US2844148A - Hypodermic syringe - Google Patents

Description

July 22, 1958 A. RAIFE 2,844,148

HYPODERMIC SYRINGE FiledO ct. 15, 1955 a4 72 IIIY/ZENTOR. BY ZZZ United States Patent HYPODERMIC SYRINGE Archie Raife, Chicago, Hl. Application October 13, 1955, Serial No. 540,217

1 Claim. (Cl. 128-218) My invention relates to improvements in hypodermic syringes.

One of the objects of my invention is the provision of an improved syringe affording means for rapidly dispensing with a high degree of accuracy a plurality of successive doses of medicament or other liquid media.

Another object of my invention is the provision of a syringe of the foregoing type having means for arresting the travel of the plunger at predetermined points so as to permit the dispensing of successive predetermined quantities of liquid media without requiring the operator to observe the graduate markings on the barrel of the syringe.

A further object of my invention is the provision of a device of the foregoing character, which is simple in construction, efficient in operation and durable in service.

Other and further objects and advantages of my invention will become apparent from the following description when considered in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal cross-sectional view of a hypodermic syringe embodying my invention;

Fig. 2 is an enlarged elevational view of a portion of the plunger, looking in the direction of the arrows 2-2 of Fig. 1;

Figs. 3, 4 and 5 are cross-sectional views taken, respectively, online 3, 4 and 5 of Fig. 2; and

Fig. 6 is a fragmentary perspective view of a portion of 'the plunger rod.

Referring to the drawings, numeral 10 indicates generally a hypodermic type syringe comprising atubular frame 11 enclosing aglass barrel 12. The forward end of theframe 11 is inwardly flanged, affording a retainingshoulder 13 for ataplet 14 into which is screwed anadapter 16 into which is fitted a hypodermic needle 17. The end of thebarrel 12 abuts awasher 18 lying adjacent an annular wall of the taplet. The opposite end of the frame is threaded exteriorly to receive a retaining cap 19, which is centrally threaded to receive aretaining member 21. Amember 22 providing diametrically opposed finger-engaging portions 23 is threaded on the end portion of theframe 11. The fore going structure is of conventional construction and forms no part of the present invention.

My invention is particularly related to a plunger rod construction, presently to be described. The plunger rod indicated generally by thenumeral 25 is of generally cylindrical construction provided at each end with a reduced threaded portion. The forward end of said plunger rod is adapted to be received within a plunger orpiston 26, which is in fluid-tight relation with the inner wall of thebarrel 12. The opposite end of the said plunger rod is in threaded engagement with aknob 27. It will be understood that the plunger and knob are of conventional construction. A major portion of theplunger rod 25 intermediate the plunger and knob is provided with 2 a longitudinally extendinggroove 28. Spaced from the ends of the plunger rod are front and rearannular grooves 29 and 30, respectively, the said grooves intersecting thelongitudinal groove 28.

On the surface portion of the plunger rod opposite thegroove 28 the rod is provided with a series of flats or flat surfaces, with adjacent flats disposed in angularly related planes so that thejunctures of adjacent flats afford shoulders or abutments for a purpose, as will be hereinafter described. Specifically, adjacent the forwardannular groove 29 there is provided a first flat 31 which is substantially tangent to the bottom of the said groove. Asecond fiat 32 is disposed adjacent said first flat, but occupies a plane in angular relation thereto. At the end of flat 31 coinciding with the line of juncture of flats 31 and 32 ashoulder 33 is formed providing an abutment or stop. A relatively narrow auxiliary-flat 34 is providedadjacent thefshoulder 33, the plane of said auxiliary flat being angularly intermediate both said first and second flats 31 and '32, respectively, and affording a means of crossover between said first and second flats, as will be hereinafter explained. Athird flat 35 is disposed adjacent to thesecond flat 32 but is co-planar with'the first flat 31. Asecond shoulder 36 is formed at the end of flat 32 coinciding with the line of juncture of the second andthird flats 32 and 34, respectively. The second flat 32 is connected to thethird flat 34 by a relatively narrowauxiliary flat 37 which is co-planar with theauxiliary flat 34 but laterally offset therefrom. Fourth. andfifth flats 38 and 39, respectively, are provided, formingshoulders 41 and 42 the first, third andfifth flats 31,35 and 39, respectively, being co-planar and the second andfourth flats 32 and 38, respectively, being co-planar.Auxiliary flats 43 and 44 similar toauxiliary flats 34 and 37 afford crossover means betweenflats 35 and 38 andflats 38 and 39, respectively. It will be observed that all of the flats are substantially tangent.

