Abstract: The geometry of the cast part is provided as a digital pattern and an inverse pattern for the lost casting mold including any core is generated from the digital pattern. A layer of a particulate molding material is provided. The molding material is made of a first material and a second material. The first material is chemically inert when irradiated by electromagnetic radiation. The second material is curable by a chemical curing process that is initiated by electromagnetic radiation. The layer is scanned by irradiating electromagnetic radiation on places of the layer corresponding to the inverse pattern for the lost casting mold including any core. The irradiation is controlled to initiate the chemical curing process in the second material.

Abstract: A method of producing an object by successive solidification of layers of a powder material is disclosed. The method provides a preformed base plate having a metal plate with a solidified layer of a powder material formed thereon. Then, successive layers of said powder material are applied and solidified on the solidified layer of the base plate to form the object. In further detail, the method for produces a three-dimensional by providing a support and a preformed base plate having an upper surface for supporting the object. The base plate is removably attached to the support. Means are provided for adjusting the elevation of said upper surface. A layer of the powder material is applied to the upper surface of the base plate. The powder material is solidified at points corresponding to a cross-section of the object by irradiation with electromagnetic or particle radiation. Then, the applying and solidifying steps are repeated for completing the object.

Abstract: An apparatus for producing a three-dimensional object by successive solidification of layers of a solidifiable material (7) at places corresponding to the respective cross-section of the object by means of radiation is provided whereby the apparatus comprises a support (4) for supporting the object (6) to be formed, a coating device (12) for applying layers of the solidifiable material (7) onto the support (4) or a previously solidified layer, a solidifying device (14) for solidifying the layers of the material (7) at places corresponding to the respective cross-section of the object and a heating apparatus (8) disposed above the support (4) in operational position for heating the solidifiable material (7), the heating apparatus (8) comprising at least one straight radiant heater (81) with a varying heating power along its length.

Abstract: In order to achieve a homogeneous density distribution in a layer to be solidified of a three-dimensional object produced by laser sintering a laser beam is passed across the surface of the layer to be solidified, whereby the travelling speed of the beam varies as a function of the length of lines of a line pattern.

Abstract: An apparatus for layerwise production of an object using laser sintering by solidifying a material which is solidifiable by electromagnetic radiation comprises a device (5) for producing an electromagnetic beam (6) and a focusing device (8) for focusing the beam (6) onto the material within a working plane (7), whereby the focusing device (8) comprises a lens (9) and a mount (10) holding the lens (9), a ring nozzle (12) arranged adjacent to the image-side surface (11) of the lens (9) facing the working plane (7), the ring nozzle having its outlet oriented relative to the image-side surface (11) so that a discharged stream strokes tangentially along the image-side surface (11) towards the center, the inlet of the ring nozzle being selectively connected with a source of pressurized gas.

Abstract: In a method for calibrating the deflection control of a laser beam a light-sensitive medium (5) is exposed to a laser beam (2) at predetermined positions for generating a test pattern (20), thereafter digitized partial pictures of pattern portions (21) of the test pattern (20) are produced and the digitized partial pictures are composed to a digitized overall picture of the test pattern (20). The correction data for the control (4) for deflecting the laser beam (2) are calculated on the basis of a comparison of actual positions of the laser beam (2) on the digitized overall picture with predetermined desired coordinates.

Abstract: An apparatus for producing a three-dimensional object by successive solidification of layers of a powder material at points corresponding to a cross-section of said object using electromagnetic or particle radiation comprises support means having an upper side for supporting the object thereon at a determined elevation, elevation adjustment means for varying the elevation, means for applying a layer of the material onto the upper side or onto another layer formed on the upper side, and irradiation means for irradiating the layer of the material at the points corresponding to a cross-section of the object. For reducing the production time of the object the apparatus further comprises a prefabricated base plate on the upper side, the base plate being made of a material which the powder material adheres to when being solidified, and means for removably connecting the base plate to the upper side of the support means.

Abstract: In an apparatus for producing a three-dimensional object by laser sintering the object is produced by successive solidification of layers of a powder material at points corresponding to a cross-section of said object using radiation for solidifying said powder material. The apparatus includes a support having a substantially plane upper side for supporting the object, a material applying device for applying a layer of the material onto the upper side or onto another layer formed on the upper side, and a solidification device for solidifying a layer of the material by irradiation. The material applying device has a coating device and a drive for displacing the coating device in a direction parallel to the upper side of the support.

Abstract: An article and process for the formation and molding of articles such as gaskets from useful areas of a flat textile panel. This panel is divisible into useful areas possessing textile reinforcement inlay threads in greater thickness and density than in the majority of the areas of the panel remaining outside the useful areas. The textile panel is produced from a ground pattern with the reinforcement threads inlaid thereinto. The useful areas are separated from the textile panel and embedding material is embedded onto the appropriate useful areas corresponding to the articles before or after the separation of the articles.

