Disposable additive syringe

Claim 2

A disposable additive syringe having a cylindrical barrel closed at the rear end by a slidable plunger and at the front end by a diaphragm including: a flexible wall facing rearwardly in a convex manner, a medicament chamber formed between the slidable plunger and the flexible wall, a cap and spike assembly mounted on the forward end portion of the cylindrical barrel, said spike being positioned within the cylindrical barrel with its pointed end spaced from and outside the flexible wall, said spike having a passage therethrough, a cannula extending forwardly from the cap and spike assembly in fluid communication with the spike passage, a cylindrical safety guide surrounding the cannula in a spaced manner, a spike mounted on the forward end portion of the safety guide, said spike having a throughbore aligned with the cannula whereby the forward end portion of the cannula fits within said throughbore, and a sheath covering the spike.

Claim 3

The invention as set forth in claim 1 and wherein the cap and spike assembly are of unitary construction.

Claim 4

The invention as set forth in claim 1 and wherein the cap and spike assembly and the cylindrical safety guide are of unitary construction.

Claim 5

The invention as set forth in claim 1 and wherein the spike mounted on the forward end portion of the cylindrical safety guide has a circular base portion provided with two oppositely threaded sections, one to cooperate with threads on the forward end portion of the cylindrical safety guide and the other to cooperate with threads on the rearward end of the sheath.

Claim 6

A disposable additive syringe having a cylindrical barrel closed at the rear end by a slidable plunger and at the front end by a diaphragm including a body portion sealingly engaging the inner wall of the cylindrical barrel and a flexible wall connected to the rearward side of the body and extending rearwardly therefrom, a medicament chamber formed between the slidable plunger and the flexible wall, a cap and spike assembly mounted on the forward end portion of the cylindrical barrel, said cap fitting over the cylindrical barrel and supporting the spike so that its end will be spaced from and outside the flexible wall, said spike having a passage therethrough, a cylindrical projection extending forwardly from the cap and axially aligned with the spike passage, a forwardly extending cannula mounted by the projection, a cylindrical safety guide extending forwardly from the cap and surrounding the cannula in a spaced manner, a spike mounted on the end portion of the safety guide, said spike having a throughbore aligned with the cannula whereby the forward end portion of the cannula will fit within said throughbore, and a sheath threadedly secured to the spike to cover same.

Claim 7

A disposable additive syringe having a cylindrical barrel closed at the rear end by a slidable plunger and at the front end by a diaphragm including a body portion sealingly engaging the inner wall of the cylindrical barrel and a flexible wall connected to the rearward side of the body and extending rearwardly therefrom, a medicament chamber formed between the slidable plunger and the flexible wall, a cap and spike assembly mounted on the forward end portion of the cylindrical barrel, said cap fitting over the cylindrical barrel and supporting the spike so that its end will be spaced from and outside the flexible wall, said spike having a passage therethrough, a cylindrical projection extending forwardly from the cap and axially aligned with the spike passage, a forwardly extending cannula mounted by the projection, a cylindrical safety guide extending forwardly from the cap and surrounding the cannula in a spaced manner, a spike mounted on the end portion of the safety guide, said spike having a throughbore aligned with the cannula whereby the forward end portion of the cannula will fit within said throughbore, and a sheath threadedly secured to the spike to cover same.

Claim 8

The invention as set forth in claim 5 and wherein the cannula is slightly longer than the cylindrical safety guide whereby the end portion of the cannula extends only slightly beyond the end of the guide so that injection into a patient is virtually impossible.