Abstract: A device for controlling the temperatures in a cooling chamber for a microtome, in particular an ultramicrotome, comprises at least two different temperature control circuits for controlling the temperatures of the specimen and of the cutter. The control circuit for the temperature of the specimen (8) and the control circuit for the temperature of the cutter (9), as well as, if appropriate, the control circuit for the temperature of the chamber gas, have a common setting element (17), such that the control circuit can be programmed to an identical temperature as the set value.

Abstract: Method for the incubation of specimens (7) in fluids (5) for subsequent embedding in capsules by polymerization, the specimens (7) being put into hole capsules (2') which are open at the top and, in the lower third of their cylindrical wall, have at least a circle of passage orifices (6) which are smaller than the diameter of the specimens (7). These specimens (7) are incubated in a fluid (5) extending above these passage orifices (6). The hole capsules (2') are then introduced into enveloping capsules (3) of a larger diameter and with a likewise preferably cylindrical wall, a fluid (5) (a polymerizable monomer batch) present in the enveloping capsules (3) filling at least the gap (S) between the hole capsule (2') and the enveloping capsule (3), and this fluid (5) being finally polymerized under UV radiation or action of heat. The hole capsules (2') and the enveloping capsules (3) can be successively slipped over rams (4') which are located on a carrier (1).

Abstract: Device for dehydrating and/or embedding preferably frozen samples, comprising a Dewar vessel (1) filled with liquid nitrogen (2) and a metallic element (4), anchored to the floor (3), of material of good thermal conductivity, which exhibits at its upper end in the region of attachment of the Dewar neck a cover (5) with a metallic cooling surface (6, 7) which corresponds with the complementarily designed lower contact surfaces of the thermostatically heated (9, 10) substitution (PLT) containers (8) or respectively of the lower part of a freeze-drying chamber in a manner which ensures a good heat transfer between the corresponding surfaces.

Abstract: A chamber system for cryosorption freeze-drying of biological specimens in a Dewar vessel, comprises a chamber having a cylindrical metal wall and fitted within the Dewar vessel, a lower outer edge of which chamber is connected in a vacuum-tight manner to a lower edge of a metallic rotational component, the metallic rotational component having a bottom contact surface, which bottom contact surface corresponds with a complementary top contact surface on top of a cylindrical body around which liquid nitrogen flows and cools the metallic rotational component, the rotational component having a chamber to receive a drying agent for conducting cryosorption, for example a molecular screen, as well as a connection to the drying chamber.The upper edge of the metal wall or a ring connected thereto in a vacuum-tight manner is situated outside the Dewar vessel and is therefore approximately at ambient temperature and has a vacuum connection for the connection of commercially available vacuum components.

Abstract: A device automatically applies an object (7) to a cutting edge (11) of a knife 10), and automatically makes an initial cut in the object (7), in microtomes, especially ultramicrotomes. Force sensors (27,28), length sensors (29) or other sensors, an elecrotronic control unit (25) and an encoder (22) coupled to a drive device register forces (k,-k) connected with the separation of sections by the knife edge (11) or variations in the system triggered by these forces. Subsequently, via the electronic control unit (25), a transition from a rapid speed or rate of feed to a lower cutting speed or a lesser rate of feed for making an initial cut is automatically performed. A visual and/or acoustic signal informs the user of this change. Signals (S.sub.1, S.sub.2) from the sensors (27-29) serve for automatic adjustment of the position of two switch-over points (U.sub.1, U.sub.2) from the rapid return speed (V.sub.R) to the slower cutting movement (V.sub.

Abstract: A device for controlling the drive and forward feed of a microtome, particularly an ultramicrotome, includes a driving motor for moving a specimen or knife and a servomotor for generating a forward feed of the specimen towards an edge of the knife or vice versa. A high travelling speed of the specimen needed for rapid initial cutting is coupled to a high rate of forward feed. One single switching operation is performed, for instance, by a snap-engaging step switch via relay switches. The driving motor and the servomotor can be simultaneously switched over to pairs of values which correspond to subsequent rough cutting and ultra-thin cutting. Individual values for cutting speed and forward feed are separately preselected, readjusted, and read from a display. Selected program stages are indicated by signals.

Abstract: A refrigerated chamber includes, inside a metal wall and a foam insulating layer thereof, a sheet metal tank, in which, depending on levels of filling with liquid nitrogen, various compartments of the tank divided by separations, of different height are filled with LN.sub.2. Thereby, different cooling powers are available for varying temperature ranges between ambient temperature and the temperature of the liquid nitrogen. In this way one avoids an excessive consumption of nitrogen. Filling with LN.sub.2 is effected from a separating tank by means of a horizontal small-diameter pipe which during operation of the chamber is always exposed to and cooled by liquid nitrogen. Nitrogen in the form of a sweeping gas emerges in a boiling state from the tank and is guided through a cutting space (41') and can be heated by a heating plate fixed to sheet metal deflectors.

