Abstract: An evacuated blood collection tube has a stopper made of deformable synthetic rubber, incorporating a skirt fitting over the outer wall of the tube neck, and integral with the skirt a plug that penetrates the neck of the tube. The sealing function is performed by two embodiments, the upper cylindrical sealing portion of the skirt and the plug. An annular recess surrounds the plug. A compression ring made of a more rigid material is set around the upper peripheral wall of the skirt that overlaps the cylindrical sealing portion. The compression ring cooperates with the rubber stopper and the tube to provide a clenching mechanism ensuring automated guidance of the tube in full sealing engagement over the plug. Furthermore it maintains a constant sealing pressure of the skirt over the tube optimizing vacuum preservation.

Abstract: A blood collection unit has a primary tube of narrow bore hermetically and concentrically assembled to a secondary tube of larger diameter either by a plunger attached to the primary tube and on which the secondary tube is slidably mounted, or by the skirt of a stopper closing both tubes. One of the tubes is closed by a stopper of fitting-over form, the two tubes forming a closed communicating space into which a blood sample is introduced through a double ended needle, passing into one of the tube prior to passing into the other tube. For sedimentation rate determinations, the plunger system can be operated either with or without the closed communicating space under vacuum. Progressive entry of blood into the system is controlled by the narrow bore primary tube.

Abstract: An evacuated blood-sampling tube has a stopper with a skirt which fits over the open end of the tube. The stopper can be displaced to a venting position, in which an axial groove in the skirt communicates the interior of the tube with the exterior, to facilitate processing of the tube sample, including pipetting, with the tube stoppered. The tube may have a bead which engages one annular groove in the stopper to provide a sealing fit and another annular groove in the stopper skirt to define the venting position.

Abstract: A stopper of an evacuated-tube blood sampling system has a sealing portion fitting in or on the tube and an enlarged external hollow head having a chamber closed by a thin sealing diaphragm which obturates the evacuated tube or vial. Flexible lips on an outer end wall of the head define a narrow central opening receiving and lightly gripping a flexible needle sleeve to pre-assemble the evacuated tube with the needle and its holder without a need to partially perforate the membrane. As the needle pierces the diaphragm, the needle sleeve is free to buckle within the chamber, thus reducting or cancelling the biasing effect exerted by the buckled sleeve. The sealing portion of the stopper can have annular and axial grooves providing a ventilating system.