate, polyoxyethylene 5 sorbitan monooleate, polyoxyethylene 20, sorbitan trioleate, sorbitan monopalmitate, sorbitan monolaurate, propylene glycol monolaurate , glycerol monostearate , diglycerol monostearate, glycerol lactyl-palmitate; mono and di-glyerides and the like. A particularly preferred fat crystal inhibitor is Caprol ET, commercially available from A.C. Humko, which is a mixture of polyglycerol fatty acid esters. Typically these materials are incorporated at levels of from 0.1 to about 3.0 percent by weight, preferably from about 0.2 to about 2.0 and most preferably about 0.5 weight percent.
Useful emulsifiers in the practice of the present invention include polyglycerol esters, mono and diglycerides of fatty acids, propylene glycol esters, sucrose fatty acid esters and polyoxyethylene derivatives of sorbitan fatty acid esters and the like. Mixtures of emulsifiers may also be employed. These emulsifiers are well known in the art and are commercially available. The emulsifier level is typically from about 0.01 to about 1.5 weight percent, preferably from about 0.1 to about 1.2 and most preferably from about 0.5 to about 1.0 weight percent.
Suitable polyglycerol esters include triglyceryl monostearate, hexaglyceryl distearate, hexaglyceryl monopalimate, hexaglyceryl dipalmitate, decaglyceryl distearate, decaglyceryl monoleate, decaglyceryl dioleate, decaglycerol monopalmitate, decaglycerol dipalmitate, decaglyceryl monostearate, octaglycerol monoleate, octaglycerol monostearate and decaglycerol monocaprylate.
Other suitable emulsifiers include, with HLB values provided in brackets, [], include decaglycerol monolaurate [15.5]; decaglycerol distearate [10.5]; decaglycerol dioleate [10.5]; decaglycerol dipalmitate [11.0]; decaglycerol monostearate [13.0]; decaglycerol monooleate [13.5]; hexaglycerol monostearate [12.0]; hexaglycerol monooleate [10.5]; hexaglycerol monoshortening [12.0]; polyoxyethylene (20) sorbitan monolaurate [16.7]; polyoxyethylene (4) sorbitan monolaurate [13.3]; polyoxyethylene (20) sorbitan monopalmitate [15.6]; polyoxyethylene (20) sorbitan monostearate [14.9]; polyoxyethylene (20) sorbitan tristearate [10.5]; polyoxyethylene (20) sorbitan monooleate [15.0]; polyoxyethylene (5) sorbitan monooleate [10.0]; polyoxyethylene (20) sorbitan trioleate [11.0]. As is appreciated by those with skill in the art, the HLB value for a surfactant is an expression of its Hydrophile-Lipophile balance, i.e., the balance of the size and strength of the hydrophilic (polar) and lipophilic (non-polar) groups of the surfactant.
Lactic acid derivatives include sodium stearoyl lactylate and calcium stearoyl lactylate.
In addition to emulsifiers, hydrocolloids may also be used to stabilize the emulsion at the same levels as the emulsifiers. Suitable hydrocolloids include xantham gum, propylene glycol alginate, guar gum, gum Tragarcanth, locust bean gum, gellan gum, gum Arabic, cellulose gums, cellulose derivatives such hydroxymethylpropyl cellulose, carboxymethyl cellulose, microcrystalline cellulose and the like; modified food starches and the like. In a preferred embodiment, both an emulsifier and hydrocolloid are employed.
Hydrocolloids are commonly used in combination with whole egg, egg yolks as well as the emulsifiers set forth above. The preferred stabilizers are combinations of xantham gum, propylene glycol alginate, egg yolk and modified food starches. However it was discovered that the incorporation of stanol esters in the formulations caused crystallization at temperatures below about 65 F. The destabilization of the emulsion was particularly noted when the amount of egg yolk was limited. In order to have the product defined as cholesterol free, egg yolk in the formulations was limited to less than 2 milligrams per serving.
The foods of the present invention also include preservatives, colorings, vitamins, seasonings and excipients which are well known to those in the art.
The present invention also provides a method for preparing a stable food emulsion comprising: providing an aqueous stream; providing an food grade acceptable oil; providing a stanol ester; providing a crystal fat inhibitor and an emulsifier; admixing said oil, stanol ester, crystal fat inhibitor and emulsifier; heating the admixture to a temperature of from about 100 to about 150 F to form a heated oil adding the heated oil to said aqueous system. More preferably the admixture is heated to a temperature of from about 120 to about 140 F.
