Abstract: A process is described for the controlled oxidation roasting of zinc bearing sulphidic ores and concentrates by adjusting the furnace temperature and residence time together with the oxygen availability to the sulphide retention requirements in the calcine. The obtained calcine is subsequently subjected to various physical and chemical process steps to separate the unreacted sulphides which are then dead roasted and treated for zinc recovery, according to one embodiment of the process. In another embodiment the separated, unreacted sulphides are returned to the controlled oxidation roasting step.The chemical separation process steps include sulphur dioxide leaching. In one embodiment zinc is preferentially dissolved as sulphite and the solution obtained is further treated for zinc recovery. In other embodiments sulphuric acid, or ammonical ammonium carbonate or similar leaching reagents are used for the preferential dissolution of the zinc oxide present in the calcine.

Abstract: A device for holding planar implements, for example knives, has a body. The body has a portion extending horizontally outwardly from it, and defining a number of vertical slots. For each slot, there is a number of gripping elements, and a spring urging the grippinig elements into the slot, for grasping a planar implement or knife. Each gripping element can be generally channel-shaped and include flanges projecting through openings of a side wall of a slot. The body can be shaped to include an intermediate part spaced rearwardly from the portion and a lower, forwardly projecting lip. This ensures that handles of knives or other gripping elements are spaced from the intermediate part, to enable them to be readily grasped. The gripping elements define a tapered entry zone, so that a knife can be inserted simply by pushing it into a slot.

Abstract: This invention relates to a vertically drawn shower curtain having a raised position and a lowered position and being movable therebetween, for preventing water from escaping from a shower enclosure. The shower curtain is composed of waterproof panels, flexible hanging straps, clamps, and drawstrings. In the lowered position, the hanging straps support the panels in an inwardly overlapping relationship. The hanging straps are attached to the upper edge of each panel, leaving the lower edge free to rotate inwardly. The hanging straps have guides for the drawstrings. The drawstrings are attached to the lowest panel, are lead through the guides, and then through an eyelet on the clamp. All drawstrings terminate in a single pull ring. In the raised position, the panels are supported in a substantially nested relationship, by the combination of the drawstrings and clamps. The shower curtain may also include a valence panel, supported by the clamps, to hide the workings of the drawstrings and the clamps.

Abstract: A process for electroplating metals in an electroplating bath having an anode and a cathode. The cathode is formed by a workpiece to be plated and the anode includes soluble material in the form of the metal to be plated and insoluble material in a proportion selected so that the anode efficiency equals the cathode efficiency. This avoids metal salt build-up in the bath. Metal salt solution carried out of the bath with the workpiece is recovered and recycled to the bath, avoiding loss of metal to the system and waste disposal problems.

Abstract: A grass collection system for a reel mower in which an auger extends across each reel. The part of the auger not facing the reel is enclosed by a shield, so the auger conveys cut grass laterally to one end of the mower, from which end the cut grass is conveyed through an air duct and impeller to a hopper. Where the duct connects to the auger shield, an extra opening is provided to entrain outside air, to maintain the flow of air past the auger shield outlet and thus reduce the likelihood of clogging.

Abstract: A rack for storing lids has a base and a plurality of support members extending from the base. The base is intended for mounting on a vertical surface with the support members extending outwardly and upwardly. The support members are arranged in pairs, for locating and holding lids. Each support member has a ledge portion and a support arm extending upwardly. The ledge portions of each pair have inclined support surfaces which are inclinded downwardly towards one another, to center a lid.

Abstract: A panel and frame mounting system for electrical lighting fixtures. The system has a number of individual panels each of shallow box shape. Some panels have unbroken front surfaces and serve as filler panels. Other panels have rearwardly dished compartments which, together with the fixture bases, form enclosed metal electrical boxes to house connectors to the fixtures. The panels slide into a frame having rear hooks. The rear hooks suspend the frame on a mounting bar having brackets at its ends to fit into standard slotted tracks mounted on a wall. The frame can carry a power bar into which fixtures on the frame can be plugged.

Abstract: A process is described for the mineral separation of rare earth metal compounds, such as bastnaesite, contained in oxidic minerals. The process is a froth flotation process utilizing a novel collector emulsion, which is an emulsified mixture of:a secondary amine modified sulphonated fatty acid,a high rosin containing tall oil fatty acid,an anionic petroleum sulphonate, anda high molecular weight primary amine.The collector emulsion mixture is added to the aqueous slurry of the comminuted rare earth metal compound containing oxidic mineral, which has been previously conditioned in a conventional manner. The conditioning reagents may include alkaline pH modifiers and gangue depressants such as citric acid, oxalic acid, sodium silicates and fatty acids.The rare earth metal compounds will be concentrated in the froth, and are separated in the conventional manner.

