Abstract: A regulator for evacuation systems including hospital aspiration systems, such regulator being inexpensively manufactured and assembled and providing a number of unique features. The subject regulator is designed to be essentially independent of altitude of operation or humidity conditions, may be made discretely or continuously variable, and also is provided with features reducing, if not eliminating, any noise of air drawn into the system for regulation purposes. An important feature of the invention is the provision of one or more metering apertures of reduced cross section such that possible error of observable knob setting is reduced to an absolute minumum, thus eliminating the necessity of mechanical-adjustment calibration. Settings are essentially accurate for all altitudes, humidity conditions, and particular pumping parameters of existing vacuum systems.

Abstract: A syringe device having smaller and larger, coaxially aligned cylinder bores each provided with respective pistons. The larger rearmost piston is in slidable sealing engagement with its bore but is free-floating on the syringe plunger shaft so that as the forward piston is withdrawn the plunger shaft slips centrally through the rear piston. Thus, fluid drawn in by the forward piston is ultimately mixed with any contents of the large cylinder or bore associated with the larger piston. The rearward piston is free to adjust its disposition on the plunger shaft in response to positive fluid pressure existing forwardly thereof. At a predetermined point in the rearward travel of the plunger, during withdrawal strokes, the pistons are linked together by provided structure for enabling simultaneous, corresponding forward travel to eject the combined substances from the over-all syringe construction.

Abstract: A fluid-transfer syringe for medical usage wherein, by use of such syringe, fluid matter may be removed from an afflicted area, such as a knee, of a patient. The spring-loaded plunger of the subject syringe is provided with a piston constructed to have an automatic fluid bypass during forward strokes. The piston serves thereby as a double-acting piston for both drawing into the area forwardly of the piston the fluid to be expelled and, simultaneously, pumping previously expelled fluid from the syringe barrel to a provided outlet port.

Abstract: A pumping syringe and attachment for withdrawing fluids from patients and other objects, wherein the fore part of the syringe is provided with a T-passageway configuration accommodating double check valves which need not be spring loaded. Successive withdrawals of the plunge relative to the barrel of the syringe produces successive withdrawals of respective charges of withdrawn liquid; subsequent, respective depressions automatically change the fluid circuit, via check valve self-adjustment, so that fluid is ejected into a laboratory-type or other container or sump.

Abstract: A fluid-transfer syringe for medical usage wherein, by use of such syringe, fluid matter may be removed from an afflicted area, such as a knee, of a patient. The springloaded plunger of the subject syringe is provided with a piston constructed to have an automatic fluid bypass during forward strokes. The piston serves thereby as a double-acting piston for both drawing into the area forwardly of the piston the fluid to be expelled and, simultaneously, pumping previously expelled fluid from the syringe barrel to a provided outlet port.