A wiper that provides a controlled release anti-microbial agent has a substrate layer to which the anti-microbial agent is adhered. In addition, the wiper will have one or more laminate layers, at least one of which will be absorbent. Various anti-microbial agents such as silver containing additives, calcium hypochlorite, and chlorine dioxide generating compounds may be employed. The substrate layer may be a poly(ethylene vinyl acetate) meltblown web and the laminate layer may be a hydroentangled composite absorbent fabric.

The present invention generally relates to a wiper, such as the type used to disinfect hard surfaces in food service and medical applications. More particularly, the present invention is directed to a wiper having an anti-microbial agent that can be controllably released over an extended period of time and which remains effective after repeated washings and rinsings.
Microbial contamination can have a detrimental effect on any item ordinarily used by consumers or merchants, particularly items used in the medical and food service industries. For example, due to various bacterial outbreaks, there have been at least 200 food poisoning deaths reported in the last 10 years. Moreover, more Americans die from hospital infections each year than from car accidents and homicides combined.
Much of this contamination occurs due to migration of microorganisms from hard surfaces such as table tops or counter tops to food or to the hands of food handlers and, thence, to the food itself. For example, in the food service industry, contamination commonly occurs on stainless steel surfaces used for food preparation. Various food products are prepared on hard surfaces such as counters, tables, and the like. Bacteria from these products will often collect on such surfaces and, if the surface is not disinfected regularly, will transfer from product to product or from a product to the food handler. Numerous studies indicate that cross-contamination occurs as a result of a microorganism coming into contact with a person""s hands or a cleaning cloth and thereafter contaminating other items touched by the cloth or hands, such as equipment or other surfaces.
As a result, wipers that contain anti-microbial agents have been employed to prevent such surface and cloth contamination. Currently, most of these anti-microbial wipers are impregnated with anti-microbial agents and are delivered to the user in a premoistened form. With these pre-moistened wipers, however, the disinfecting agent within the wiper is commonly readily exhausted after washing and rinsing of the wiper to remove dirt after a period of use. Thus, it is believed that such premoistened wipers either inhibit growth on the wipers and/or the hard surfaces cleaned only mildly or may only be used for a limited number of wipes.
Some anti-microbial wipers have been developed that are not pre-moistened. For example, one such anti-microbial wiper that can be delivered in a dry condition is disclosed in U.S. Pat. No. 5,213,884 to Fellows. In the Fellows patent, a wiper is described that contains a hot melt adhesive powder mixed with a chlorine release agent. The adhesive powder and chlorine release agents are incorporated into a tissue suitable for use in the disinfection of hard surfaces.
Although the wiper disclosed by Fellows can be delivered in a dry form, it apparently fails to provide sufficient disinfection over an extended period of timexe2x80x94similar to pre-moistened wipers. After being contacted with water, the release of the anti-microbial agent in such wipers capable of being delivered in a dry state occurs readily without control. This prevents the wiper from sustaining its anti-microbial activity after repeated washings and rinsings.
Another anti-microbial wiper has been marketed by Pal International Inc. of England under the name WIPEX. According to sales literature, this wiper contains poly(hexamethylenebiguanide hydrochloride), alkyldimethybenzyl ammonium chloride, and the disodium salt of ethylenediaminetetraacetic acid (E.D.T.A.). In addition, the wipes include indicator stripes that are stated to fade gradually as the disinfectants in the wiper are depleted. It is believed that U.S. Pat. No. 4,311,479 to Fenn et al. is related to this particular anti-microbial cloth. It is unclear, however, whether these wipes would prove to be very effective in reducing cellular activity. Also, it is believed that they would retain only limited anti-microbial activity after washing and rinsing.
Accordingly, a need currently exists for a more effective wiper that disinfects hard surfaces and inhibits cross-contamination. In particular, a need exists for a wiper that contains an anti-microbial agent that is slowly released when contacted by water, thereby allowing the wiper to provide an anti-microbial solution and to sustain its anti-microbial effectiveness after repeated washing and rinsing operations.
Accordingly, an object of the present invention is to provide a wiper suitable for use in disinfecting hard surfaces.
It is another object of the present invention to provide a wiper containing an anti-microbial agent that can remain effective after repeated washing and rinsing operations.
Still another object of the present invention is to provide a wiper containing an anti-microbial agent that can remain effective after repeated washing and rinsing by controlling the release rate of the anti-microbial agent.
Yet another object of the present invention is to provide a wiper containing a controlled release anti-microbial agent that is incorporated within a fibrous substrate layer.
It is another object of the present invention to provide a wiper containing a controlled release anti-microbial agent incorporated within a hydrophobic substrate layer that adheres to a fibrous substrate material.
These and other objects of the present invention are achieved by providing a wiper suitable for disinfecting hard surfaces and inhibiting or preventing cross-contamination. A wiper of the present invention generally includes a substrate layer, at least one laminate layer, and an anti-microbial agent which is adhered to the substrate layer.
In accordance with the present invention, any material commonly used in the art to manufacture cleaning cloths, such as wipers, can be used as the substrate material. Commonly, but not restricted to such materials are hydrophobic materials. Generally, the substrate material may have a basis weight of more than about 10 grams per square meter (gsm). In one embodiment of the present invention, the wiper contains a meltblown substrate layer formed from poly(ethylene vinyl acetate) co-polymer (EVA).
In addition to a substrate layer, a wiper of the present invention also contains a laminate layer. In general, a laminate layer of the present invention can include any absorbent material (or if an additional laminate layer is employed, a hydrophobic material) that may be bonded to the substrate layer. For example, in one embodiment, two laminate layers formed from a hydroentangled material sold under the name HYDROKNIT(copyright) and having a basis weight of 49 gsm, are bonded to both surfaces of an EVA meltblown substrate layer. HYDROKNIT(copyright) is further disclosed in U.S. Pat. No. 5,284,703 to Everhart et al. which is incorporated herein in its entirety by reference thereto. In addition, the web can be a co-form material such as disclosed in U.S. Pat. No. 4,100,324 to Anderson et al. and U.S. Pat. No. 5,350,624 to Georger et al., which are incorporated herein in their entireties by reference thereto.
As stated, the substrate layer of the present invention can be hydrophobic. Consequently, such layers can have a substantial effect on water penetration because the layer itself has a thickness. As such, the substrate layer can enhance the ability of a wiper made according to the present invention to operate over an extended period of time after repeated washings and rinsings. In particular, when the substrate layer is hydrophobic, it is believed that the layer can inhibit water from readily migrating out of the wiper, thus providing a longer release time for an anti-microbial agent incorporated therein.
According to the present invention, a subject wiper also includes an anti-microbial agent that can be controllably released over an extended period of time after repeated washing and rinsing. xe2x80x9cRepeated washing and rinsingxe2x80x9d, for purposes of the present invention, generally refers to at least 5 cycles of rinsing the wiper between wiping applications. As used herein a xe2x80x9crinse cyclexe2x80x9d includes the steps of contacting the wiper with water and wringing or squeezing the excess water from the wiper. The anti-microbial agent is generally adhered to the fibers forming the substrate layer. In one particular embodiment, the anti-microbial agent is adhered to meltblown poly(ethylene vinyl acetate) (EVA) fibers.
In general, any anti-microbial agent capable of being controllably released can be used in accordance with the present invention. Some examples of anti-microbial agents that are suitable for use in the present invention include various solid particulate anti-microbial agents such as calcium hypochlorite particles, halogen generating formulations, chlorine dioxide generating formulations, particles containing silver ions, and quaternary amines complexed with a carrier.
In one embodiment of the present invention, an anti-microbial agent such as calcium hypochlorite, having different particle sizes is provided. Because smaller particles generally have higher rates of dissolution than larger particles, control of the release rate of the anti-microbial agent can be achieved through use of such particulates having a size differential.
Another embodiment of the present invention includes particulate forms of an anti-microbial agent that are coated with various polymers so that the particles are at least partially encapsulated. In this embodiment, various amounts and types of coatings may be provided to obtain the particular anti-microbial agent release rate desired. For example, a lower release rate is generally provided by a particle having a thicker or more complete coating, and vice-versa. In addition, mechanisms such as polymerization chemistries, porous absorbents, soluble binders, or combinations thereof, may be employed to modulate the controlled release properties of the anti-microbial agent.
The anti-microbial agent of the present invention may be incorporated into a substrate layer before the fibers comprising the substrate layer have become solidified. In one embodiment, calcium hypochlorite particles are added to unsolidified meltblown poly(ethylene vinyl acetate) fibers during formation of the meltblown substrate layer. The particles may be fed into the stream of meltblown fibers while the fibers are still tacky. If desired, the meltblown substrate layer containing calcium hypochlorite particles adhered to the EVA fibers may be formed directly onto a pre-formed absorbent laminate layer so that no additional adhesive is necessary to bond the laminate and substrate layers together, although the use of a separate adhesive for this purpose is within the scope of the present invention. The meltblown fibers are then allowed to solidify into a meltblown web. If desired, an additional laminate layer comprising the same material as the original laminate layer, or a different material, may be bonded to the other surface of the meltblown substrate layer. The additional laminate layer can be bonded to the substrate layer by any means, for example, by chemical or thermal bonding.
