US2267074A - Cartridge for hypodermic syringes - Google Patents

Description

' Dec. 23, 1941. w, Roc w 2,267,074

CARTRIDGE FOR HYPODERMIC SYRINGES Filed April 30, 1940 INVENTOR W4 LAED H B/wc/rn/A y H I ATTORNEYS Patented Dec. 23, i941 CARTRIDGE FOR HYPODERMIC SYRINGES Willard H. Brockway, Needham, Mass.

Application April 30, 1940, Serial No. 332,493

4 Claims.

My present invention relates to an improvement in cartridges and like units, and more particularly to such units filled or to be filled with a fluid medicament intended for hypodermic administration. Such units are usually used in a suitable hand operated syringe such as I showed and described in my prior Letters Patent No. 1,604,018, granted to me October 19, 1926, and which has become a standard type and one quite generally in use by dentists or dental surgeons.

The pain deadening solutions as in procaine, morphia or opiate solutions used in dental surgery olIer particular problems and particularly those in which the pH. value has to be insured by so-called buiiering. As this process renders the solution subject to deterioration with age, it has been necessary heretofore to date each such unit and instruct its use within a definite time. This was, of course, inconvenient and subjected the surgical profession to an additional responsibility and anxiety as to results in cases where it is found necessary to give such treatment.

My concept involves a radical departure in the basis of handling such solutions as well as a certain improvement in such unit structures effective of increase in convenience, strength, safety and general utility.

As illustrative of my invention and improvement I have selected a form in which I have embodied my concept in a unit of what might be called a generally standard or conventional type. As its general aspects and technique in use are familiar to the profession, such an embodiment offers many immediate advantages. To this I have added suggestive modifications.

In the drawing I have illustrated a simple form ofiny improvement which will be hereinafter described and which is set forth as follows:

Fig. 1 is a general view of one of my units shown in combination with one of my syringes, the parts being broken out centrally for the purpose of shortening the view, and

Fig. 2 is a longitudinal section of a unit in accordance with my invention.

Fig. 3 is a view of the plunger-stopper construction and its primer or secondary container.

Fig. 4 is a view of the plunger-stopper construction with a modified primary and secondary container.

Referring to Fig. 1 I have indicated my cartrldge imit generally as T loaded in the frame I of one of my standard types of syringes. In this it is held at one end by a head cap 5 pivoted to the frame as at l and at its opposite end by a cap 2 to which the needle 3 is attached by a clamp 4. In such an instance, the needle 3 would be of a double ended type.

As shown in Fig. 2, the cartridge unit consists of the tube T which has an inturned lip t forming a shoulder about its end opening. Against this shoulder t is lodged internally of the tube end, an end seal consisting of a plug 2| having an exterior annular shoulder 22 and a central disc or button 23. As the disc or button 23 is resilient, the parts of the plub 2| being of rubber or like resilient material, it is readily compressible and thus easily lodged and locked in the end of the tube T. The outer end of the central disc or button 23 projects slightly beyond the outer face of the lip t so as to make a resilient cushion for this end of the cartridge both in packing and in clamping in the syringe frame in which it bears against the inner face of the end cap 2. By rewon of its shoulder 22 and the opposed lip t any expulsive tendency by plunger or pressure of the fluid charge S is done away with. The plug 2| is provided with a cavity 24 which reduces the effective thickness axially through the button 23 so that the inner end of the double ended needle 3 which penetrates the plug does not have to pierce through its whole length.

At its opposite end the tube T is closed by a frictionally fitting plunger-stopper or cork C. This is preferably provided with external groove rings c to increase its efllciency as a piston when it is pushed down by the plunger 9 to expel the charge S when an injection is being made.

This plunger-stopper of cork C is furthermore, as shown in Fig. 2, provided in its outer portion with an axial pocket 30 preferably of cylindrical bore. In the form shown in this figure, the pocket 30 terminates just short of the innerend of the plunger-stopper or cork C leaving a wall or diaphragm 3|.

Frictionally lodged in the pocket 30 is a priming quill or secondary container 40 having a closed outer end and an open inner end ll. The priming quill or secondary container shown is made conveniently as a cup of non-corrodable metal.

In the form oi secondary container shown in Fig. 3, I provide a plunger-stopper or cork 0 provided with an axial pocket as at 52 terminating just short of its inner end as in Fig. 2, but leaving a somewhat thinner wall or diaphragm 5|. I form my secondary container with a retaining ring 53 which is seated in a corresponding re- (265$ 54 in the pocket 52.

In this form the container ill is held against movement and is discharged by heating the exposed outer end of 5| which generates an internal pressure and ruptures the thin diaphragm 5| thus discharging into the primary charge of the cartridge;

In another modification, illustrated in Fig. 4, the container 50' has no retaining ring and is held against movement simply by knurling or roughing up its surface so that it will be frictionally engaged in the axial pocket 52. It will then stay putwhen heat is applied to the outer end.

In operation, after the container 50 has been discharged, the unit T is clamped in the frame I of the surgeon's syringe being held therein between the head 8 or, more strictly speaking in the form of syringe shown, by the block I2 resiliently urged by the spring I0 and with its lower end seated in the cap I as before described. This spring III also functions as a frictional control on the plunger stem 9 so that the ,outer end of the secondary container lli is, therefore, up to this time, not subjected to any pressure from the plunger head 9 a When, however, the operator is ready to use the syringe so loaded, he presses the handle II with his working thumb so that the pressure first moves the piston head 9 into contact with the end of the secondary container 40 in the pocket 30 of the cork C.

The syringe is now ready for use and the operator after inserting the point of the needle 3 into the tissues at the desired locus, again finds the handle II with his working thumb and carries through with the plunger pressure as desired. In this movement, the end face of the plunger head 9 contacts the outer end of 40 and thus carries the entire cork 0 along as an advance plunger or piston to discharge the now buffered or modified contents of the unit T.

It will be understood that the type of primary charge requiring buffering is used by way of illustration and not as limiting, as various charges or solutions might be used and the secondary charge be provided for its modification on a basis other than buifering. All such modifications in the form and use will be understood as within the spirit of my invention.

. This is a continuation in part of application Serial No. 48,726, filed Nov. '1, 1935.

What I claim is:

1. A cartridge for use with a syringe consisting of a body member having a primary chamber formed therein, a piston head closure member sealing one of the ends of the said body member, a secondary chamber formed in the said piston head closure member and provided with an axial pocket terminating just short of the inner end of the piston head closure member but leaving a thin diaphragm, and open at the outer end thereof, and a container lodged in said secondary chamber provided with means to retain it in fixed position relative to the piston head closure member, said container projecting at its outer end beyond the outer face of said member and being closed at said end, and provided with an open dull-edged inner end facing said diaphragm.

2. A cartridge in accordance with claim 1 in which the means to retain the container lodged in the secondary chamber is a retaining ring seated in a recess attached to said secondary chamber.

3. A cartridge in accordance with claim 1 in which the means to retain the container lodged in the secondary chamber is a knurled surface of the container by which the container is frictionally engaged and held in said secondary chamber.

4. A cartridge in accordance with claim 1 in which the means to retain the container lodged in the secondary chamber is a roughed-up surface of the container by which the container is frictionally engaged and held in said secondary chamber.

WILLARD H. BROCKWAY.

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