Abstract: Prefabricated element arranged on a single wall of a room for forming a double sound insulating and sound absorbing wall. The prefabricated element provides efficient sound insulation of the room and a total sound absorption of sound waves whose frequency is centered at one of the natural frequencies of the room. The element comprises a frame supporting a flexible panel by means of elastic sealing means, the flexible panel being maintained at a predetermined distance from the single wall due to the thickness of said frame whereby the resonant frequency of the double wall becomes equal to a natural resonant frequency of the room corresponding to sound waves propagating perpendicularly to the single wall. In addition, the prefabricated element may also comprise an additional element placed in the middle of the panel which permits equalization of the natural resonant frequency of the assembly comprising the flexible panel and the additional element to the low natural frequency of the room.

Abstract: An equipment for measuring length or refractive index of a dielectric element capable of transmitting optical frequency signals, for instance an optical wave guide. The used method consists in making at least one measurement of the propagation time of a light impulse over a length of the said element, and deducing therefrom the unknown length or index, if one of the latter is previously known. The equipment includes an injector of light signals, a separator dividing each light pulse signal into a delayed and a non-delayed one respectively transmitted through a first and a second path one of which contains the dielectric element to be measured and the other of which is used as a comparison one, a detector at the output of each of said paths, and a viewing element displaying the outputs of both detectors on a common screen, for instance that of an oscilloscope whereby the propagation time difference between said paths is translated into the spacing between the said outputs observed on said screen.

Abstract: An auxiliary device for boring dowel holes in boards which are to be doweled together comprising a flat plate provided with a handle and having a centrally located guiding hole for guiding a boring tool, such as a drill, through the plate. Vertically projecting pegs are provided on each side of the flat plate to diametrically oppose the boring hole at equal distances therefrom, each peg being at the same height. One side of the flat plate is provided with a longitudinal slit in alignment directed radially toward the centrally located guiding hole. The narrow side of the board is placed at the rear of the flat plate with the pegs projecting downwardly to move the board between the pegs whereby the centrally located guiding hole is aligned at the center of the board in order that a dowel hole may be bored at the desired first location.

Abstract: Mode converter for electromagnetic, light or infrared waves. This mode converter converts particle non-confining modes to particle confining modes. In a confining mode wave beam the phase of the wave with respect to time at a point of the beam having a given azimuth with respect to the beam axis is proportional to this azimuth. Two types of mode converter are disclosed. In the first type, the wave passes through a block of transparent isotropic material the thickness of which is proportional to the azimuth around the beam axis. In the second type, the converter is formed with triangular or sectoral plates of birefringent material and in each plate the slow and fast axes are given an adequate orientation.

Abstract: A method for on-site connection of two transmission cables comprising optical fibres, each cable having a protective armouring enclosing a central core provided with regularly spaced grooves on its periphery. Each groove holds a fibre provided with a thin sheath of uniform thickness. After the end of one of the cables has been bared over a given length, the uncovered fibres are moved towards the exterior and secured to a holder surrounding the cable. Thereafter the core is cut perpendicularly to its axis and a grooved portion of an extension core is secured thereto; the fibres are bent back into the grooves in the said portion, and the core portion and the fibres which it bears are cut and subsequently coated with a lubricant. The same operations are performed on the end of the other cable and the two cables are clamped together under a predetermined pressure.Various devices for the embodiment of the method are described.

Abstract: The invention relates to a movable apparatus for removal of filter plates from a filter press, these plates resting on two horizontal guide carriers. The apparatus has a carriage, movable on the guide carriers, which has a driving apparatus for a driver means, in order to always pull off the outside filter plate from a pack of filter plates, and a bolt for holding back the remaining filter plates in the pack. The driver means and bolt are arranged in such manner that the driver means and bolt are movable up and down between a lower engaging position aligned with stops on the sides of the filter plates and an upper dis-engaging position away from such stops.

Abstract: The invention relates to a filter press construction of the type having a plurality of filter plates suspended from two parallel I beam carriers, the filter plates being provided with a novel supporting arm suspension which prevents undesired swinging. The supporting arms are bent to diverge on both front and back sides of the filter plates, two arms on each side of the vertical center of the plate to provide a novel suspension consisting of two leading bent arms and two lagging bent arms for each filter plate in its operating condition suspended for movement on the I beam carrier. The arms of the filter plates are provided with roller or equivalent sliding elements to facilitate shifting movement on the guiding flange surface of the parallel I beam carriers. This unique leading and lagging supporting arm construction on the I beam carrier eliminates serious swinging problems encountered with conventional filter presses using the parallel I beam carrier suspension for the filter plates.

