Abstract: In the process described, a limited number of shaping tools (T.sub.1, T.sub.2, . . . , T.sub.N) having standardized parameters (for the production of the following contact lens parameters: contact lens diameter, radius of curvature of the rear face of the contact lens, vertex refraction) is used for the manufacture of standardized moulds (M.sub.1, M.sub.2, . . . , M.sub.N). Preferably by material-removing machining of the moulds, moulds are produced that have additional altered parameters. The multiplicity of moulds produced in that manner is used for the one-step manufacture (F) of contact lenses (L) having different parameters that largely do not have to be finished.

Abstract: A fast, relatively inexpensive and simple method is disclosed for producing a finished plastic multifocal or progressive lens from a preformed lens which has a predetermined lens correction (i.e., curvature or prescription) at its optical center. The method comprises providing a mold; providing an optical quality resin composition; providing a preformed plastic lens contacting the mold such that the surfaces of the preformed lens and the mold form a cavity enclosing the resin composition; and curing the resin composition. The cavity formed by the preformed lens and the mold is shaped, among other purposes, (1) to correspond to the desired change in curvature, and (2) to ensure that the lens correction at the optical center of the resulting lens is substantially the same (preferably the same) as the predetermined lens correction at the optical center of the preformed lens.

Abstract: A mold blank for manufacturing eyeglass lenses containing a flat top bifocal segment. A ceramic platform is first constructed containing an optical surface having a recess corresponding to the flat top bifocal segment. A concave-convex glass mold blank polished on both sides is placed on the optical surface and across the recess of the platform and the mold blank together with the platform is placed in a furnace. The furnace is then heated to a preselected temperature at which the mold blank thermally deforms and sags against the optical surface and into the recess. Upon cooling the mold blank can be used to mold plastic eyeglass lenses. A method for making the mold blank is also disclosed.

Abstract: An apparatus and method for fabricating integral three-dimensional objects from successive layers of photoformable compositions by exposing the layers of the composition through a detachable flexible transparent film, one side of the film being in contact with the composition and the other side of the film with a rigid transparent plate, which guides and supports the film.

Abstract: A fast, simple and relatively inexpensive method for forming disposable molds for use in casting optical quality lenses. A method of producing a disposable mold having a casting surface is disclosed which comprises providing a base master having a first contacting surface; providing a casting surface master having a second contacting surface having a shape corresponding to the shape of the casting surface; providing a resin composition; contacting the base master and the casting surface master such that the first and second contacting surfaces form a cavity enclosing the resin composition, wherein the cavity is shaped to correspond to the shape of the disposable mold; and curing the resin composition to form the disposable mold.

Abstract: A multifocal optical device is provided for focusing light traveling parallel to an optical axis of the device. The multifocal optical device comprises a multifocal phase zone plate including at least two annular zones disposed substantially concentrically about the optical axis and spaced in a radial dimension from the optical axis in proportion to the square root of q, where q is an integer zone number; and an absorbing material disposed on a portion of ones of the annular zones for absorbing a portion of the light.

Abstract: A foam material, particularly suitable for use as a midsole material for an athletic shoe, comprises polyethylene modified by an elastomer modifier and cross-linked, preferably using a peroxide cross-linking agent, to form a closed cell foam material which has superior strength properties, improved energy return and reduced sensitivity to temperature change.

Abstract: In a method for the production of cylindrically symmetric bodies with given radial gradient of the material properties, for example of the refractive index, at least two rod-shaped molded bodies consisting of materials with different properties are joined in parallel and, following lowering of the viscosity of both materials, the bodies are twisted many times in a spiral around a longitudinal axis, such that a desired radial gradient of the material properties arises, where metallic, semiconducting, or insulating materials may be used, and the viscosity is varied through changing the temperature or adding or removing a solvent.

Abstract: A method of making lifelike dentures which includes the characterization of an outer layer of the gum and soft tissue. Several different colored polymeric powders ranging from off-white to dark pink are applied to a surface of the denture mold cavity and characterized by a polymerizable liquid or heat curable curing agent. The method produces a denture whose gums gradually deepen in color farther from the teeth to produce a lifelike denture.

