Abstract: Method of separating blood, in particular for recovering thrombocytes and/or leucocytes, the whole blood coming from the donor being separated in a separation means of a centrifuge into an erythrocyte fraction, cell-poor plasma, a thrombocyte fraction and/or possibly a leucocyte fraction, the separated fractions of the blood being discharged via a flexible tubing system of discharge lines out of the separation chambers of the centrifuge and constantly predetermined amounts of separated cell-poor plasma returned to the whole blood to be separated or to the already separated erythrocytes in the separation chamber, and a separation apparatus for carrying out the method comprising a separator having one or more separating chambers connected together and a flexible tubing system which includes a supply line (1, 2) for the supply of the whole blood to be separated to the separator and discharge lines each for the separate discharge of the erythrocyte fraction (10), the cell-poor plasma (3, 5), the thrombocyte fract

Abstract: A peristaltically operating roller pump, in particular a hose pump for medical technology, comprises a pump bed (25) whose bearing wall (28) in the exit region (31) has a curvature which is in the same sense as the circular path (33a) of a roller (33) mounted on a pump rotor (1) and which has a radius of curvature which is constant with respect to the circular path (33a) or gradually increases in the direction of rotation of the roller (33). The pump rotor (1) comprises a gear connection so that a constrained radial movement of a roller is converted to a corresponding follow-up movement of the other rollers or roller. By this combination of pump bed and pump rotor pressure peaks and fluctuations of the flow rate are effectively prevented.

Abstract: A plurality of scanning regions (22) are disposed about the anticipated region of a phase boundary (32) of two media. The change in position of the phase boundary (32) is detected by a scanning means (18) with which each scanning region (22) is scanned and a signal is generated for each of the scanning regions (22). The first media is more radiation-permeable than the second media. A beam path is generated by the scanning means and is detected and evaluated by a discriminator circuit as a logic one. The second media is less radiation-permeable than the first media. The absence of a beam path corresponding to scanning regions in the second media is evaluated by the discriminator circuit as a logic zero. The number of signals per measuring cycle is compared against the actual number of scanning regions (22) to locate and control the position of the phase boundary (32).

Abstract: A roller pump (1) comprises a stator member (2) in which a pump bed (3) is formed with specific geometry. In the interior of the pump bed (3) a rotor (6) is rotatably mounted. A pump hose (10) can be inserted into the pump bed (3), said hose being curved in loop-like manner and its two ends being combined in immediate vicinity to each other in a connecting piece (11). The connecting piece (11) can be fixed in location in the stator member (2), the arrangement in the stator member (2) being uniquely defined by cooperation of a location tongue (23) and a location slot (22). Interchanging of the pressure-side and suction-side connection is thus impossible. A holding-down member (24) arranged on the rotor (6) permits automatic insertion and ejection of the pump hose (10) or hose system (9).

Abstract: Disclosed is a device for indicating that the level of a dosable material has fallen below a predetermined level in a dosing container having a shaft mounted horizontally for rotation inside of the container and a dosing brush mounted on the shaft. This device comprises an elastic contact tongue radially fixed to the shaft for rotation therewith, the contact tongue being sufficiently elastic so that it assumes a bent configuration having a first radius when rotated in contact over a predetermined portion of its length with the dosable material and so that it assumes an extended configuration having a second radius when rotated so that it is not in contact over the predetermined portion of its length with the dosable material; a contact pin mounted at a distance from the shaft greater than the first radius but not greater than the second radius, so as to be contacted by the contact tongue in its extended configuration; and means for producing a signal when the contact tongue contacts the contact pin.

Abstract: A bearing plate for a moving band of photo-conductive recording medium, wherein the band is provided with perforations close to and parallel to one of its two longitudinal edges and is adapted to be contacted by a metal brush pressing against the recording medium in the zone of the perforated longitudinal edge. The bearing plate is formed from a base plate of a conductive material having an aperture therethrough and an electrically conductive grid covering the aperture.

Abstract: Disclosed is a device for mixing and/or conveying, in particular for mixing and conveying a developer composition in an electrophotographic copying machine. The device comprises an elongated member which is rotatable about its longitudinal axis, this member comprising a T-shaped lateral cross-section which has been spirally twisted about its longitudinal axis, whereby at least two portions of the T cross-section comprise helically extending mixing and/or conveying elements. Also disclosed is a method for manufacturing such a device.

Abstract: A base for a container for fine material adapted to be discharged pneumatically from the container. The container base has a generally central material outlet in communication with a number of pneumatic feed channels extending radially inwardly from the periphery, the channels dividing the container base into sector-like sections. Each such section has two upwardly converging, oblique surfaces which meet along a ridge-like edge extending towards the container center and at least one of such surfaces is aeratable from below. Overlying each feed channel is an aeratable, downwardly inclined cover having one or more openings at the periphery of the base through which material may pass into the channel.

Abstract: Disclosed is a process and apparatus for separating aspherical particles from spherical particles in an admixture thereof, preferably in the preparation of a particulate carrier material for two-component developer systems for electrostatic copy devices. The process comprises directing the mixture of particles onto a surface which is inclined with respect to the horizontal; producing a relative velocity between the inclined surface and the mixture of particles, the velocity having a directional component transverse to the steepest inclination gradient of the inclined surface; and collecting a portion of the mixture of particles in a zone of the inclined surface wherein predominantly spherical particles have accummulated as a result of their greater tendency to roll in response to the relative velocity than the aspherical particles.