The substrate and the laminate layers of the present invention can also contain chemicals in addition to the anti-microbial agent. Moreover, a visual sensor or dye can be incorporated into one or more of the layers to indicate when the anti-microbial agent has been depleted. Some examples of such visual sensors are provided by the indicators described in U.S. Pat. Nos. 3,704,096; 4,205,043; 5,699,326; 5,317,987; 4,248,597 and 4,311,479, which are incorporated in their entireties by reference thereto. In addition, sodium thiosulfate and various blue dye mechanisms such as those employed herein in the WIPEX(copyright) wipes may also be employed.
Other objects, features and aspects of the present invention are discussed in greater detail below.
Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
In general, the present invention is directed to a wiper containing an anti-microbial agent that can be released to liquid contained within the wiper after a rinse cycle, where the agent is released at a controlled rate over a period of time. It has been discovered that by using an anti-microbial agent in solid or particulate form, the anti-microbial agent is slowly released when contacted by water. Surprisingly, this permits stronger anti-microbial agents to be employed than would be possible with wipers that do not control the release rate of the agent. Moreover, it has been found that the wiper can retain its anti-microbial activity over the course of multiple rinsing cycles. In fact, with certain embodiments of the present invention, as many as 6 or more rinsing cycles are possible. In other embodiments of the present invention, 10 or more rinsing cycles are possible, while in other embodiments of the present invention, 15 to 20 rinsing cycles can be obtained, and even 20 or more rinsing cycles are possible.
In accordance with the present invention, an anti-microbial surface wiper is provided that contains a substrate layer, at least one laminate layer, and an anti-microbial agent. In one embodiment, a wiper of the present invention includes a substrate layer that bonds with a first and second laminate layer. Further, an anti-microbial agent can be incorporated into the substrate layer such that the agent can be released at a controlled rate when contacted with water.
A laminate layer of the present invention can generally be made from any absorbent material commonly used in the art for wipers. For example, a laminate layer of the present invention can be made from absorbent nonwoven fabrics, and more particularly, from absorbent nonwoven composite fabrics having a high pulp concentration. Some examples of laminate layers that are suitable for use in the present invention are disclosed in U.S. Pat. No. 5,389,202 to Everhart et al., U.S. Pat. No. 5,284,703 to Everhart et al., and U.S. Pat. No. 5,573,841 to Adam et al., which are incorporated herein in their entireties by reference thereto. In one embodiment, the laminate layer(s) comprises a HYDROKNIT(copyright) nonwoven composite fabric that contains approximately 70% by weight pulp fibers that are hydraulically entangled into a continuous filament substrate. HYDROKNIT(copyright) material is commercially available from Kimberly-Clark Corporation of Neenah, Wis. In addition, the web can be a co-form material such as disclosed in U.S. Pat. Nos. 4,100,324 to Anderson et al. and U.S. Pat. No. 5,350,624 to Georger et al., which are incorporated herein in their entireties by reference thereto. The wipers may be packaged and made according to the disclosures of U.S. Pat. Nos. 4,833,003 and 4,853,281 to Win et al.
Depending on the particular application, the basis weight of a laminate layer used in accordance with the present invention can vary. In general, the basis weight of the laminate layer incorporated into a wiper of the present invention is at least about 10 grams per square meter (gsm). The basis weight of such laminate layer can also be at least about 20 gsm. In one embodiment of the present invention, the basis weight of the material used for the laminate layer is about 49 gsm.
Although not required, a wiper of the present invention may include more than one laminate layer. In one embodiment of the present invention, for example, the wiper includes two laminate layers, both of which can be made from an absorbent nonwoven fabric, such as a HYDROKNIT(copyright) material. In other embodiments, the additional laminate layer may itself be a hydrophobic material like one embodiment of the substrate layer. This allows the wiper to be engineered for specific performance criteria, such as for oil wiping.
A wiper made in accordance with the present invention includes a substrate layer that can adhere to the laminate layer, either through self-bonding or through the use of a separate adhesive bonding material. In particular, a substrate layer of the present invention is made from a fibrous material. In particular, a hydrophobic fibrous material can be used. Some examples of materials that are suitable for use in the substrate layer of the present invention are disclosed in U.S. Pat. No. 5,350,624 to Georger et al., which is incorporated in its entirety herein by reference thereto. Other examples of suitable substrate materials include, for example, meltblown polypropylene, spunbond polypropylene, HYDROKNIT(copyright) material, double recreped webs and tissue paper. In one particular embodiment of the present invention, the substrate layer comprises meltblown poly(ethylene vinyl acetate). One example of a commercially available form of poly(ethylene vinyl acetate) that is suitable for use in accordance with the present invention is EVA Grade LC 724.36, having a melt index of 135xc2x0 C., made by EXXON Chemicals.
The substrate layers employed in the present invention may exhibit various basis weights. In one particular embodiment, when laminate layers of approximately 49 gsm are employed, the total composite may have a basis weight of between about 125 gsm and 130 gsm, and more particularly about 130 gsm.
When adhered to the laminate layer according to the present invention, the substrate layer is believed to contain void spaces that can increase the ability of the wiper to hold moisture. Each time the wiper is subjected to a rinse cycle, the liquid within the wiper, including the liquid within the substrate layer, is totally or partially exchanged with liquid from an external source (e.g., a wash bucket). Liquid that enters the wiper generally has very little or no content of anti-microbial agent dissolved therein, and consequently is a poor anti-microbial solution. However, the liquid that is in contact with the subject substrate layerxe2x80x94and the anti-microbial agent in controlled release form that is adhered theretoxe2x80x94dissolves a portion of the anti-microbial agent and thereby forms an anti-microbial solution.
As used herein, the terms xe2x80x9canti-microbial solutionxe2x80x9d mean a liquid having in solution an amount of an anti-microbial agent that is sufficient to kill or reduce the growth rate of strains of common disease causing bacteria as compared with the same liquid without that amount of anti-microbial agent. In some of the embodiments of this invention, it is possible for the anti-microbial solution to act as a sanitizer solution or a disinfectant solution.
When the wiper is used to cleanse surfaces, some of the retained wiper liquid is forced out of the wiper and is left on the surface. Since this liquid is an anti-microbial solution, it is capable of acting as a biocide or biostat on the surface that has been wiped.
It is believed that because the substrate layer has a measurable and controllable void volume, the amount of liquid that is retained within the layer after a rinse can be determined and controlled. Accordingly, the anti-microbial agent that is adhered to the substrate layer must only provide enough anti-microbial agent to make this retained liquid an anti-microbial solution. Therefore, by controlling the amount and form of anti-microbial agent that is adhered to the substrate layer, and by providing the substrate layer as a fibrous mat having a measurable and controllable void volume, one is able to control the amount of anti-microbial agent that enters the retained liquid after each rinse cycle, and thereby to provide a wiper that is capable of replenishing the anti-microbial agent in the retained liquid after numerous rinse cycles.
It is believed that the use of a hydrophobic fibrous web as the substrate layer can also affect the fluid retention properties of that layer, and can thereby provide desirable control over the controlled-release characteristics of the wiper.
Furthermore, in one embodiment, the substrate layer is contained between two separate absorbent laminate layers, which allows the wiper to retain good wipe-dry properties, while also possessing the ability to hold moisture and prevent or reduce the loss of particles of a non-activated, highly concentrated, anti-microbial agent. An advantage of this structure is that it permits the isolation of anti-microbial agents from direct touch with any surface that the wiper contacts. This is an advantage when using anti-microbial agents that are irritating to the skin, because it prevents particles or concentrated sources of such agents from being left on surfaces which may come in contact with human skin (e.g., toilet seats). In addition, it is believed that such wipers tend to be less irritating to the hands of the user.
As stated above, a wiper of the present invention also includes an anti-microbial agent that can be controllably released. Generally, the anti-microbial agent is incorporated into the substrate layer of the subject wiper. In particular, the anti-microbial agent may be added to the substrate layer while the substrate layer remains in an unsolidified state. By being added at this stage, the anti-microbial agent can be highly dispersed and become part of the substrate layer""s fibrous web, thereby substantially prohibiting unwanted leakage of the agent. The cooling and solidification of the fibers into a structured web results in the adhesion of the particles to the substrate layer and substantially prevents them from being detached during repeating rinse cycles. The strength of adhesion of the particles to the substrate layer substantially prevents the migration of such particles from the substrate layer, and also reduces the loss of particles by abrasion.
In general, an anti-microbial agent of the present invention can comprise a number of different chemicals commonly used as disinfectants in the field. Useful anti-microbial agents include a chlorine dioxide-generating formulation containing chlorine dioxide, sodium chlorate surfactant, and an acid moiety as the anti-microbial agent. A commercially available example of such a controlled-release chlorine dioxide formulation is made by Bernard Technologies, Inc. and is sold under the name MICROSPHERE(copyright) 2500. This product may be described in U.S. Pat. Nos. 5,631,300; 5,639,295; 5,650,446; and 5,668,185.
In one embodiment of the present invention, the anti-microbial agent can include silver ions. In this embodiment, a silver-zeolite complex can be utilized to provide controlled release of the anti-microbial agent. One commercially available example of such a controlled-release anti-microbial agent has been available from AgION Technologies, LLC., under the name AgION(trademark) (which was previously available under the name HEALTH SHIELD(copyright) from K. B. Technologies, Inc.). This material has been incorporated into a fabric, which is available under the name GUARDTEX(copyright). This material is constructed from polyester and rayon and contains a silver-zeolite complex. Other suitable silver containing microbial agents are disclosed in Japanese Unexamined Patent No. JP 10/259325, which is incorporated herein by reference.
