Abstract: A razor knife has an elongated housing formed of a front housing part and a rear housing part and having a longitudinally extending guide. The rear housing part is backwardly separable from the front housing part and carries a blade holder which has a seat for a razor blade and an actuator button exposed at a slot formed in the front housing part. This holder is displaceable by sliding of the actuator button from a back position with the blade wholly enclosed by the housing into a front position with a portion of the blade projecting forwardly from the housing. A tension spring inside the insert or back housing part continuously urges the holder into the back position. Interengaging formations on the operating button and the housing, however, allow the blade to be held in the outer position so long as a slight inward force is exerted on the slidable actuator button.

Abstract: A method of and an apparatus for controlling the water added to concrete batches wherein for a given concrete recipe and batch size, while mixing same, a series of empirical values of water quantity and consistency of the resulting mix are determined by initially feeding a quantity of water to the batch reduced by an amount equivalent to the moisture content of the aggregates of the batch at maximum intrinsic moisture content and thereafter incrementally adding water while measuring the consistency after each water addition, and these values are stored for the respective recipe and batch size. For the addition of water to a further batch of the recipe, while mixing the further batch, an initial quantity of water is added to the further batch which is not reduced by the quantity of water equivalent to the moisture contents of the aggregates and the consistency of the further batch after the initial addition of water thereto is measured.

Abstract: A device for the groupwise cleaning of filter tubes in a filter assembly in which the tubes are disposed in a plurality of parallel rows with each tube being connected to a rod forming a tube carrier and having a seat upon which a spring bears. The other end of each spring engages an arm of a rocker which acts upon two rows of tubes.

Abstract: The subject invention relates to a straddle cartridge for a straddle cartridge anchor having a central bore which is adjusted to the conicity of the anchor head and wherein the cartridge parts are held together by means of straddle members arranged in succession parallel with respect to the cartridge axis and in direction of the thick ends of the cartridge parts extending outwardly from the outer walls of the cartridge parts.

Abstract: A camera with a focusable objective including an axially shiftable lens member has two ancillary projection systems continuously or intermittently intercepting incident light rays downstream of that lens member and deflecting them onto respective inputs of a photoelectric comparator which emits a coincidence signal whenever these light rays project substantially identical images of an object to be photographed or filmed. One of the projection systems may include a periodically movable element which varies the relative orientation of the two beams constituted by the deflected light rays so that different angles of incidence give rise to a coincidence signal in different parts of a sweep cycle; in one position of this element, in which the incident rays will have a predetermined orientation (e.g. parallel to the objective axis) with proper focusing, a position sensor generates a correlation signal.

Abstract: A shear or like scissor-type tool, especially an electric cable cutter, having two blades at least one of which is movable and a pivot about which this blade moves in a scissor-type action. The device is provided with a mechanism for increasing the pressing force at the blade pivot in response to the instantaneous cutting resistance with this pressing force on the blades being relieved upon or prior to opening of the cutter.

Abstract: A blind riveter has a T-shaped housing whose one T-arm forms a working tip provided with a reciprocal internal chuck, whose other arm is formed as a hollow compartment, and whose central T-leg incorporates a pneumatic cylinder. The cylinder can displace the chuck to pull the mandrel of a blind rivet, thereby pulling the rivet back against the tip to upset the rivet. A passage extends from the chuck back into the compartment. The cover of the compartment is formed with a jet pump that is powered off the pneumatic supply that operates the riveter and serves to suck a mandrel pulled from a rivet back from the chuck into the compartment.

Abstract: A speaker enclosure with a multiplicity of sound-openings in which the back sound pressure from a plurality of front radiating speaker-units mounted in a vertical row on a baffle board, is completely divided at the back of the speaker-units by a centrally located dividing board. Reflecting boards at the corners of the sound paths and left and right sound pressure guide boards fixed to the edges of the baffle board effectively guide the back sound pressure through left and right front openings formed between the guide boards and the sides of the enclosure. The front openings are adjusted by hinged volume and tone control boards to effectively combine the sound pressure radiated from the front-side of the speaker-units with that from the back-side.

Abstract: A process for the treatment of an aluminum-salt slag produced in the remelting of aluminum by the addition of salt to aluminum scrap wherein the aluminum salt slag is subjected to pressure and impact rolling to a thickness of about 0.2 mm to about 1 mm and the product is milled to an X.sub.80 value of about 130 to 150 microns. The milled product is classified in a plurality of stages to recover therefrom a large-particle fraction consisting at least predominantly of aluminum particles, and a fine-particle fraction. The fine-particle fraction is subjected to flotation in at least one flotation stage to which a base is added in an amount of 0.04 to 0.4 g of the base per ton of the material subjected to flotation to bring the pH to between 10 and 11, whereupon a cation active collector of the formula RO--(CH.sub.2).sub.n --NH--(CH.sub.2).sub.n --NH.sub.2 is added to recover an impurity-containing froth of low chloride level and a concentrate containing most of the chlorides of said slag.

