Abstract: A polishing apparatus is used for polishing a workpiece such as a semiconductor wafer to a flat mirror finish. The polishing apparatus includes a turntable having a polishing surface, a top ring for holding a workpiece and pressing the workpiece against the polishing surface to polish the workpiece. The polishing apparatus further includes a rotary transporter disposed in a position which can be accessed by the top ring and having a plurality of stages positioned on a predetermined circumference from a center of rotation of the rotary transporter for holding the workpieces. The polishing apparatus further includes a plurality of support tables removably held by the respective stages of the rotary transporter for supporting the workpieces, and a pusher for transferring the workpiece between the support table and the top ring.

Abstract: An improved extrusion-based manufacturing system includes one or more extruders, with each extruder containing at least two stages of increasing pressurization. In a preferred embodiment, a first stage of pressurization is created by the motion of a solid wafer of thermoplastic through an orifice into a heater chamber. In another preferred embodiment, the wafers are stored in removable, electronically tagged, cassettes and are removed therefrom by a stapler mechanism which feeds the wafers from the cassette to a tractor feed mechanism on demand. In each embodiment, a second stage of pressurization is provided by a pump, with the first stage pressurization maintaining a flow of thermoplastic to the pump under all expected pump rates.

Abstract: A panel assembly that may be used in doors, particularly hollow metal doors, and other types of panels such as interior and exterior walls, room partitions, and the like. The panel assembly exemplified by a hollow or filled metal door is constructed from a deep pan and a shallow pan made from unitary pieces of sheet metal sheet and each pan includes top, bottom, and two opposing side flanges extending from rectangular face members. The flanges of the deep pan are substantially perpendicular to its rectangular face member and higher than those of the shallow pan. Side flanges of one of the pans have first latch members formed along free side edges of their side flanges remote from their respective face member and side flanges of the other pan have second mating latch members formed along free side edges of their side flanges remote from their respective face members.

Abstract: A panel assembly that may be used in doors, particularly hollow metal doors, and other types of panels such as interior and exterior walls, room partitions, and the like. The panel assembly exemplified by a hollow or filled metal door is constructed from a deep pan and a shallow pan made from unitary pieces of sheet metal sheet and each pan includes top, bottom, and two opposing side flanges extending from rectangular face members. The flanges of the deep pan are substantially perpendicular to its rectangular face member and higher than those of the shallow pan. Side flanges of one of the pans have first latch members formed along free side edges of their side flanges remote from their respective face member and side flanges of the other pan have second mating latch members formed along free side edges of their side flanges remote from their respective face members.

Abstract: Disclosed are methods and apparatus for fabricating a three-dimensional object in accordance with a computer-generated definition of the object that is stored within a memory. A method includes the steps of (a) evaluating the stored definition of the object to locate any un-supported features of the object; in response to locating an un-supported feature, (b) defining a support structure for the un-supported feature; (c) generating a fabrication tool movement list expressive of movements required by a fabrication tool to fabricate the object and any defined support structures; and (d) translating the fabrication tool in accordance with the generated fabrication tool movement list to fabricate the object and any defined support structures.

Abstract: A rotary viscosity pump is provided that has a housing and an impeller. The housing has a conical chamber with an outlet at a narrow end of the chamber. The impeller has a conical section with a logarithmic spiral groove along its exterior. The spacing between the housing and the impeller can have either a constant gap or a gap that decreases along the length of the impeller. The depth of the groove can be constant, increase, or decrease in depth along the length of the impeller.

Abstract: Apparatus and method for fabricating a three-dimensional object in accordance with a CAD-generated specification of the object. A closed-loop extrusion system (10) includes a nozzle (12) for extruding a material, such as a hot melt adhesive; apparatus (14, 18, 46) for controllably positioning the nozzle in accordance with the specification; and a sensor (60) for generating a feedback signal that is indicative of at least one characteristic of a most recently extruded portion of the material. Visual and non-visual feedback sensors may be employed, including optical sensors, infrared emission sensors, and proximity detection sensors. The specification of the object is converted to a bit-mapped representation thereof to improve accuracy relative to vector-based representations. Methods for determining a need for supporting structures and anti-aliasing features and for integrating the structures and features into the object specification are also disclosed.

Abstract: Measurement apparatus and procedure for use with lithographic equipment is provided for the construction of electronic and other devices wherein a photoresist is deposited as a layer upon a substrate. A Nomarski differential interference contrast microscope in conjunction with a scanned image detector is employed to examine verification marks produced by projection of an overlay, such as the mask or reticle, upon the photoresist layer. The projection results in a production of verification marks in the form of a latent image which, while invisible with conventional viewing means, can be viewed by phase-contrast imaging employing differential phase shift. Various characteristics of the resultant image are employed to align secondary verification marks with primary verification marks previously provided on the substrate, and to allow for a checking of line width, dosage, focusing, temperature control, and global alignment.

Abstract: The disclosure embraces a method of and apparatus for simultaneously winding linear bundles of filaments, such as strands of glass filaments, in a filament-forming operation into two or more packages on a driven rotatable collet and the linear bundles or strands traversed by guide members axially of the packages, the progressively increasing sizes of the packages normally intermittently moving the traverse guide members away from the packages, and wherein an undersized package activates an instrumentality, indication or signal warning the operator of such condition and interrupting movement of the traverse means away from the packages.

Abstract: A wheelchair tray assembly is provided which includes spring biased hook elements to secure a tray to the arms of a wheelchair. The tray is mounted to tray supports which permit movement of the tray perpendicular to the direction of movement of the hook elements. The entire unit when collapsed is substantially the same size as a conventional cafeteria tray.

Abstract: Method and apparatus for advancing continuous glass strand during times the strand is not being collected into a package by a winder. A pair of cooperating rolls having a plurality of helical teeth are rotated to advance the strand therebetween.