US2753867A

US2753867A - Cartridge-type hypodermic syringe

Info

Publication number: US2753867A
Application number: US462193A
Authority: US
Inventors: Samuel D Goldberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-10-14
Filing date: 1954-10-14
Publication date: 1956-07-10
Anticipated expiration: 1973-07-10

Description

July 10, 1956 s. D. GOLDBERG CARTRIDGE-TYPE HYPODERMIC SYRINGE Filed Oct. 14, 1954 a gy United States Patent CARTRIDGE-TYPE HYPODERMIC SYRINGE Samuel D. Goldberg, West Hempstead, N. Y.

Application October 14, 1954, Serial No. 462,193 1 Claim. (Cl. 128-218) This invention relates, generally, to syringes of the type commonly employed for parenteral administration of drugs and other substances and, more particularly, it relates to an improved and novel syringe of the type mentioned that is suited for use with conventional types of single-dose, disposable cartridge containing drugs and/or other substances requiring administration by parenteral routes.

It is known to provide materials intended for parenteral administration in disposable tubular cartridges, closed at one end by a movable piston frictionally engaged with the interior surface of the cartridge, and closed at the opposite end by an easily pierceable diaphragm of rubber or the like. These cartridges are used in conjunction with a syringe comprised of a tubular barrel, adapted to receive the cartridge, having a double-pointed hypodermic needle mounted at one end, adapted to pierce the diaphragm when the cartridge is forced into the barrel, and having a head mounted at the opposite end bearing a slidable piston-actuating means whereby the piston can be moved axially into the cartridge, causing the contents thereof to be expelled through the needle.

One of the chief disadvantages of previously known types of cartridge syringes is that these syringes individually have been adapted to use with merely a single form and dosage-size of cartridge, hence it has been necessary for the physician to have available, both in the field and in his office, a whole series of syringes, adapted to accommodate cartridges of various sizes containing different dosages of medicaments.

This lack of adaptability of prior art types of syringes to use with cartridges differing slightly in length from that of the cartridges for which the syringes specifically were designed has created problems, also, in instances when it is desired to administer different forms of a medicament. For example, cartridges containing suspension forms of medicaments normally exceed in length the cartridges containing an equal volume, liquid, of other forms of the medicaments. This slight additional cartridge length, in many instances, has prevented use of such cartridges interchangeably with standard types of prior art syringes.

A further disadvantage of these prior art types of hypodermic syringes is that they are comprised of a multiplicity of parts, each of which perfoms merely a single function, hence, necessarily, the syringes are very bulky, weighty and cumbersome to use.

One of the chief objects of this invention is to provide a light yet sturdy hypodermic syringe, adapted to use with cartridge-packaged medicaments and the like, that is comprised of merely a few parts, simple in structure and capable of low cost production, and that is free of the above mentioned disadvantages of prior art types of syringes.

7 Another object of this invention is to provide a novel,

structurally simplified syringe of the type aforesaid, that can be used with full effectiveness, as desired, with different dosage-size cartridges differing substantially in length.

A further object of this invention is to provide a syringe for use with cartridge-packaged medicaments and the like, which, positively, holds and retains the cartridge, irrespective of variations in cartridge length, against motion axially within the syringe barrel, thereby substantially precluding accidental disengagement of the cartridge from the needle upon retraction of the cartridge piston under the conditions aforesaid.

Still another object of this invention is to provide a syringe having the features and advantages above mentioned and that, further, is characterized by such simplicity of structure and absence of complicated elements that it can be manufactured easily in mass production using automatic screw machinery.

Other objects of this invention will be apparent hereinafter to those skilled in the field to which this invention relates as the detailed description of the presently preferred embodiment of the invention proceeds.

To facilitate a fuller and more complete understanding of the subject matter of this invention and of how the principles thereof best may be applied to provide animproved cartridge-type hypodermic syringe, reference is made now to the figures of the accompanying drawing, illustrating the presently preferred embodiment of this invention, wherein:

Figure 1 is a substantially a front view, in perspective,

of a hypodermic syringe embodying the present invention;

Figure 2 is substantially a longitudinal sectional view of the syringe illustrated in Figure l, partly broken away to facilitate showing of internal structure, with a conventional medicament-containing cartridge shown within the syringe barrel and a conventional needle shown mounted on the barrel end; and

Figure 3 is substantially a fragmentary enlarged sectional view, illustrating in detail the preferred mode of engaging the cartridge piston with the piston actuating means.