Abstract: A gyrocompass with a tilt ring pivotable about a substantially horizontal axis has a U-frame swingable about that axis which forms part of a pendular system and carries a coupling lever engageable with projections on the lower end of the U-frame to immobilize the latter with respect to the tilt ring when the instrument is inactive, in order to hold a gyroscope axis perpendicular to the tilt-ring axis in a horizontal position. An antipendular system, comprising a liquid-filled U-tube swingable about the gyroscope axis, is overridden by the pendular system in the engaged position of the coupling lever but becomes effective upon disengagement thereof to let the gyroscope mechanism carry out necessary precession movements.

Abstract: A mold has at least two primary mold parts movable in a primary direction away from each other from a closed position defining a mold cavity to an open position, and at least one secondary mold part which may be a core pin or a stripper which is movable in the secondary direction transverse to the primary direction relative to at least one of the primary mold parts. An actuator has a primary rack extending parallel to the primary direction and a secondary rack extending parallel to the secondary direction and secured to the secondary mold part. These racks have respective primary and secondary rows of teeth having substantially parallel tooth flanks inclined to the respective directions, the primary row meshing with the secondary row.

Abstract: A belt-advance system for a belt-fed gas-loading automatic weapon, e.g. a machine gun, revises the usual energy flow path by obtaining at its input side a gas-pressure pulse upon the firing of the weapon and providing an energy-storage unit functionally combined with a cylinder/gas-piston unit for transforming the pneumatic energy into mechanical energy for stepping the belt-advance ratchet pawl.

Abstract: A fluid-level detector comprises a container, here a brake-fluid reservoir for an automotive vehicle, adapted to hold a supply of a fluid and containing a float connected via a link arm to a permanent magnet for displacement of the magnet vertically through a predetermined magnet position on vertical displacement of the float through a predetermined float position corresponding to a fluid level at which a signal is to be given. A pair of contacts outside the container can be engaged by a switch element which is displaceable toggle-fashion by the magnet between a closed position engaging and forming a closed circuit with the contacts and an open position out of engagement with at least one of the contacts.

Abstract: A rail-mounting assembly in which a rigid member supporting the rail is received with clearance in an opening of an overlying rigid body. The clearance has downwardly and inwardly inclined flanks which bear upon a rubber-metal support damping sound, shock and vibration.

Abstract: A detector responsive to an angular offset between a gyrosphere of a gyrocompass and a tilt ring, forming part of a gimbal mounting therefor, controls a follower motor coupled through a reduction gearing with a suspension shaft for that mounting, the shaft being further coupled with a first synchro transmitter. A second synchro transmitter, electrically connected to several synchro receivers forming part of respective repeaters, is driven by a servomotor through a reduction gearing of step-down ratio 1:3 and is mechanically linked with a third synchro transmitter through a reduction gearing of step-down ratio 1:360, the third synchro transmitter being electrically connected to the first synchro transmitter for producing an error signal delivered through a feedback loop to the servomotor for keeping same slaved to the suspension shaft.

Abstract: An objective of the pancratic type includes a varifocal front lens group and a fixed-focus rear lens group, the latter consisting of five air-spaced singlets. The front lens group is constituted by a positive first component consisting of three singlets, an axially shiftable negative second component consisting of a singlet and a doublet, and an axially shiftable positive third component in the form of a nearly planoconvex singlet of low power.

Abstract: A step-down transmission for driving a plurality of extrusion screws from a common power source comprises a main shaft, directly connected with one screw and coupled with the source via a reduction gearing, and one or more pairs of corotating ancillary shafts coupled with the main shaft via gear trains each including a cylindrical gear in mesh with two spur gears respectively keyed to the shafts of the corresponding pair. The paired ancillary shafts carry helical gears in mesh with a common pinion on a shaft of another screw closely adjoining and possibly intermeshing with the first-mentioned screw.

Abstract: A device for mixing flowable materials, especially relatively viscous liquids and flowable solids, comprises a pipe or tube section, preferably of circular cross section, provided internally with at least one mixing element helically twisted in a uniform manner about the axis of the pipe and formed with only two groups of surface regions which are folded relative to one another and which alternate along the mixing element. Each of these surface regions is of flat triangular outline with a base of the triangle formed along one of the helically twisted longitudinal edges of the mixing element and converging toward the other. The flat surface regions may be truncated, i.e. of generally trapezoidal outline with their narrow triangle side lying along the opposite edge of the mixing element from that occupied by the base, or of a pointed configuration where the triangle apex lies along this opposite side of the mixing element.

Abstract: A cine camera for taking talking pictures, in which a film is moved intermittently past an image gate by a reciprocating traction claw and continuously past a recording head by a rotating capstan coacting with a pinch roller, includes a latch by which the pinch roller can be held spaced from the capstan in an inactive position. The latching of the pinch roller in this inactive position, against the force of a biasing spring providing the necessary contact pressure during filming, is accomplished upon deactivation of the film drive by the residual kinetic energy of an inertial mass such as a flywheel which is coupled with either the capstan drive or the claw drive. The latch is released upon actuation of a trigger, either directly or through the intermediary of the claw drive. The biasing spring may be part of a toggle mechanism tripped by a presetting member, such as a sensor detecting the presence of a sound-film cassette in the camera.