Abstract: A single-use syringe has a piston assembly sealingly slidable within a bal. The piston assembly has a plunger (1) with a divergently tapered portion (4) and a resiliently deformable piston (2) with a through aperture (7), correspondingly tapered so that part of the tapered portion (4) may fit within the aperture, and a tapered skirt portion (6) adapted to surround a further part of the tapered portion (4). The through aperture is adapted to be plugged by the plunger. A locking ring (3) having a tapered aperture to surround said skirt portion is provided to hold the skirt (6) against the plunger end portion (4). When the plunger (1) is depressed within the barrel, the locking ring (3) is delayed by the wall of the barrel while the skirt (6) is pushed inwardly. Once the skirt (6) is unrestrained by the locking ring (3), outward movement of the plunger (1) will cause its end portion (4) to be pulled free from the piston (2 ). The piston (2) is thus non-retractable to prevent a second drawing-in of liquid.

Abstract: A single-use syringe has a piston assembly having a plunger (1) with a divergently tapered end portion (4). A resiliently deformable piston (2), with a blind aperture (7) correspondingly tapered so that part of the plunger end portion (4) may fit within, also has a tapered skirt portion (6) adapted to surround a further part of the end portion (4). A locking ring (3) having a tapered aperture to surround said skirt portion is provided to hold the skirt (6) against the plunger end portion (4). When the plunger (1) is depressed within a barrel, the locking ring (3) is delayed by the wall of the barrel while the skirt (6) is pushed inwardly. Once the skirt (6) is unrestrained by the locking ring (3), outward movement of the plunger (1) will cause its end portion (4) to be pulled free from the piston (2). The piston (2) is thus non-retractible to prevent a second drawing in of liquid.

Abstract: A sealing cap for a bottle or other container comprises a tubular body and a plug disposed within the through-bore of the tubular body. The plug is displaceable within the through-bore from an initial position in which it seals the through-bore, to an intermediate position in which it is a loose fit so that the container may be evacuated through the body, and then to a final position in which it seals the through-bore. The cap has particular utility for blood sampling bottles, which are evacuated and then pierced through the cap by a fine tubular needle so as to apply suction to the needle, from within the bottle, and thus draw a sample of blood through the needle and into the bottle.

Abstract: The evacuating apparatus is used to evacuate a bottle which is fitted with a sealing cap which has a cap bore that accommodates a displaceable plug. The apparatus comprises a platform on which to stand the bottle, and a plunger directed towards the platform. An actuating arrangement operated by a manually operable lever serves firstly to extend the plunger together with an assembly in which the plunger is mounted, to push the displaceable cap plug from a first, sealing position within the cap to a second, non-sealing position. Continued movement of the actuating lever operates to apply suction through the plunger to evacuate the bottle via the cap bore. After the bottle is evacuated the plunger is further extended by displacement displacing relative to the assembly in which it is mounted, to push the displaceable plug into a third, sealing position within the cap.

Abstract: A suction generating device comprises a barrel 10 within which may slide a plunger 26. A chamber 30 within the plunger is so sealed at each end that it increases in volume as the plunger is manually displaced inwardly of the barrel. An inlet 16 of the device is connected to the chamber 30 by a stem 18 so that inward movement of the plunger generates suction at the inlet 16. The device is particularly suited for single handed utilization as a blood sampling syringe or as a fluid transfer device.

Abstract: A sample tube for obtaining a column of liquid of predetermined height in laboratory applications comprises a simple and effective construction, with a local restriction in internal diameter a predetermined distance from an inlet end and a movable valve member such as a lead shot disposed in the tube between the restriction and the opposite end, for co-operating with the restriction to retain a column of liquid at the level of the valve member and restriction by surface tension effects. In operation, liquid is drawn into the tube by suction to a level substantially above restriction, then the suction is removed and the liquid is allowed to drain out of the end, passing the lead shot owing to an imperfect seal between the lead shot and the restriction. When the liquid reaches the level of the lead shot and restriction, it is retained at this level by surface tension effects interacting with the lead shot and restriction.