Abstract: Methods and apparatus for providing a vibrational enhancement to the recoating process in stereolithography are disclosed. The formation of a thin layer of building material over a previous layer of structure of a partially completed three-dimensional object, in preparation for formation of an additional layer of structure, is enhanced by the use of vibrational energy imparted to the building medium. In a first preferred apparatus, vibration is induced into the surface of the material by a plurality of vibrating needles that penetrate below the working surface to a sufficient depth to ensure adequate coupling but not deep enough to come into contact with the surface of the partially completed part. In a second preferred apparatus, vibration is coupled directly to the object support. The vibrational energy is then transmitted through the part to the surface of the building material.
Type:
Grant
Filed:
March 16, 1995
Date of Patent:
November 18, 1997
Assignee:
3D Systems, Inc.
Inventors:
Paul F. Jacobs, J. Scot Thompson, Hop D. Nguyen, Dennis R. Smalley
Abstract: A method of and system for inserting reinforcing pins in a composite structure in which a number of reinforcing pins are inserted in a compressible material; the compressible material/pin combination is assembled on the composite structure; ultrasonic energy is applied to the pins; and pressure is applied simultaneously with the application of ultrasonic energy to compress the compressible material and insert the pins into the composite structure to join two laminates or reinforce a single composite structure.
Type:
Grant
Filed:
February 13, 1996
Date of Patent:
December 31, 1996
Assignee:
Foster-Miller, Inc.
Inventors:
Thomas M. Fusco, Constance Magee, Glenn Freitas
Abstract: An internal molding having a predetermined shape of a hollow portion of a manifold is integrally molded by blow molding or the like, and external molding elements having a predetermined shape of the exterior of the manifold and being split into a plurality of parts are molded. The internal molding is integrated with the external molding elements by adhesion or fusion. Further, an external molding is molded, and an internal molding having a shape substantially identical with or smaller than a predetermined shape of a hollow portion of the hollow resin molding is integrally molded. Then, the internal molding is softened by arranging the internal molding inside the external molding and heating the internal molding, and the inside of the internal molding is thereafter pressurized to cause the internal molding to contact the external molding, so that the internal molding is integrated with the external molding.
Abstract: A pressure medium composed of plural kinds of fluids each of which have a different density is charged in a pressure chamber forming, for example, fluid layers. A material is suspended by way of buoyancy brought by this pressure medium. By properly controlling the density of the pressure medium of plural kinds of fluids, various kinds of materials having different densities can be supported in a suspending state at an almost constant pressure. The apparatus and the method processes the material under a state of compensated-gravitation, and is capable of forming an easy-handling weightless state for a long period of time at low cost in a simple manner for ease of handling of the material being processed and can contribute to developing useful materials and novel materials and to the supplying of them in bulk.
Abstract: An improved method of inducing piezoelectric properties in polymer films, ch as polyvinylidene fluoride (PVDF) films and co-polymers thereof. This improved method involves applying uniaxial tensile forces to pre-aligned polymer films while simultaneously applying an electric poling field to the pre-aligned polymer films at room temperature to provide enhanced piezoelectric properties. This improved method does not require the use of heating equipment or temperature cycling equipment during the electric field poling of the polymer and thus represents a simpler and more cost efficient process of inducing piezoelectric properties in polymers.
Type:
Grant
Filed:
May 16, 1994
Date of Patent:
February 27, 1996
Assignee:
The United States of America as represented by the Secretary of the Navy
Abstract: A method for forming thinned areas in a thin sheet material. The method includes the steps of (1) placing the thin sheet material on a pattern anvil having a pattern of raised areas wherein the height of the raised areas is generally less than the thickness of the sheet material; (2) conveying the sheet material, while placed on the pattern anvil, through an area where a fluid is applied to the sheet material; and (3) subjecting the sheet material to a sufficient amount of ultrasonic vibrations in the area where the fluid is applied to the sheet material to area thin the sheet material in a pattern generally the same as the pattern of raised areas on the pattern anvil. In some embodiments, the thinned areas may be micro areas.
Abstract: A plastic material is injected in the fluid state into a flexible closed mold having a molding cavity in which is placed the edge of a glass pane. The plastic material is injected into the cavity of the mold in the inert state and is then activated by high-frequency electromagnetic radiation or by microwave radiation. An insert is placed in the cavity of the mold before the injection of the plastic material. The injection and subsequent hardening of the plastic material are carried out inside the cavity of the mold in which cavity the edge of the glass pane and the insert are arranged in their definitive relative position. Glass panes for motor vehicles having a trim strip or elements such as ducts, cables or fastening screws can be prepared.
Abstract: Compositions suitable for application in powder coating processes are produced by melt atomisation of thermosettable mixtures. The product is characterised by improved particle size distribution and by a generally rounded particle shape.