US2880725A - Syringe assembly - Google Patents

Description

April 7, 1959 c. o. KENDALL SYRINGE ASSEMBLY 4 Sheets-Sheet 1 Filed June 11, 1954 INVENTOR (liar/es dfimda ZZ ATTORNEY April 7, 1959 c. o. KENDALL SYRINGE ASSEMBLY 4 Sheets-Sheet 2 Filed June 11, 1954 INVENTOR ATTORNE April 7, 1959 c. o KENDALL SYRINGE ASSEMBLY 4 Sheets-Sheet 3 Filed June 11, 1954 INVENTOR almrlzs dfiflma ll 1 I 1 1 1 I I 1 1 1 1 1 1 1 I I l I ATTORNEYS United States Patent SYRINGE ASSEMBLY Charles 0. Kendall, Waldwick, NJ., assignor to Becton,

Dickinson and Company, Rutherford, N.J., a corporation of New Jersey Application June 11, 1954, Serial No. 436,036

6 Claims. (Cl. 128-218) This invention relates to a structurally and functionally improved syringe assembly.

It is a primary object of the present invention to furnish an improved hypodermic syringe, the parts of which may readily be manufactured, assembled, cleaned, sterilized and maintained in that condition for indefinite periods of time until used by a physician, technician or patient.

A further object is that of designing an assembly embodying unique construction and which assembly when used may have its barrel filled from medicament contained, for example, within a vial and under techniques such as conventionally obtain in the medical profession. Therefore, no new procedure will have to be learned by the ultimate user. Additionally, in so filling the barrel of the assembly the medicament remaining within the vial will not be contaminated incident to that vial receiving a charge of non-sterile air such as ordinarily occurs in employing hypodermic syringes.

Moreover, by following the present teachings an assembly is furnished which will preferably have a onetime use such that it may be discarded after a single injection by the physician or other person employing it; the assembly being capable of production at a relatively nominal figure and involving a simple procedure to render it operative, charge or fill it and to effect the desired injection without it being necessary to impart to the user special instructions.

With these and other objects in mind reference is had to the attached sheets of drawings illustrating practical embodiments of the invention and in which Fig. l is a sectional side view of a complete syringe assembly;

Fig. 2 is a fragmentary, sectional view in enlarged scale of certain parts of that assembly with such parts having assumed a position diiferent from that illustrated in Fig. 1;

Figs. 3 and 4 are bottom perspective views of metal hub portions which may be included in the assembly;

Fig. 5 is a view similar to Fig. 2 but illustrating an alternative structure and also showing a still further positioning of the parts from that illustrated in Figs. 1 and 2;

Fig. 6 is a perspective view of an extension which may be included in the assembly as shown in preceding and following views;

Fig. 7 is a view similar to Fig. l but showing the invention embodied in an ampule for disposition within an actuating holder;

Figs. 8, l0 and 12 are views similar to Figs. 2 and 5 but illustrating alternative forms of structure;

Figs. 9, 11 and 13 are transverse sectional views taken respectively along the line 9-9, 11-11 and 1313 and in the direction of the arrows as indicated in Figs. 8, and 12;

Figs. 14, 16, 18 and 20 are views again corresponding generally to Figs. 2 and 5 but showing still further forms of construction;

Figs. 15, l7, l9 and 21 are perspective views of ele- "ice ments of the type embodied in Figs. 14, 16, 18 and 20 respectively;

Figs. 22, 23, 24 and 25 are again views correspond ing generally to Fig. 2 but showing still further forms of structure;

Fig. 26 is a fragmentary, sectional view in enlarged scale of still another arrangement of the parts; and

Fig. 27 is a view similar to Fig. 26 but showing a still further arrangement of elements.

Referring primarily to Fig. 1, there has been shown a complete syringe assembly prior to its being used. In connection with this view as well as in succeeding views, preferred types of materials will be designated. This is to be taken in an illustrative rather than a limiting sense, having in mind that subject to the limitations of design as well as the purposes for which the assembly is to be used many alternate or substitute materials might be employed.

