Abstract: A preheater for a casting ladle includes a stationary horizontal refractory deck having vertical apertures in which are disposed refractory plugs, each of which supports an electrical heating element that depends downwardly from the refractory deck. A lifting table is movable into registration with the set of depending electrical heating elements and is also adapted to support the casting ladle thereon and to raise it into surrounding relation with the electric heating elements that depend from the refractory deck. Individual defective heating elements can be removed and replaced during operation of other operative heating elements.

Abstract: An annealing oven for wire and the like includes a tubular elongated heater made of electrical resistance alloy material. The wire passing therethrough is so guided that it remains at all times out of contact with the heater and no current passes through the wire. Relatively movable sections of heat-insulating material laterally jacket the tube to facilitate threading a wire through a slot in the tube and so as to facilitate rigid heating with a minimum of heat loss, so as to adjust heat loss as a part of temperature control, and so as to effect rapid cooling of the tube. The sections are arranged in pairs, and a pair of such sections has a lesser insulating capacity than the preceding section, taken in the direction of wire movement. The device is compact and takes a minimum of space adjacent to any material processing machine.

Abstract: A silicon carbide body wherein the silicon carbide forms a skeleton which is pore free in itself, occupies at least 70 percent by volume of the body volume and has the intercommunicating cavities thereof filled entirely by an almost porefree molybdenum disilicide alloy.

Abstract: A process of zinc coating fasteners such as screws and nuts, wherein the fastener is first provided with a zinc coat by hot coating, which coat is then equalized chemically, whereafter there is applied a superficial zinc coat by electrocoating. If desired, the fastener may then be chromated.

Abstract: An electrical resistance element with electrode portions comprising a thin resistance wire of a heat resistant material, such as molybdenum disilicide, MoSi.sub.2, which resistance wire has at least one end electrode of aluminium, having a much greater cross-sectional area than that of the resistance wire, wherein the end portion of the resistance wire is fused into the end portion of the respective electrode portion.Also disclosed is a method of connecting an electrode portion to one end of the resistance wire in an electrical resistance element by placing the end portion of the electrode within a surrounding sleeve, heating the sleeve with the electrode end therein to cause the outermost end portion of the electrode end to form a melt, introducing the resistance wire end into the melt and permitting the melt to solidify and finally removing the electrode and resistance wire connected thereto from the sleeve.

Abstract: A screw package comprising a carrier strip through which the screws extend transversely with the essentially flat under surface of the screw heads resting against the upper surface of the strip. The strip has holes the diameter of which is closely related to the shank diameter of the screws. Around each hole there extend arcuate slots, between the ends of which comparatively weak webs have been left, or deep weakening lines, in such a manner that, as a screw is driven in, a washer consisting of the carrier strip material will be separated from the carrier strip to be clamped between the under surface of the screw head and the work piece wherein the screw is applied.

Abstract: A fastener package comprising a carrier tape having at equally spaced intervals throughgoing holes in each of which there is received from one side of the tape a screw with a head and a threaded shank, with the under side of the screw head resting against said one side of the tape. The holes are so designed and dimensioned in relation to the dimensions of the screw shanks that, on introduction of the screw shanks into the holes, the tape edges around the holes are deformed into lips which retainingly engage with the screw threads. Radial slots may facilitate the development of the retaining lips, and the slots may be long enough to permit deflection of the lips to let through the screw heads. Adjacent longitudinal slots may be so closely spaced that the tape is split up in two tape portions as the screws are driven home, through the tape.

Abstract: A heat resistant material comprising a recrystallized (self bound) skeleton of silicon carbide the pores of which are filled by infiltration of a heat resistant infiltration material, such as a silicon-molybdenum disilicide composition, so that the porosity is less than 5 % and preferably less than 2 %, the composition of the final material being such that the bending strength thereof at room temperature is at least 5 kp/mm.sup.2, and preferably above 10 kg/mm.sup.2, such as of the order of 20 kp/mm.sup.2.

Abstract: A screw tightening apparatus comprising a motor-driven tool, a screw magazine for screws affixed to a strip-like carrier, and a screw advancing and tightening means for advancing the screws one at a time to a preparatory screw tightening position in which a bit portion of the motor-driven tool may engage with the screw for tightening thereof. The screw advancing and tightening means comprises two axially movable portions, one of which is secured to the tool and the other one of which carries the screw magazine and a spring biased screw advancing mechanism. A push and pull member on the stationary portion is adapted to cooperate with a dog means on the spring biased screw advancing mechanism for advancement of a new screw at the end of the retractive movement of the movable parts into a rest position, subsequent to a completed driving home of a screw.

Abstract: An internal spline drive formation for screws is provided wherein the spline drive formation comprises a plurality of circumferentially alternating equiangularly spaced grooves and splines, said splines being defined in part by part-cylindrical surfaces and said grooves being defined in part by surfaces which, when viewed in plan, are arcuate to form a parabola-like line in that the radius of curvature is very small at the regions of intersection between the spline side surfaces and the groove bottom and increases gradually towards the center line of the groove bottoms.Also disclosed is a screw driving tool the bit end of which comprises an external spline drive formation having a surface which, when viewed in plan, comprises an outer cylinder having sunk therein a plurality of equiangularly spaced grooves, defined in part by re-entrant part-cylindrical surfaces, the regions of intersection between said grooves and said outer cylinder being sharp as contrasted to curved.

Abstract: The wrenching portion of a nut or a bolt head is provided with a configuration which, when viewed in plan, comprises an outer cylinder having a plurality of grooves defined in part by re-entrant concave surfaces and equiangularly spaced about its periphery, the regions of intersection of the grooves with the outer cylinder being planar. The grooves may be altogether part-cylindrical in cross section, or may they have a part-cylindrical bottom surface which merges with two planar inclined side surfaces.Also disclosed is a matrix or die for use in manufacture of nuts or bolts having a splined wrenching portion, said matrix or die having a die cavity adapted to form the regions of intersection of the grooves with the outer cylinder as planar surfaces.

Abstract: A bundle of fasteners, such as screws, are held in parallel relation between two strips. One of the strips is substantially planar and the second strip is connected against the planar strip so as to partially encase the individual fasteners therebetween. The second strip is formed of an elastic material capable of stretching to the configuration of the individual fasteners. The package retains the accuracy of positioning of the individual fasteners. A layer of plastic material makes the bundle moisture resistant and avoids leaving any residue from the strips on the work.