Abstract: A plastic multifocal point spherical lens comprising a unitary structure of (A) a first synthetic resin layer having a fixed refractive index, (B) a second synthetic resin layer having a substantially fixed refractive index different from the refractive index of the first synthetic resin layer, and (C) a third synthetic resin layer existing between the first synthetic resin layer and the second synthetic resin layer and having a refractive index gradient varying continuously from the refractive index of the first synthetic resin layer to that of the second synthetic resin layer, part of the second synthetic resin layer and part of the third synthetic resin layer together being recessed into the first synthetic resin layer, and the second synthetic resin layer being thicker at the recessed part than the rest.

Abstract: A method and apparatus for forming a laminated bifocal lens which includes forming a frontal lens component having a bifocal element in a substantially stress-free manner and bonding the frontal lens component to a rear lens component which is also formed in a substantially stress-free manner. The laminated lens so provided may be inexpensively formed, is lightweight, and has optimum optical and physical characteristics.

Abstract: According to the present invention, a plurality of first lens elements each having specific lens optical values and a plurality of second lens elements each having specific lens optical values are kept in stock; each one of the first and second lens elements are selected from those kept in stock, based on optical calculation; and these two lens elements are laminated to form an opthalmic lens meeting a desired prescription. Accordingly, the present invention has advantages such as shortening of the period from order receiving to product delivery.

Abstract: The disclosure relates to a method and apparatus for manufacturing lenses including the use of a wafer in conjunction with liquid monomer to provide a molded plastic lens. In the molding process, a first mold form is sealingly secured to a gasket to form a part of a mold for receiving liquid monomer. The liquid monomer is poured into the first mold form and the wafer material which can be tinted or have a different index of refraction is then placed in contiguous relationship with the liquid monomer. A second mold form is then secured into the gasket in sealing relationship therewith and spaced from the wafer to form a cavity therebetween. Liquid monomer is then introduced into the cavity to fill all the voids. The mold with the material to be molded is then placed in the oven and cured. After the curing process is completed, the mold is removed and the formed lens extracted.

Abstract: A method of producing multifocal ophthalmic lenses having a near vision minor lens element adhesively secured to the ocular surface of a major lens is disclosed. The ocular surface of the major lens is finished to provide an ophthalmic prescription lens. This ocular surface may have a spherical, cylindrical, or prismatic curvature, or any combination thereof, and thus generally may have a complex toric curvature. The minor lens has a predetermined "add power", to provide a near vision segment on the major lens, and preferably is flexible, or is made flexible as by heating, so that it can conform to the shape of the toric curve on the ocular surface of the major lens without distortion or change in its add power. An adhesive material is placed on the major lens, and the minor lens is carefully positioned and gently pressed against it so that it conforms to the curvature of the major lens.

Abstract: For use in making dental restorations, a model is prepared by taking an intra-oral impression and molding in the impression a replica model made from thermoplastic resin and an optional thermoset resin. The model includes a flexible support adhered to the underside of the model. When the model is flexed or cut, cracks will form through the replica gingival tissue between adjacent replica teeth. The flexible support acts as a hinge to provide access to interproximal spaces between replica teeth. A preferred flexible support is a layer of a tough and flexible second thermoplastic resin.

Abstract: Apparatus and a method of making an eyeglass lens module in which two lens components are disclosed. The first component is a conventional single vision stock lens having conventional corrections in the negative or positive diopter range. The second lens component is an overlay lens desirably formed from a plastic or glass and is as thin as practical. The overlays are in modules containing bifocals or trifocals or vocational modifications of a given diopter correction. The method of casting the overlaid lens includes aging a mixture of a plastic monomer and an inorganic peroxide catalyst prior to use. The two lens components are then optically and physically bonded together. Once the two lens components are secured to each other, they can then be fitted into a spectacle frame and delivered to the patient. When tinting is required, the plastic overlay can be readily tinted by conventional dye and methods.

Abstract: A method of fabricating "adjustment-free" artificial dentures and a jig therefor. A precise jaw model is formed by pouring soft plaster into the concave surface of a precise provisional denture formed by any conventional dental procedure. A plaster block is formed having a recess conforming to the actual shape of the provisional denture. The recess is filled with a synthetic resin compound and then the precise jaw model is moved into the recess to form a plenum defined by the concave surface in the recess and the convex surface of the precise jaw model. During polymerization, any excess synthetic resin compound spilling over from the plenum can escape into a relatively wide clearance between the precise jaw model and the plaster block thus enabling the plenum to retain its original shape.

Abstract: Ethoxylated siloxane surfactants, and mixtures of such surfactants with curable silicone prepolymers. The mixtures are hydrophilic after cure, have semipermanent hydrophilicity, and are especially useful as dental impressions.

