Abstract: The furnace effects a partial heat-treatment of drills and similar tools having a clamping portion and a working portion and with respect to which it is important to subjecting only the working portion, to a heat treatment, particularly hardening. The physical properties of the clamping portion are, retained essentially in their original state during the heat treatment. The furnace is provided with a tool receiver that cooperates with hearth-bottom plates that are traversed by cooling fluid. The tool receiver assures that the drills or other similar tools are maintained in their clamping portion at substantially the same temperature level during the heat treatment while the working portion of the tools is freely exposed to the heating and quenching.

Abstract: A conveyor arrangement incorporated in a continuous oven comprises a plurality of support rails, one mounted in each oven chamber, and load-carrying frames suspended from the rails and arranged to move through the chambers. Each chamber has at least one drive pinion assembly comprising two pinions drivingly coupled by a chain drive, and each pinion can mesh with a rack to advance the load-carrying frames through the oven chamber. Each rack is secured to a respective load-carrying frame.

Abstract: An industrial furnace, particularly a single-chamber vacuum furnace, for heat treatment of metallic workpieces, with a heating chamber which is formed in a housing, which heating chamber is heatable via heating elements and is provided on the bottom and on the ceiling with a closable chamber opening for the passage of a quenching gas which can be circulated by means of a blower. A flap is swingably mounted at the chamber opening underneath a closing slide, which chamber opening is provided for the entrance of the gas. The flap controls the incoming flow of gas within the range of the free cross-section of the chamber opening.

Abstract: An apparatus for the control of the carburizing of parts under vacuum in a acuum furnace, with which as a carbon carrier a hydrocarbon gas is introduced controlled in the furnace. A detector detects the occurrence of a soot mist formation. Upon the occurrence of the soot mist a feeder for the hydrocarbon addition is completely or partially interrupted. The detector cooperates with the feeder such that the hydrocarbon addition is again received when the soot mist formation has decayed.

Abstract: A vacuum aluminum soldering furnace comprising an evacuatable soldering cber having two lateral heating zones. The soldering chamber has a middle heating zone arranged parallel to the lateral heating zones and the heating element of the middle heating zone is preferably arranged removable from the soldering chamber.

Abstract: A method and apparatus for the control of the carburizing of parts under vacuum in a vacuum furnace, with which as a carbon carrier a hydrocarbon gas is introduced controlled in the furance. As the control quantity a soot mist formation is used in such a manner that the occurrence of the soot mist is determined, that upon the occurrence of the soot mist the hydrocarbon addition is completely or partially interrupted, and that the hydrocarbon addition is again received if the soot mist formation has dampened out.

Abstract: The method for gas circulation in a furnace, such as a vacuum furnace, for the heat treatment of work pieces wherein the gas is caused to circulate with turbulence while avoiding a set or stable flow pattern and the vacuum furnace adapted to carry out this method by means of fans so located and operated as to circulate the gas with turbulence and vorticity.