US2408323A - Hypodermic syringe - Google Patents

Description

Sept. 24, 1946. M; L. LOCKHART vHYPODERMIC SYRINGE 2 Sheets-Sheet 2 Filed June 10 194;

n is desired to use the. syringe.

Patented Sept. 24, 1946 UNITED STATES PATENT. o ncE one-half to Margaret L." Lockhart, Detroit,

. Application June 10, 1943, Serial No. 499,250

6 Claims. (Cl. 128-22'0) My present invention relates to a hypodermic syringe which may be filled with proper medicam'ent, efeully' sterilized and then sealed, with assurance th'at all parts thereof will remain sterile until the syringe is used to hypodermically inject the. medicament into a patient.

7 One object of the invention is to provide a hypodermic syringe of this .character which may be made at relatively small cost so that it is feasible and. economical to discard the syringe after it-is once used, thus eliminating the dan-- the parts assembled in a minimum of time; the structure being so designed as to permit convenient pre sterilizationf of all parts thereof and sealing of the parts in an absolutely closed container which prevents infiltratio-nof germs after assembly.

A still further object is to provide a syringe structure comprising a pair of telescopically mounted tubes which. can b readily sealed at Qthe' joint between them, the tubes enclosing a .hypoderinicneedle and the medicament orother I liq'uidt'o be injected in separate compartments,

which compartments are separated by a plug which may also serve the purpose of a piston for displacing the liquid through th needle when it Still' anotherobjec't is to provide the needle which is usually of metal is'olatedfrolnthe liquid by the piston so that there is no, possibility of either deterioration of the needle or contamination of the liquid by corrosion o'f'theneedlej both the needle and the liquid being enclosed in the tubes forming the casing of the structure to prevent infiltration of germs or dust to either theneedle or the liquid.

With these and other objects in view, my invehtion consists in the combination, construction and arrangement of the various parts of my hypodermic syringe whereby the objects contemplated areattained, as hereinafter niorefully set forth pointed out in my claims and mustrated in the accompanying drawings, in which:

Figure 1 is a perspective View 015 a hypodermic syringe embodying myinvention, the figure being shown approximately full-size for a .Syringejhaving #2 cubic centimeter volume in the liquid or medicament space; j I

Figure 2 is a side elevation showing the four essential'parts of the syringe;

inthe directionof the arrows as indicated in Figure 1 showing the parts in the position they assume at the smear initial assembly, this figure being substantially twice the scale of Figure'l;

' igure 4 is a similar sectional View showing the syringe in use;

Figure 5 is a similar sectional View of an alternative form of the invention;

Figure 6 is a further enlarged cross-sectional view'of still another'form of the present invention;

Figure 7 is a sectional view on the line 'l'l andin the direction'o'f the arrows as indicated in Figure 6 showing a joint between the medicine tube and then'eedle tube;

Figure B' is a-sectional view on the line 88 and ini-the; direction of the arrows as indicated in Figure 7 showing further details of th joint and Fi gu're'Q is a sectional view on the line 99 and in the direction of the arrows as indicated in Figure 6; showing particularly a needle lockirig element. I

In the accompanying drawings, in Figures 1 to 4 I ,haveused the reference numeral It! to indicate, in general, a medicine tube, I'Za piston,

' M a hypodermic needle structure, and [6 a needle enclosing tube. The tube l0 mayv be molded of glass or transparent plastic so that the medic ament or liquid I 8 therein may be readily seen through the wall of the tube. The medicine tube ""Hl has a closedend 20 and at its open end has a small annularbead 22 around it'. The open end is slotted slightly, as at 24, for a purpose which will'herein'after appear.

' The piston' 12 may be made of rubber or similar material, preferably impregnated with wax or other lubricant. The piston [2 has asocket 26 to receive one-end of the needle structure M.

The socket, since it passes only part-way through,

f leave' s a thick, diaphragm-like wall 28, adapted to be, punctured by th needle.

'Ifhe medicament tube I!) is telescopically fitted in the needle tube" 16 for a short distance (slightlyg'iieater than the depth of theslot 24). The needle tube lfi'likewise may be molded of glass "er plastic material, preferably transp-arent-,.and has'a-shallow;annular groov 30 therein to recive the-beadZZ of the medicine tube 10'. The

'slot' 2'4 permitgslight springing of the bead into the groove for the purpose of preventing telescoping movement of the tube Ill relative to the 1 tube t6; except when a predetermined telescopic pressure is exerted on the tubes.