Thus, in this figure the numeral 30 indicates a syringe barrel formed of glass. In accordance with conventional technique one end of this barrel is open and defined by a flange 31 extending outwardly from its surface so that a gripping portion for the fingers of the operator is provided. Adjacent its opposite end the barrel is constricted to furnish a neck portion 32 preferably terminating in an outwardly extending bead 33. The bore of this neck has its outer end sealed by, for example, a disk or layer 34 formed of synthetic rubber, polyethylene or any other perforable material which is suitable for the establishment of a proper seal. This disk is maintained in position by a cap or ring 35 formed of metallic foil or thin stock which is spun or constricted around the bead 33 and overlies the outer face of layer 34 to firmly retain the latter. This cap or ring provides a central opening or perforation 36 in line with the axis of the barrel.

Adjacent its opposite or open end the syringe mounts a piston type stopper 37. The latter is formed of natural or synthetic rubber and is provided with the usual corrugated or ribbed exterior surface. In its forward or inner end a recess is provided and mounts an extension 38 again conveniently formed of polyethylene. This extension-for purposes hereinafter brought out-may be formed with one or more grooves 38 in its side face..

A metal bolt 40 may have its head portion molded in stopper 37 with its shank extending beyond the rear face of the latter. This stopper, as illustrated, initially occupies a position adjacent the open or flanged end of the barrel. At that zone the barrel bore may be formed with one or more axially extending venting grooves 39 which have their rear ends terminating at the adjacent end of the barrel. The threaded rearwardly extending end of bolt 40 may be engaged by the corresponding threaded surface of a recess formed in the forward end of an actuator 41. somewhat diagrammatically shown in Fig. l in that it may take one of numerous different forms but in any event is necessary in order that it may be coupled to the piston stopper 37 to shift the latter.

Supported upon the inner end of extension 38 is a hub indicated at 42 which, as shown in Fig. 3, may have integral tongue or latch portions 43 extending from its face. The cup-shaped element thus provided is made of metal and according to any desired conventional technique. It is secured to the base portion of a hollow needle 44, the pointed end of which extends into the bore of neck 32 to a plane slightly below the inner face of layer 34. If it is desired to employ a more cheaply manufactured hub element then, as in Fig. 4,'a hub may be blanked out to include a head portion 45 as well as arms or pawls 46 which are folded inwardly to extend in a direction axial of the needle. Regardless of the construction followed, arms or latch elements 43 This actuator has been and 46 should normally occupy positions slightly divergent in a downward direction and should yieldingly tend to assume such positions. To cooperate with these latch elements the entrance portion of the neck bore presents a converging surface 47 beyond which that bore is enlarged. This enlargement is defined by the shoulder 48 providing a latch part cooperating with detents 43 or 46 to lock the assembly in projected position. The height of the space intervening this shoulder and the face of layer 34 should be equivalent to the height of the hub as shown in Figs. 3 and 4.

Considering the operation of the foregoing assembly it is to be understood that the parts are primarily manufactured, cleaned, assembled and sterilized. The outer end of the barrel is closed by the seal provided by layer 34. The inner end of the barrel is closed by the piston stopper 37. Prior to this, the sterile needle 44 is mounted upon extension 38 and disposed within the barrel. is within the completely sealed barrel bore which contains only sterilized air. Under these circumstances, if a physician or other user determines that an injection is to be made he will, for example, employ a multi-dosage vial filled with the desired medicament and will attach an.

actuator, such as 41, to the stopper 37. In that attachment it will of course be understood that numerous forms of couplings other than the bolt 40 carried by the stopper and the threaded recess formed in the actuator might be employed. Arran ing the outer end of the assembly adjacent the perforable stopper of the vial, actuator 41 is projected to cause needle 4-4 to perforate seal 34, pass through opening 36 and perforate the vial stopper. As this movement of the parts occurs, the sterilized air within the barrel bore will be subjected to compression and will flow through groove 38 and the lumen of the needle out through the pointed forward end of the latter. The needle being within the vial, the sterilized air will be discharged within the body of the medicament contained by the latter and will be subjected to pressure. It is to be emphasized that the air being sterilized, the interior of the vial will not become contaminated.

