Abstract: A heat treatment apparatus for vacuum and high pressure operation includes a container within a vessel separated by thermal insulation. The vessel has a door for access to the container. Both the container and thermal insulation have separate doors mounted on a common frame pivotally mounted inwardly of the vessel door. The container door can be opened and closed from otuside the vessel when the thermal insulation and vessel doors are closed. Normally the container door is kept open in case of failure of the closing mechanism or in the event of a power failure.

Abstract: An electrically heated vacuum furnace is provided with special lead-through devices for transmitting current to the heating elements. In order to recognize gas discharges which can occur between a lead-through and a tank wall, the insulation of the lead-through is surrounded by an auxiliary electrode. A thermocouple can also be used instead of an auxiliary electrode. A signal derived from the auxiliary electrode can be used to shut off the furnace power to avoid damage thereto.

Abstract: A pump for conveying liquids and gases is formed by a drive motor having a stator (1) and a rotor (2). Helically shaped conveying grooves (3) are formed in the rotor (2) so that the rotor also serves as the shaft for the pump.

Abstract: DC motors without collectors require position sensors, which recognize or identify the angular position of the rotor, in order to supply a pulse for control of the current in the coil at a suitable point in time. Hall probes which, as a rule, are used as positional sensors, involve a series of disadvantages, such as for instance sensitivity to temperature and radiation. In order to avoid these disadvantages, coils with a magnetic core through which alternating current is passed are installed in the stator-rotor air gap in accordance with the invention. The rotor comprises in the axial segment opposite the coils a magnetic portion and a nonmagnetic portion. This generates a change in the voltage drop at the coil during each rotor revolution.

Abstract: A multi-chamber vacuum installation includes a charge-changing chamber (5) and a plurality of processing chambers (1, 2, 3, 4) located within the charge-changing chamber. One of the processing chambers (4) also serves as an air lock chamber. The air lock chamber (4) is formed of two parts, and inner part (4a) and an outer part (4b). The inner part is secured to the inside and the outer part is secured to the outside of the charge-changing chamber.

Abstract: In pumps for conveying gases and providing a differential pressure between the pump inlet and outlet, a pumping space within the pump is hermetically sealed from the pump drive unit. No oil or grease-lubricated parts are located within the pumping space. Accordingly, the pump can be characterized as completely dry running. The hermetical seal is provided by a hollow or tubular member (5) capable of torsion movement and located between a shaft (1) and a container (6). A drive unit (7) connected to the shaft provides it with an oscillating rotary motion transmitted through the shaft to the container (6). Segmented pistons (8a, 8b) are located on the container and oscillate in the pumping space between stationary parts (10a, 10b) and afford the pumping effect.

Abstract: A molecular pump of the Hollweck type is composed of a plurality of stages in order to improve the pumping characteristics. Rotor and stator consist of different portions which are provided alternately with helical grooves and with smooth outer and inner surfaces respectively. The cooperating surfaces of the individual rotor and stator portions are tapered.

Abstract: In an installation for the vacuum heat treatment and subsequent hot isostatic redensification of materials comprising a work space inside a container, heating unit, work-space insulation and an outer chamber with a vacuum connection and a pressure-gas connection, insulation is also provided at the interior of the chamber wall. The chamber is water-cooled.

Abstract: A turbo-molecular pump has stator discs 2 separated from one another by spacer rings 3 constructed in such a manner that gases streaming back can re-enter the suction space 8 through reduced portions 5 at the outer diameter and through radial recesses 6. Inner reduced portions 7 serve for the additional location of the stator discs 2.

Abstract: A turbo-molecular vacuum pump has a high vacuum side and a fore vacuum side in the form of a molecular pump in which the rotor and stator are frusto-conically shaped. The frusto-conically shaped rotor surface has a helical groove. An axial bearing for the rotor is located at an imaginary apex point of the conically-shaped surface of the rotor. The surface of the bearing containing the imaginary apex point is stationary relative to the stator. The rotor and stator are formed of a high heat conductivity material.