When the tubes are assembled the joint between them is sealed, as by a suitable wax shown at 32, which preferably remains plastic at all ranges of temperature which the syringe may encounter. The lower end of the tube I may be coated on its outer surface with a layer of such wax, and then when it is thrust into th tube It during assembly the wax will fill the space between the two tubes, thereby effecting a hermetic seal against infiltration of dust or germs which.

would render the needle structure l4 unsterile.

The needle structure l4 comprises ahollow needle 34 of small diameter, having sharpenedends 36 and 38. Astop tube 40, havingends 42 and 44, is mounted on theneedle 34 as by welding at theend 42. 1 v

The needle tube I6 has a taperedlower end 46 terminating in athin diaphragm 48 which closes the lower end of the tube. This diaphragm may be in the form of a flash left by the molding process when the tube [6 is made of plastic material. Most plastics can be readily punctured 'by theneedle 34 when this diaphragm or flash is .001 to .005 inch thick. The needle tube l6 further has a pair ofhandles 56 formed thereon for convenience in manipulating the syringe.

In Figure 5, I show an alternative construction wherein, instead of the closedend 20, the tube I is open at the upper end and has aclosure plug 52 therein. This plug may-be made of rubber or the like, and is adapted to contain medicament in the form of a tablet or powder, indicated at 54. A rod 56 (formed of plastic or glass, if a metal rod is subject to attack by the powder 54) has its upper end received in asocket 58 of theclosure plug 52. Theplug 52, in turn, is plugged at its lower end by aclosure element 60, of plastic or glass. Theliquid 18 in the tube may be sterile water.

In Figure 5, I also show a pair ofstop washers 42 and 44 instead of thetube 46 on theneedle 34. In cases where the tube I6 is formed of glass, its lower end may be molded open, and then closed and sealed by-a cap- 62 of rubber or plastic material.

In Figure 6, I showanother form of the invention having mostly the same parts that have already been described and which therefore bear similar reference numerals with the addition of b. In addition to these parts, there is a different type of joint between the needle tube l6", and the medicament tube lll This joint consists essentially ofopposite projections 2! on the medicament tube adjacent the lower end thereof and.opposite projections 23,shoulders 25 andtapered grooves 21 inside the needle tube adjacent the top thereof. The parts are greatly enlarged on the drawings whereas in the actual device their heights are actually less than .010 inch.

During assembly the lower end of the medicament tube is dipped into a suitable wax to form a sealed joint the same as shown at 32 in Figure 3 (the wax being omitted from Figure 6 for greater clarity) after which theprojections 2| are aligned with thetapered grooves 21 and the parts then telescopically forced together. Thetapered grooves 21 cause the upper end of the needle tube to be sprung to an elliptical shape for permitting theprojections 2| to pass the shoulders '25 and snap beneath them. Theprojections 23 prevent theprojections 2| from going too far during the telescoping operation.

A needle lock is provided in the form of aleaf spring element 29 cut to the shape shown in Figure 9 and initially bent to the shape shown dotted at 29*, in Figure 6.Washers 3| and 33 tightly engage theneedle 34 so as to remain fixed against longitudinal movement relative thereto, and confine between them theneedle locking element 29. For coaction with the locking element 29 I provide anannular ridge 35 the purpose of which will hereinafter appear.

The spacer 4!! is in the form of a relatively thick plastic tube. The upper end of the medicament tube I0 is modified by having a truncated cone shapedart 31 with a pair ofopposite wings 39 extending from the sides thereof.

Practical operation I desirable to use the syringe, thelower end 48 thereof is placed against the patient at the point Where the injection is to be made, and it is then merely necessary to press firmly on theclosed end 20 of the medicament tube ID. The thumb may be used for this operation, with the first two fingers hooked under the handles to aid in getting a good operating grip on the injector.

The first operation which occurs is for the sharpenedend 36 of theneedle 34 to puncture thediaphragm 48 because it offers less resistance to puncture than does thethicker diaphragm 28 of thepiston I 2. The sharpenedend 36 of theneedle 34 then is extended, as shown in Figur 4, during which time theend 36 of the needle assumes a hypodermic position. The needle structure I4 is limited in its movement by thelower end 42 of thestop tube 40 engaging in thereduced end 46 of the tube IS.