This action of the parts may be continued as in Fig. 2 until extension 38 causes hub 42 to ride through bore portion 47. As it so shifts the arms or latches 43 or 46 will be constricted. As the hub passes to a point where its lower edge clears shoulder 43, these arms will snap outwardly to bear against the latch part embracing the ledge defined by that shoulder. So disposed, the hub will be braced between layer 34 and shoulder 48 to become in effect fixed against movement with respect to the barrel; with the seal 34 being under slight compression or deflection. Accordingly, the needle 44 will likewise become a fixed and stable extension of the barrel. With the needle assembly in this position it may not be returned to a retracted position. Also, piston stopper 38 will lie adjacent the restricted part of the barrel defining the neck portion thereof as in Fig. 2.

Now by exerting a retracting force on actuator 41 piston 37 may be withdrawn through the barrel bore. In such withdrawal suction will be exerted through the hollow needle 44 and the medicament will pass from the interior of the vial (this relieving the pressure therein) into the barrel bore to fill the latter with a dosage of desired volume. The site of injection having been selected, surface sterilization may be resorted to and in accordance with conventional procedure, the epidermis may be punctured and the tissues penetrated to the desired depth such as will provide for a subcutaneous or intramuscular injection. If it is desired to aspirate then this of course may readily be achieved after needle penetration by slightly retracting the piston. In any event, the user will thereupon fully project the piston, in the usual manner, causing the medicament to be forced through the bore of the cannula. This action will continue until substantially all of the medicament is discharged. In this connection, it will be noted that not alone does piston 37 4 I assume under fully projected position a station adjacent the base of neck 32, but also extension 38 rides into the cup defined by hub 42 so as to displace the medicament therein contained. Accordingly, the user may be assured that the patient is receiving substantially the entire medicament dosage which is to be injected. The needle is now withdrawn and the syringe may be discarded although, of course, the assembly can be cleaned, sterilized and reused, in accordance with standard procedure. The actuator 4-1 may, of course, be saved.

In lieu of a piston stopper 37, as shown in Figs. 1 and 2, a stopper such as is illustrated in Figs. 5 and 6 might be utilized. That stopper would. conventionally be formed of molded polyethylene and could be characterized by flared surfaces 49 and 50 extending in opposite directions so as to provide an effective piston action, both during projecting and retracting strokes. A coupling between it and the actuator 41 could again be established by a threaded bolt 40 the head of which would be molded into its body. Likewise, extension 38 as in Figs. 5 and 6 might be provided with outstanding ribs 51 which; would assure a spacing between it and the inner face of the needle hub such that air could flow freely into the; bore of the latter. To prevent a sealing engagement. between the inner face of that hub and the outer end of the extension, a rib 52 might. extend transversely of the surface of that end. it is apparent, referring to the preceding description of operation, that with the parts thus constructed they would function in a completely similar: manner to the operation as aforedescribed.

In most instances the assembly will be used by itself. In other words, it will not be employed in a holder. However, should it be desired to practice the present teachings by embodying the structure in an ampule for reception in a holder this may readily be accomplished as in Fig. 7. In that view the numeral 53 indicated a metallic, tubular receiving member which has its side faces formed with sight openings or windows 54 through which the ampule may be observed. The upper or outer end of the tube 53 is preferably constricted as at 55. Adjacent its inner or rear end a hub assembly 56 is pivotally supported as at 57 by yoke arms. An actuating flange or finger piece 58 is mounted by member 53 and a tubular rearward extension is included in the yoke assembly.