Abstract: A method for metal-mirror cryofixation of bio-medical or similar technical specimens in which a specimen is brought into contact with a highly polished, cooled metal mirror in order to cool at least a marginal zone of the specimen suddenly to a low temperature. In order to avoid deformation of the specimen caused by freezing, provision is made, immediately after the first contact between the specimen and the metal mirror, to press the latter against one another by an additional independent force until the specimen is completely frozen. A cryofixation device for this purpose comprises a force generating device, for example, a separate power storage device (135) which, under control, functions after contact between the specimen (106) and metal mirror (102), in other words exerts the additional force between the specimen and the metal mirror (FIG. 7).

Abstract: Apparatus for treating biological specimens at low temperatures for subsequent microscopic examination comprises a container having a specimen treatment chamber disposed in a vessel adapted to contain liquid coolant. The specimen treatment chamber is adapted to receive a specimen to be treated and a specimen treatment medium. Precooling means is provided for precooling the specimen treatment medium before it is introduced to the specimen treatment chamber. The precooling means comprises a reservoir communicating with the specimen treatment chamber, and delivery means for delivering the specimen treatment medium to the reservoir. The reservoir and delivery means are arranged so that specimen treatment medium flowing through the reservoir and delivery means is cooled by the liquid coolant, and so that the specimen treatment medium can flow through the delivery means in countercurrent heat exchange with specimen treatment medium flowing from the reservoir to the specimen treatment chamber.

Abstract: A device for use in transferring a specimen from an apparatus containing a cryogenic coolant, comprises a specimen holder and coolant transfer means. The coolant transfer means permits coolant from within the apparatus to be introduced into the specimen holder in order to immerse a specimen within the specimen holder in the coolant. This enables the specimen holder to be transferred to another apparatus, while the specimen is kept cool by the coolant.

Abstract: Apparatus for the cryofixation of biological, medical or technical specimens having a high water content or fluid content by immersion in a cooling bath or on a metal mirror surface, comprises a container for coolant within which is disposed in a tank for specimen cooling medium. An injector is provided for holding a specimen and moving it along a delivery path. A member having a mirror surface is provided for mirror surface cryofixation, said member being adapted to be removably disposed at a position located in the injection path. A highly thermally conductive contact is provided between the tank and the member.

Abstract: Apparatus for the cryofixation of specimens, comprises a tank adapted to contain a cold gaseous medium having an upper boundary with an atmosphere external to the tank, and cooling means having an upper surface, said cooling means being disposed within the tank. The upper surface is movable between a lower level and an upper level which is below the upper boundary. The upper surface is maintained at the upper level for a period sufficient to permit the application of a specimen to the upper surface, and is then lowered to the lower level.

Abstract: A device for immersing a specimen into a cryogenic cooling liquid comprising an injector for carrying a specimen, means for accelerating the injector to a predetermined velocity vertically into the liquid, and means for rotating the injector, before the vertical movement ends, or at the moment it ends, to promote heat transfer from the specimen. Various means for effecting rotation of the injector are described.

Abstract: Apparatus for cooling a biological or medical specimen comprises a cooling bath, an injection device for injecting a specimen into cooling liquid in the bath at a velocity of between 5 and 15 m/sec, and a sleeve. The sleeve is movable between a lower position in the bath and an upper position for limiting the effects of splashing as a specimen enters the bath. The injection device comprises a closure plate for co-operating with the sleeve to further limit the effects of splashing. The sleeve is operatively associated with the injection device in a manner such that movement of a specimen carrier of the device towards the bath to immerse a specimen is initiated when the sleeve is moved from the lower position to the upper position.

Abstract: Apparatus for fixation, dessication, and embedding of biologic specimens for microscopic, especially electron microscopic studies having compartment for treating specimens held in liquid permeable specimen holders, a supply of treatment liquid connected to the compartment, to introduce liquid from the supply, and remove liquid from the compartment, a chamber (14c) in the compartment for holding a quantity of fluid, a passage connected to the chamber, pump (15) located in the chamber for moving fluid through the passage, at least one tubular cell (14a) for supporting a plurality of specimen holders (10, 10a) is an end to end relationship, one end of said cell being connected to said passage, the other end of each of said chamber and said cell being connected to a common portion of said tank to permit liquid to be circulated by said pump.

Abstract: The invention concerns a device for the cryo-substitution of small biological objects for microscopic, especially electron microscopic investigations, with a metal receptacle for the reception of at least one object, which is mounted in a dewar flask containing a liquid cryogen and which can be regulated to a desired temperature by means of the cryogen and a regulatable heating device joined to the receptacle.

Abstract: The invention concerns a device for metallic mirror-cryofixation and subsequent cryopreparation of biological materials for microscopic, in particular electron microscopic examinations, employing a highly polished metallic mirror cooled to very low temperatures by a cryogen and mounted in a metal freezing chamber, which can be flooded with a gaseous cryogen, on which an object can be placed by means of an injection mechanism or the like, wherein the freezing chamber has an adequate volume for cryopreparation and for accepting the required accessory devices.

Abstract: A specimen working chamber having heat-conductive walls instead of insulative walls is disclosed.

Abstract: A joint having a plurality of spherical elements cemented to one member and the other member having adjustable sockets which cooperate with the spherical elements to permit rotation about a single axis. The joint is particularly useful in microtomes and ultramicrotomes.