In order to make the salad dressings of the present invention any suitable food grade oils may be employed including soybean, sunflower, corn, vegetable and the like. The oils are typically less than 50% of the salad dressing, more preferably from about 25 to about 40 weight percent.


A protective cap for a medical high-frequency instrument is configured such that it covers the high-frequency instrument in insulating fashion at least in the vicinity of an electrical connector for a high-frequency cable.

The present invention relates to a protective cap for medical HF instruments.
HF (high-frequency) instruments are commonly known, and are presented, for example, in the catalog of the company styled Karl Storz GmbH and Co., xe2x80x9cEndoskopische Chirurgiellxe2x80x9d [Endoscopic surgery], Section 6, 2nd ed. 1/94.
HF instruments are used for high-frequency coagulation or for high-frequency cutting.
High-frequency coagulation is used for surgical destruction of tissue areas, for hemostasis, to remove portions of tissue, or for thermal coagulation of tumors.
High-frequency cutting can be performed with HF instruments of the same design as for high-frequency coagulation high-frequency cutting is used, for example, to remove cysts, to cut through vessels, or for similar surgical interventions.
For use in the widely practiced technique of minimally invasive surgery, HF instruments are configured as tubular-shaft instruments.
Tubular-shaft instruments comprise a proximal handle and a shaft, joined immovably or detachably thereto, that is configured as a tubular shaft. Guided through this tubular shaft is a working insert that, at its distal end, projects beyond the shaft and carries the actual working device, for example a needle-shaped electrode or the mouth parts of a cutting or grasping tool.
The current to be applied is delivered via a high-frequency cable from a high-frequency generator arranged remotely from the HF instrument. For electrical connection to the instrument, a connector is provided on it. This connector usually comprises a metal pin mounted on the handle of the instrument and protruding from it.
The connector is in electrical contact with the actual working device, so that the current is guided through it to the distal end.
Whereas the connector for the high-frequency cable is generally immovably joined to the HF instrument, the generator is connected to the HF instrument, via the cable, only as necessary.
A distinction is made between unipolar and bipolar HF instruments, depending on the type of current delivery.
In a unipolar (also called monopolar) HF instrument, a connector for only one pole is provided on the instrument. The patient lies on an electrically conductive mat that constitutes the second pole. The current emerging from the distal end of the unipolar HF instrument flows over a large area through the patient""s body to the conductive mat.
In bipolar HF instruments, two connectors are present on the instrument, i.e. the current is fed in at the proximal end, delivered to a tool (e.g. a coagulation loop) at the distal end, then returned back to the proximal end and there discharged.
The term xe2x80x9cconnectorxe2x80x9d hereinafter comprises, in the case of mono- or unipolar HF instruments one connector, and in the case of bipolar HF instruments two connectors or connector plugs.
It has been found in practical use that electrical arcs can occur in the region of the connector plug, resulting in jerky reactions on the part of the surgeon. Adverse effects can also result from leakage currents.
A variety of solutions have hitherto been proposed for protecting the surgeon from such adverse effects.
For example the aforementioned catalog of Karl Storz GmbH and Co. shows, in Section 5 on page SCT 5/1 A, a handle for a tubular-shaft instrument having a connector for a unipolar high-frequency cable, in which insulation is achieved by the fact that the handle is made substantially of nonconductive plastic. Only the connector pin is made of metal, and is insert molded into the plastic. The handle has one fixed and one movable handle element, which can be moved relative to one another by way of a hinge joint made of plastic.
This type of insulation has the disadvantage that the handles do not exhibit sufficient mechanical stability.
The plastic hinge that was used could not withstand the mechanical stresses.
The pivot pins were therefore once again made of metal.
Since, however, the joints are located in close proximity to the connector for the high-frequency cable, the risk once again exists of voltage arcing or leakage currents from the connector to the metal hinge pin.
Because of the poor mechanical stability of plastic handle elements for HF instruments, it was alternatively proposed to utilize metal parts and to cover them with an electrically insulating plastic coating.
These coatings have not, however, proven durable over the long term. Handling, especially during cleaning and autoclaving, creates the risk that the coating can become damaged and can detach, and thereby expose metal areas of the instrument. In particular, a coating can exhibit less than complete coverage in areas where moving parts make contact with one another, for example at joints. This can result in arcs or leakage currents during HF use.
The purpose of the handle at the proximal end of the instrument, on which the connector for the high-frequency cable is present, is to control the distal end of the working device, e.g. spreadable mouth parts, extending through the tubular shaft.
