Abstract: Apparatus and method for stuffer box crimping yarn is disclosed in which continuous filament yarn having a thermoplastic component and varying in denier along its length is substantially uniformly drawn and then treated in the same crimping area and where that portion of the yarn of higher denier is texturized to a lesser extent than that portion of the yarn of lower denier. The apparatus for carrying out the method provides a crimp site and a very short plug guiding area which establishes the lateral width of the plug. A pair of pressure shoes are oppositely disposed on either side of the plug of crimped yarn as it leaves the guiding area.

Abstract: Apparatus for compression crimping fibrous material, such as synthetic continuous filament yarn, is provided comprising means defining a compression crimping zone, means for feeding fibrous material into the compression crimping zone and a pair of movable members each having a face substantially opposed to a face of the other, said faces defining lateral walls of the zone and being biased toward each other to restrict egress of the fibrous material from the zone and thereby exert a back pressure on the fibrous material, causing the fibrous material to buckle, form a plug in the zone and thereby crimp in the zone, the aforementioned face of each of the members being laterally restricted by means rigidly connected to the member whereby the plug is prevented from escaping laterally from between the substantially opposed faces of the members.

Abstract: In apparatus for compression crimping fibrous material, such as yarn, comprising a chamber for receiving the yarn from a pair of feed rollers and in which chamber the yarn is compressed, the chamber having corners intercepted by the periphery of the rollers adjacent the sides; there are provided guiding ramps adjacent the nip of the rollers to keep the yarn away from the corners as the yarn advances from the rollers into the chamber.

Abstract: Apparatus for compression crimping is provided comprising means defining a compression crimping zone, means for feeding fibrous material into and means for withdrawing crimped fibrous material from the compression crimping zone, at least one movable member defining a lateral wall of the zone and being biased toward the fibrous material to restrict egress of the fibrous material from the zone and thereby exert a back pressure on the fibrous material, causing the fibrous material to buckle and thereby crimp in the zone, control means for acting on at least one of the fibrous material feeding means and fibrous material withdrawing means, preferably for deactuating both, in response to displacement beyond a predetermined extent of the movable member in a direction opposite to the direction in which the movable member is biased, and means for sensing the presence of the plug at a predetermined position in the zone and for regulating at least one of the fibrous material feeding means and fibrous material withdrawal

Abstract: A thyristor is provided with a low forward voltage drop (V.sub.f) while providing a typical gate current to trigger (I.sub.g). The working point in the cathode-base region of the thyristor has an impurity concentration less than 5 .times. 10.sup.15 and preferably less than 1 .times. 10.sup.15 per cm.sup.3. The gating portion of the device is selectively irradiated, preferably with electron radiation, to maintain the gate current. The forward blocking voltage (V.sub.BO) and rate of rise of application of forward voltage (dV/dt) of the thyristor may also be maintained at typical values by a fine shunt pattern and/or doping of the shunt portions.

Abstract: A liquid finish composition is applied to a plurality of continuous thermoplastic polymer filaments in such a way that the composition is applied to all the filaments uniformly from filament to filament. More particularly, the filaments are arranged side-by-side in a substantially planar array, at a first location one face of the array is contacted with the liquid finish composition and, then, at a second location spaced apart from the first location the other face of the array is contacted with the same composition. During the contacting at the first and second locations the tension is controlled so that it is in a range in which the contacting applies the composition to the filaments uniformly from filament to filament.

Abstract: A method is provided for making a light activated semiconductor controlled rectifier in a semiconductor body having opposed first and second major surfaces. Impurities are sequentially provided in the major surfaces to form four regions of alternate type conductivity disposed alternatively through the body between the major surfaces, with a PN junction between each region. An etchant solution is prepared preferably substantially equal amounts of chromium trioxide and water, and adding to said first solution just prior to use a given, preferably about 50% hydrofluoric acid solution in predetermined amounts preferably of substantially one part for each two parts of the first solution.

Abstract: A thyristor is provided with a low forward voltage drop (V.sub.f) while providing a typical gate current to trigger (I.sub.g). The working point in the cathode-base region of the thyristor has an impurity concentration less than 5 .times. 10.sup.15 and preferably less than 1 .times. 10.sup.15 per cm.sup.3. The gating portion of the device is selectively irradiated, preferably with electron radiation, to maintain the gate current. The forward blocking voltage (V.sub.BO) and rate of rise of application of forward voltage (dV/dt) of the thyristor may also be maintained at typical values by a fine shunt pattern and/or doping of the shunt portions.

Abstract: Apparatus and method for stuffer box crimping yarn is disclosed in which continuous filament drawn yarn having a thermoplastic component and varying in denier along its length is treated in the same crimping area and where that portion of the yarn of higher denier is texturized to a lesser extent than that portion of the yarn of lower denier. The apparatus for carrying out the method provides a crimp site and a very short plug guiding area which establishes the lateral width of the plug. A pair of pressure shoes are oppositely disposed on either side of the plug of crimped yarn as it leaves the guiding area.