US2568173A - Aspirating hypodermic syringe - Google Patents

Description

Sept. 18, 1951 T. D. sPlvAcK ASPIRATING HYPODERMIC SYRINGE Filed June l2, v1948 ATTORNEY; I

Patented Sept. 18, 1951 UNITED STATES PATENr orties y [f- 2.56am AsPIRA'riNGLHyPoDERmosyRINGE 'Theodore D. `S-pivack, Stratford, Conn.v Anpncatialueiz, lsfig-seiiaiivaeavoi videclwith -threaded ends, and the ampules were constructed with .special .plungers .having threaded recesses to receive the threads of the plunger rods. In -the -operation -of Isuch fa syringe, an ampule is rst inserted in theisy-r'ingle tray or barrel, and then the plunger rod :is .moved forward and turned to cause the threaded end to be .screwed into the ampule plunger. After .this is done, the syringe can be 'used `'for either :injecting or aspirating 'at any time,- as' desired I 'While these aspirating syringesjare advantageous, they :have a serious drawbackinnot-being able ftowuse any standard vtype of vampli-letto carry out the aspirating function, but instead require ampules havingplungers with recessed and threaded `cen- -tral metal inserts.

The present invention overcomes this objection, and an object of the invention isfto provide an improved hypodermic syringe of the type empolying cartridges or ampules, which isoperable with ordinary ampules having non-recessed and non-threaded rubber plungers to aspirate as well as inject, therefore not requiring thespe'cial ampules provided with the recessed and-threaded plungers, but which is at the same time capable of using such ampules, when necessary, in spite of their usual central metallic inserts.

Another object of the invention is to provide an improved hypodermic syringe as above characterized, which is simple and sturdy in construction and economical to fabricate.

In accomplishing the above objects I provide, in accordance with the invention, an improved syringe structure having the usual means for receiving and holding an ampule orcartridge, as for example a tray or barrel. Operatively connected with said means is a plunger rod for engaging and operating the rubber plunger in the ampule, and I provide on the plunger-engaging end of the rod a hollow, centerless, pointed helical extension somewhat in the form of a short corkscrew. This extension is so arranged and con- `2 same time turning it. This will `cause the .pointed helix tochter the rubbery plunger `off -theampule .in the na'nner thata corkscrew yenters the cork o ,a bottle. Due tol the hollow, centei'less' structure, only a slight amount lof ,pressure and V.turning is necessary, whereupon Ithe Yhelix will become Vcompletely embedded ,in the plunger 4,andthe rod thereby attached Asecure'- Ily enough tofthe'gplunger for withdrawing the .saine Lor aspirating. Thereafter Athe operator may 'eitherinject or aspirate Aas desired.

.Other features and advantages will 'hereinafter appear.

"In 'the z'alccompanying drawings:

Figure Al is a 'plan view of' a' syringe 'made Iin accordance with itheinvention, a porti-on 'being rbrokenaw'ayand shown in section to'rev'eal the Vfhelixcarryingendpf the plunger rod.v

y Fig. 2 is an enlargeddetail, in'sectiomshow-ing 2the inner end of'lthe plunger and the helix carried A'thereby, land showing 1the adjacent -endof an ampule, together with adjacent portions of the syringe, and

Fig. 3 is an enlarged detail in section showing the helix carried on the end of the plunger rod being embedded in the plunger.

As shown, the improved syringe of the present invention comprises a tray or barrel III having at one end a needle I I secured in place by the usual threaded nut I2, and having the usual sight opening I3 for viewing the contents of an ampule I4 carrried in the barrel.

The syringe may have finger grips I5 as shown, attached to the barrel I0, and may have a plunger rod I6 insertable in the barrel and operable by a nger grip I1.

It will be noted that the ampule I4 may be of the standard or ordinary type comprising a transparent cylindrical vessel or tube I8 carrying uid I9 which is to be injected, the tube being closed by a solid, soft rubber stopper 20.

In accordance with the present invention the inner end 2i of the plunger rod I5 adjacent the stopper 20 of the ampule is provided with a pointed, helical extension 22. The extension 22 is preferably formed of metal wire, of sufficient thickness to be generally rigid and inflexible, and to withstand bending or deformation under ordinary conditions of use. The helix or extension has a very sharp, gradually tapered entering point 23, and is so arranged that when the plunger rod I6 is pushed inward and turned in a clockwise direction, as viewed from the handle end of the syringe, the extension will easily snag the rubber of the plunger 20, and screw itself into the same, and will thereby become embedded and attached to the plunger to provide for aspirating as well as injecting.

During this process of making the connection, the sharp, tapering entering point 23 proceeds to form a passage into which the remainder of the helix 22 exactly fits, and the total volume of the helix is so small that the swelling of the plunger occasioned by the additional helix material will be negligible, although the extension 22 has a firm grip on the plunger due to its helical conguration. This factor is important since plungers are normally tightly fitted in they ampules to protect the contents thereof and insure sterility. For this reason any significant expansion thereof would tend to bind the plunger in the ampule tube and prevent proper operation of the device.

The advantages of an aspirating syringe are well known and need riot be elaborated on here, it being understood that by the aspirating operation it is possible to determine whether or not the needle Il has struck a vein or other large blood vessel prior to giving the injections. By the present invention it is not necessary to employ am- Apules having special recessed or threaded plungers in order to provide for aspirating, and therefore the usual type of ampules with solid soft rubber plungers and which are readily obtainable from :tral embedded threaded metallic connecting element, the syringe of the present invention may still be used, for the oenterless helix will surround the central metallic insert and engage only the Vrubber material of the plunger proper.

Variations and modications may be made jwithin the scope of the subjoined claim and pormounted on the rod, and said wire being gradually tapered to a sharp point at its free end, whereby said extension will dig readily into the surface of an ampule plunger in response to rotary movement ofthe rod, will grip the plunger securely without creating any substantial wedging action against the walls of the ampule, and whereby the extension is also capable of engaging and holding ampule plungers vof the type having a centrally 'embedded connection member, by engaging the plunger portions surrounding such member and receiving the member within its hollow center. THEODORE D. SPIVACK.

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

UNITED STATES PATENTS Number Name Date 1,495,924 Quayle May 2'7, 1924 1.752384 Jamison Apr. 1, 1930 1,971,687' A Kratz Aug. 28, 1934 2,460,039 Scherer et al Jan. 28, 1949 FOREIGN vPATENTS Number l Country Date 61,467 Germany Mar. 9, 1892

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