Abstract: A method, apparatus, and article of manufacture provide a distributed computing system delivering and manipulating electronic model images to end users. One aspect of the present invention includes a method for providing electronic delivery of electronic model images. The method generates one or more electronic model images, a portion of the electronic model images being generated from scanned electronic data of a physical object, stores the electronic model images within computer readable memory of a server-based computing system, delivers the electronic model images to a remote client computer over a distributed communications network, manipulates the electronic model images upon the remote client computer, and performs analysis and a course of action using the manipulated electronic model images. The electronic model images comprise in part a polygonal mesh representation of the physical object.

Abstract: Injection molding method and apparatus for ejecting a molded plastic article from a mold. A lifting structure and/or step is provided with a lifting portion which is configured to contact substantially one half of an end of the molded plastic article along a line substantially perpendicular to the lifting direction. Since the molded plastic article is lifted by its end, the article does not have to be solidified at its interior, thus allowing earlier removal of the article from the mold, reducing cycle time. A tapered surface forms an acute angle with respect to the lifting portion to form a tight seal with the mold, preventing leakage. Preferably, the neck ring engages only an outer circumferential portion of the molded plastic article during a majority of a mold opening stroke.

Abstract: Dental appliances including multiple components and a system and method for constructing the same are disclosed herein. The dental components are designed to fit together to form the dental appliance. The components of the dental appliance are electronically modeled, printed, and pressed sequentially, separately, or as a unitary piece. Forming the dental appliance from multiple components enables each component of the dental appliance to be formed from a different material, each material having different features associated with it. In various embodiments, different materials have different colors, textures, opacities, and transformation factors associated with them. Furthermore, each component can be formed from multiple components. In some other embodiments, a support structure is designed and constructed in order to minimize deformation of a dental component during fabrication of the component.

Abstract: A system and method for determining condyle displacement during jaw articulation includes a physical model with corresponding reference points. The physical model is positioned and scanned to obtain positional data representing a first and second bite position. This positional data is used to generate a transformation matrix. The position of at least one condyle is determined in reference to positional data scanned from the physical model. The transformation matrix is used to map the position of the condyle with respect to the second bite position.

Abstract: Injection molding method and apparatus for ejecting a molded plastic article from a mold. A lifting structure and/or step is provided with a lifting portion which is configured to contact substantially one half of an end of the molded plastic article along a line substantially perpendicular to the lifting direction. Since the molded plastic article is lifted by its end, the article does not have to be solidified at its interior, thus allowing earlier removal of the article from the mold, reducing cycle time. A tapered surface forms an acute angle with respect to the lifting portion to form a tight seal with the mold, preventing leakage. Preferably, the neck ring engages only an outer circumferential portion of the molded plastic article during a majority of a mold opening stroke.

Abstract: A concentric strander has an elongate concentric shaft that defines a shaft axis and supports for rotatably supporting the concentric shaft. A number of wire bobbins are spaced at substantially equal intervals along the shaft to form spaces between the bobbins. Each bobbin has an axis substantially coextensive with the shaft axis for rotation about the shaft, and each bobbin has a maximum radial diameter. The strander has take-off sheaves, mounted on the shaft, that are associated with a wire bobbin and that take the wires from the bobbins and guide them to a point radially outwardly beyond the maximum predetermined radial bobbin diameter. The take-off sheaves subsequently guide the wires in a direction substantially parallel to the shaft axis and define, on rotation of the concentric shaft, a cylindrical envelope. At a downstream end of the shaft, the strander has a closing device that receives the wires from the bobbins and applies them on a core.

Abstract: A system and method for generating an electronic model for a dental impression having a common coordinate system. The system includes two scanning apparatus for positioning physical objects within a scanning device when generating an electronic model corresponding to each of the physical objects; a data processing system for processing the electronic models corresponding to each of the physical objects to posses polygonal mesh representations of the physical objects within a common coordinate system. The scanning apparatus comprises a scanning base plate module for coupling the scanning apparatus to the scanning device and a physical model plate module to coupling the physical object to the scanning base plate module within a coordinate system of the scanning device. The scanning apparatus are used to mount physical models onto corresponding scanning apparatus, the scanning apparatus positions the physical models within a coordinate system of a scanning device.

Abstract: A method of dental restoration treatment utilizing the electronic delivery of an electronic model image of the dental restoration treatment. The method includes generating an electronic model image of a proposed dental restoration treatment; storing the electronic model image within computer readable memory of a server-based computing system; delivering the electronic model image to a doctor having a remote client computer over a distributed communications network; and displaying the electronic model image upon the remote client computer and performing analysis of the electronic model image. The doctor is provided with a variety of viewing and analysis tools, and can add notations to the electronic model image.

Abstract: A handrail and bracket assembly includes a pair of brackets having two off-set channels that permit the hand rail to be positioned in an expanded or in-use position or a collapsed or stowed position. At least one mounting opening is provided in each bracket for securing it to a wall or other surface. The channels and openings are positioned such that the brackets can be attached to the handrail prior to attaching the brackets to a wall or other surface.