In addition to silver-zeolites, other metal-containing inorganic additives can also be used in the present invention. Examples of such additives include, but are not limited to, copper, zinc, mercury, antimony, lead, bismuth, cadmium, chromium, thallium, or other various additives, such as disclosed in Japanese Patent No. JP 1257124 A and U.S. Pat. No. 5,011,602 to Totani et al, which are incorporated herein by reference. In some embodiments, the activity of the additive can also be increased, such as described in U.S. Pat. No. 5,900,383 to Davis et al., which is also incorporated herein by reference.
In another embodiment of the present invention, the anti-microbial agent can be a material that is a source of free chlorine. Calcium hypochlorite or sodium hypochlorite can be used for this purpose, and calcium hypochlorite particles, in particular, can be useful. An example of a commercially available form of calcium hypochlorite particles suitable for use in the present invention is ALDRICH-brand #24-415-5 stabilized technical grade (ground and screened to approximately 150 micron particle size).
In addition to the above-mentioned embodiments, other anti-microbial agents can also be utilized in a wiper made in accordance with the present invention. Examples of such anti-microbial agents include, but are not limited to, quaternary amines, halogens, chlorine dioxide, oxidants, peroxides, such as sodium peroxide, other silver ions, such as Ag+, Ag++, and Ag+++ and silver complexes, or combinations thereof. Some examples of systems that can be used to generate chlorine dioxide, for instance, are disclosed in U.S. Pat. Nos. 5,126,070; 5,407,685; 5,227,168; 4,689,169; and 4,681,739, all of which are incorporated herein in their entireties by reference thereto. Another anti-microbial agent which could be employed is disclosed in U.S. Pat. No. 5,837,274 to Shick et al. which is incorporated herein in its entirety by reference thereto.
The anti-microbial agent of the present invention can be in a form that provides control of the rate of release of the agent from its source into the liquid that is in contact with the agent. A variety of mechanisms for adjusting solubility are known in the art and can be employed to control the release rate of the anti-microbial agent incorporated within a wiper made according to the present invention.
In some embodiments of the present invention, anti-microbial particles having varying sizes can be employed to control the release of the agents. For example, the release rate of calcium hypochlorite can be controlled by employing hypochlorite particles that have a certain size distribution. Because they provide higher surface area, smaller calcium hypochlorite particles have a faster dissolution rate into water than larger particles. Thus, in one embodiment of the present invention, the rate of calcium hypochlorite release by the wiper can be controlled by providing particles of different sizes. To reduce the overall release rate, larger particle sizes can simply be added as needed to the controlled-release composition prior to incorporation into the substrate layer.
An example of such an anti-microbial controlled-release agent is disclosed in PCT Application No. WO 98/53679, entitled xe2x80x9cSolid Disinfectant Material/Surfactant Compositionsxe2x80x9d and assigned to Olin Corporation. As described therein, disinfectant compositions are controllably released over time as anti-microbial agents.
In addition to varying particle size, other mechanisms for controlling release rate can be used to control the release of the anti-microbial agent present within a subject wiper. In particular, mechanisms for controlled release such as polymerization chemistries, encapsulation, porous absorbents, soluble binders, and other similar technologies can be employed to further enhance the ability to control the amount of anti-microbial agent released over a period of time.
For example, in one embodiment, calcium hypochlorite particles can be totally or partially encapsulated within a polymer coating to reduce the dissolution rate of the particles in water. By reducing the dissolution rate, the calcium hypochlorite is released in controlled amounts over a longer period of time, providing for the ability to withstand continued washing and rinsing, while still remaining effective as the anti-microbial agent of the wiper. When incorporating a coating with an anti-microbial agent of the present invention, any coating known in the art to reduce the release rate or dissolution rate of the agent can be used. For example, in one embodiment, an aqueous emulsion of an acrylic polymer is used to coat a calcium hypochlorite anti-microbial agent. In another embodiment, a microcrystalline wax coating can be used. In yet another embodiment, polyethylene can be used.
To sufficiently reduce the release rate of the anti-microbial agent in accordance with the present invention, it is not generally necessary to completely coat the particles. For instance, in one embodiment, a 20% acrylic polymer coating is used, while in another embodiment, a 33.5% acrylic polymer coating is used. In still another embodiment, a 60% microcrystalline wax coating is used.
According to the present invention, other chemicals can be incorporated into the subject wiper to enhance the performance of the wiper. For example, a wiper of the present invention can also contain surfactants, saponins, and other chemicals to control biofilm formation on the surface being cleaned. Furthermore, a wiper of the present invention can contain chemicals that act as visual sensors to detect the exhaustion of the anti-microbial agent. In particular, an indicator can be incorporated into a clear binder contained within the wiper to communicate an exhaustion of the anti-microbial agent by changing color. Several indicator methods are known in the art and may be utilized in the present invention. Examples include time indicators, chemical indicators, pH indicators, binder/dye indicators, and dye solubility indicators.
A method for producing an anti-microbial wiper of the present invention may be generally described as follows. It should be noted that the discussion below is intended only as a description sufficient to enable one skilled in the art to produce an embodiment of an anti-microbial wiper of the present invention. Other similar processes known in the art are also suitable for producing the anti-microbial wipers of the present invention.
To produce a wiper of the present invention, the anti-microbial agent is first generally entrapped within the substrate layer while the substrate layer remains in an unsolidified state. In particular, calcium hypochlorite particles, for example, may be entrapped within an unsolidified fibrous web of a poly(ethylene vinyl acetate) meltblown substrate layer. Other means could be employed, however, to attach the particles to the fibers. One example that could be utilized is disclosed in U.S. Pat. No. 5,736,473 to Cohen et al. which is incorporated herein in its entirety by reference thereto. Cohen et al. disclose a method of attaching a particulate material to individual surfaces of a fibrous material by employing an electrically charged matrix of fibrous material.
In one particular embodiment of the present invention, poly(ethylene vinyl acetate) (EXXON EVA Grade LC 724.36, melt index 135xc2x0 C.) is initially meltblown into a fibrous web. Processes and apparatuses employed for producing meltblown fibers and the resulting nonwoven webs are well known in the art. Meltblown fibers are fibers formed by extruding a molten polymeric material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging, usually hot and high velocity, gas (e.g. air) streams to attenuate the filaments of molten material and form fibers. During the meltblowing process, the diameters of the molten filaments are generally reduced by the force exerted by the drawing air to a desired size. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Buntin et al, U.S. Pat. No. 4,526,733 to Lau, and U.S. Pat. No. 5,160,746 to Dodge, II et al., all of which are hereby incorporated herein in their entireties by reference thereto. Meltblown fibers may be continuous or discontinuous and are generally smaller than ten microns in average diameter. Various materials may be used to form the meltblown fibers such as polyethylene or polypropylene.
In one embodiment, poly(ethylene vinyl acetate) is extruded at a temperature such as 420xc2x0 F., at an extruder pressure of, for example, 135 psig, and at a primary attenuation air temperature of, for example, 435xc2x0 F. After extrusion, calcium hypochlorite particles (ALDRICH #24-415-5 stabilized granular technical grade) are then delivered to the meltblown poly(ethylene vinyl acetate) stream using a hopper apparatus having a regulated metering roll and are metered at 16.8 g/min (xcx9c12.4 g/m2) over a 7xe2x80x3 width of the meltblown ethyl vinyl acetate stream.
The discharge nozzle of the hopper apparatus is generally in close proximity to the hot exiting meltblown poly(ethylene vinyl acetate) fibers to facilitate adherence of the calcium hypochlorite particles to the molten fibers and to form the fibers into a consolidated web. The nozzle of the hopper apparatus may be spaced about 3 inches to about 4 inches, or less, away from the exiting fibers such that a consolidated web with a basis weight of approximately 24 grams per square meter can be formed.
After forming the poly(ethylene vinyl acetate)/calcium hypochlorite composite substrate layer, it is then necessary to bond the composite to one or more laminate layers for forming the subject hard surface wiper. A standard 49 gram per square meter HYDROKNIT(copyright) material may be employed as the absorbent laminate layer by being unwound upstream of the composite stream and positioned onto a foraminous forming wire operating at about 25 feet per minute. The tacky composite may then be formed directly onto the HYDROKNIT(copyright) material without adhering to the wire itself.
Thereafter, if desired, a second laminate layer may be adhered to the composite substrate layer. A second 49-gsm HYDROKNIT(copyright) material is likewise thermally bonded to the composite such that the substrate layer is positioned between the first and second laminate layers to act as an adhesive between the layers. In this regard, the spunbond sides of each layer of HYDROKNIT(copyright) material typically face the composite substrate layer.
After the three layers are appropriately positioned, a thermal bonder may be utilized to bond together the layers using a bond pattern (such as a xe2x80x9c714 bond patternxe2x80x9d as described in U.S. Pat. No. 5,389,202, which is incorporated herein in its entirety by reference thereto) roll positioned against a smooth steel roll. The roll parameters may be adjusted such that the roll temperature is, for example, about 214xc2x0 F., the bonding pressure is, for example, about 30 psig, and the line speed is, for example, about 10 feet per minute. As a result of the above described process, the anti-microbial agents (in one embodiment, calcium hypochlorite particles) are sufficiently positioned between the laminate layers within the substrate matrix such that only a negligible amount of particles are lost during mechanical working of the web when either dry or wet.

