Abstract: The invention relates to a process and apparatus for cleaning a swimming pool, where the apparatus or device, moves back and forth in the swimming pool, and where the device has driving gears or belts that can be switched to drive reverse or forward during operation. A contact rail is frontally positioned in the cleaning casing of the device, and a swich rail is positioned at the rear of the casing. Correction-dependent signals are obtained by the device striking an obstacle and these signals are supplied to a gear via a control mechanism. Upon obtaining such signals, the driving gear or belt slows down and remains still for so long until the other driving gear or belt which is still moving turns the cleaning device around and until the rear switch rail is activated. The signals resulting from the switch rail are used for switching the gear to reverse and for straightening out the cleaning device to a new position and prepare it to a forwards motion to continue its course along the swimming pool.

Abstract: In a self-propelled cleaning apparatus, particularly for swimming pools, a cleaning apparatus drive (9) is integrated into a basic casing (1) and at least one cleaning brush (21) and a suction duct (29) are provided. By means of the said suction duct (29) the liquid to be cleaned is delivered by means of a pump (40) into a filter chamber (35). The filter chamber (35) extends over almost the entire top of the basic casing (1) and is covered by a casing cover (41).

Abstract: An autogenous flame spraying apparatus includes a supply line housing having gas supply lines for combustion gas, carrier gas and acceleration gas; a main housing connected to the supply line housing and having a supply line for a spray powder, and ducts communicating with the gas supply lines, the housing having a first injector for mixing the spray powder and the carrier gas to form a first mixture; an interchangeable nozzle carrier for carrying a releasable torch nozzle, the carrier being releasably attached to the main housing and having a second injector for mixing the combustion gas and the carrier gas to form a second mixture, the nozzle carrier also having ducts for conveying the first mixture and the second mixture to the torch nozzle, whereby the carrier can be replaced so as to alter both flame power and feed of spray powder.

Abstract: A spin stabilized projectile unit includes a sub-caliber projectile having a cylindrical section connected to a conical tail section including an external circumferential holding groove. A propelling cage casing encloses the projectile. A propelling base includes a receptacle holding the projectile and connected with the projectile and the propelling cage casing. The receptacle includes inwardly projecting axial webs presenting an inner diameter of the receptacle in a region of the cylindrical section of the projectile which corresponds to the outer diameter of the cylindrical section. The inner diameter of the receptacle formed by the webs becomes increasingly larger than the respective outer diameter of the conical section beginning in the transition region between the cylindrical and conical sections to form an annular gap extending to a bottom region of the bottom of the receptacle.

Abstract: A process for heat treating a metallic workpiece comprises the steps of first heating the metallic workpiece in a gas stream fluidized bed made from a plurality of refractory particles for 2 min to 10 min under an inert-gas atmosphere to a treatment temperature of from about 500.degree. to 650.degree. C. Then the heated workpiece is preoxidized with an oxidizing gas stream in the fluidized bed. Finally the heated workpiece is nitrocarburized by contacting it for between 0.5 h and 10 h in the fluidized bed with a gas mixture composed of nitrogen, ammonia, and a carbon-rich gas.

Abstract: The process carburizes a steel workpiece, particularly a steel piece made of casehardened steel, to a predetermined surface carbon content in a fluidized bed oven. In a first carburizing step one carburizing gas is used whose carbon content exceeds that corresponding to the surface carbon set or desired content and whose C-level is above the soot limit. Thus an actual surface carbon content is provided which lies above the predetermined surface carbon set or desired content. Then after that in the same fluidized bed oven a diffusion treatment of the workpiece is performed in another carburizing gas which has a C-level above the soot limit, but a reduced carbon content relative to the first carbon containing gas, this carbon content being less than or equal to that corresponding to the surface carbon set or desired content. The described sequence of carburization followed by diffusion treatment is repeated until a predetermined carbon depth or penetration is reached.

Abstract: A fluidized-bed assembly for the treatment of metallic and nonmetallic objects utilizes a replaceable nozzle-plate which assembly can be received within the chamber and includes an inwardly inclined side wall which is provided with nozzles in addition to those of the central portion of the nozzle-plate. The assembly can be fed with gas by pipes from above or from below.

Abstract: A metallic object is heat treated by suspending it in a fluidizable bed through which a gas can be passed at a volume/time rate to fluidize it. The temperature of the bed is varied in accordance with a temperature curve having regions of considerable slope and temperature change and regions of inconsiderable slope and temperature change and the workpiece temperature varies in accordance with the bed temperature principally by heat conduction between the bed and workpiece. Enough gas is passed through the bed at a predetermined relatively high volume/time rate sufficient to fluidize the bed only during the periods corresponding to the regions of considerable slope and gas is passed through the bed at a relatively low volume/time rate equal to more than 0% and less than 75%, and preferably between 5% and 45%, of the high rate and insufficient to fluidize the bed during the periods corresponding to the regions of inconsiderable slope. The low rate is about 10% of the high rate.

Abstract: An apparatus for the thermal removal of lacquer and like coating materials from metal and ceramic objects comprises a fluidized-bed retort which is partly heated by a burner in a burner chamber formed in a unitary housing with the retort. Combustibles in the retort gases are recycled to an afterburner chamber for combustion to provide additional heating for the retort. The bottom of the retort is surrounded by an annular gap through which the afterburner gases pass and then to an outlet connected to the afterburner chamber by a valve.

Abstract: An apparatus for the thermal removal of lacquer and like coating materials from metal and ceramic objects comprises a fluidized-bed retort which is partly heated by a burner in a burner chamber. Combustibles in the retort gases are recycled to an afterburner chamber for combustion to provide additional heating for the retort. The bottom of the retort is provided with a layer of refractory heat-storage material which serves as a thermal buffer leveling the heating of the interior of the retort.

Abstract: A cleaning apparatus for a pool or tank has caterpillar tracks controlled by steering clutches actuated by a regulating device with a compass as a measured course value sensor, a setting device for the desired course value, a comparator for determining the error between the measured course value and the desired course value. The apparatus follows in oblique path from one travel path to the next by modifying the desired course by a given angle. After a given time, the desired course value is again modified by the same amount in the opposite direction, so that the cleaning apparatus returns parallel to the first path. By setting the angle and duration for the oblique travel, the new travel path can be selected independently of the dimensions of the pool to be cleaned.

Abstract: A tapering flow duct is formed below a chassis having a caterpillar track and forms lateral openings between a cleaning brush and the tracks. The flow duct is connected through an opening to a suction duct of a suction pump which conveys the sucked up liquids with the contaminants contained therein into a filter. Due to the increased flow velocity, the static pressure in the flow duct is reduced, so that the chassis is pressed onto the bottom surface and can overcome severe gradients without sliding.

Abstract: An apparatus or implement for underwater cleaning of swimming pool bottoms and/or walls having a chassis with traction drive and a suction pump mounted on the chassis. A suction nozzle is connected to the suction side of the pump, for drawing in settled particles. A filter is connected to the pressure side of the pump for catching the particles. A controlled diving cell which is floodable and clearable in a controlled manner is arranged on the chassis for varying the buoyancy of the apparatus sufficiently to raise and lower it in the water. A brush with a particular bristle configuration may be mounted in the suction nozzle.