The next operation which occurs as thetube 10 is further telescoped into the tube I6 is the puncturing of thediaphragm 28, as shown in Figure 4,-by the sharpenedend 38 of theneedle 34. The liquid I8 is now in communication with the needle so that further telescoping movement of the tube l0 displaces the liquid through the needle to the desired position. The liquid has been about two-thirds displaced in Figure 4, and, obviously, as the tubes are further telescoped together, dispensing will take place. The discharged liquid is indicated at', I8 After full telescoping together of the tubes, the needle may be withdrawn from the patient and the entire syringe discarded.

Thehead 22 and thegroove 30 coact initially to require a predetermined pressure [before the telescoping movement can take place. I am thus assured that slight accidental jarring or pressure,

or accidental pulling, to some extent, on the tube I0 relative to the tube IE, will not result in breaking the seal at 32, nor will the parts come apart and result in an unsterile condition thereof before use. If desired, thebead 22 and thegroove 30 may be omitted, as shown in Figure 5, where the character of the wax or other seal at 32 is such that it will hold firmly enough to eliminate the necessity of having to use the coacting bead and groove arrangement.

In the operation of the form of invention shown in Figure 5, substantially the same operations occur as already described, with the exception that, ahead of any of them, pressure on thesocket member 58 forces therod 56 downwardly to push theclosure element 60 out of theplug 52. Thematerial 54 may then mix with the liquid l8 to form the desired medicament, after which further pressure on thesocket member 8 will telescope the tubes together in the manner already described. Thecap 62 will first be punctured, after which thewasher 42 stops the movement of the needle, and, thereupon, the piston is punctured, thewasher 44 stopping themoveme'nt of the piston in the same manner in which the upper end M of the tube 45 does so in Figure 3.

In the operation of the form of invention shown rotated relative to the needle tu'be I'Ei which results in theprojection 2! (see Figure 7) following a path indicated by the dotted lines a to finally assume a position such as indicated at 2P The shape of theshoulder 25 causes the medicine tube to be started downwardly, and after the end of theprojection 23 has been passed by the'projection 2 I, the'medicament tube may be pushed inwardly. Thewings 39 on the upper end of the tube aid in the rotation of this tube and are found necessary under some circumstances such as a soldier giving a selfinjection when his hand is bloody or wet.

The first inward telescoping of the medicine tube relative to the needle tube causes the needie to puncture thediaphragm 48 and then move to an extended position for thrusting the needle into the flesh before the upper end of the needle punctures the piston IZ During this operation the ends of the bowed lockingelements 29 are forced to pass the annular ridge (-35 to the dotted position shown adjacent the lower end of Figure 6. To accomplish this order of operations, the piston offers greater resistance to puncture by the needle than the force required to puncture the diaphragm and to move the locking element pastridge 35 as previously described. The needle is positively locked against movement back into the syringe while the needle is being thrust into the flesh by the engagement of the looking element with the annular ridge. The shape and tension of the locking element also are such, and its ends are square, so that it wedges into the wall of the needle tube (if plastic) at any position so that there can be no accidental retraction of the needle. Theridge 35 merely provides a more positive form of lock against such retraction. The periphery of the piston 12', it will be noted, is V-grooved so as to give a better sealing effect in relation to the medicine tube.

My syringe structure is so designed that the medicament i8 is seal-ed within the tube ID by the piston l2, and the needle structure I4 is sealed within the needle tube [6 by the diaphragm 43 or thecap 62 and the sealing material at 32.

The partsmay accordingly be sterilized before assembly, and, after assembly, will remain sterile until the seal at 32 is broken by using the syringe in the proper manner contemplated. No preliminary preparations are necessary when an injection is to be made. After removing the syringe from a suitable carrying case, it may be immediately placed against the patient and the telescoping operation quickly performed without the necessity of any complicated steps, and with the assurance that a sterile needle is being used. At the same time, thearrang-ement is such that the structure can be made cheap enough to justify discarding after one use.

The parts of the syringe are reduced to a minimum, some of themserving multiple purposes. For instance, thepiston 12 serves as a stopper as well as a piston and as a closure means until such time as'it is punctured, after which the medicament abovethe piston is in communication with the needle. The needle itself serves to puncture theseals 48 or 62, as well as to puncture the epidermis of the patient and project serves both as a sterile enclosure for the needle structure and a guide for the telescoping movementof the medicament tube I 0. This avoids the necessity of using theslender needle 34 as a guide for the lattertube.

The needle is further reinforced [by the'tube All against undesirable bending, whereby a relatively light needle may be used. Thetube 40 takes the thrust between the lower end of the tube l6 and the piston i2 during the telescoping operation, as in Figure i. Where stop washers, as at 42*- and 44 are used, theneedle 34 may have to be larger to avoid buckling under thrust.