For this purpose, an actuation element, usually in the form of a rod, projects proximally beyond the tubular shaft and is joined to a movable handle element of the handle. When the handles are, as is usual, scissor-like, one end of the handle element that is movable (i.e. pivotable) about the hinge axis is mechanically connected to the proximal end of the actuation element projecting beyond the tubular shaft, in order to convert a pivoting movement of the handle element into a linear displacement movement of the rod-shaped actuation element.
Ball-and-socket joints have proven successful as the mechanical connection, especially for instruments that can be disassembled. The usually solid, proximally projecting end of the metal actuation element is located, depending on the design, in the vicinity of the connector for the HF cable, and during HF operation also constitutes an exit point for arcs. Even insulation of this area cannot provide a remedy, since any insulation would soon be rubbed off by the frictional ball-and-socket mechanism.
With bipolar HF instruments, there exists the additional risk of arcing from the connector plug of the one pole to the connector plug of the other pole.
Against this background, it is the object of the present invention to create a reliable insulation system for HF instruments that does not adversely affect the stability and functionality of the other components of the HF instrument.
According to the present invention, the object is achieved by a protective cap which is configured such that it covers the instrument in insulating fashion at least in the vicinity of an electrical connector for a high-frequency cable.
This object is furthermore achieved by a medical HF instrument that has a protective cap of this kind.
The provision of an insulating protective cap eliminates the absolute necessity either for the HF instrument, or at least those regions of the HF instrument in which the connector for the high-frequency cable is located, to be produced entirely from insulating material; or, in the case of metallic materials, for them to be completely equipped with an insulating covering. For example, the handle including its joint and the connector for the high-frequency cable can be produced from metal, and nevertheless protected, in optimally electrically insulating fashion, against arcing once the protective cap has been attached. The protective cap thus makes it possible to manufacture those components that contain the electrical connector from mechanically stable and resistant material. Since the protective cap covers at least the vicinity of the electrical connector in insulating fashion, the danger of arcing or leakage currents to conductive elements and thus to the surgeon is eliminated. The electrical connector as such is, of course, electrically insulated with respect to the handles.
Depending on whether the instrument is configured as a unipolar or bipolar instrument, one connector plug or two connector plugs and their vicinity are covered in insulating fashion.
The protective cap can be manufactured as a relatively economical component from any material having good electrical insulation. When it is produced as a plastic injection-molded part, it can, for example, be designed for one-time use.
The HF instrument can thus be manufactured from suitable mechanically stable materials with no consideration of insulation against arcing in the region of the connector, since this is now accomplished by the protective cap that can be put in place subsequently or as required.
In a further embodiment of the invention, current-carrying components in the vicinity of the connector that are exposed, or that become exposed due to actuation of the HF instrument, are also covered by the protective cap.
This feature has the considerable advantage of ensuring, in all possible operating and handling positions, that not only exposed metal parts but also metal parts that become exposed during handling are covered. In the case of the aforementioned ball-and-socket joint connection between the actuation element in the tubular shaft and the handle element, a segment of greater or lesser length, depending on the pivot position of the handle element, is pulled proximally out of the shaft. Since the actuation element is at the same time utilized for electrical conduction to the distal end, it is necessarily manufactured from metallically conductive material and constitutes an exit point for arcs or leakage currents. The result is therefore to ensure that not only arcing from the electrical connector, but also adverse effects resulting from the proximally projecting metallically conductive actuation element, are eliminated.
In a further embodiment, the protective cap can be placed onto the HF instrument.
This feature has the advantage that the protective cap can be put in place only when needed, i.e. during HF operation, and otherwise the instrument can be used without the protective cap.
In a further embodiment of the invention, the protective cap can be placed onto a handle that has handle elements joined via a hinge joint, the protective cap extending over the hinge joint.
The advantage of this feature is that the hinge joint, regardless of whether the remaining handle elements are manufactured from plastic material or other materials, can comprise a metal pin, which contributes greatly to the mechanical stability of the handle and the joint. The protective cap proceeds from the connector and extends over the region of the joint, so that arcing to the metal joint pin is ruled out.
In a further embodiment of the invention, the shape of the protective cap is adapted to the contour of those parts of the HF instrument onto which it is placed.
The advantage of this feature is that the protective cap, once put in place, conforms closely to the contour of the HF instrument and does not constitute a bulky component that interferes with the surgeon. This rules out any need for the surgeon to grip the HF instrument differently, because the protective cap is in place, than in non-HF operation without the protective cap, thus enhancing handling ease and operating reliability.