Abstract: A method for directly preparing a plated denture having improved accuracy within a short period of time by properly using photo-polymerizable resins having varied viscosities, and using as the impression material a dough product of photo-polymerizable resins having different viscosities with preparing of a basic plate, formation of alveolar ridge portion, arrangement of artificial teeth, formation of gingival portion, whereby the impression of the details of the mucosal surface of the oral mouth is reproduced with high fidelity, and is then polymerized and cured as such by active energy beams to use it as the resin surface.

Abstract: A technique by which a denture formed from light-curable plastic material, and including individually positioned artificial teeth, is produced by the use of a custom, substantially U-shaped, matrix formed from an elongated shape of light-curable plastic material which is impressed into and is releasably affixed to the incisal and occlusal surfaces of the teeth when mounted in set-up wax on a model of a patient's gum.

Abstract: A contact lens for correction of astigmatism is formed from a single polymeric or copolymeric material. The lens has a central optical zone of greater rigidity than a surrounding non-optical zone. The rigidity of the central optical zone is sufficient for it to retain an astigmatism-correcting shape when worn on an eye, while the surrounding non-optical zone conforms to the shape of the eye.

Abstract: A steam expandable alkenyl aromatic polymer composition and methods of preparation are provided. The composition is mixed with a volatile blowing agent containing, as a primary blowing agent, dichlorodifluoromethane and as a secondary blowing agent, a halogenated hydrocarbon, a hydrocarbon, or an aliphatic alcohol containing from 1 to 4 carbon atoms, the secondary blowing agent having a normal atmospherpic boiling point of from about 0.degree. to about 100.degree. C. The composition may be expanded by steam immediately after extrusion foaming or may be expanded after aging of the composition which has been impregnated with volatile blowing agent.

Abstract: Curable silicon prepolymers are made hydrophilic after cure by mixing the prepolymer with ethoxylated nonionic surface active agent or cationic or amphoteric fluorochemical surface active agent. The cured silicones have semipermanent hydrophilicity and are especially useful as dental impressions.

Abstract: Customized dentures are manufactured by first producing denture bases in one of a plurality of standard sizes each having sockets therein for receiving an array of artificial teeth. Next, an array of artificial teeth removably coupled together by means of a U-shaped appliance which maintains the occlusal aspects of the teeth is positioned in the sockets. Such denture bases which may be wax, uncured synthetic resin or a cured synthetic resin are then shipped and inventoried by a dentist. To fit a particular oral cavity, the dentist first makes an impression of the oral cavity and from that impression upper and lower models are casted. The dentist then selects a denture base having the artificial teeth positioned thereon in one of the standard sizes which most closely accommodates the models. The denture bases are then conformed to the surface contours of the models and the prosthetic teeth are secured in the sockets.

Abstract: A polyester fiber having a tenacity of at least 4.0 g/d is formed from a copolyester having a degree of polymerization of from 80 to 100 of which copolyester 1.0 to 2.0 mol % of its acid component has a metal sulfoisophthalic group and 0.5 to 1.9 weight % of which copolyester is provided by a glycol component provided by glycol having a molecular weight of from 400 to 6000. The polyester fiber is readily dyed with basic dyes.The polyester fiber can be prepared by spinning the copolyester at a shear rate of.ltoreq.10.sup.4 sec.sup.-1, a spinning draft ratio of .ltoreq.250, a back pressure of the spinneret of.gtoreq.40 kg/cm.sup.2 and a shear stress of .ltoreq.(Q+0.7).times.10.sup.7 dyne/cm.sup.2, where Q is the mass output rate per single hole (g/min).

Abstract: A method of making bifocal resinous lenses by providing a positioning cylinder connected to a low refractive index polymer. Cutting a convex optical surface orientated to the positioning cylinder. A high index polymer is cast on the low index optical surface and a second shorter radius convex optical surface which intersects both the high and low refractive index materials is cut and polished. Additional low index polymer is cast over the second shorter radius surface and polymerized. A bifocal lens blank is cut from the polymer mass having the high refractive index surfaces orientated to the exterior blank surfaces.