Abstract: A machine tool includes a carrier supporting a plurality of rotary spindles each carrying a chuck for holding a workpiece and each having an individual drive motor. The carrier can be indexed to move the spindles between different stations, while the drive motors remain stationary. Clutches are provided to couple each drive motor to a spindle to be driven. The carrier includes a central shaft supported at its ends on bearings and spindles are coupled to the shaft by supports. Each spindle may be provided with a friction clutch and a tooth clutch for coupling the spindle to the drive motor. The chuck is actuated by a hydraulic piston and cylinder which may be internal to the spindle. Alternatively, the cylinder may be formed by a stationary housing around the spindle containing an annular piston. A shuttle assemble capable of providing a mechanical advantage may be provided for transmitting motion of the piston to the chuck.

Abstract: This invention relates to a modular float, which is in the form of an integral, closed shell, hollow float that is light weight portable and easy to use. It is intended to support marine devices such as docks, rafts and the like. The modular float has two side walls, two end walls extending between the side walls, and a generally rounded lower portion and generally rectangular upper portion, both when viewed from one side. The upper portion has a number of intersecting grooves, which are designed to carry standard sized support members, which in turn carry a deck. The grooves have resilient ridges for releasably engaging the support members.

Abstract: A portable toilet of the type having a waste holding tank which is separable from a bowl unit of the toilet. The tank includes a vent for permitting entry of air to the holding tank during emptying thereof. This avoids surging of the contents of the tank during emptying, assuring a smooth flow of the liquid and minimizing splashing. In a preferred embodiment, the vent takes the form of a sleeve projecting upwardly from the holding tank and defining a vent passageway, and a cap on the sleeve which can be manually raised to open the vent passageway but which is automatically depressed to close the vent when the bowl unit is secured to the holding tank.

Abstract: An apparatus for dyeing leather has an application roller and a backup device defining a gap therebetween. The application roller has recesses, and dye is supplied to it to fill the recesses. Sheet articles, e.g. leather pieces, are fed through the gap. The apparatus is operated so that a uniform coating of dye is continuously spread over one surface of the article by the application roller. The dye can have a low viscosity comparable to that of water.

Abstract: A fire damper having a temperature-sensitive link assembly designed to permit ease of maintenance of the damper. In one embodiment, the link assembly includes a fusible link that extends across and holds the blades folded. At each end, the link is coupled to a bracket embracing the blades by a pivot pin and an associated latch that is manually releaseable. During maintenance of the damper, either latch can be released and the link will then swing down about the pivot pin at the opposite end of the link, permitting the damper blades to close. In normal use, the blades will also close in response to an over-temperature condition causing the fusible link to break. In an alternative embodiment, a plain non-fusible link is used and one of the latches is released by a temperature-sensitive actuator made of memory metal.

Abstract: An artificial disc for a human spine. The disc has upper and lower members hinged together at their rear portions and biased apart at their fronts by stiff coil springs. Rear stop surfaces limit the opening movement of the members. Vertically projecting tabs at the front and side of each member are rigidly screwed to the adjacent vertebrae. Tolerances in the hinge allow limited side to side rocking. The disc and screws are made of titanium alloy or cobalt chrome alloy. In a modified version a hinge pin is replaced by cables tying the members together.

Abstract: A sod laying machine having front rear sections articulated together. A boom on the front section has arms extending forwardly, with gripper arms extending downwardly from the boom to grip a roll of sod. A control roller connected to the boom arms drives the sod roll to control its speed of unwinding. The sod roll has its grass side facing outwardly and its top unwinds rearwardly so an operator in a seat at the front of the machine, between the boom arms, has an unobstructed view of the critical area of sod extending in the air from the roll to the ground, to reduce the likelihood of buckles and tears therein. The machine passes over the sod after it is laid, to roll the sod.

Abstract: A method and apparatus for coloring a black and white film. The film is converted to video tape and the locations of edges of moving objects in frames of the video signal are used to develop a motion indicator key. The motion indicator key is used to reduce noise in the video signal without smearing motion and is used to assign colors to the black and white signal. For each scene of the black and white film, a color mask is produced for one frame. The adjacent frame is then colored the same as the initial frame except where motion is indicated. Where motion is indicated, a selected process assigns colors, for example based on direction of movement or grey levels of adjacent pixels. The new color mask thus produced is used as a reference for coloring the next frame. In this way the whole film may be colored, scene by scene. The color mask produced may then be combined with the black and white video signal to produce a colored video signal.

Abstract: A powered desk is described. The desk has a work surface supported by a base consisting of a pair of generally vertical support members connected by an elongate, generally horizontal structural member which has a hollow interior. The ends of the structural member are mounted in annular openings formed in the vertical support members, with end faces exposed and accessible. Electrical connectors are mounted in the opposing end faces and are connected by electrical wiring extending through the interior of the structural member, whereby electric power or signals can be transferred across the full length of the desk and coupled by a suitable jumper to a similar desk. Additionally, electrical connectors are mounted along the surface of the structural member intermediate of the end faces, and tap into the contained electrical wiring to make electric power, telephone signals and other electrically transferred information available at the desk.