An air flow amplifier of relatively high air flow amplification ratios in which a thin film of pressurized primary air flowing in a transverse direction is mechanically deflected to impinge on a generally frusto-conical surface tapering towards the throat of the amplifier. The deflecting action is produced by a deflection ring which is spaced inwardly from the amplifier's annular nozzle. The ring has an internal diameter substantially larger than the amplifier's throat so that secondary air ente...

A syringe includes a retractable needle assembly comprising a needle seat, a hypodermic needle, and a barrel. A hollow plunger is slidably mounted within the barrel. A seal is provided between the plunger and barrel to prevent air from passing into or out of the barrel. A piston is slidably mounted within the plunger such that movement of the plunger into the fill position locks the piston in place. A seal between the piston and the interior of the plunger prevents air or fluid from passing into...

An elongated tubular enclosure or receptacle has a radially outward extending shield for protecting the hand of the user when the disposable needle of a hypodermic syringe is being placed into the enclosure after use and before discarding.

A hypodermic syringe incorporating a post-injection safety sheath for enclosing the sharpened needle tip. The hypodermic syringe incorporates parallel main and sheath chambers, the main chamber being to store fluid being injected or withdrawn, the parallel sheath chamber positioning the protective sheath. An axially aligned slot is disposed in the wall of the protective needle sheath and is aligned in communication with the ingress of the arcuate needle. A helical compression spring is coaxially...

A tool to protect professionals who use hypodermic needles in their work from inadvertent punctures to themselves by contaminated needles comprising a sliding member (16) and a stationary member (28). The first step in using this tool is to retract sliding member (16) by compressing protruding member (24 left and 24 right) together thereby reducing the overall width of (24). (24) is then manipulated into channel (26) and retracted to the point to where leaf (18) can be depressed. The user then a...

A hypodermic syringe barrel is provided with an external rotatable and slidable protective sleeve extendable and retractable relative to a needle mounted from the barrel and the sleeve is lightly biased toward the extended position thereof with the needle fully enclosed within the sleeve. The sleeve and barrel are operatively interconnected through utilization of a pin and slot connection defining limits of extension and retraction of the sleeve and the pin and slot connection includes structure...

In order to minimize the risk of infection when a large number of animals are injected with the same needle, the injecting gun is provided with a stainless steel sleeve which surrounds the needle. The sleeve comprises a first tube attached to the needle connecting body and a second tube telescopically slidable within the first tube against a spring. A detachable plastics cap incorporating a sterilizing substance is fitted on the free end of the second tube. In use of the gun to inject an animal,...

This invention includes an external protective sheath for normally enclosing a medical needle to provide a safety protective enclosure normally surrounding the needle, but being adapted to be temporarily removed from needle enclosing protective position to expose the needle for use in penetrating a patient's blood vessel for injection of medication from a syringe or for introduction of intravenous tubing and said sheath being moveable back into protective position around the needle after use.

A needle guard for a syringe or other instrument with a sharp point is disclosed having a protective sleeve with a fitting, and having a retracted position and a locked extended position, that may be used with or added to a conventional syringe and needle assembly. Prior to and during use of the needle, the sleeve remains in a retracted position covering the barrel of the syringe. After the needle has been used, the sleeve is pushed forward into its locked extended position, so that the end of t...

The several embodiments include a hypodermic needle with a hollow member positioned over a portion of the needle, thus covering that portion of the needle. Prior to and during use, the hollow member is held away from the piercing end of the needle to allow it to be used in the normal manner. After the needle has become contaminated, a simple action by the user places the hollow member in a position covering the piercing end of the needle, and the hollow member is supported in this position again...