Abstract: A concentric tape applicator has a support shaft that defines an axis and includes a structure for supporting a tape pad for rotation with the support shaft about the axis. Guide rollers are mounted on the support shaft for rotation concentrically about the axis for guiding tape from the tape pad for application to an elongated member advancing along the axis relative to the support shaft. A drive is directly coupled to the guide elements. A differential clutch is provided that has an input shaft directly coupled to the drive and an output shaft coupled to the support shaft for applying braking forces to the pad. A feedback circuit is provided for sensing the speed of rotation of the pad and applying a feedback signal to the clutch for regulating the excitation of the clutch to maintain a substantial uniform tension on the tape dispensed from the pad so potentially independently of the amount of tape remaining on the pad.

Abstract: A method, apparatus, and article of manufacture is disclosed for providing a dental treatment plans using electronic models, and more particularly to a method, apparatus, and article of manufacture for utilizing electronic models of patient teeth in interdisciplinary dental treatment plans. The system and method permit the electronic generation and specification of electronic models and then dental treatment plans for patients that require interdisciplinary treatment that may include orthodontic treatment, may include the generation of crown, bridge, and implant dental appliances that may be specified in an industry standard file specification. This specification is utilized in a rapid prototyping process to generate a wax impression for the appliance that may then be fabricated using standard lost-wax fabrication techniques.

Abstract: A concentric strander has an elongate concentric shaft that defines a shaft axis and supports for rotatably supporting the concentric shaft. A number of wire bobbins are spaced at substantially equal intervals along the shaft to form spaces between the bobbins. Each bobbin has an axis substantially coextensive with the shaft axis for rotation about the shaft, and each bobbin has a maximum radial diameter. The strander has take-off sheaves, mounted on the shaft, that are associated with a wire bobbin and that take the wires from the bobbins and guide them to a point radially outwardly beyond the maximum predetermined radial bobbin diameter. The take-off sheaves subsequently guide the wires in a direction substantially parallel to the shaft axis and define, on rotation of the concentric shaft, a cylindrical envelope. At a downstream end of the shaft, the strander has a closing device that receives the wires from the bobbins and applies them on a core.

Abstract: A concentric tape applicator has a support shaft that defines an axis and includes a structure for supporting a tape pad for rotation with the support shaft about the axis. Guide rollers are mounted on the support shaft for rotation concentrically about the axis for guiding tape from the tape pad for application to an elongated member advancing along the axis relative to the support shaft. A drive is directly coupled to the guide elements. A differential clutch is provided that has an input shaft directly coupled to the drive and an output shaft coupled to the support shaft for applying braking forces to the pad. A feedback circuit is provided for sensing the speed of rotation of the pad and applying a feedback signal to the clutch for regulating the excitation of the clutch to maintain a substantial uniform tension on the tape dispensed from the pad so potentially independently of the amount of tape remaining on the pad.

Abstract: Injection molding method and apparatus for ejecting a molded plastic article from a mold. A lifting structure and/or step is provided with a lifting portion which is configured to contact substantially one half of an end of the molded plastic article along a line substantially perpendicular to the lifting direction. Since the molded plastic article is lifted by its end, the article does not have to be solidified at its interior, thus allowing earlier removal of the article from the mold, reducing cycle time. A tapered surface forms an acute angle with respect to the lifting portion to form a tight seal with the mold, preventing leakage. Preferably, the neck ring engages only an outer circumferential portion of the molded plastic article during a majority of a mold opening stroke.

Abstract: Chromium trioxide is made by reacting sodium dichromate with sulphuric acid in an aqueous reaction mixture, evaporating the resultant liquor to cause crystallization of most of the chromium trioxide and to cause the concentration of sodium sulphates to be close to but below that at which sulphate crystals start to form, and separating the chromium trioxide crystals from the evaporated liquor. The liquor may then be cooled so as to cause crystallization of sodium sulphates, generally as sodium bisulphate, and the resultant liquor, after separation of the crystals, may be recycled to the reaction mixture containing dichromate and sulphuric acid.

Abstract: Chromic oxide of very low (below 40 ppm) insoluble sulphur content is obtained by calcination of a less pure product at a temperature above 1100.degree. C. for at least 10 minutes.

Abstract: Chromium trioxide contaminated with sulphate is purified by washing with an aqueous purifying wash liquor, generally water or aqueous chromic acid, while at a temperature above 50.degree. C. and centrifuging the washed product. Washing is generally conducted on the centrifuge. The chromium trioxide is preferably made by reacting sodium dichromate with from 2.4 to 2.8 mols sulphuric acid. The process can be operated to produce a novel product consisting of crystalline, non-fused, chromium trioxide that is substantially pure. The novel product can be in the form of pellets.

Abstract: An harmonica having a conventional body shaped so as to form a series of adjacent cavities and a plurality of reeds each of which is responsive to the passage of air to produce an audible musical note of a certain fixed pitch. Two reeds are associated with each cavity such that one reed is responsive to blowing into the cavity to produce a blownote and the other is responsive to drawing on such cavity to produce a drawnote. In one embodiment, the reeds are constructed and arranged such that the blownotes include the first, fourth and sixth notes of the major scale of a keynote and all the drawnotes are notes of the major scale of that keynote. Harmonicas utilizing modal scales are also provided.