US2539510A - Hypodermic syringe - Google Patents

Description

Jan. 30, 1951 J. H. FRIDEN HYPODERMIC SYRINGE Filed June 3, 1949 FIG! INVENTOR JOHN H. FRIDEN 313%! AT TORNE Y.

Patented Jan. 30, 1951 HYPODERMIC SYRINGE John H. Friden, Maplewood, N. J., assignor to Bristol Laboratories, Inc., Syracuse, N. Y., a

corporation of New York Application June 3, 1949, Serial No. 97,027 7 2 Claims. I

This invention relates to'hypodermic syringes, and in one of its more specific aspects, to relatively small, compact syringes intended to be used once and then discarded.

It is a principal object of the invention to provide an improved hypodermic syringe that is simple and compact in construction and is capable of accomplishing its intended functions in an eflicient and trouble-free manner.

Another object of the invention is to provide a single-use, disposable hypodermic syringe that is inexpensive in manufacturing cost.

Another object of the invention is to provide an instrument of the character indicated, wherein a medicament-containing capsule of ampule and a needle-carrying plunger are assembled in a condition ready for use at the time of manufacture, and wherein the operating needle and the contents of the ampule are protected against in- Jury or contamination during the interval between the time of manufacture and use.

A further object of the invention is to provide a hypodermic needle having its parts so arranged as to visually indicate to the user, prior to injection of the medicament, whether the distal end of the needle, when inserted in the body of a patient, is in communication with a vein, or other blood vessel, or is positioned in body tissue.

To the end that the foregoing objects may be attained, the hypodermic syringe of this invention preferably comprises a tubular body closed at its lower end and open at its upper end. The tubular body may be made of glass or may be molded from a suitable plastic material that will not contaminate the liquid medicament contained in the lower portion of the body. A rupturable partition is disposed across the interior of the tubular body intermediate its ends and hermetically seals the medicament therewithin.

A reciprocable plunger is positioned in the portion of the tubular body above the partition and is formed with coaxial, generally frusto-conical end portions. Below the upper irusto-conical end portion is a suitable means, such as a pair of diametrically opposed wings, engageable by the fingers of the user, in the course of use of the instrument, to efiect movement of the tubular body with respect to the plunger. The plunger, preferably made of a suitable plastic, is formed with an annular recess above the lower frustoconical end portion, and is provided with a resilient distortable sealing ring that registers with the annular recess and is in intimate contact with the interior of the tubular body. The sealing ring is, in turn, provided with one or more external annular grooves.

A hypodermic needle, pointed at each end, is coaxial with the frusto-conical portions of the plunger and extends beyond each end of the plunger. The needle is secured to and is movable with the plunger.

A generally conical cap, likewise preferably made of a suitable plastic material and having a series of angularly spaced external stiffening ribs, covers the portion of the needle that extends above the plunger and frictionally engages the upper frusto-conical portion of the plunger. cap is so arranged with respect to the plunger as to be maintained in spaced relation to the upper portion of the needle.

The above enumerated objects, as well as other objects, together with the advantages of the invention, will be readily comprehended by persons skilled in the art upon reference to the following detailed description, taken in conjunction with the annexed drawing, which respectively describe and illustrate a preferred form of hypodermic syringe constructed in accordance with the invention.

In the drawing:

Figure l is a view in elevation of a hypodermic syringe embodying the invention, the protective cap of the complete instrument being shown in a position removed from the plunger;

Figure 2 is an enlarged central vertical crosssectional view of the instrument shown in Figure l with the parts in assembled position;

Figure 3 is a view taken along line 3-3 of Figure 2; and

Figure 4 is a view taken along line 4-4 of Figure 2.

Referring now to the drawing, wherein like reference numerals denote corresponding parts throughout the several views, the hypodermic syringe of this invention includes a first unit or ampule ID that comprises a right cylindrical tubular body 12 closed at its lower end I4 and preferably formed of a suitable transparent plastic material that will not contaminate or adversely affect liquid medicament l6 contained therein. A rupturable partition 18, made of rubber, plastic or the like, is disposed across the interior of tubular body I2 and hermetically seals the medicament therewithin.

A second unit 20, reciprocable in tubular body 12, includes a plunger 22, preferably made of a suitable plastic material. Plunger 22 comprises an upwardly tapering frusto-conical upper end portion 24, a pair of diametrically opposed lateral wings or extensions 26, and a downwardly tapering frusto-conical lower end portion 30 that is coaxial with frusto-conical upper end portion 24.

