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: An optical component having a gradient refractive index produced by multiple windings of a glass fiber over a glass mandrel. The fiber is provided with a refractive index gradation which varies from an approximate match with the mandrel to selected lower values along its length thereby causing refractive index in the depth of windings to vary accordingly. Fusion and drawing of the mandrel and windings provide a rod (or fiber) of solid cross-section having a radial index gradient of predetermined profile.

Abstract: A hard shell capsule for the exact dosage of substances, especially for pharmaceutical use, having a body part and a cap part which is joinable with said body. The body part has a side wall, a closed end and an open end. The cap part is die-molded or extruded as a stopper directly into the open end of the body after the body has been filled, so as to seal the contents within the capsule.

Abstract: In a microscope, a nosepiece support assembly and a coarse and fine adjustment mechanism in direct operative control of the support assembly, the support assembly including a nosepiece mounting carriage with a depending rod rigid therewith and mounting a cam follower which rides on the edge of a cam, rotation of which is controlled by the adjustment mechanism. The adjustment mechanism in turn includes a reduction gear assembly utilizing dual gear trains and mounted to a cam-mounting shaft externally of the frame of the microscope and housed within a coarse adjustment handwheel for immediate access thereto. One of the gear trains incorporates a compound gear having a torsion spring between the individual gears to enhance gear train interengagement throughout the gear assembly.

Abstract: A drafting apparatus, or macrophotography attachment, for a microscope of the inverted type, the apparatus being arranged to provide an erect and laterally non-reversed image of an object on a drawing-surface, and in the observation plane, or an erect and laterally non-reversed image of a drawing or object at the observation and film planes of a microscope.

Abstract: A valve body (20) for an endoscope is moulded from polypropylene and has a straight through bore (27) to aid cleaning of the valve body. The valve body (20) has spaced external ribs (48, 50) which locate the valve body (20) with respect to the casing of a handle (10) of the endoscope. At one end the valve body (20) receives a threaded sleeve (30) which retains a slidable valve member (34) in position, a cap (42) being manually depressed against spring loading to open the valve and place a source of suction in communication with a side stem (38) which is intended to be connected to a passageway leading to the distal end of the endoscope shaft.

Abstract: A marking image control system for a microscope arrangement in which the image of a marking on a mask is reflected into the optical path and combined with an object image of the microscope, the system forming an intermediate image of the marking in order to facilitate shifting of the image of the marking in a film plane or a viewing plane of the microscope.

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 using a coherent mono-chromatic radiation source, preferably using a laser, for bonding capsule elements is disclosed. The systems described include means for providing a spot, short-line, or continuous seam. Also described are methods to enhance the bonding technique which utilize a small quantity of water or plasticol in the region to be bonded.

Abstract: A cryostat microtome apparatus comprises a cooling enclosure which can be set to a predetermined internal temperature and a microtome disposed in the enclosure. The enclosure is supported on a support assembly which is vertically adjustable to permit stepless adjustment of the height of the enclosure, for adaptation to operator requirements. A mechanical actuating assembly and/or a gas spring assembly is provided for height adjustment of the apparatus.

Abstract: A current to frequency converter comprising a current source, for example a photocell, a voltage to frequency converter, an integrator in the feedback loop of the converter, the current source being connected to the summing junction of the converter and integrator such that the frequency of output pulses from the converter is directly proportional to the magnitude of current injected from the converter to the summing junction, and a controlled circuit for attenuating the current injected from the converter to the summing junction to increase the frequency of output pulses. The controlled attenuating circuit includes a transistor switching arrangement for introducing increased resistance in the path for current injected from the converter to the summing junction in response to the presence of a control signal.

Abstract: Cryogenic-fixation apparatus comprises a light source, a beam from which enter cooling liquid in a bath, through a window in the underside of the bath. The beam can be directed upwardly by means of a reflecting prism. When a lid of the bath is closed, the beam leaves the space defined by the path through an exit port in the lid, and is incident upon a specimen mounted on a specimen holder located above the exit port, the specimen holder being secured to an injector rod.

Abstract: In an optical deflecting device with an optical bridge and with two optical sub-units which can be rotated relative to the optical bridge, the optical sub-units are, in the datum position, aligned in a manner such that the optical entrance axis of the first optical sub-unit is substantially perpendicular to the optical exit axis of the second optical sub-unit and substantially parallel to the optical axis of the optical bridge. This arrangement enables a light beam to be deflected without altering the orientation of the image.

Abstract: Methods are disclosed for the sealing of gelatin capsules having hard shell coaxial cap and body parts which overlap when telescopically joined. Also described are apparatus and sealing fluids to seal the capsules.

Abstract: A magnetic coupling comprises two parts of an optical instrument, for example, of a microscope, which are to be releasably coupled together. A locating surface is formed on one part, this surface comprising one or more areas defined by bodies composed of a magnetic material which are spaced apart at intervals, the other part comprising a locating surface comprising areas defined by bodies composed of a material which can be magnetized. In order to avoid mechanical shocks caused by a powerful magnetic attraction as the parts are coupled, the material which can be magnetized, and which is associated with one of the locating surfaces, is confined to one or more areas of this surface, the arrangement of these areas corresponding to that of the areas on the locating surface. Other parts of the locating surface are composed of a material which cannot be magnetized.

Abstract: An endoscope has a shaft (4) detachably connected to a handle (2) to enable the shaft (4) to be detached for repair or maintenance. The shaft (4) and handle (2) are detachably connected by spring-loaded latches (10) in the handle which are frictionally engageable with pins (8) projecting from the coupling face of the shaft (4). An external locking sleeve (20) prevents inadvertent separation of the shaft and handle. Illuminating light and the image to be viewed are coupled across the handle/shaft interface by abutting ends of fiber optic bundles (76, 80, 86, 92). The shaft (4) can be flexed by adjustment of manual controls on the handle as a result of racks (40, 44) in the handle (2) exerting a pushing motion on racks (50, 52) in the shaft (4), this pushing motion being transmitted into a pulling action applied to flexure wires (66, 62) extending in the shaft by virtue of pinions (54, 56) interconnecting the two racks of each pair of racks (50, 52) in the shaft (4). An alternative embodiment (FIGS.