US2767710A - Hypodermic syringes - Google Patents

Description

Oct. 23, 1956 l' s, N. BLACKMAN 2,767,710

` HYPODERMIC SYRINGES Filed Nov. 6, 1952 Ti lz..

United States Patent HYPODERMIC SYRINGES Seymour N. Blackman, Teaneck, N. J., assignor to Premo Pharmaceutical Laboratories, Inc., South Hackensack, N. J., a corporation of New York Application November 6, 1952, Serial No. 319,133 Claims. (Cl. 12S-218) This invention relates to hypodermic syringes, and more particularly to syringe tips.

Conventionally, a syringe is made from glass in one piece with the barrel. The ditiiculty with such a tipV is that it has to be very finely and accurately ground to insure a tight frictional iit with the hub of a needle. Besides being expensive to make, such tips are brittle and easily broken in use. Glass tips have the advantage, however, of being easy to clean since, being integral with the barrel, they have no hard to reach interstices where matter can lodge.

Metal syringe tips have been found to be much easier to fabricate in a proper size to receive the hub of a needle; of course, they also are less susceptible to break-age. But matter invariably lodges in the joint between the metal tip and glass barrel. Since the metal tip is permanently secured to the barrel, metal tip syringes cannot be thoroughly cleaned and have to be discarded after being used la few times and sometimes after only a single use.

It is an object of the present invention to provide a metal tipped hypodermic syringe having all the advantages of glass tipped and metal tipped syringes but the disadvantages of neither.

it is another object of the present invention to provide a hypodermic syringe of the character described which can be easily `and thoroughly cleaned.

It is another object of the present invention to provide a hypodermic syringe of the character described which is simple and inexpensive to produce in mass production.

It is another object of the present invention to provide a hypodermic syringe of the character described which is rugged and long-lasting.

Other objects of the present invention will in part be obvious and in part will be pointed out hereinafter.

The invention accordingly consists in the features of constructions, combinations of elements and arrangements of parts which will be examplitied in the devices hereinafter described and of which the scope of application will be indicated in the appended claims.

ln the accompanying drawings in which are shown the various possible embodiments of the invention:

Fig. 1 is a side view of a hypodermic syringe constructed in accordance with the present invention;

Fig. 2 is an enlarged exploded view of the tip of the syringe shown in Fig. l;

Fig. 3 is -an enlarged sectional view taken substantially along the line 3 3 of Fig. l;

Fig. 4 is a sectional view taken substantially along the line 4-4 of Fig. 3;

Fig. 5 is a fragmentary plan view of a hypodermic syringe embodying a modied form of the present invention;

Fig. 6 is an enlarged sectional view taken substantially along the line 6 6 of Fig. 5; `and Fig. 7 is a sectional View taken substantially along the line 7-7 of Fig. 6.

Referring now in detail to the drawings, and more particularly to Figs. 1 4, the reference numeral 10 de-` notes a hypodermic syringe having a metal tip 12 embodying the present invention. The syringe includes a glass barrel 14 having an integral cylindrical plug 16 at its bottom. The bore of the barrel is smoothly ground to s lidably receive a similarly ground plunger 18.

A metal tip 20 is integral with the bottom of an opentopped tubular socket 22 adapted to permanently frictionally engage the glass plug. A central passageway 24 in the plug is aligned with a central passageway 26 in the tip.

It is between the top surface 28 of the base of the socket and the parallel under surface 30 of the glass plug that matter lodges. Washing the syringe cannot dislodge this material.

Pursuant generally to the present invention, a ilexible resilient washer 32 composed, for example, of polyamid resins, e. g. nylon, is sandwiched between said top surface 28 and under surface 30. Said washer has an aperture 33 registered with the passageways 24, 26 and of the same or barely larger diameter. When the socket is assembled on the plug, the washer is compressed thereby preventing material fromcollecting between said opposed surfaces. No matter can be caught between the washer and the surfaces it abuts because the elasticity of the washer and the compression under which it is held create a tight tit between said washer and surfaces. Such a tit could not be obtained practicably between the glass surface 3@ and metal surface 28.

Although a planar top surface 23 will accomplish the objects of the present invention, in the illustrated syringe said surface is provided with an upstanding narrow annular stub ilange 34 around the top of the passageway 26. When the socket is tightened on the glass plug, the flange is forced into the washer, ensuring a very tight t between the washer, socket and plug with a localized high pressure in the region of the flange. If desired, the upper end 35 or" the passageway in the metal tip may be flared somewhat to allow for tolerances in the size and position of the opening in the washer. It will be observed that this -arrangement does not form cracks from which material cannot be flushed.

The metal tip removably and frictionally engages the Luer hub 36 of a hypodermic needle 38, the tip being tapered to match the standard hub cavity.

In the modied form of the invention shown in Figs. 5-7, the metal tip is identical to that already described, except for the addition of a needle lock. Said lock constitutes a skirt 40 on the socket in which the hub of the needle is received. The inside of the skirt includes a thread 42 with which corners 44 on the needle hub mesh.

Thus it will be seen that there are provided devices which achieve all the objects of invention and are well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described, or shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, there is claimed as new and desired to be secured by Letters P-atent:

1. In a hypodermic syringe having a glass barrel with a plug at its bottom, said barrel having an aperture at its bottom extending through said plug in a direction axially of the barrel, Ia metal socket with an integral tip, said socket having an aperture extending through said tip in an axial direction, said plug being permanently secured in said socket with said barrel and socket apertures in alignment, the upper end of the aperture in the socket being larger than the lower end of the aperture in the barrel, and a ilexible resilient washer of synthetic plastic compressed between said plug and socket, said washer having an opening therethrough, said opening in the washer being in alingement with the barrel and socket apertures, the aperture at the upper end of the tip of the socket being larger than the opening in the washer and the opening in the washer being larger than the lower end of the aperture in the barrel.

2. A combination as set forth in claim 1 wherein the socket has a narrow annular stub Harige around the top of the aperture therein.

3. A combination as set forth in claim 2 wherein the aperture in the socket is ared at its top.

4. For use with a hypodermic syringe having an apertured glass plug and a ilexible resilient washer of synthetic plastic disposed therebelow, said washer having an opening therethrough, the opening in the washer being larger than the lower end of the aperture in the barrel, a. metal socket permanently secured to the plug and holding the washer under compression, said socket having an apertured tip extending therefrom, the upper end of the aperture in the tip being larger than the lower end of the aperture in the plug, and a narrow annular stub flange in the socket around the top of the aperture in the tip, the upper end of the aperture in the socket being larger than the opening in the washer.

5. For use with a hypodermic syringe having an apertured glass plug and a flexible resilient washer of synthetic plastic disposed therebelow, said washer having an opening therethrough, the opening in the washer being larger than the lower end of the aperture in the barrel, a metal socket permanently secured to the plug and holding the washer under compression, said socket having an apertured tip extending therefrom, the upper end of the aperture in the tip being larger than the lower end of the aperture in the plug, and a narrow annular stub ange in the socket around the top of the aperture in the tip, the aperture in the tip being flared at its top, the upper end of the aperture in the socket being larger than the opening in the washer.

References Cited in the tile of this patent UNITED STATES PATENTS 1,471,644 Bandman Oct. 23, 1923 2,520,092 Fredrickson et al. Aug. 22, 1950 2,656,836 Hickey Oct. 27, 1953 FOREIGN PATENTS 494,921 Great Britain Nov. 3, 1938

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