Abstract: The invention is directed to a warp knitting machine having a weft thread insertion arrangement comprising two parallel transfer devices which carry the weft threads in holders having a predetermined separation from each other and which are driveable in the direction of the needle bed. Also included is a reciprocally moveable weft sled arrangement carrying thread guides to lay mutually crossing layers of diagonal weft threads that subtend mutually opposed angles to the stitch rows. The guides place the threads into the weft thread holders first in one of said transfer devices and then in the other transfer device in exact and predetermined separations. The invention is further directed to a novel fabric having inlaid weft and warp inlay threads.

Abstract: A warp knitted fabric employs a warp knitted pattern as the ground stitches. In this novel fabric there are reinforcing threads of a substantially rigid material. The weft threads may run parallel to each other and are located between the needle loops of stitch rows that follow each other sequentially in the warping direction. Additionally, there are two sets of diagonal threads both of which run alternatively: (a) between two needle loops of neighboring wales and (b) between two needle loops of successive stitch rows. Laid-in warp threads may be provided between needle loops of adjacent wales. There is thus provided a fabric having higher rigidity in all directions.

Abstract: A warp knitting machine using warp and weft threads produces a fabric with a woven appearance on one side. The machine has at least one forward thread system for forming stitches and at least one rearward thread system for forming stitches. This rearward thread system is successively operable to reciprocally form a common stitch with a corresponding pair of the warp threads of the forward thread system. A weft thread magazine can repetitively place weft threads between the forward and rearward thread system. The forward thread system is successively operable to reciprocally lay a portion of each of its warp threads at one of two corresponding, alternate wales over at least one of the weft threads. The rearward thread system is operable to lay its warp threads behind the weft threads.

Abstract: A weft thread magazine operates in a warp knitting machine having a needle bed. This magazine includes a pair of endless transfer chains, each having a plurality of holders for retaining weft threads in parallel and for delivering them to the needle bed. Also included is a thread laying arrangement operable to transversely reciprocate between the transfer chains and to transport weft threads from one chain to the other. The arrangement also includes a carriage having a plurality of thread guides for transferring weft threads around the holders as the thread laying arrangement reverses direction. These thread guides can reciprocate between an operative and inoperative position. In the inoperative position, the thread guides are precluded from transferring thread to the holders. The magazine also includes a control device for moving the thread guides between the operative and inoperative position.

Abstract: A weft thread magazine for a warp knitting machine has two endless transfer chains. The chains have holders for retaining weft threads in parallel and presenting them to a needle bed. Also included is a thread laying arrangement which transports the weft threads from one transfer chain to the other, and which is provided with a comb arrangement. The comb arrangement includes a comb element having at least one combing peg which is introduced between the weft threads proximate to one of the transfer chains and which moves parallel to the weft threads and is removed proximate to the other transfer chain. A carriage has a thread guide for guiding at least one weft thread into a position parallel to a previously laid weft thread. The comb element is carried on the end of the carriage directed toward the needle bed.

Abstract: A process for the manufacture of contoured pile ware on a conventional double needle bar warp knitting machine yields textured pile fabric with an unusual appearance. The pattern is formed of pile threads of different length and in different positions in the pile ribs and are bound together with the base fabric. The ware is formed on a twin bed warp knitting machine and subsequently is cut to form two individual panels.

Abstract: A right-right warp knitting machine capable of providing pile fabrics such as velour includes two needle beds, each needle bed producing one fabric panel, utilizes one guide bar supplying a ground thread and at least a second guide bar for providing a pile thread. The panels may be connected together by a common thread which is cut after the completion of the fabric panels thereby forming two separate independent fabric panels having at least one velour surface.

Abstract: The process for preparing high density pile ware on a warp knitting machine wherein the pile loops formed from at least one thread system are knotted in by the stitches of the ground fabric structure formed from at least one other thread system includes at least one elastic thread. The high density pile ware includes an elastic thread having an elongation of at least fifty percent which may be woven into the ware or be utilized as an inlay, weft or straight inlay thread, thereby retaining the adjacent stitch wales and/or stitch rows in compression.

Abstract: A warp knitting machine having at least two guide bars, a needle bar, and a cooperating driving means utilizes a plurality of slider needles affixed to the needle bar and in combination with a trick plate member disposed between the guide bars in front of the needles is adapted to interact with the fall plate threads and the needles, to provide a trick plate weft thread lay in bound by the ground thread without the fall plate thread forming a stitch.

Abstract: A displacing means is used to move at least one guide bar by at least one needle space in order to remove the loops on a terry cloth towel material such as knitted on a warp knitting machine. The displacing device basically comprises a transfer means for driving a second pattern gear wheel from a conventional first set of gear wheels, a cam follower arrangement operatively associated with the second set of pattern chains; a clutch means actuated by the cam follower mechanism, another cam actuated by the clutch and a cam follower and linkage mechanism associated with the clutch cam for moving the guide bar in the direction of its normal motion by at least one additional needle space. The transfer means comprises first and second coaxially mounted gears which are driven by an idler gear mounted near the periphery of the circumference of the first set of pattern chain wheel.