Abstract: Apparatus for treating workpieces under the action of hot gases within a chamber in order to achieve as homogeneous a treatment or processing as possible are provided with a valve mechanism whereby the gas is made to flow alternately from one side to the other over objects or workpieces within the chamber, the valve mechanism being especially designed to operate with heated gases and serving to reverse the gas flow.

Abstract: In a method of producing flexible and durable biological specimens, tissue water and any preservative which may be present is replaced by one or more water-soluble impregnating agents by direct molecular substitution without any intermedium or solvent and without removing the tissue lipides. Polyethylene glycol may be used as the impregnating agent. The replacement preferably occurs under vacuum and the specimen may be subsequently sealed.

Abstract: Slots are sawn into the edges of discs for pumps with a cup saw so as to produce blades having a curved cross-section. The blades may taper inwardly or outwardly or have no taper.

Abstract: Metals and/or metallic compounds are condensed from a vapor in a reaction vessel into a condenser, the condensate initially solidifying to block an outlet at the bottom of condenser; subsequent operation of heating stages from the top to the bottom of the condenser to melt the solidified condensate ensures that, as the outlet becomes unblocked, the whole melt flows into a mould.

Abstract: A turbo-molecular pump with passive, radial magnetic bearings and axial bearings has both direct and indirect damping arrangements for unwanted oscillations. Direct damping is produced by eddy currents produced in copper rings around the magnetic stators of the magnetic bearings. Indirect damping is provided through a platform, carried by springs and connected to the pump housing by oscillation dampers.

Abstract: A drive arrangement for the shaft of a turbo molecular pump comprises a motor supply, including a chopper which controls a voltage source, and a motor with two phase windings connected via a current measuring resistor to the neutral point of the voltage source. The voltage drop at the resistor is proportional to the motor current and so influences the width of the control pulses of a pulse-width modulator connected to control the chopper that the motor current remains constant. Switching transistors for the motor have parallel oppositely-connected diodes which, upon disconnection of a phase winding, supply residual energy to capacitors in the circuit.

Abstract: An arrangement for transmitting torque between the two rotors of a two stage rotary vane pump, consists of a coupling element, which forms between engagements on opposing faces of the two rotors, a connection which permits two degrees of freedom between the two rotors in the plane perpendicular to the rotor axis.

Abstract: A turbo-molecular pump has passive magnetic bearings which are radially stable but axially unstable and mechanical thrust bearings acting axially, the magnetic bearings and the stator forming a structural unit movable axially within the pump housing and connected to an element adjustably supporting one thrust bearing while the other thrust bearing is fixed to the housing with control gear being provided for adjusting the structural unit relative to the housing and the thrust bearing relative to the structural unit in dependence on force sensing devices.

Abstract: A rotary piston pump includes a casing and partitions within the casing defining an expansion chamber and with a gear and bearing chamber on one side of the expansion chamber and a bearing chamber on the other side. The partitions between the expansion chamber and the bearing and gear and bearing chambers are provided with passages for receiving shafts serving for the transmission of the rotary movement from gears to the pistons of the pumps. The passages between the chambers are provided with split seals which are composed of two parts separated by a pressure equalization chamber.

Abstract: Apparatus for heating and drying articles including an evacuable drying chamber for heating therein articles by condensation heat of the vapor of a first liquid supplied to the drying chamber, a vacuum pump for evacuating the boiler, a first vapor condenser and a second vapor condenser connected betwen the drying chamber and the vacuum pump, a thin film evaporator for receiving condensate from the drying chamber in the form of the first liquid and a second liquid having a higher boiling point than the first liquid, the second liquid being obtained from the articles within the drying chamber, a condensate collecting container for receiving from the evaporator liquid condensate which is not evaporated in the evaporator, a pressure barrier arranged between the evaporator and the collecting container and a re-evaporator arranged between the pressure barrier and the collecting container.