In the embodiment illustrated, the distances betweenshoulders 33, 36, 41 and 42 are equal. Accordingly, as will be apparent, the total travel of theplunger rod 25 is divided into five equal increments. It will be understood, however, that the invention is not limited to the number of flats shown but may embody a lesser or greater number.

The retainingmember 21 is provided with an inwardly directedpin 46 which is adapted to engage in the grooves and against the shoulders provided on the plunger rod, as will be hereinafter explained.

In the operation of the device, when theplunger rod 25 is at the forward limit of its stroke and occupies the position illustrated in Fig. 1, thepin 46 is in registration with the rearwardannular groove 30. Accordingly, the plunger rod may be rotated axially by means of theknob 27 until thelongitudinal groove 28 is in registration with thepin 46. Filling of the barrel is accomplished in a conventional manner by submerging the tip of the needle in a liquid media and withdrawing the plunger rod outwardly in the direction of the dotted line portion illustrated-in Fig. 1. When the plunger rod is in its outermost position, thepin 46 is in registration with the forwardannular groove 29 and the plunger rod then may be rocked about its longitudinal axis to align the first flat 31 with thepin 46. The plunger rod then may be pushed forwardly until thepin 46 engages thefirst shoulder 33, which limits axial movement of the plunger and plunger rod. The amount of liquid media ejected in the first increment of travel of the plunger corresponds to a predetermined volume of media. In the use of my invention the operator is not required to observe the liquid level within the barrel in relation to the graduation lines on the barrel. In order to dispense the next dosage, the

the barrel with a liquid media.

aligned substantially with the median line of the third fiat 3,5. For successive dispensing of dosages of liquid media contained Within the barrel12, the operations heretofore described are repeated until theplunger 26 reaches the end of its stroke and is in substantial abutment with the inner face of the t-aplet 14. In this position thepin 46 is aligned with therearwardannular groove 30, and theplunger rod 25 may be: rotated axially in order to align thelongitudinal channel groove 28 with thepin 46,

so that the plunger rod maybe withdrawn to again fill However, it will be apparent that, while only five abutments or shoulders are illustrated in the drawings, it is contemplated that a greater or smaller number of such abutrnents or shoulders may be provided on the plunger rod.

It will be noted that when thepin 46 is aligned with any of the flats the plunger rod may be rocked axially only to a very limited degree, because thepin 46 will be caused to engage the side marginal edge portions of the main flats. Thus theplunger rod 25 is held to its course during each increment of travel, assuring accuracy in the dispensing of a predetermined quantity of liquid media.

It will be apparent from the foregoing that the length of each main fiat may be varied in order to yield a desired quantity of liquid media. It will also be apparent from the foregoing that I have provided an improved syringe which is capable of dispensing a plurality of pre- 4 determined quantities of liquid media rapidly in successive order.

Various changes coming within the spirit of my invention may suggest themselves to those skilled in the art. Hence, I do not wish to be limited to the specific embodiments shown and described or uses mentioned, but intend the same to be merely exemplary, the scope of my invention being limited only by the appended claim.

I claim:

A syringe type dispenser comprising a barrel, a plunger and plunger rod reciprocable within said barrel, a stationary abutment associated with the rearward portion of said barrel, said plunger rod having an annular recess substantially at each end and a longitudinally extending recess connecting said annular recesses, said plunger rod having intermediate said annular recesses and connecting therewith a series of longitudinally extending recesses of predetermined lengths with adjacent recesses misaligned to afford a stop at the end of each recess, said abutment being adapted to be selectively disposed in registration with said recesses 'by movement of said plunger rodwhereby when said longitudinally extending recess is in registration with said abutment said plunger rod may be moved longitudinally Within the limits defined by said annular recesses, said abutment when disposed in registr-ation with said series of recesses during the forward travel of said plunger rod being successively engaged by said stops, whereby the movement of said plungerrod is arrested at predetermined increments of travel.

References Cited in the file of this patent UNITED STATES PATENTS Lomas et al. Oct. 11, 1921

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