Abstract: A mobile storage and transport rectangular roller unit with a roller and drawbar device for use in a shelf storage system. Each unit is provided with four wheels, one adjacent each corner in a four sided frame. The roller bar is provided with pair of rollers and cooperates with a coupling member of substantially cubic shape which is pivotally mounted on the drawbar. Two transverse cross members are at the front and back of the frame and lie opposite to each other, each formed by an inverted U-section having limbs of unequal length. The coupling member is provided with a top groove to receive the shorter limb of the inverted U-section and is thereby coupled at the shorter limb of the cross member to the four sided frame.

Abstract: A digital switching unit is used in a multirate time-division multiplex digital switching network, in which first-order digital data channels transmitting words consisting of a given number of bits and having first rates which are different from, but multiple of, one another are given a first multiplexing converting them into the second-order digital data channels having a second predetermined rate. The switching unit comprises at least one buffer store in which the first-order channel words multiplexed into third-order channels are grouped at an address having first and second part, whose first part is the address of the second-order channel containing the first-order channel word in the third-order channel and whose second part is the address of the first-order channel in the second-order channel.

Abstract: An auxiliary device for facilitating re-grinding and sharpening of spiral drills used by a home or do-it-yourself amateur in conjunction with a conventional grinding machine mounted on a table and having a rotating grinding wheel or disk exposed on a horizontal shaft. The device comprises a fork-shaped bracket including means for clamping to the table. Grooves are provided in the upper surfaces of the forks for bearings which rest in these grooves and are aligned thereby. The device includes a swiveling part which is loosely held into the grooves to accomodate the drill workpiece which is to be reground. Axle journal members in the bearings provide the swiveling movement of the workpiece.The swiveling part is provided with a groove between the axle journal members into which the workpiece is inserted and this groove has a clearance below the axis of the axle journals and is directed slantingly toward the grinding surface or path of the grinding disc thereby providing the desired re-grinding angle.

Abstract: A single stage or multi-stage coal washing plant comprises a plurality of bunched cyclones supplied with raw crushed coal water slurry at high solids content and high velocity common from a tank through a distributor line that contains an equalizer for supplying equal quantities of solids to each cyclone through an inlet pipe having a critically dimensioned deflector that assists in maintaining streamlined laminar flow. A dewatering screen is used in combination with a centrifugal drier; the water separated from the refuse and clean coal is recycled to a silt pond. A make up water reservoir receives the overflowing water from the silt pond and a caustic soda tank supplies sodium hydroxide between the pump and the reservoir to neutralize acidity during continuous operation.

Abstract: A telephone amplifier and attenuator circuit comprising an amplifier and an attenuator inserted in the transmit channel and an attenuator inserted in the receive channel of a telephone set. The speech signals conveyed by the transmit and receive channels are detected and added together for forming a sum control signal. The transmit amplifier is controlled by the detected transmit signal and the two attenuators are controlled in opposite directions by the sum control signal. In the preferred embodiment, the amplifier and attenuators are formed respectively by a balanced modulator and by balanced modulators inserted in the loop of negative feed back amplifiers.

Abstract: System for optically aiming a laser beam on to a target. The system comprises a mirror which reflects the laser beam towards the target and which is supported by a base by means of a pivot and first and second vibrating control members. This pivot and the control members together determine a first mirror rotation axis and a second mirror rotation axis perpendicular to the first axis. Means are provided for respectively generating a first and a second reference signals for driving the mirror. A laser radiation detector receives the laser radiation reflected by the target and produces a reception signal from which are derived first and second reaiming signal components. The first and second vibrating control members are operated by respectively the sum of the first reference signal and the first reaiming signal component and the sum of the second reference signal and the second reaiming signal component.