Controlled release anti-microbial hard surface wiper


A receptacle contact includes a resilient contact arm having at least one contact area for contacting a mating contact. A support arm is stamped and formed from an area of a wall of the receptacle contact. The support arm cooperates with the resilient contact arm to support the resilient contact arm. An overstress member is provided on the wall of the receptacle contact. The overstress member is formed to extend into the area of the wall from which the support arm was formed. The overstress member cooperates with the support arm to prevent the support arm from being moved beyond the overstress member and beyond the area of the wall from which the support arm was formed, thereby ensuring that the resilient contact arm and the support arm will provide sufficient normal force to maintain a mechanical and electrical engagement with a mating contact.

Currently electrical contacts or wire contacts are used to terminate a wire. Wire contacts require a strong mechanical means of attaching to the wire to create a permanent termination and a means to mate to a mating contact to form an electrical connection. For example, a wire contact may have a crimp end for terminating the wire and a male or female mating end for a mating contact. Some contacts have been developed from metal strips or pre-plated metal strips, which are stamped and then folded or formed into the appropriate shape. These contacts have a generally box shaped mating end for mating to a contact having a pin or blade type mating end. Contacts with a boxed shaped mating end have external size and shape requirements to fit into a cavity of a connector and an internal design for providing the mechanical and electrical connection means for receiving and holding the pin or blade contact of the mating contact. In current contacts having generally boxed shaped mating ends, a contact or compliant beam may be the means to receive and hold the mating pin contact.
However, known connectors typically contact and mate the pin or mating contact at up to two areas. This can result in a lack of sufficient physical contact that reduces the reliability of the electrical connection and renders the connector susceptible to reduction or loss of connection. Further, vibration or other motion or movement may result in a loss of connection.
In addition, some known connectors have contact beams that have a high spring force, which decreases the ability to control the normal force applied by the contact beam, increasing the mating force of the connector, and increasing tolerance sensitivity. Other connector problems may arise from having the contact beam exposed to the mating pin, leaving the contact beam unprotected from damage from external factors.
What is needed is a contact and method of insertion that satisfies one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.


Apparatus and methods for removing overlapping material such as occurs in wrinkles and folds in the open edge of a pliable package, such as plastic prior to sealing the package. The apparatus includes a set of transport belts which grip the open edges of the package and move them in a selected direction of travel. The open package edges then encounter a set of opposing programmable pinch wheels before the trailing edge of the package leaves the first set of transport wheels. The pinch wheels have a rate of rotation selected to move the package edge along the direction of travel at a speed faster than that provided by the transport belts. Consequently, the leading package edge is pulled taut. Subsequent to the trailing edge of the package leaving the transport belt, the leading edge of the open package edges encounters a second set of transport wheels which also move the package edge in the selected direction of travel. Upon this engagement, and while a substantial portion of the package edges still must travel through the programmable pinch wheels, rotation of the pinch wheels is stopped and the pinch wheels are then driven so as to be biased to a "null" position or against allowing the package edges to move in the direction of travel. They are also programmed to have less torque available to maintain the zero or "null" bias than the torque provided to the second set of transport wheels. Thus, if a fold or wrinkle is encountered it will be eliminated as the pinch wheel passes over the fold and then returns to its zero or "null" position.

Both transparent and opaque plastic films are used as wrapping and/or packaging materials in substantially every area of manufacturing and marketing of modern commerce. The plastic packaging materials include rigid materials which provide protection from outside impact or crushing forces, including the somewhat flexible but brittle packaging materials which provide a form fit around the product. This type of plastic packaging material may typically be heated so that it shrinks around the product. In addition, pliable plastic films which vary from being extremely thin and flexible to those which are substantially thicker and less pliable are used which do not always protect the product from outside crushing or impact forces, but do provide excellent protection from an undesirable environment, such as moisture, dirt, sand, corrosive air or gases, etc. The present invention is primarily concerned with pliable materials such as plastic used in packaging which must effectively seal the packages contents from the environment and/or contamination.
More particularly, the present invention is concerned with removing all folds and wrinkles in two confronting edge portions of the packaging material at the open end of a package prior to sealing or bonding the two confronting edges one to the other to create a liquid and/or air tight package. Removing the folds or wrinkles in the two confronting edge portions helps to insure that the resulting seal will be fluid tight. Tests on a prototype apparatus incorporating the features of this invention indicate that the rejection rate caused by ineffective seals can be decreased from from around 15% to 20% down to substantially zero.
Therefore, it is an object of this invention to provide methods and apparatus for removing folds and wrinkles in confronting portions of an edge prior to sealing or bonding the open edge.
It is another object of this invention to provide simple and inexpensive apparatus and methods for preparing the edge portion of an open pliable plastic package prior to sealing the edge of the package so as to facilitate achieving a liquid and/or air tight package.
Although the applicant is not aware of any prior art references or actual apparatus which is similar to the apparatus and methods of the present invention, some prior art references which illustrate the known state of the art include U.S. Pat. No. 4,723,390 issued to the present inventor Horace W. Duke on Feb. 9, 1988; U.S. Pat. No. 3,621,632 issued to S. A. C. Browining on Nov. 23, 1971; U.S. Pat. No. 3,552,088 issued to Akiro Niwa on Jan. 5, 1971; U.S. Pat. No. 3,471,990 issued to J. A. Bonuchi et al on Oct. 14, 1969; U.S. Pat. No. 3,420,034 issued to A. B. Saraisky et al on Jan. 7, 1969; and U.S. Pat. No. 3,163,969 issued to J. F. Irwin et al on Jan. 5, 1965.
The Browing and Irwin et al patents deal with closing the end of a plastic bag around a loaf of bread, and both patent specifications show how the open end of the bag of bread is gathered and then the gathered plastic material is enclosed and held closed with a closure tie or device.
The Niwa patent discloses apparatus for individually and successively packaging articles by the use of continuous sheets of heat-sealable packaging material. The apparatus also shows the sealed package being separated or cut from the continuous packaging material.
The Bounchi et al patent discloses packaging apparatus which has heating structure for producing a line of seal across the initially open end of a polyethylene bag containing poultry products. The apparatus includes a sponge which clamps against the package prior to sealing to expel air so as to produce a tight package. The apparatus also provides a pair of opposed rollers which receive the initially open end of the bag and pulls the end away from the remainder of the bag to stretch the bag over the product so as to allow removal of excess material.
The Saraisky et al patent discloses apparatus for packaging articles in a close-fitting package without the necessity of shrinking the wrapper or expanding the article after sealing the package. The close fitting package is accomplished by incorporating with the heat-sealing means a heat-shielding sheet material-fitting means arranged to draw the wrapping material towards and tightly against substantially all of the exterior surfaces of the article being wrapped. This includes drawing the material tight against the surfaces immediate adjacent to the seal, while shielding the sheet material and the article from the heat arising from the heat-shielding means except at the point that the seal is being formed so as to eliminate loose wrapping material around the package.
Thus, although all of the above discussed patents deal with closing a pliable plastic packaging material around a product, and although the Duke, Niwa, Bonuchi, and Saraisky patents deal with sealing confronting edge material of a package, none of the patents teach or even suggest the unique apparatus and methods of the present invention for substantially eliminating all wrinkles and folds from such confronting edges of a package prior to sealing.

Apparatus and methods for removing folds in the confronting material at the open edges of flexible packaging material prior to sealing


A firefighting monitor system includes a monitor, a controller selectively generating signals to the monitor for controlling the monitor, and a computer. The computer is configured to receive input from a user relative to the monitor or the controller. The computer generates an output based on the input, and the output is transmitted to the controller for controlling the monitor or the controller in accordance with the output.

Firefighting monitors are used to control the flow of fluid, such as water, and are typically formed from curved pipe sections that form an outlet (to which a nozzle is mounted) and an inlet that connects to a supply of fluid. The pipe sections are connected together to form a curved fluid passageway and mounted to allow articulation of the pipe sections so that the position of the outlet can be varied.
Monitors may be controlled manually or may be driven by motors, which are either hardwired or connected via radio frequency transmission to a controller. Each driven version of monitor typically has a separate physical configuration based on the communication format that is desired. Additionally, driven monitors may be configured with different motor speeds. For example, most monitors have pipe sections that rotate about vertical and horizontal axes of rotation. Optionally, each axis of rotation may have a different motor speed to tailor the travel speeds of the outlet to the particular application. For example, for a monitor that is mounted for washing railroad cars, it may be desirable to have a fast horizontal motor for the left to right sweep and a slow vertical motor because of the limited vertical up and down travel that is needed.
In addition to the different motors and different communication formats, monitors often need different stow configurations and set limits on their range of motion. Many of these operational characteristics must be manually set. In addition to the stowed position and travel limits, in the case of a radio frequency communication version the RFID must be set. Further, when using more than one control input device, control protocols must be set. Also, most controls have resident firmware. When firmware updates are required, these updates typically require physical change to the control board of the respective controls.
Accordingly, while current monitors are becoming more and more customizable and, hence, specialized in their application each modification requires some sort of manual adjustment or setting. This can add to inventory requirements and the cost to the users.

Firefighting monitor and control system therefor

Elkhart Brass Manufacturing Company, Inc.


A patient support system comprises a patient support apparatus for patients. The patient support apparatus comprises a base and a patient support surface supported by the base. The patient support apparatus also comprises powered devices that perform one or more predetermined functions on the patient support apparatus. Multiple input devices are employed to control the powered devices. The input devices are designed to enable caregivers to cause operation of the powered devices, as needed, while freeing the caregivers to perform other tasks.

Patient support systems facilitate care of patients in a health care setting. Patient support systems comprise patient support apparatuses such as, for example, hospital beds, stretchers, cots, tables, and wheelchairs. Conventional patient support apparatuses comprise a base and a patient support surface upon which the patient is supported. Often, these patient support apparatuses have one or more powered devices to perform one or more functions on the patient support apparatus. These functions can include lifting and lowering the patient support surface, raising a patient from a slouched position, turning a patient, centering a patient, extending a length or width of the patient support apparatus, and the like. When the caregiver wishes to operate a powered device to perform a function, the caregiver actuates a user input device, often in the form of a button on a control panel. To continue performing the function, the caregiver is required to continue depressing the button until a desired outcome is achieved, e.g., the patient support surface is lifted to a desired height, the patient is sufficiently raised from the slouched position to a desired position, etc. As a result, the caregiver's hand is occupied by the user input device and unable to provide much assistance to the patient.
A patient support system designed to free one or more hands of the caregiver to perform other tasks and overcome one or more of the aforementioned challenges is desired.