Some changes may be made in the construction and arrangement of the parts of my hypodermic syringe without departing from the real spirit and purpose of invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

I claim as my invention:

1. A manufactured hypodermic syringe assembly comprising a medicine filled tube having one end closed, a piston inthe other end thereof, a needle tube having one end closed, the other end thereof being telescopically arranged in extended relationship relative to the piston end of said medicine tube, lock means for said medicine tube relative to said needle tube comprising coacting elements initially engageable with each other and disengageable for use by rotation of the medicine tube relative to the needle tube, means for sealing said needle tube relative to said medicine tube, and a double-ended hollow needle in said needle tube between the closed end thereof and said piston, the closed end of said needle tube being puncturable by one end of said needle and said piston being puncturable by the other end thereof upon telescoping movement of said tubes.

2. In a manufactured hypodermic syringe assembly, a pair of tubular elements each having a closed end, said tubular elements being telescopically fitted together and sealed at their open ends in extended relationship, liquid in one of said tubular elements, a piston closing the open end of said tubular element, a double-ended h'ollow needle in the other of said tubular elements, the closed end of said other tubular element and said piston being puncturable by opposite ends of said needle upon telescoping movement of said 7 tubes each having a closed end, said tubes being telescopically fitted together and sealed at their I open ends in extended relationship, liquid in one of said tubes, a piston closing the open end of said one of said tubes, a double-ended hollow needle in the other of said tubes, the closed end of said other tube and said piston being puncturable by opposite ends of said needle upon telescoping movement of said tubes whereby to afiord communication between the liquid and the discharge end of said needle, and latch means carried by said needle and cooperable with the inner face of the other of said tubes to prevent a retraction of said needle Within the latter tube after it is once projected.

4. In a hypodermic syringe assembly, a pair of tubular elements each having a closed end, said tubular elements being telescopically fitted together and sealed at their open ends in extended relationship, liquid in one of said tubular elements, a piston closing the open end of said tubular element, a double-ended hollow needle in the other of said tubular elements, the closed end of said other tubular element and said piston being puncturable by opposite ends of said needle upon telescoping movement of said tubular element whereby to ailord communication between the liquid and the discharge end of said needle, and needle locking means on said needle to prevent retraction thereof once the needle is extended relative to the tubular elements, said needle locking means comprising a bowed element under tension to engage the wall of the tubular element in which it is mounted and center the needle relative thereto, the wall of said tubular element cooperating with the ends of said bowed element,

to prevent retraction of said needle.

5. A hypodermic syringe including in combination a pair of tubes, the inner end of one tube overlapping and being telescopically disposed with respect to the inner end of the other tube, one of said tubes being adapted to receive medicament, a pierceable closure-member sealing the medicament within such tube and being slidably mounted therein, a tubular needle disposed with in the other of said tubes and being formed with piercing portions at each of its ends, the outer end of said other tube being constricted, a seal .carried by that tube at such outer end and initially extending beyond the adjacent piercing point of the needle, means carried by said needle and cooperable with the inner face of the constricted tube end for limiting the projection'of the needle beyond the seal and end, means also carried by the needle and lying adjacent its opposite end to cooperate with the closure of the first-named tube to cause such closure to be longitudinally shifted Within its tube and to act on the medicament as a piston, and means forming a part of said tubes adjacent their overlapped inner ends and cooperable to initially prevent telescoping movement of said tubes with respect t each other.

6. A hypodermic syringe including in combination a pair of tubes, the inner end of one tube overlapping and bein telescopically disposed with respect to the inner end of the other tube, one of said tubes being adapted to receive medicament, a pierceable closure-member sealing the medicament within such tube and being slidably mounted therein, a, tubular needle disposed within the other of said tubes and being formed with piercing portions at each of its ends, the outer end of said other tube being constricted a seal carried by that tube at such outer end and initially extending beyond the adjacent piercing point of the needle, means carried by said needle and cooperable with the inner face of the constricted tube end for limiting the projection of the needle beyond the seal'and end, means also carried by the needle and lying adjacent its opposite end to cooperate with the closure of the first-named tube to cause such closure to be longitudinally shifted within its tube and to act on the medicament as a piston, and means forming a part of said other tube and cooperable with the means carried by said needle to prevent a retraction of said needle into said tube once said needle has been projected with respect to the same.

MARSHALL L. LOCKI-IART.

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