The diameter of the plunger is slightly smaller than the internal diameter of tubular body l2 to eliminate undue friction. The plunger is formed with an annular recess 32 above irusto-conical lower portion 30. The annular recess is adapted to receive and retain a sealing ring 34 made of a suitable distortable resilient material, such as rubber. Ring 34 is provided with a plurality of external annular grooves as intermediate its ends. The major diameter of lower frusto-conical portion 30 is substantially less than the internal diameter of the tubular body to facilitate slipping sealing ring 34 on the plunger and inserting the plunger and sealing ring into the tubular body.

Embedded in plunger 22 and movable therewith is a hypodermic needle 40 that is coaxial with frusto- conical portions 24 and 30. As is best shown in Figure 2, the ends of the needle extend beyond the corresponding ends of the plunger; also, the needle is pointed at its ends, as indicated at 42 and 44. When the parts are in the relative 1 position shown in Figure 2, lower end 44 of the needle is positioned in spaced relation to the upper surface of partition I8.

The portion of the needle that extends above the plunger is protected against damage or contamination when the instrument is not in use by a generally conical cap 46, having a lateral external flange 48 at its open end. The protective cap frictionally engages the portion of the plunger above the wings and bears against the upper surface of wings 26, whereby the cap is maintained in the position shown in Figure 2 with respect to the plunger. The cap includes a plurality of angularly spaced longitudinal external ribs 50, as is shown in Figures 1 and 2. Ribs 50 serve to lend rigidity to the cap proper and its flange 48.

The parts are sterilized and assembled, as shown in Figure 2, at the time of manufacture. With the parts so arranged, ring 34 not only provides an eflective seal to prevent entry of dust or other foreign material which might contaminate the contents of the tubular body, but also frictionally maintains plunger 22 in the illustrated position with respect to the tubular body so that lower needle point 44 is spaced above partition l8.

The hypodermic syringe of this invention is used in a. manner that will now be briefly described. Cap 46 is removed from plunger 22 and the user grips the syringe, placing his index and middle fingers on corresponding wings 26, and his thumb against closed end 14 of the tubular body. Exposed point 42 of the needle is inserted in the patients body. The user may readily determine whether end 42 of the needle is properly positioned in the patient by moving ampule l0 downwardly a short distance with respect to plunger 22, as viewed in Figure 1. If point "42 of the needle communicates with a. vein or other blood vessel, blood will be drawn into the needle and appear in the space above partition l8. If the injection is to be intramuscular, the user withdraws the needle and moves the plunger back to the position shown in Figures 1 and 2, thereby ejecting the blood remaining in the needle. The needle is reintroduced into the body and the described procedure is repeated until no appreciable amount of blood appears.

After the needle has been inserted into the desired location, ampule I0 is moved by thumb pressure along piston 22 so that lower end 44 of the needle pierces partition i8 and the liquid medica-' ment "3 is transmitted through the needle into the patients body. Ampule in may be moved upwardly along plunger 22 until the upper extremity of tubular body [2 bears against the under surface of wings 26, whereby further upward movement of the ampule with respect to the plunger is arrested.

From the foregoing, it is believed that the construction, operation and advantages of my present invention will be readily comprehended by persons skilled in the art. It is to be clearly understood, however, that various changes in the apparatus set forth above may be made without departing from the scope of the invention as defined in the claims of this application, it being intended that all matter contained in the description or shown in the drawing shall be interpreted as illustrative only and not in a limiting sense.

I claim:

1. A hypodermic syringe comprising a tubular body closed at its lower end and open at its upper end and containing liquid to be dispensed therefrom, a rupturable partition across the interior of the tubular body intermediate its ends and hermetically sealing the liquid therewithin, a reciprccable plunger in the upper end of the body. said plunger comprising generally frusto-conical upper and lower end portions and laterally extending finger engageable means below the frustoconical upper end portion, said plunger having an annular recess between the flange and the frustoconical lower end portion, a resilient distortable sealing ring positioned in the annular recess and in intimate contact with the inner surface of the tubular body, a double-pointed hypodermic needle secured to and movable with the plunger, said needle being coaxial with the frusto-conical portions and extending beyond each end of the plunger, and a protective cap covering and spaced from the portion of the needle that extends beyond the upper end of the plunger, said cap frictionally engaging the upper portion of the plunger and bearing against said means.

2. A hypodermic syringe as defined in claim 1, wherein the means comprises oppositely disposed extensions having coplanar upper surfaces and the protective cap comprises a generally conical tubular member having an external lateral flange at its open end and a plurality of angularly spaced longitudinal external ribs integral with the flange and the tubular member.

. JOHN H. FRIDEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 159,192 Leiter Jan. 26, 1875 446,125 Schirmer Feb. 10, 1891 791,802 DeLisle June 6, 1905 1,100,798 Wedig June 23, 1914 1,179,561 Reed Apr. 18, 1916 1,817,003 Hein Aug. 4, 1931

Images