Patient support systems and methods for assisting caregivers with patient care


A spark gap switch for high power ultra-wideband electromagnetic wave radiation is provided. The spark gap switch includes a casing, electrodes, brackets and an electrode protrusion. Openings are formed in respective opposite ends of the casing. The electrodes are installed in the casing at positions spaced apart from each other in such a way that the electrodes face each other and are disposed inside the openings. The brackets are installed in the respective openings of the casing. The brackets fasten rear ends of the corresponding electrodes to the casing. The electrode protrusion is provided on a central portion of at least either of the electrodes to induce stabilized discharge. The maximum diameter of the electrodes is smaller than the inner diameter of the casing so that the circumferential outer surfaces of the electrodes do not make contact with the circumferential inner surface of the casing.

1. Field of the invention
The present invention relates generally to spark gap switches for high power ultra-wideband electromagnetic wave radiation for stabilized discharge and, more particularly, to a spark gap switch for high power ultra-wideband electromagnetic wave radiation which is configured such that it can have stabilized discharge characteristics that allow discharge to occur on central portions of electrodes, whereby the output power of radiated electromagnetic waves can be markedly stabilized.
2. Description of the Related Art
Generally, ultra-wideband electromagnetic wave generation sources refer to apparatuses which are widely used in fields, such as a field using ultra-wideband radar or a field involving the detection of buried objects. An ultra-wideband electromagnetic wave generation source typically includes an energy storage device which stores electric or magnetic energy, a switching device which generates ultra-wideband pulses from the stored energy, and an antenna which radiates ultra-wideband waves.
To increase the peak output power of electromagnetic waves radiated into space from such an ultra-wideband electromagnetic wave generation source, it is most important to increase the capacitance or inductance of the energy storage device, reduce mismatching between the switching device and the antenna, and enhance the electric insulation of the antenna.
The applicant of the present invention proposed a spark gap switch for high power ultra-wideband electromagnetic wave radiation in Korean Patent Registration No. 1015958, which can be used as a high power switching device and can conduct functions of storage of electric energy and generation and radiation of ultra-wideband electromagnetic pulses or waves.
FIGS. 1 and 2 illustrate the above-stated conventional spark gap switch for high power ultra-wideband electromagnetic wave radiation. As shown in FIGS. 1 and 2, the conventional spark gap switch for high power ultra-wideband electromagnetic wave radiation includes a casing 100, electrodes 111 and 112, a fixing bracket 120 and a movable bracket 121.
The casing 100 has a hollow cylindrical structure which has openings 101 and 102 in opposite ends thereof and is made of nonmetallic electric insulation material.
The electrodes 111 and 112 are disposed in the openings 101 and 102 of the casing 100 at positions spaced apart from each other by a predetermined distance in such a way that they face each other. The electrode 111 is a high-voltage electrode to which high voltage is supplied, and the other electrode 112 is a ground electrode which forms a potential difference with respect to the high-voltage electrode. The electrodes 111 and 112, when power is applied thereto, together conduct functions of storage of electric energy, generation of ultra-wideband electromagnetic, pulses and radiation of electromagnetic waves. Particularly, the spark gap switch is designed such that areas of surfaces of the electrodes 111 and 112 that face each other are comparatively large and the distance between the electrodes 111 and 112 is comparatively short, whereby the capacitance formed by the electrodes 111 and 112 can be enhanced. In other words, before functioning as a switch for generating electromagnetic pulses, the electrodes 111 and 112 are designed such that the capacitance at which an electric field is stored in the insulation space 115 defined between the electrodes 111 and 112 and the casing 100 is increased.
The fixing bracket 120 and the movable bracket 121 are made of electric insulation material in the same manner as that of the casing 100 and are installed in the electrodes 111 and 112. The fixing bracket 120 and the movable bracket 121 function to adjust the distance between the electrodes 111 and 112, fix the positions of the electrodes 111 and 112, and maintain gas pressure between the electrodes 111 and 112. The fixing bracket 120 is fixed in the opening 102 of the casing 100. The electrode 112 is fastened to the casing 100 by the fixing bracket 120. The movable bracket 121 has an external thread 122 and is threadedly coupled to the opening 101 of the casing 100 so that it can be movably installed in the opening 101 of the casing 100.
Cable guides 125 are provided in the fixing bracket 120 and the movable bracket 121. High-voltage cables through which high-voltage is supplied to the electrodes 111 and 112 are guided into the corresponding electrodes by the cable guides 125. An inner end of each cable guide 125 is supported on an inner surface of the corresponding electrode 111, 112. An annular plate 126 which is supported on the fixing bracket 120 or the movable bracket 321 is provided around an outer portion of each cable guide 125. The cable guides 125 are made of insulation material and function to protect high-voltage cables and prevent generation of an are from the high-voltage cables.
Gaskets 117 are closely interposed between a circumferential inner surface of the casing 100 and circumferential outer surfaces of the respective electrodes 11 and 112 to seal space defined between the casing 100 and the electrodes 111 and 112.
The conventional spark gap switch having the above-mentioned construction can be used as an ultra-wideband electromagnetic wave generation source which is widely used as a high power switching device and conducts functions of storage of electric energy and generation and radiation of ultra-wideband electromagnetic pulses. Furthermore, the electrodes 111 and 112 are configured such that the areas of the surfaces that face each other are comparatively large to increase the capacitance between the electrodes 111 and 112, the distance therebetween is adjusted, and the space therebetween is insulated by high-pressure gas. Therefore, switch storage energy which is an energy source for the generation of electromagnetic waves is comparatively high. Moreover, the shape of each electrode 111, 112 is designed such that it can become an antenna. Thus, mismatching between a switching channel and an antenna is reduced. The electrodes 111 and 112 which form an antenna are enclosed by high-pressure gas with which the spark gap switch is filled. Hence, the electric insulation strength of the electrodes 111 and 112 is enhanced, and the intensity of ultra-wideband electromagnetic waves radiated between the electrodes 111 and 112 is increased.
However, in the conventional spark gap switch for high power ultra-wideband electromagnetic wave radiation, because the surfaces of the electrodes 111 and 112 that face each other are comparatively large and are gently curved to increase the capacitance of the electrodes, although it is ideal that discharge occurs on central portions of the electrodes at which the distance between the electrodes is shortest, there is actually the possibility of discharge occurring at a random position of the surfaces of the two electrodes that face each other.
Furthermore, the conventional spark gap switch is designed such that the maximum diameter of the electrodes is almost the same as the inner diameter of the casing 100. Thus, the spark gap switch is prone to discharge occurring on the inner surface of the casing 100. That is, as shown in FIG. 1, because outer surfaces of rear ends of the electrodes 111 and 112 which face each other make contact with an inner surface of the casing 100, a surface insulation distance d1 formed along the inner surface of the casing 100 may not be sufficiently long.
Therefore, a surface discharge may be caused on the inner surface of the casing 100. As such, if discharge occurs at a position displaced from the central portions of the electrodes 111 and 112, the output power of electromagnetic waves is reduced, and a radiation pattern is deformed, in this case, the spark gap switch cannot serve its intended purpose.

Spark gap switch for high power ultra-wideband electromagnetic wave radiation for stabilized discharge


The present invention relates to Death Receptor-6 (DR6) proteins which are members of the tumor necrosis factor (TNF) receptor family, and have now been shown to be important for regulating apoptosis in cells of the nervous system. In addition, it has been discovered that p75 is a ligand for DR6. As a result, this invention relates to methods for inhibiting the interaction of DR6 and p75 using DR6 and/or p75 antagonists. In addition, the methods described herein include methods of promoting survival of cells of the nervous system using DR6 antagonists, optionally in combination with p75 antagonists, and methods of treating neurodegenerative conditions by the administration of a DR6 antagonists, optionally in combination with a p75 antagonist.

1. Field of the Invention
This invention relates to neurobiology, neurology and pharmacology. More particularly, it relates to methods for promoting survival of cells of the nervous system using Death Receptor-6 (DR6) antagonists, optionally in combination with p75 antagonists. The invention also relates to methods of treating neurodegenerative conditions by the administration of a DR6 antagonist, optionally in combination with a p75 antagonist. The invention also relates to methods of preventing the interaction of DR6 and p75 using DR6 and/or p75 antagonists.
2. Background
Apoptosis (i.e. programmed cell death) has been shown to play an important role in numerous diseases of the nervous system including both acute and chronic injuries. For example, the role of apoptosis has been demonstrated in Alzheimer's disease, Parkinson's disease, Huntington's disease, motor neuron disease (e.g. amyotrophic lateral sclerosis, which is also called ALS or Lou Gehrig's disease), multiple sclerosis, neuronal trauma and cerebral ischemia (e.g. stroke).
Many studies have been directed to understanding the molecular mechanisms of apoptosis, and these studies have led to the discovery of a family of receptors called the death receptors. Eight death receptors, which are characterized by a cytoplasmic death domain, have been identified thus far. The death receptors have been grouped into two different families. Members of the first family recruit a death inducing signaling complex (DISC), which promotes apoptotic signaling. Members of the second family recruit a different set of molecules to transduce apoptotic signals. Interestingly, members of the second family also transduce cell survival signals.
Death receptor 6 (DR6) is a member of the second family of death receptors. DR6 is widely expressed, but appears to function differently in different cell types. DR6 mRNA has been observed in heart, brain, placental, pancreas, lymph node, thymus and prostate tissues. Lower levels have been observed in other cell types including skeletal muscle, kidney and testes, but little or no expression has previously been observed in adult liver or any lines of hematopoeitic origin. Interestingly, it has been observed that DR6 is capable of inducing apoptosis in only a subset of cells tested. For example, overexpression of DR6 in HeLa S3 cervical carcinoma cells resulted in apoptosis in a death-domain-dependent manner (Pan et al. FEBS 431:351-356 (1998)). In addition, Nikoleav et al. (Nature 457:981-990 (2009)) have shown that beta-amyloid precursor protein (APP) is a DR6 ligand and suggested that the binding of an APP fragment to DR6 triggers degeneration of neuronal cell bodies and axons. In contrast, DR6 did not induce cell death in MCF7 (a human breast adenocarcinoma line) cells (Pan et al. FEBS 431:351-356 (1998)). The characteristics that differentiate a cell's response to DR6 expression and signaling have not yet been identified.
Drugs that can specifically modulate apoptosis may be useful for treating diseases involving neuronal cell death, for example, because neurons may have less capacity to regenerate than other cell types. However, currently available anti-apoptotic drugs have low specificity and selectivity and as a result, produce undesirable side effects. Such side effects might be reduced or avoided by for example, targeting anti-apoptotic drugs specifically to the desired site of action. Alternatively, characterization of death receptors such as DR6 that specifically act in a particular subset of cell types has the potential to provide a more specific therapeutic effect.

