5,637,169 – Expiring June 10, 2014
Current Assignment Data Unavailable
U.S. Patent No. 5,637,169 to Hull et al. entitled “Method of Building Three Dimensional Objects with Sheets” discloses methods of producing a 3D object using radiation. One method involves dispensing a sheet of material capable of selective solidification onto a working surface and forming successive cross-sections of the object by selectively exposing portions of each sheet to electromagnetic radiation. After portions of the sheets solidify, unexposed regions of the sheets are removed and the process is repeated to form the 3D object. Two related methods are also disclosed, the main differences being that one incorporates sheets of insoluble material which become soluble upon exposure to electromagnetic radiation and the other incorporates sheets of material which are capable of selective cutting upon exposure to electromagnetic radiation.
5,639,070 – Expiring June 17, 2014
Assigned to DTM Corporation
U.S. Patent No. 5, 639,070 to Deckard entitled “Method for Producing Parts by Selective Sintering” discloses a method for producing a 3D part from powder. The method involves dispensing a first layer of powder onto a target area and directing energy (e.g., a laser) at selected locations of the powder to fuse together a first cross-section of the part, leaving unfused powder remaining. The next step involves dispensing a second layer of powder over both fused and unfused portions of the first layer and heating (e.g., with gas or a laser) the second layer of powder, but not all the way to its sintering temperature. The method further involves directing energy at selected locations of the second layer of powder to fuse together a second cross-section of the part, while fusing the first and second fused layers together. This process can be repeated to form the 3D part.
5,494,618 – Expiring June 27, 2014
Assigned to 3D Systems
U.S. Patent No. 5,494,618 to Sitzmann et al. entitled “Increasing the Useful Range of Cationic Photoinitiators in Stereolithography” discloses a process of stereolithography in which a 3D object is built up by polymerizing cationically polymerizable monomers by the catalytic action of cationic photoinitiators activated by a moving beam of UV light, such as an Argon ion laser. The monomers comprise, e.g., vinyl ethers and epoxides, which make it possible to rapidly cure the vinyl ethers while leaving the epoxide largely uncured. By post-curing the epoxides, any additional shrinking that occurs should not produce additional distortion of the object. The process reduces the depth of cure and consequently enables production of thinner, more accurate polymer layers.
5,651,934 – Expiring July 29, 2014
Current Assignment Data Unavailable
U.S. Patent No. 5,651,934 to Almquist et al. entitled “Recoating of Stereolithographic Layers” discloses a method for forming a 3D object by adding subsequent layers to previously formed layers. The method involves providing a volume of a building medium that is capable of selective physical transformation upon exposure to synergistic stimulation and forming a uniform coating over a previously formed layer of material, which includes sweeping a smoothing element over the previously formed layer to smooth the surface of the building material. Synergistic stimulation is then applied to the building material to form the subsequent layer. This process can be repeated to form the 3D object. The patent also discloses an apparatus, which provides the means for carrying out the above method.
5,555,176 – Expiring October 19, 2014
Assigned to Jerry Zucker
U.S. Patent No. 5,555,176 to Menhennett et al. entitled “Apparatus and Method for Making Three-Dimensional Articles Using Bursts of Droplets” discloses an apparatus and method for producing a 3D object using successive bursts of flowable material. The apparatus comprises a platform on which the droplets are placed, a material dispenser, and a dispenser positioning means for advancing the dispenser along a predetermined path. The build material dispenser can be, e.g., a jet including a piezoelectric actuator. In addition to the mechanical components, the apparatus further comprises a processor for controlling the dispenser and dispenser positioning means. The processor can further comprise a burst control means for operating the dispenser to dispense a series of bursts of material or a corner forming means for constructing a corner of the object. In contrast to a droplet-by-droplet approach, each burst in this apparatus is a plurality of successive droplets dispensed in relatively rapid succession to each other so that the material of the successive droplets combines at a target position.
5,572,431 – Expiring October 19, 2014
Assigned to Jerry Zucker
U.S. Patent No. 5,572,431 to Brown et al. entitled “Apparatus and Method for Thermal Normalization in Three-Dimensional Article Manufacturing” discloses an apparatus and method for producing a 3D object by re-solidifying build materials using a heat source. The method involves dispensing a build material onto a platform to construct an object in layers which solidify after dispensing. The object is then heated and melted such that it re-flows, and portions of the previously solidified building material are reshaped. This process produces an object that more accurately reflects the predetermined coordinates and evens out surface irregularities. The apparatus comprises a platform and dispensing means for jetting materials onto the platform. The apparatus also comprises a heater, a body in connection with the heater, and position means for advancing the body along a predetermined path to heat the object and reshape the previously solidified portions.
5,529,471 – Expiring February 3, 2015
Assigned to University of Southern California
U.S. Patent No. 5,529,471 to Khoshevis entitled “Additive Fabrication Apparatus and Method” discloses an apparatus for producing 3D objects using additive fabrication techniques. The apparatus comprises two nozzles for delivering fluid materials, two supply means for delivering fluid material to each nozzle, and two control means for moving and positioning the nozzles with respect to the object being produced. An additional feature of the apparatus is the utilization of trowels, which enable rapid creation of smooth surfaces with better accuracy. The trowels permit creation of various shapes using only the two trowels, instead of using a variety of tools needed in more traditional sculpturing and plastering.
5,733,497 – Expiring March 20, 2015
Assigned to DTM Corporation
U.S. Patent No. 5,733,497 to McAlea et al. entitled “Selective Laser Sintering with Composite Plastic Material” discloses a method for producing a 3D object by fusing powder materials. The method involves applying a layer of composite powder on a target surface, where the composite powder consists of a polymer powder and a reinforcement powder. After the powder is applied to the surface, energy (e.g., a laser) is directed at selected locations of the powder layer to fuse the powder and form a cross-section of the desired object. This process is repeated and the unfused powder is removed, leaving the formed 3D object.
5,762,856 – Expiring June 9, 2015
Assigned to 3D Systems
U.S. Patent No. 5,762,856 to Hull entitled “Method for Production of Three-Dimensional Objects by Stereolithography” discloses a method of producing a 3D object from a material that is capable of solidifying upon exposure to radiation or synergistic stimulation. The method involves providing a bath of a curable medium in a container and exposing it to heat or stimulation to form a lamina of an object. As the previously formed lamina is lowered in the bath, a new layer of medium is then subjected to heat or stimulation to form another lamina. This process is repeated to form the 3D object.