In a further embodiment of the invention, the shape of the protective cap is configured such that movement of the handle elements in the region of the protective cap is possible without being limited thereby.
The advantage of this feature is that the protective cap covers the entire movement range of the handle elements, i.e. sufficient insulation is ensured in every handle element position, while at the same time the freedom of movement of the handle element is not limited despite the presence of the protective cap.
In a further embodiment of the invention, the protective cap can be slid onto a connector for a high-frequency cable that is joined immovably to the HF instrument and protrudes therefrom.
The advantage of this feature is that the cap can be slid over the connector onto the instrument in securely guided fashion. This procedure can be performed easily, quickly, and without close attention. A corresponding opening can be provided in the cap, through which the connector, protruding from the instrument, passes as it is slid on, so that the slid-on cap can then directly surround and cover the connector and therefore the principal source of the arcing hazard is insulated in particularly secure fashion.
In a further embodiment of the invention, the protective cap has a tubular extension that can be slid over a pin-shaped connector protruding from the HF instrument.
The advantage of this feature is that the cap, guided by the tubular extension, can be slid in directed fashion into a specific position on the HF instrument.
In a further embodiment of the invention, an attachment element is provided with which the protective cap can be secured on the HF instrument.
The advantage of this feature is that the protective cap is secured in particularly reliable and lossproof fashion, so that it cannot slip or become detached even if the HF instrument is set down between multiple treatment procedures.
In a further embodiment of the invention, the protective cap is made of an electrically insulating plastic material.
The advantage of this feature is that the protective cap can be manufactured from an economical material that can be manufactured, for example, using the injection-molding method, and thus can be designed as a disposable part for one-time use.
In a further embodiment of the invention, the protective cap is made of a ceramic material, e.g. an oxide ceramic or a glass ceramic.
The advantage of this feature is that a material that is not only insulating but also extremely mechanically strong is present, so that the protective cap can withstand even a large number of cleaning and autoclaving procedures.
In a further embodiment of the invention, the protective cap can be placed onto the HF instrument in detachable fashion.
The advantage of this feature is that the cap can be removed, either for cleaning or if the instrument is no longer being used in HF mode.
In a particular embodiment of the invention, the protective cap can be placed onto an HF instrument in which a handle is joined to a tubular shaft element via a releasable snap-lock connection, an actuation knob being present for closing and releasing the snap-lock connection, said knob being utilized to secure the protective cap.
The considerable advantage of this feature in this specific case is that attachment of the protective cap can be simultaneously accomplished using a component already present on the HF instrument. For the cleaning process, the instrument can be disassembled in such a way that the protective cap is present as an individual part, and can be cleaned correspondingly.
In a further embodiment of the invention, the protective cap itself has a connector for a high-frequency cable, and after placement onto an HF instrument, the connector is connected to a conductive part of the HF instrument.
This feature has the advantage that the connector, which is usually configured as a metal connector pin, is integrated into the protective cap, so that provision is already made during manufacture for a correspondingly insulated connection between these two components. Once the protective cap is put in place, the connector integrated into it creates the electrical connection between the HF connector cable and the conductive component of the HF instrument. In the case of a bipolar HF instrument, two connector plug pins are present.
In a further embodiment of the invention, provision is made for handling features, which facilitate placement or removal of the protective cap, to be present on the protective cap.
The advantage of this feature is that a replacement operation can be performed easily and reliably.
In a further embodiment of the invention, the handling features comprise grip elements, grip ribs, a shaped-on handle, or a roughening.
These features on the one hand are very easy to carry out in terms of production engineering, especially in the case of a configuration as an injection-molded part; and on the other hand they constitute unequivocal handling features for the fingers of a human hand, so that secure grasping and removal or placement are possible even without close attention, and in particular without direct visual contact.
In a further embodiment of the invention, the protective cap can be mounted onto the HF instrument and pulled off from it only when the grip elements are in a specific position.
The advantage of this feature is that the grip elements constitute a specific securing means for the protective cap with no necessity for an additional operating element for the purpose.
In a further embodiment of the invention, the protective cap is joined to the high-frequency cable.
The advantage of this feature is that the protective cap becomes part of the plug connector.
It is understood that the features mentioned above and those yet to be explained below can be used not only in the respective combination indicated, but also in other combinations or in isolation, without leaving the context of the present invention.

Protective cap for medical hf instruments