Use of DR6 and p75 antagonists to promote survival of cells of the nervous system


Apparatus including a cylindrical housing retractably containing an elongate continuous web retractable therefrom. The web is mounted in a surrounding relationship to a support cylinder that is biased into a retracted position to a central port spindle. The web is retracted through a elongate flexible lip cooperative with an absorbent sponge like roller to contain and confine lotion onto the associated web. A friction cylinder maintains engagement to enhance retraction and extension of the web in cooperation with the support cylinder and exit opening defined within the cylinder.

1. Field of the Invention
The field of the invention relates to lotion applicator apparatus, and more particularly pertains to a new and improved body lotion applicator apparatus wherein the same includes a self-contained housing permitting extension or retraction for an elongate lotion applicator web therefrom.
2. Description of the Prior Art
This applicator is frequently utilized to apply lotion to portions of the human anatomy difficult to outwardly cope with a fluid. Such portions include the back surface of the human anatomy and to this extent, brushes and elongate webs are frequently utilized. The use of webs, their storage prior to and subsequent to their use presents a degree of difficulty to maintain the lotion in a clean and non-contaminated state. Examples of the prior art include U.S. Pat. No. 3,959,841 to Horne setting forth an elongate web with a pocket positioned medially therewithin to receive a sponge for storage and application of a fluid through the sponge and applied by a application of the web about an anatomical portion of individual.
U.S. Pat. No. 4,196,490 to Jonzon sets forth a sponge mounted medially of an elongate flexible web wherein the web includes a handle mounted on each end thereof and the sponge is provided with an absorbent nature to direct an application of fluid onto an individual.
U.S. Pat. No. 3,674,374 to Jennings sets forth an elongate back scrubber apparatus formed with a plurality of pockets for application of a soap onto an individual.
U.S. Pat. No. 2,764,771 to Marchese provides a sponge mounted to a flange member and the flange includes a loop structure mounted at each end pivotally to the flange with a bulb applicator arranged to direct a quantity of soap into the sponge member.
U.S. Pat. No. 3,870,419 to SAGE sets forth a resilient body including a chamber therewithin to receive a quantity of soap therewithin with straps mounted to each end of the body to permit directing of soap from within the chamber to an individual's body portion wherein the chamber is directed through to the body by various openings formed therethrough.
As such, it may be appreciated that there continues to be a need for a new and improved body lotion applicator apparatus wherein the same addresses both the problems of ease of use as well as effectiveness in construction and in this respect, the present invention substantially fulfills this need.


Disclosed are devices for determining an analyte concentration (e.g., glucose). The devices comprise a sensor configured to generate a signal associated with a concentration of an analyte and a sensing membrane located over the sensor. The sensing membrane comprises a biointerface layer which interfaces with a biological fluid containing the analyte to be measured. The biointerface layer can comprises a biointerface polymer, wherein the biointerface polymer comprises polyurethane and/or polyurea segments and one or more zwitterionic repeating units. The sensing membrane can also comprise an enzyme layer, wherein the enzyme layer comprises an enzyme and a polymer comprising polyurethane and/or polyurea segments and one or more zwitterionic repeating units. The sensing membrane can also comprise a diffusion-resistance layer, which can comprise a base polymer having a lowest Tg of greater than −50 C.

Electrochemical sensors are useful for determining the presence or concentration of a biological analyte, such as blood glucose. Such sensors are effective, for example, at monitoring glucose in diabetic patients and lactate during critical care events. A variety of intravascular, transcutaneous and implantable sensors have been developed for continuously detecting and quantifying blood analytes, such as blood glucose levels.
A challenge associated with long-term use of continuous sensors and other medical devices is biomaterial-associated inflammation, which is the inflammation caused by implantation of foreign materials into the body. Biomaterial-associated inflammation is the result of a dynamic microenvironment around an implanted device, which includes the initial injury, neutrophil and macrophage recruitment, foreign body giant cell (FBGC) response, neovascularization, fibroblast recruitment, and downstream fibrosis. The formation of a barrier cell layer around the implanted device can result in impaired tissue integration.
In the case of a continuous sensor, biomaterial-associated inflammation can impair analyte transport from tissues to the sensor surface, whether by creating a diffusion barrier or active consumption of analytes. The FBGC response to implantable materials results in fibrous capsule formation that impedes sensor function through the modulation of glucose diffusion through dense fibrotic "scar-tissue" layers. Other constituents of the biomaterial-associated inflammatory cascade, such as inflammatory cytokines and other small molecules, sometimes act as interferents to sensor performance. These interferents can cause sensor inaccuracy due to the constant change in transport properties at the sensor/tissue interface. Aside from diffusion limitations, there exists an active cellular component of the biomaterial-associated inflammatory cascade, involving inflammatory and wound healing cells; these cells that can be activated by implanted materials can actively consume glucose and produce H2O2, which can also lead to sensor inaccuracy. Reduction in biomaterial-associated inflammation is thus important in creating long-term, stable, implantable sensors and devices. Thus what are needed are methods and compositions that can reduce inaccuracies in an implanted sensor that can be caused by biomaterial-associated inflammation. What are also needed are methods and compositions that can increase the longevity of an implanted device. The methods and compositions disclosed herein address these and other needs.
Also, in such analyte sensors there is a membrane layer or domain that contains an enzyme responsible for converting the analyte into agent that can be registered as a measurable signal. For example, glucose sensors contain enzymes that convert glucose into hydroperoxide, which is further converted into a sensor signal. So the performance of enzymatic glucose sensors, like other sensors that rely on enzymatic conversions, can be affected by the amount of active enzyme incorporated in the sensor's membrane layer.
It is often a challenge to have sufficient active enzyme incorporated and maintained in the membrane to efficiently catalyze analyte reactions (e.g., glucose to hydrogen peroxide). Enzyme can leach out of the membrane in hydrated conditions. Leached enzyme can also result in a severe Foreign Body Response (FBR). These events change sensor sensitivity and degrade the resistance layer, which will finally decrease the accuracy and longevity of the sensor. Furthermore, enzyme degradation can occur by many different mechanisms leading to irreversible or reversible inactivation of enzyme. Enzymes can be sensitive to environment conditions including, for example, temperature changes, pH changes, and exposure to the reactive chemicals including crosslinkers often employed in immobilization the enzyme such as glutaraldehyde and carbodiimide, as well as bi-products from the redox reaction such as hydrogen peroxide and gluconic acid and endogenous bi-products. Enzyme degradation severely limits the functional life of analyte sensors in vivo and can result in gradual sensor sensitivity decline and early onset of sensor end-of-life.
The incorporation and immobilization of enzymes into various carriers or binders including polymers, sol gel, particles, and mixtures thereof to create an enzyme layer has been tried to prevent the leaching of enzymes in analyte sensors. These layers can, however, swell and degrade in aqueous environments and suffer from poor adhesion to adjacent layers in the membrane system. As a result, these by-products can also leach out of the membrane and also contribute to the FBR and affect sensor sensitivity and accuracy. Poor adhesion can further result in reduced mechanical stability and delamination of the membrane layers in vivo.
There is thus a desire for engineered enzyme layers in which enzymes are immobilized in the membrane via strong molecular level interactions between enzymes and base polymeric materials. Such layers can reduce (or prevent) leaching of enzymes, which will lessen the FBR, and improve the longevity, sensitivity, and accuracy of the sensor. What are also needed are enzyme layers engineered with physiochemical stability and catalytic performance stability in aqueous environment and have good adhesion to other layers in the sensor's membrane system. The compositions, methods, and devices disclosed herein address these and other needs.
Further, in such analyte sensors there is a membrane layer or domain that is primarily responsible for limiting the diffusion of the analyte to the sensor. The function of this so-called diffusion-resistance layer can be important when the analyte of interest is present in the patient in amounts that can exceed the sensor's sensitivity. For example, there exists a molar excess of glucose relative to the amount of oxygen in the body. So for every free oxygen molecule in extracellular fluid, there are typically more than 100 glucose molecules present (see Updike et al., Diabetes Care 5:207-21 (1982)). However, an immobilized enzyme-based glucose sensor employing oxygen as co-reactant is preferably supplied with oxygen in non-rate-limiting excess in order for the sensor to respond linearly to changes in glucose concentration, while not responding to changes in oxygen concentration. Specifically, when a glucose-monitoring reaction is oxygen limited, linearity is not achieved above minimal concentrations of glucose. Without a semipermeable membrane situated over the enzyme domain to control the flux of glucose and oxygen, a linear response to glucose levels can be obtained only for glucose concentrations of up to about 40 mg/dL. However, in a clinical setting, a linear response to glucose levels is desirable up to at least about 400 mg/dL.
Some diffusion-resistance layers suffer from changes in permeability to analyte due to changes in microstructure, phase separation, degradation, and interferants from external molecules. These changes can affect sensor sensitivity and therefore result in changes in sensor output for the same analyte concentration over time—a phenomenon known as "drift." This also confounds the development of robust algorithms due to the need for sensor "drift" correction. There is thus a desire for an engineered semipermeable diffusion-resistance layer that contains polymers capable of providing a structurally stable matrix wherein an analyte permeable phase resides throughout, and electrochemical sensors equipped with such membrane. The compositions, methods, and devices disclosed herein address these and other needs.