Referring now to the figures of the drawing, especially Figures 1 and 2 thereof, wherein like reference numerals designate the same structural element or feature, it will be observed that the hypodermic syringe according to this invention, generally indicated by the reference numeral 10, essentially comprises three associated and coacting parts: a barrel, a plug engaging the barrel end, and a plunger assembly mounted in said plug. The barrel 11, which is adapted for receiving and holding a conventional medicament-containing cartridge, is substantially tubular in form and provided with one or more longitudinally extending inspection openings or slots, one of which is designated 11a. One end of the barrel 11 is provided with a constricted formation, generally indicated by the numeral 12, upon which a double-pointed conventional hypodermic needle, generally designated 13, is engageably mounted. The plug 14 is comprised of a relatively elongate, essentially cylindrical body having an opening extending axially therethrough, provided .with highlypitched external threading 15, extending along substantially its entire length, engaging with mating threading 16 in the interior end portion of the barrel 11 when the plug is positioned therein substantially as shown.. It will be noticed that the plug 14 is provided with a pair of integrally formed, diametrically positioned, oppositely radially. extending lugs 17, together constituting the syringe finger grip as will be hereinafter described, and

serving also to facilitate rotating the plug relative to the syringe barrel whereby the plugmay be advanced toward or retracted from the constricted end formation 12 at the barrel portion bearing the needle.

The syringe plunger assembly, which serves as the piston actuating means, comprises a group of permanently integrated elements, generally designated 18, including a rod-like shaft portion 19, freely slidably received in the axially extending opening formed in the plug 14, terminating. at one end in a head 2 shaped to fit the syringe users hand and constitute the hand grip of the syringe, and, at the opposite end, terminating in a threaded portion 21, which engages with and carries thereon an internally threaded stop collar 22, substantially as shown in detail in Figure 3, which serves to prevent withdrawal of the shaft from the plug opening.

It will be understood that, when in use, a medicamentcontaining cartridge is placed within the syringe barrel and a double-pointed hypodermic needle is mounted on the constricted end portion of the barrel, the parts being arranged substantially as shown in Figure 2. This is accomplished, preferably, as follows: Either before or after autoclaving the parts to effect essential sterilization, the plunger and plug assembly is removed from the breech end of the syringe barrel. A conventional medicamentcontaining cartridge 23, provided at one end with a partial' closure 24, adapted to being punctured by a needle, is inserted into the syringe barrel with the partial closure end facing toward the constricted end 12 of the barrel.

The threaded portion of the plug 14 is then engaged with the internal threading of. the syringe barrel breech portion and, by relative rotation of the plug and barrel, the plug is advanced axially into the barrel until the end portion 14a of the plug 14 abuts against the end portion 23a of the cartridge 23. It wil be understood that when the syringe elements and the cartridge have been so positioned with relation to each other, frictional forces acting upon the threaded parts will suifice to resist reverse motion of the plug relative to the syringe barrel, thus, the cartridge will be held firmly within the barrel between the plug and the constricted barrel end without possibility of motion axially within the barrel.

By suitable manipulation and rotation of the plunger shaft 19 and the head 20, the shaft is advanced axially within the barrel until a threaded opening 19a, formed in the shaft end, is brought into engagement with and engages. a threaded stud 25, imbedded in and carried by the piston 26, positioned in the end portion of the cartridge 23 distal. from the partial closure 24. When the various parts and elements have been so positioned, a sterilized, doublepointed hypodermic needle 13, coaxially mounted in a tubular, internally threaded ferrule 27, is introduced into an axially extending opening formed in an externally threaded, integrally formed, hollow stud 23, provided on the constricted end portion 12 of the barrel. The needle is advanced axially toward the partial closure 24 at the near end of the cartridge 23 and the threads of the ferrule and stud are interengaged, whereby the needle is advanced further, causing it to pierce the partial closure and enter the medicament-containing chamber of the cartridge. The syringe then is ready for its intended use and the medicament contained within the cartridge may be discharged through the needle by pressing the plunger head Ztl toward the radially extending lugs 17 constituting the syringe finger grip, whereby the piston 26 is advanced axially within the cartridge. After administration of the medicament and withdrawal of the needle from the patient, the plunger shaft 19 and the head may again be manipulated, this time to disengage the shaft threaded end portion 19a from the stud 25, then the plug 14 is retracted by rotating it relative to the barrel, it is removed from the barrel breech and the cartridge is removed and discarded.

