US2432605A - Graduated receptacle for syringes - Google Patents

Description

Dec. 16, 1947. J, H, BARACH 2,432,605

GRADUATED RECEPTACLE FOR SYRINGES Filed March 1, 1944 |1||l| Ill i lllllllll |ll lllllll WITNESSES: INVENTOR J0 5 0A fifiarac/z ATTORNEY Patented Dec. 16, 1947 UNITED STATES PATENT OFFICE GRADUATED RECEPTACLE FOR SYRINGES Joseph H. Barach, Pittsburgh, Pa.

Application March 1, 1944, Serial No. 524,588

2 Claims.

My invention relates to syringes, and has special relation to hypodermic syringes for administering of medicinal liquids, such as are suitable for subcutaneous or intravenous injections and for the introduction of medicinal fluids into body cavities.

For many 'afllictions of mankind, the amount of medicinal liquid to be administered subcutaneously or intravenously to a patient must be of an exact volume for a given concentration of the medicine. This is particularly important in the administering of insulin.

Insulin is at present available in four concentra'tions designated as U-10, U-20, U-40, U-80 and a fifth concentration U-100 may be used. The higher concentrations are multiples of the lower concentrations. Thus, insulin designated as U has twice the concentration of U-lO, insulin U-40 has twice the concentration of U-ZO, and U-80 has twice the concentration of U-iO. The insulin dosage is commonly prescribed in terms of a number of units of a certain concentration. If the concentration prescribed is not available, the patient may use one of the other concentrations but the quantity should be divided or multiplied by a factor corresponding to the concentration used.

"In accordance with the teachings of the prior art a graduated syringe is used for administering the insulin. The syringe is graduated to correspond to one .or the other of the concentrations. If the person administering insulin has a syringe corresponding to one concentration and only insulin of another concentration is at hand, he should carryout the necessary-calculations to determine the quantity of insulin to be applied. I have found that although a relatively simple computationis involved, mistakes are often made in practice by patients and sometimes even nurses, and an improper quantity of insulin .is given. The person administering the insulin misinterprets the significance of the identifications and multiplies .by a factor rather than divides or vice versa. Too little or too much insulin is thus administered and the patient is injured or endangered.

Syringes, for the purposes above generally specified, now in universal use are, without .exception, made of glass. In the making of the tubular part, or cylindrical portion, or tube, of the-syringathe part is blown into shape. In this process thoughthemanufacturer may exercise the greatest of care and employ the highest type of craftsmen. the internal diameter of the tube can 2 not be maintained uniform over its internal axial length.

In calibrating the syringe, great care must be exercised with each tube. It is thus apparent that large scale, or mass, production is not possible. Furthermore, the manufacturing cost per syringe is high. This difiiculty is by no means obviated if the internal diameter is cut to a given dimension. Since the wall thickness of the tube is not uniform enough glass has to be cut away to produce the uniform dimension. The tubes thus vary in strength. There are thus many rejects. Besides the cost of cutting the glass tubes is by no means a simple and inexpensive process.

Over and in addition to this high cost per syringe is the deplorable fact that glass, for articles of this character, is extremely fragile. The useful life per syringe is thus low.

It is an object of my invention to provide a vessel for administering dosages of medicaments, the use of which shall involve substantially no possibi 1ity of error.

Another object of my invention is to provide a vessel for administering dosages of insulin, in the use of which no computation shall be required.

A more general object of my invention is to provide a receptacle of simple structure for the administration of various substances in varying doses.

An ancillary object of my invention is to provide a syringe of novel structure.

More specifically stated, it is an object of my invention to provide a syringe for administering dosages of a liquid that is available in a plurality of concentrations without the necessity of computing the quantity of any available concentration that is to be used.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention, itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof will best be understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

Figure l is a View in longitudinal section except for portions of the piston, or plunger, showing a preferred embodiment of my invention;

Fig. 2 is a view in perspective showing two surfaces of the block used in the practice of my invention;

Fig. 3 is a view in perspective showing the remaining two surfaces of the block;

Fig. 4 is a diagrammatic view showing a development of the block; and

Fig. is an enlarged view showing a detail of the end structure of the piston or plunger.

The syringe shown in Fig. 1 comprises a cylindrical barrel l composed of a transparent plastic 39. My experiments have shown that the plastics known as thermoplastic methyl methacrylate resin and polystyrene also have merit. Some discussion of these will be made hereinafter.

This barrel I is prov ded at one end with a. nozzle 2 and a hypodermic needle attachment 3 shrunk-fit on the end of the resin. The attachment may be of stainless steel or any other alloy and may be attached by means other than a shrunk-fit as for instance threads or cement, or both, This attachment is provided with a shoulder 4 against which the removable graduated rectangular ferrule or sheath 5 abuts. The attachment may be provided with threads, as shown at 6, for receiving conventional syringe elements as nozzles or needles.

The barrel I, as already stated, is transparent. In the preferred embodiment the plunger '3 is made of tinted plastic of the same type as the barrel. A dark blue color is the preferred color, but any other color as red or green may be used. The color chosen should contrast with the color of the medicine to be administered. If the medicine is a clear liquid, which is usually the case, the choice of color for the piston may suit the taste of the user.

At the other end of the barrel, I provide another reinforcing metallic end or attachment 8. This attachment may be threaded as shown at 9. A knurled sleeve nut ill shaped as shown is screwed against the ferrule 5 to hold it firmly against stop 4. The ferrule may be provided with a notch l I to hold the ferrule in a given desired relation to the attachment 3.