Abstract: Device for providing the end portions of the fibers of a flat optical fiber ribbon with connectors. It comprises an elongated connector having two adjacent inner surfaces defining a re-entrant orthogonal connector dihedron and two adjacent outer surfaces defining a projecting orthogonal connector dihedron and a third surface formed with at least a longitudinal groove, and a template having a first and a second adjacent surfaces defining a re-entrant orthogonal template dihedron. At least two members transverse to the template bear a first groove for receiving the sheathed part of the optical fiber and a second groove aligned with the first groove for receiving the stripped part of the fiber. The projecting connector dihedron is applied against the re-entrant template dihedron and the fiber is guided in the grooves on each side of its path along the connector groove, whereby it can be bonded to the connector in predefined position.

Abstract: Digital transmission system providing multipoint connections in which a main data transceiver can communicate with a plurality of secondary data transceivers and the secondary data transceivers can each, in turn, communicate with the main data transceiver, transmission occurring via component digital words at certain low rates multiplexed into intermediate rate incoming digital channels which are themselves multiplexed into a high rate incoming highway. The words are given a first partial address in the low to intermediate rate multiplexing step and a second partial address in the intermediate to high rate multiplexing step. A digital switching network is provided for selectively switching the component words from the high rate incoming highway to word positions in a high rate outgoing highway according to their first and second partial addresses. A multipoint unit is connected to the switching network by intermediate rate incoming and outgoing digital channels and the high rate highway.

Abstract: The invention relates to a process for the manufacture of a generally flat triangularly shaped metal deflector for installation to the interior non-tangential surface of an inlet pipe to the bowl of a centrifugal separating cyclone. The deflector constricts the inlet cross section to the bowl by about 19% to about 32%. The process comprises the steps of selecting a pipe section of the same size as the inlet pipe and marking the chord ends at the center angle between 118.degree. and 149.degree., preferably close to 120.degree.

Abstract: A sink-float method and apparatus for testing and separating a mineral such as coal in mineral products containing inert matter which employs a novel trapezoidally shaped testing tank, a mixture of perchloroethylene as a parting liquid and white gasoline as a dispersant and surfactant, and an implement in the form of a long stirring rod angulated at its end. The tank is provided with bars at the bottom to limit the movement of the implement. The invention provides a quick and precise test for specific gravity of raw crushed coal and its impurities.

Abstract: A soft, chewable lozenge delivering to the mouth a solid unit package comprising a fluoride ion source, a starch adhesive, a polishing agent, a non-cariogenic sweetener in a minimum amount of water for solution such as xylitol or a non-cariogenic sweetener without water such as lycasin, a flavoring agent, if desired, and a combined viscosity builder/softening agent such as vegetable oil, all of which interact with saliva on chewing to coat the surfaces of the teeth, particularly interproximal surfaces, with a sticky mass removable only by brushing with a toothbrush. Chewing of this lozenge aids in incorporating the sticky mass in lingual interdental areas frequently not touched by brushing, especially when one is in a hurry, thereby assuring extra care in brushing to remove. Thus, brushing habits are improved for both adults and children. The unit package of saliva saturated paste thus applied by the lozenge insures adequate dosing for cleaning.

Abstract: A unitary package for water treatment for attachment to a home hot water heater which is adapted to be easily serviced and readily monitored by the homeowner. The water treatment device is an electrical machine especially adapted for separating magnetic particles in feed water pipes to home hot water heaters and the like. The electrical parts for operating the machine comprise a transformer fitted with a safety fuse in the primary winding thereof which steps down incoming household line voltage from 110-125 volts AC to about 24.+-. 4 volts DC in the secondary winding. The secondary winding provides a constant DC voltage to an electromagnetic coil surrounding the inlet pipe. The inside of the inlet pipe is fitted with a special spiral band impeller or a solid helical impeller which rotates only when the water flows.

Abstract: Apparatus for use in settling or separating finely divided solids, i.e., minerals, from a liquid such as water in which they are suspended. A plurality of settling tanks is provided, each of which is flow connected in series at about the mid-level, which receives processed supernatant fluid in stages. The mineral content of the water in each tank tends to settle by gravity toward the bottom of each tank and is extracted from each tank by extractor pumps. The initial high mineral water is pumped into the first stage tank and is pre-treated by an electromagnet unit surrounding a pipe which contains a helical screw impeller, and each of the succeeding tanks is provided with a pump at about the mid-level and is similarly pre-treated by a similar electromagnetic field and screw impeller in the flow line.