Abstract: The invention concerns an apparatus for preparing samples for analysis having at least a liquid-injecting needle (6), at least a column (32) for receiving the injecting needle, at least a tube (48), device (6, 26) for the tube and the column relative horizontal displacement between a position of coincidence in which the column bottom aperture (36) extends above the tube top aperture (50), and a relative lateral offset position of the two apertures (36, 50), and adapted device (6, 60) for the tube (48) and the column (32) relative vertical displacement such that in position of coincidence, the apertures (36, 50) interpenetrate, including vertical guide device for either the tube (48) or the column (32). The vertical guide device is adapted to operate the guiding under horizontal loading effect.

Abstract: The invention relates to a pipette for dispensing successive volumes of liquid by repeated action on a pusher (22). A drive lever (26) is provided to drive a pushrod (15) and a piston rod (5) downwards only. The lever (26) extends transversely to the longitudinal axis (X) of the thrust rod (15) and it includes a hole (27) through which the pushrod (15) passes with a small amount of clearance. The pusher (22) can act on one end of the lever (26) to cause it to tilt relative to the pushrod (15) and then to drive the pushrod downwards by wedging, together with the piston rod (5), and to expel a predetermined volume of liquid. The lever (26) is mounted to rotate about a tilt axis (Y) that intersects the axis of the hole (27) perpendicularly substantially halfway along the hole.

Abstract: The present invention provides an XYZ type laboratory robot to be used with various peripherals suitable for analyzing and/or preparing samples of liquid. The robot has a work surface (1) including a moving system (2) for supporting elements (7) required for analyzing and/or preparing the samples of liquid. The work surface is associated with an appropriate sample-taking device such as a needle (5) connected to an automatic syringe and displaced vertically on appropriate sampling arms (3, 4) so that the needle (5) can be displaced along three orthogonal axes X, Y and Z. The needle (5) can be inserted into an appropriate stopper member (8) temporarily secured to the elements (7) such that a bottom portion of the needle (5) actively cooperates with the stopper member (8) resulting in the stopper member (8) exerting frictional forces on the outside of the bottom portion of the needle (5) to temporarily connect one of the elements (7) to the needle (5).

Abstract: The invention relates to a process and a device for calibrating a sampling and metering pipette and a pipette adapted to be used in the process with the device. The volume of the sampling chamber of the pipette is adjusted to zero by means of a knurled button (3) and an adjusting screw (7) is actuated to set the stroke of a plunger for taking a sample at a zero value. The volume of the sample chamber is adjusted by means of the knurled button (3) to determine a mean value of the sample volume, and a new adjustment of the brake screw (7) is made to a value corresponding to the difference between a displayed volume value and the mean value of the sample volume.

Abstract: The present invention relates to a method of preparing samples for the purpose of analysis, in which at least one reaction agent and an initial sample are successively injected into a cartridge (90) provided with an orifice (92) in its lower portion, in such a manner as to cause the injected matter to pass through a column (91) of powdery agent contained within the cartridge, and in which the product of the last passage of injected matter through the column is retained for analysis. According to the invention, the reaction agents and the initial sample are successively injected into each cartridge after the top of the cartridge has been sealed in such a manner that the injection of the reaction agent or the sample causes the pressure at the top of the cartridge to rise, thereby accelerating the passage of the reaction agent or the sample through the column.

Abstract: The pipette according to the invention has a body of the pipette at the lower end of which is fitted an end fitting of a calibrated capillary tube in which a piston is movable, and a gripping device at the upper end of the piston. It is characterized in that the piston has, in the region of its upper end intended to be gripped by the gripping device, a flange adapted to cooperate at its upper face with the free ends of the resilient fingers of the gripping device and by its lower face with an abutment surface arranged on the interior surface of the said end fitting of the capillary tube.

Abstract: High-precision positive-displacement pipette having a nozzle with calibrated capillary channel and capable of disengageably fitting together with the free lower end of the pipette body. A piston fits tightly in the capillary channel and is controlled by a manually operable control rod equipped with a gripping device with which it grips the piston. An opening at this end of the body permits at least a part of the gripping device to pass through and come into contact with a stop provided on the inner surface of the nozzle so as to ensure the simultaneous ejection of the nozzle and of the piston which remains captive in the capillary channel.

Abstract: A device for sampling and dispensing adjustable volumes of liquid samples, with numerical display, is provided with a compact adjusting and display mechanism which comprises: an externally threaded sleeve which screw threadedly engages with the device housing; a prismatic control rod whose profile ensures that it rotates with the sleeve; a bush equipped, removably, with a means of causing it to rotate with the control rod; and a plurality of volume-indicator drums mounted around said bush. The sleeve serves as an adjustable end stop for a reciprocable piston actuated by the control rod.

Abstract: The present invention relates to an adjustable device for distributing liquid samples, comprising a casing incorporating a mechanism for adjusting the volume and a volume indicator unit; a tip member which comprises a lateral supply tube, provided with means allowing the tight adaptation of a reservoir; a measuring chamber arranged in said tip member so as to receive, with a slight clearance, a calibrated piston elastically urged upwardly and the upper end of which cooperates with a stop for limiting the upward stroke, adjustable in position by means of the adjusting mechanism; a control shaft, of which the lower end cooperates with the upper end of the calibrated piston and means ensuring the tightness of the measuring chamber. The invention finds particular application to the continuous distribution of liquid.

Abstract: The present invention relates to an adjustable diluting device, comprising a member for regulating the stroke of a first piston, presenting on its outer surface a thread adapted to cooperate with a thread made on the inner surface of the casing of said device, the lower end of said regulating member acting as stop limiting the upward stroke of the first piston; a tubular adjusting member whose lower end has a stop surface adapted to cooperate with the upper end of a sleeve for controlling the first piston and of which the inner surface is threaded; and a tubular push element fast with a shaft for controlling a second piston having an outer threaded adapted to cooperate with the inner thread of the tubular adjusting member. The invention is more particularly applied to laboratory equipment.

Abstract: A pipette in which the volume of liquid measured is a function of the stroke of a piston and can be calibrated to vary the volume measured, by varying the stroke. The pipette has a casing formed with a vertically elongate, open ended cavity, part of which cavity threadably engages a threaded portion on an open ended tube disposed in the cavity. A piston actuating rod passes through the tube. A push-button is mounted on the upper end of the rod and projects from the upper end of the tube which is countersunk into the casing. Below the lower end of the tube, a bush is integrally mounted on the rod and urged upwardly by spring pressure towards the lower end of the tube. The stroke of the piston is the distance between the lower end of the tube and the upper face of the bush when the push-button is not being depressed. This distance is variable to calibrate the pipette by rotatably screwing the tube in or out relatively to the casing, using a special key engageable with the upper end of the tube.