The invention relates to a roller (1), preferably comprising two wheels (2) and a locking device, an activating part (10) being able to act on the locking device for releasing or locking in a position that corresponds to a directional lock and/or in a position that corresponds to a total lock, and the activating part (10) being movable by a drive, a linear movement of a transmission part (7) that is generated by the drive being transmitted via spring force to the activating part (10) in order to move the activating part, and the activating part (10), in any case in a position corresponding to the total lock or in any case in a position corresponding to the direction lock, being in addition movable relative to the stationary transmission part, against a spring supported on the transmission part, into a release position by means of an actuating handle (11) that is movable independently of the drive and preferably by hand so as to override the total lock or the directional lock. In order to provide a roller that is formed in an advantageous manner with regard to an emergency release, it is proposed that a geometric axis of rotation (d) of the actuating handle (11) is disposed on the same side as the activating part (10) with respect to the axis of rotation (D) of the wheel (2), the activating part being disposed offset, in a vertical section, with respect to an axis of rotation (D) of the wheel (2).

1. Field of the Invention
The invention relates to a roller, preferably comprising two wheels and a locking device, an activating part being able to act on the locking device for releasing or locking in a position that corresponds to a directional lock and/or in a position that corresponds to a total lock, and the activating part being movable by a drive, a linear movement of a transmission part that is generated by the drive being transmitted via spring force to the activating part in order to move the activating part, and the activating part, in any case in a position corresponding to the total lock or in any case in a position corresponding to the directional lock, being in addition movable relative to the stationary transmission part into a release position, against a spring supported on the transmission part, by means of an actuating handle that is movable independently of the drive and preferably by hand so as to override the total lock or the directional lock.
2. The Prior Art
With regard to rollers of this type in general, reference is made in first instance to DE 10 2007 039 208 A1 (US 2010/0077562 A1), for example. In particular when such rollers are moved by an electric motor with regard to the directional and/or total lock, precautions have to be taken so that in the event of a motor failure, releasing is nevertheless still possible. For this purpose, an advantageous embodiment is sought for a release that is possible by manual intervention in the event of an emergency.


A coalescing element is provided which is capable of separating a continuous phase fluid from a discontinuous phase fluid. The coalescing element includes a wrap structure which facilitates the coalescing process by conglomerating smaller droplets of the discontinuous phase fluid into larger droplets which may be of a size that will prevent them from being re-entrained.

1. Field of the Invention
The present invention relates to a coalescer element and, more particularly, to a coalescer element with enhanced coalescence.
2. Discussion of the Related Art
Coalescers, sometimes in conjunction with separators, including inertial separators, settling devices, and separator cartridges, are generally utilized in industrial processes to separate several phases present in fluids, i.e., gases and/or liquids. In some instances such fluids constitute dispersions of two or more immiscible liquids such as oil and water. In other instances, such fluids constitute suspensions of liquid and/or solid particles in gas. In addition to separation, coalescers generally draw together or conglomerate smaller portions of one of the phases present in the fluid.
The spectrum of applications where coalescers have been used to remove minor amounts of a first phase, known as a discontinuous phase, from a second phase in which it is suspended, known as the continuous phase, covers a considerable range of situations. For example, coalescers may be utilized to remove water from compressed gas streams such as air, helium, hydrogen, nitrogen, carbon dioxide, and natural gas.
Coalescers may also be utilized to remove contaminants found in natural bodies of water such as oil spills. Additionally, coalescers may be utilized to separate small amounts of moisture, i.e., water, from petroleum based fuels, including gasoline, diesel and aviation fuels, such as kerosene.
In a coalescing process, for example, the coalescence of water from a petroleum based fuel, the fuel containing the water is passed through a coalescer comprising a coalescing medium. The fuel, which is the continuous phase fluid, passes through the medium and flows toward a first outlet. As the water, which is the discontinuous phase fluid, passes through the medium it tends to collect on the surface of the coalescing medium and form small droplets which are forced through the medium by the continuous phase fluid. The coalescing medium may be formed from or coated with a material which facilitates the formation of the droplets and the conglomeration of these small droplets into larger droplets. The larger water droplets are more easily removed via a second outlet and are less likely to be re-entrained into the fuel.
A limiting factor in the effectiveness or efficiency of the coalescing process in the re-entrainment of the droplets of the discontinuous phase fluid into the continuous phase fluid after they emerge from the coalescing medium. Re-entrainment may occur because of a number of reasons. One reason re-entrainment may occur is because the droplets of the discontinuous phase are too small and may be easily carried along by the potentially high flow rates of the continuous phase fluid to the continuous phase outlet. Accordingly, the smaller the droplets, the more likely the chance of re-entrainment. In addition, the smaller the droplets, the more likely the chance of the droplets penetrating a separator cartridge or any other type of separator, if a separator is utilized. Similarly, the larger the droplets, the less likely the chance of re-entrainment because they are less likely to be carried by the continuous phase fluid to the continuous phase fluid outlet and the less likely to penetrate into a separator.
Various mechanisms have been tried to increase the size of the droplets of the discontinuous phase fluid. For example, socks, foam, nettings, fuzzy woven or non-woven materials, or combinations thereof positioned over the coalescing medium have been utilized to increase the size of the droplets. However, in high surfactant conditions, the above-referenced materials or combination of materials which may be utilized, increase the size of the coalescing elements.

Elements and methods for coalescing a discontinuous phase of a fluid from a continuous phase


The present invention relates to an exit sign retrofit lighting system kit including a low profile switch mode power supply contained in internal and external enclosure and use Light Emitting Diodes with long life. The system is powered by a high energy efficient switch mode power supply with low power consumption. The height of this lighting system is very close to half of one inch or less. This kit can be used to save energy in existing Exit Sign fixtures using Tungsten filament lamps or linear fluorescent lamp or compact fluorescent lamp. This kit can be also used with Box type and Edge lit Exit Signs. The long life time of Light Emitting Diodes makes it practically maintenance free, in addition to saving considerable energy.

1. Field of the Invention
The present invention relates to exit sign lighting and more particularly to a retrofit kit for use with two types of existing exit signs.
2. Description of the Prior Art
Presently exit signs run with incandescent lamps or compact fluorescent lamps (CFLs). Incandescent lamps use a lot of power, and the CFLs flicker when being turned on. It would be advantageous to have a retrofit kit that could replace lighting in existing exit signs with LEDs.

Energy saving exit sign retrofit lighting system using light emitting diodes


A liquid crystal display (LCD) panel includes pixels arranged in matrix, and first and second scan lines and a storage capacitance line. Each pixel has a first sub-pixel, which is disposed between the first and second scan lines, and first to third thin-film transistors (TFTs) and a pixel electrode divided into first and second regions. The first TFT is electrically connected to the first scan line and the first region. The second TFT is electrically connected to the first scan line and the second region. The third TFT is electrically connected to the second scan line and the second region. The storage capacitance line is electrically connected to the third TFT. A distance between the storage capacitance line and the first scan line is longer than that between the storage capacitance line and the second scan line.