It is especially to be emphasized regarding this, the preferred embodiment of this invention, that the plug 14 is of a substantial length relative to the barrel length, and the threading whereby these two parts are brought into cooperative engagement is extended over such a proportion of the length of these parts, that the syringe may be used, at choice, with cartridges substantially differing in length and of proportionately different capacities.

In the foregoing description of the presently preferred embodiment of this invention, it will be observed that the plunger or piston actuating assembly is described as being comprised of three elements, the hand grip or head 20, the rod-like shaft M which is freely slidably mounted in the plug opening, and the stop collar 22, threadably engaged with the shaft at its end distal from that carrying the hand grip. It will be understood that, without departing from the spirit and substance of this invention, this assembly may be structurally modified in detail, without loss of essential functions, by having the hand grip threadably engaged with the shaft end, instead of being integrally formed or permanently integrated with it as in the embodiment of the invention illustrated, in which instance, the stop collar may be formed integrally with the shaft end, instead of being threadably engaged therewith as described. This and similar minor, uninventive modifications of the specific syringe structure above described, it will be understood, lie within the scope of this invention,

It is preferred, for the important practical consideration that the syringe weight be minimized and for the further reason that this metal is particularly well adapted to shaping by use of automatic screw machinery, that the syringe barrel, plug and plunger assembly be fabricated from aluminum or an aluminum alloy, although, of course, other light, easily machined metals may be used if desired. Non-metallic substance such as plastics lack essential properties for this use and are unsatisfactory materials for use in making the syringes according to this invention.

Having thus described the subject matter of this invention, what it is desired to secure by Letters Patent of the United States is:

An improved hypodermic syringe, adapted to use with conventional types of disposable, single-dose, medica-- ment-containing cartridges, characterized in that it may be used, at choice, with cartridges of substantially difierent length and volume, that comprises a barrel, said barrel being comprised of an elongate, tubular body portion, open at one end and provided at that end with high-pitched internal threading extending within the body portion a substantial proportion of the length thereof, and, at the other end of said body portion, provided witha constricted formation, terminating in an axially outwardly extending stud portion and provided with an axially located opening formed therein and extending therethrough; means on said stud portion for rigidly mounting and retaining thereon a double-pointed hypodermic needle with one of its end portions disposed within the axially located opening of the constricted formation and extending therethrough into the interior of the barrel; an elongate, essentially cylindrical plug mounted in the open end of said barrel, said plug having an axially located opening formed therein and extending therethrough and a pair of lugs, near one end thereof, extending radially in opposite directions to constitute a pair of diametrically positioned syringe finger grip elements, said plug being provided with external threading mating the internal. barrel threading whereby the plug is threadably engaged with the barrel and may be caused to engage and hold against axial movement a cartridge positioned within the barrel; and cartridge piston actuating means, mounted on said plug and comprising an elongate, rod-like plunger element, freely slidably mounted in the axially extending opening of the plug, said plunger element terminating, at its end positioned within the barrel when the plug is engaged therewith, with a stop collar formation, consisting of an annulus, threadably mounted thereon, to restrict Withdrawal of the plunger element from the opening in the plug, this same end of the plunger element being provided with threading for engagement with a threaded member on the cartridge piston to permit movement of the piston axially in opposite directions, said plunger element terminating at its opposite end in a hand grip element for facilitating movement of the cartridge piston during use of the syringe.

References Cited in the file of this patent UNITED STATES PATENTS Cressler Sept. 17, 1929 Saflir Oct. 10, 1939 Hyslop Jan. 12, 1954 Lockhart Nov. 2, 1954 FOREIGN PATENTS Germany Dec. 7, 1931