Abstract: A temporary denture can be rapidly produced while the denture user is in a dentist's office by filling a shell member with a molding composition. An impression of the outer surfaces only of a user's permanent denture is made in the molding compound and the tooth portions of the impression are then filled with a quick-cure, tooth colored curable acrylic composition, up to the gingival margin. Before the acrylic has cured, the remainder of the impression is covered with more of the curable acrylic composition which is colored pink until the gingival portion of the impression is covered by a thin layer of the acrylic. After setting, the thus-produced denture shell is removed from the mold, the surfaces thereof are then trimmed to correspond to the starting denture. The inner surface of the denture shell is then filled with soft curable denture liner and fitted in the user's mouth to form the temporary denture.

Abstract: A method of making custom dentures from an uncured resin module wherein the module, molded to standard dimensions and including sockets for artificial teeth, is cooled to a low temperature to impart rigidity and prevent curing. The module with teeth in place is later conformed to a heated cast representation of the patient's oral cavity and then itself heated to cure the module thereby providing a custom denture.

Abstract: Disclosed is a method for forming a denture in-situ in the mouth of a dental patient. The method starts with a try-in of the teeth in wax formed to duplicate in shape the desired form of the finished denture. An in-situ impression of the try-in in alginate is followed by placing of the teeth in the resultant impressions in the alginate and subsequent acrylic buildup and in-situ forming and setting of the final acrylic denture.

Abstract: Cast multifocal lenses are produced from ledged casting pieces molded from a master die having a molding surface made up of juxtapositioned die components each precision surfaced to a curvature and finish corresponding to a multifocal surface desired to be cast upon a lens and relatively prearranged according to desired height and position of cast lens ledging.

Abstract: A denture base is made of a photocuring resin compound by a process which includes polymerizing methacrylate and/or acrylate with the addition of a light sensitizer or a filler. Subsequent to a proper alignment of artificial teeth, the photo-curing or -hardening resin compound is hardened by exposure to light and artificial gingivae are formed by the same resin compound as above, followed by photocuring, thereby completing manufacture of the denture base.Advantageously, the method disclosed herein facilitates markedly the manufacture of denture bases in comparison with conventional methods such as thermal polymerization and casting. The resulting denture bases show excellent properties.

Abstract: The present invention relates to a method for use in creating a prosthetic denture device such as a denture component formed of a set of hard teeth bonded within an adjustable frame assembly. The frame assembly may be completely or substantially formed having adjustable frame portion which is formed from a composition that is centrifugally cast, and which when cured becomes rigid but not completely polymerized and therefore capable of being subsequently remolded with finger pressure when elevated in temperature. In this manner the adjustable frame portion is remoldable and conformable to desired portions of the oral cavity in the creating of an artificial denture.

Abstract: The present invention relates to an article for use in creating a prosthetic denture device that is an impression tray or a denture component formed of a set of hard teeth bonded within a frame assembly formed of a permanent substantially rigid hard frame portion and an adjustable frame portion that is integrally joined to the rigid frame portion and forms part of the frame assembly. The adjustable frame portion is formed from a second composition that is centrifugally cast, and which when cured becomes rigid but not completely polymerized and therefore capable of being subsequently remolded with finger pressure when elevated in temperature. In this manner the adjustable frame portion is remoldable and conformable to desired portions of the oral cavity in the creating of an artificial denture, and the rigid frame portion formed from the first composition concurrently remains fixed as the adjustable frame portion is remolded.

Abstract: The present invention relates to a method for use in creating a prosthetic denture device that is an impression tray or a denture component formed of a set of hard teeth bonded within a frame assembly formed of a permanent substantially rigid hard frame portion and an adjustable frame portion that is integrally joined to the rigid frame portion and forms part of the frame assembly. The adjustable frame portion is formed from a second composition that is centrifugally cast, and which when cured becomes rigid but not completely polymerized and therefore capable of being subsequently remolded with finger pressure when elevated in temperature. In this manner the adjustable frame portion is remoldable and conformable to desired portions of the oral cavity in the creating of an artificial denture, and the rigid frame portion formed from the first composition concurrently remains fixed as the adjustable frame portion is remolded.

Abstract: The invention relates to a method for preparing a dental impression which comprises applying a dental impression material to a tooth of which an impression is to be taken, curing the material and thereafter removing the resulting impression from the tooth, said dental impression material being a mixture ofA. a diorganopolysiloxane containing terminal triorganosiloxy groups in which at least one vinyl group is present in each of the triorganosiloxy groups,B. an organopolysiloxane having at least three Si-bonded hydrogen atoms per molecule,C. a catalyst capable of promoting the addition of Si-bonded hydrogen to vinyl groups at room temperature and, if desired,D. additives such as fillers, pigments, flavoring substances and plasticizers.