1. Technical Field
The disclosure relates in general to a display panel and a manufacturing method thereof, and, in particular, to a liquid crystal display (LCD) panel and a manufacturing method thereof.
2. Related Art
The LCD panel is one of increasingly popular display panels and advantageously has high resolution, light weight, thin thickness and low power consumption. However, the current LCD panel still has some technological problems to be solved. For example, the problem of wide view angle exists, in which the user sees the displayed image with the different gray-scale levels and brightness when he or she is watching the image from the front or at an angle from either right or left side of the display. Usually, the brightness of the image viewed by the user from the front of the display is higher than that viewed by the user from either side of the display. Therefore, the frames viewed on the LCD apparatus at different angles have different brightness, which causes different color mixing results. Thus, the phenomena of color shift and color de-saturation tend to occur.
Referring to FIGS. 1 and 2, a sub-pixel structure 1 of a conventional multi-domain vertically aligned (MVA) LCD panel includes at least one TFT (Thin Film Transistor) T, a storage capacitance line 11, a sub-pixel electrode 12, a liquid crystal layer 13 and a common electrode 14. The common electrode 14 is formed on a color filter substrate 16. The sub-pixel electrode 12 is formed on a dielectric layer 17 of a TFT substrate 15. The liquid crystal layer 13 is accommodated between the sub-pixel electrode 12 and the common electrode 14. The sub-pixel electrode 12 is disposed between two neighboring scan lines SLn and SLn+1, and the sub-pixel electrode 12 has a plurality of slits 12a so that the sub-pixel electrode 12 is formed with a pattern. The TFT T controls the operation of the sub-pixel structure 1, and a storage capacitor is formed between the storage capacitance line 11 and the sub-pixel electrode 12.
As mentioned hereinabove, the slits 12a or alignment protrusions 14a are arranged on the TFT substrate 15 or the color filter substrate 16 in the MVA LCD panel so that liquid crystal molecules are arranged in multiple directions and several alignment domains can be obtained to improve the problem of wide view angle.
Recently, another technology has been proposed in order to improve the color shift problem associated with the wide view angle problem more effectively. As shown in FIG. 2, the sub-pixel electrode 12 is divided into a first region I and a second region II in order to display different brightness ratios with respect to different gray-scale levels. In order to achieve this effect, in general, it is possible to turn on a third TFT T3, when the next scan line SLn+1 is being enabled, to conduct charges on an auxiliary capacitor, which is defined by the corresponding arrangement of an extra interconnection 11a of the storage capacitance line 11 and an electrode E having a potential equal to that of a source of the third TFT T3, to the second region II of the sub-pixel electrode 12 so that the brightness difference between the second region II and the first region I is kept constant to prevent the problem of color shift from occurring.
FIG. 3 shows an equivalent circuit diagram of the sub-pixel structure 1. The liquid crystal capacitor Clc(A) is defined by the corresponding arrangement of the first region I (e.g., a bright region) of the sub-pixel electrode 12 and the common electrode 14. The liquid crystal capacitor Clc(B) is defined by the corresponding arrangement of the second region II (e.g., a dark region) of the sub-pixel electrode 12 and the common electrode 14. The storage capacitor Cst(A) is defined by the corresponding arrangement of the storage capacitance line 11 and a capacitor electrode 112, which is electrically connected to the first region of the sub-pixel electrode 12 through a via. The storage capacitor Cst(B) is defined by the corresponding arrangement of the storage capacitance line 11 and a capacitor electrode 111, which is electrically connected to the second region of the sub-pixel electrode 12 through a via. The auxiliary capacitor CS is defined by the corresponding arrangement of the extra interconnection 11a of the storage capacitance line 11 and the electrode E having the potential equal to that of the source of the third TFT T3. The first region I and the second region II of the sub-pixel electrode 12 are respectively disposed corresponding to the common electrode 14, and electrically connected to a data line DLn and the scan line SLn opposite to the data line DLn through a first TFT T1 and a second TFT T2 opposite to the first TFT T1. The second region II of the sub-pixel electrode 12 is electrically connected to the next scan line SLn+1 and the auxiliary capacitor through the corresponding third TFT T3.
FIG. 4 is a schematic time chart showing the operation of the scan lines SLn and SLn+1 as well as nodes VP1 and VP2 in FIG. 3. First, when the scan line SLn inputs a signal to the sub-pixel electrode 12, the first TFT T1 and the second TFT T2 turn on, and sub-pixel data of positive polarity is inputted through the data line DL so that the potentials of the nodes VP1 and VP2 are equal to V1. When the scan line SLn stops inputting the signal to the sub-pixel electrode 12, the first TFT T1 and the second TFT T2 instantaneously turn off. At this time, the nodes VP1 and VP2 encounter different feed-through effects due to the influence the parasitic capacitances between the gates and the drains of the TFTs T1 and T2. Thus, the potentials of the nodes VP1 and VP2 are different from each other and are respectively V2 and V21, and the level difference therebetween relative to a common voltage Vcom is about (V2−V21). Next, when the scan line SLn+1 inputs the signal to the sub-pixel electrode 12, the previous frame is influenced by the dot inversion factor. So, when the third TFT T3 turns on, the charges stored in the storage capacitor Cst(B) neutralize the auxiliary capacitor CS and the voltage level of the node VP2 is changed to V3 while the voltage level of the node VP1 is still V2. When the scan line SLn+1 stops inputting the signal, the potentials of the nodes VP1 and VP2 are respectively kept at V2 and V3. When the next frame time comes, the scan line SLn again inputs the signal to turn on the first TFT T1 and the second TFT T2, and inputs the sub-pixel data of negative polarity through the data line DL so that the potentials of the nodes VP1 and VP2 are simultaneously made equal to V4. When the scan line SLn stops inputting the signal, the first TFT T1 and the second TFT T2 instantaneously turn off, and the potentials of the nodes VP1 and VP2 are influenced by different feed-through effects and are thus respectively equal to V5 and V51. So, the level difference therebetween relative to the common voltage Vcom is about (V5−V51). Next, the scan line SLn+1 inputs the signal to turn on the third TFT T3 so that the charges of the previous frame with the positive polarity stored in the storage capacitor Cst(B) are transferred to the auxiliary capacitor CS, and the voltage level of the node VP2 is changed to V6. Meanwhile, the voltage level of the node VP1 is still equal to V5. When the scan line SLn+1 stops inputting the signal, the potentials of the nodes VP1 and VP2 are respectively equal to V5 and V6.
However, no matter which method is utilized, the storage capacitance line 11 in the sub-pixel structure 1 is disposed at a middle position of the sub-pixel electrode 12. When the extra interconnection 11a has to be additionally formed through the storage capacitance line 11 in order to adjust the capacitance, the difficulty and the loading of interconnection of the storage capacitance line 11 will be increased, and the aperture ratio will be decreased. In addition, when the sub-pixel electrode 12 is divided into the first region (bright region) I and the second region (dark region) II and if the bright region I and the dark region II are influenced by different feed-through effects, the signals displayed by two regions of the sub-pixel structure 1 have different levels relative to the signal center point Vcom. Thus, the signal may have the problem of flickering among different frames, and a retained image caused by the polarization of the liquid crystal molecules cannot disappear after a long period of time.
Therefore, there is a need to provide a LCD panel and a manufacturing method thereof, wherein the difficulty of interconnection can be simplified, the influence of the low gray-scale region on the display property can be decreased, and the phenomenon of color shift can be improved.

Liquid crystal display panel and manufacturing method thereof


A graphic medium and a method of making same employs a paper core having a normalized opacity within a range of about 0.15 to about 0.4 percent/grams per square meter. The graphic medium includes a first material layer on a first side of the paper core and a second material layer on one or both of the first side between the paper core and the first material layer and a second, opposite side of the paper core. The graphic medium has a translucent opacity between about 40% and about 90%. The method includes mechanically refining a mixture of wood fibers until a paper substrate is formed having the normalized opacity. The paper substrate is calendered using a paper making machine and the first and second material layers are applied to form the graphic medium.

The present disclosure relates to graphic media for backlit or frontlit signage and a method of manufacturing graphic media.
Graphic media used in one or both of backlit and frontlit signage applications characteristically include a sheet of core material that is optically transparent and relatively thin. Common core materials include transparent plastics, such as polyethylene terephthalate (PET) or one or more other polyester resins. The core material sheet typically has one or more coatings formed on one side to support an image and may include one or more coatings on an opposite side to provide light diffusion properties and mechanical properties, for example. The graphic media receive an image, for example formed from ink or toner, which is displayable by back or front illumination. Moreover, graphic media endure a variety of environmental conditions for indoor and outdoor signage applications. However, graphic media are frequently replaced for a variety of reasons, for example, due to sign durability and changes in sign content, to name a few.
The use of plastics for the core material of the graphic media is expensive and not environmentally friendly since plastics are petrochemical based materials that are costly to make and are neither renewable nor readily recyclable when disposed.

Graphic medium and method of making same

Hewlett-Packard Development Company, L.P.


A laminated support for pressure-relief comprising an upper layer of visco-elastic foam, a middle layer of visco-elastic foam having a greater hardness, and a bottom layer of highly resilient polyurethane foam. These layers are sandwiched between two layers of reticulated filter polyurethane foam.

1. Technical Field
The invention relates to mattresses and cushions, and more particularly to supports made of visco-elastic material.
2. Related Prior Art
Mattresses and cushions used every day in homes and hospitals are not well-suited for people requiring pressure-relief. In hospitals, for example, long-term patients often suffer from pressure sores.

This patent is subject to a terminal disclaimer.


A braking mechanism for a retractable safety syringe is disclosed herein. In a first embodiment, the braking mechanism is disposed about the distal end of a piston. The braking mechanism may comprise a friction material about a post attached to a piston. The friction material is displaced from a seat to a landing when the piston is traversed to a fully extended position to disengage the braking mechanism. In a second embodiment, the braking mechanism is disposed at a proximal end of a syringe body. The braking mechanism has a friction member which engages an outer surface of a rigid shaft of a plunger. The friction member is selectively pivotable to disengage the braking mechanism.

The present invention relates to a retractable safety syringe, and more particularly, to a braking mechanism to resist a retraction force during normal operation of the retractable safety syringe until a piston head engages a needle holder and needle to then withdraw the needle holder and needle within the safety syringe body.
Retractable safety syringes are known in the art. For example, one type of retractable safety syringe is disclosed in U.S. Pat. No. 6,413,236 issued to Van Dyke, the entire contents of which are incorporated herein by reference. In the '236 patent, a retractable safety syringe has a piston which engages a needle holder and needle and retracts the same via a retraction force created by a variable vacuum compartment. In the retractable safety syringe disclosed in the '236 patent, the user must continuously apply a thumb pressure on the thumb platform such that the piston is not inadvertently traversed to a retracted position during operation of the safety syringe. For example, the piston may be inadvertently traversed to the retracted position while medication is being filled in a variable fluid chamber, residual air is being ejected from the variable fluid chamber and medication is being injected into the patient. As such, the user or medical professional is required to receive additional training to operate the safety syringe properly and safely. Unfortunately, the additional training may be costly. Also, since the operation of the safety syringe is not intuitive or fool proof, mistakes may be made during operation of the safety syringe.
Accordingly, there is a need in the art for an improved safety syringe.