To the left of sleeve nut I0, I position the member l2. This member [2 may be annular or oval shaped or generally rectangular so as to provide an abutment for the index finger and middle finger of the user when the syringe, in use. is held between these two fingers while the thumb is ositioned on the knob It.

The syringe is thus disposed in a hollow block, sheath, or ferrule, 5 composed of metal or composition material, such as a phenolic condensation product. The sheath 5 has an opening at one end to receive the syringe. It is of substantially the same length as the tube or barrel I and when the syringe barrel is inserted in the open end, the nut Ill, when in place, rests against the left-hand end of the sheath or block. The cross section of the block 5 is preferably a square.

Graduations l4, l5, I6 and I! are provided on the four surfaces I8, I9, 20 and 2!, respectively, of the block 5 to correspond to the four concentrations of insulin. The spacings between the graduations and the labeling on any surface corresponds to the concentration associated with the surface and the surface is clearly labeled to indicate what concentrations it represents.

The zero marks of the graduations lie in the plane of the inner end surface of the base of the syringe tube 22 when it is disposed in'the block. The distance between the zero mark and any other mark of a graduation, therefore, corresponds to the quantity of a liquid within the tube, the level of which is in the plane of the upper graduation.

The surfaces of the sheath are provided with slots or windows, as 23, extending along the whole length of the graduations so that the level of the liquid within the syringe tube may be compared with the graduations. To facilitate the comparison, the edges, as 24 and 25, of the slots 23 adjacent the barrel l are beveled so that their cross-section is sharp and the graduations extend to the extreme edges of the bevels.

Where the piston or plunger, as 26, is to fit into an accurately machined cylinder openingZl and the piston has an outside diameter that is less than the inside diameter only by from one twothousandth to one twenty-five thousandth of an inch, considerable difficulty may be experienced in assembling the piston and cylinder.

To facilitate the insertion of the piston in the cylinder, I provide the piston end to be inserted in the cylinder with a small groove 28 spaced a short distance from the end of the piston. To provide this groove, the piston is provided with a small shallow V-shaped, or semicircular-shaped, circumferential cut at the end. Between this groove, or cut, and the end of the piston, I provide a small ridge, or land 29 having exactly the same outside diameter as that of the outside diameter of the piston. This land may have a width in the axial direction of from one sixtyfourth to one sixteenth of an inch, depending somewhat on the diameter of the piston.

The groove on the other hand may have a width in the axial direction measured in the surface of the plunger of from one-thirty-second to threethirty-seconds of an inch. The referred width of the land is one-thirty-second of an inch and the preferred width of the groove is one-sixteenth of an inch. These preferred dimensions work most satisfactorily for all sizes of syringe plungers except the very small syringes.

That the diameter of the piston in the plane of the land he the same as that of the main body of the piston itself is important, otherwise the benefits of this detail of my invention are not fully realized. This will become more apparent from a study of Fig. 5. The groove permits the insertion of the piston within the cylinder at least in one region-the lower region as shown in Fig. 5--for a distance substantially the distance of the bottom of the groove from the end of the piston.

As the piston is thus moved in, the axes of the cylinder and piston are automatically brought into such a relation that they intersect at some point as 30. The first step in the proper positioning of the piston within the cylinder is thus easily and substantially automatically obtained regardless of the fact that in moving the left-hand end of the piston, the piston axis may swing to any position of a small solid angle having its origin at 30 in the axis of the cylinder. Actually but little skill is required to bring the axes 3i and 32 into alignment. The result is that a very accurately fitting piston may be inserted into a cylinder in from one seventh to one tenth the time required for a similar piston not provided with the land and groove.

The end of the piston may also be cut so that the end is very slightly concave as shown at 33. This provides for a better liquid seal. But it must be remembered that the showing is very exaggerated. The cut is actually such that on any axial section, the angle BAC is very slightly less than ninety degrees. The angle is so chosen that for normal pressures exerted at the outer end of the piston, 'when the inner end contacts the bottom of the cylinder, the angle BAC will become a right angle because of the slight resil- 5 iency of the material thus forcing every bit of liquid out of the cylinder.

These refinements provided by the groove and land and the cut at the end of the piston are usually not necessary, nor is it necessary for most purposes to attain an accuracy of both piston and cylinder to within one twenty-five thousandth of an inch. I am merely providing these refinements to make my syringe a highly precise instrument as well.

Although I have shown and described a certain specific embodiment of my invention, I am fully aware that many modifications are also possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. For use with a syringe for applying dosages of a liquid which exists in a plurality of concentrations, a block having a plurality of faces corresponding in number to said concentrations and an opening to receive said syringe, said faces being graduated to correspond to said concentrations and having slots therein so that the column of said liquid and thus the volume thereof in said syringe may be compared with the graduations, the graduations on said faces being such as 6 to indicate the volume that a liquid, of concentration corresponding to any face, should have for a dosage of a given value.

2. For use with a syringe for applying dosages of insulin or any other injectable fluid which exists in one or more concentrations, a block having a quadrilateral cross-section and an opening to receive said syringe, the faces of said block beihg graduated to correspond to various concentrations and having slots therein so that the level of said fluid in said syringe may be compared with the graduations, the graduations on said faces being such as to indicate the level that the fluid within the syringe, of concentration corresponding to any face, should have for a dosage of a given value.

JOSEPH H. BARACH.

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

UNITED STATES PATENTS Number Name Date 765,611 Carr July 19, 1904 1,832,436 Wagenseller Nov. 17, 1931 1,471,644 Bandman Oct. 23, 1923

Images