A spring 60 is interposed between the end of this exten sion and the flanged portion of a bushing 61 which extends into the bore of the extension and slidably supports. an actuator rod 62 having a coupling head 63 for attachment with the shank of bolt 4f? carried by the piston stopper 37. The outer end of rod 62 mounts a head 64 which may be engaged by the thumb of the operator or gripped between his fingers.

The bore of member 53 receives an ampule generally indicated at 65. That ampule and the parts contained therein may be identical with the assemblies heretofore and hereinafter referred to excepting that the ampule terminates in a plain edge adjacent its inner end rather than including a flange 33.. For this reason reference numerals identical with those heretofore utilized have been applied to this figure in that completely duplicate parts will preferably be involved.

As is well understood by those conversant with the use of a holder of this type and assuming that holder to'be empty, a pull is exerted in opposite directions upontube 53 and actuator 62. This causes bushing 61 to. boretracted against the action of spring 613 to a point where it clears the rear end of tube 53. Under those circumstances the arms of the yoke assembly may be swung to cause the actuator and that assembly to extend at an angle to the bore of tube 53. Accordingly, the rear end of that bore is exposed and an ampule such as o'fimay he introduced. By such introduction the forward end of the ampule will ride to a position at which it engages the re stricted forward end 55 of the tube. Atthis point its movement will be arrested. Its rear end will be housed within the bore of the tube. Now by again exerting a pull on actuator 62, spring 60 will be compressed by bushing 61 moving rearwardly and when the rod 62 is in alignment with the axis of the assembly the parts may be released. This will cause the forward end of bushing 61 to firmly bear against the rear end of ampule 65 and maintain it as a unit rigid with the holder. Now by, for example, rotating rod 62, a coupling may be effected between the head 63 of the same and the stopper 37. The procedure from here on may be identical with that heretofore described in connection with Figs. 1 and 2. It will, however, be observed that in lieu of the specific extension 38, as previously referred to, an extension 66 may be employed which is formed with the longitudinally extending bore in communication with the lumen of the needle and a transversely extending aperture 67 affording communication between that bore and the interior of the barrel or ampule.

In the form of construction shown in Figs. 8 and 9 the same principle and functional characteristics are involved as in the preceding figures. However, in this design a collar of, for example, polyethylene or styrene indicated at 68 is inserted into the neck bore to occupy a position between seal 34 and flange 48. This collar terminates in inwardly extending legs 69 which are provided at their ends with pawl portions 70. The needle 44 carries a hub 71 which may be provided with a tapered forward surface 72.

The piston stopper 73 is formed with a socket which receives an extension 74 of the hub 71. Inwardly extending ribs 75 are provided within the recess of the stopper and define in aggregate a space such that extension 74 may be received therein. Accordingly, with this extension disposed within the socket and engaged by the inner edges of ribs 75 the needle will be initially supported for movement with the piston. Therefore, as the piston is primarily projected, as also heretofore described, air will be free to flow from the interior of the barrel over the surfaces of extension 74 and enter the bore 76 of that extension which is in line with the lumen of needle 44. Accordingly, as the needle is projected into the interior of the vial only sterilized air will be discharged into that receptacle.

Under continued projection of the needle assembly the tapered surface 72 of the same will ride against the pawl portions 70 and expand arms 69 so that the needle may be continuously projected. As the forward end of the needle hub reaches a position in engagement with the seal 34 the latch arms or pawls 70 will override the rear edge of extension 71 and snap into positions underlying the latter. Thus, a retraction of the needle assembly cannot occur. Also the latter will be rigidly supported with reference to sleeve 68 which will, in turn, be rigidly supported with respect to the barrel. Now by retracting piston 73 extension 74 will ride clear of the socket providing ribs 75. Therefore, the syringe may be filled, the needle may be caused to penetrate the skin and embedded into underlying tissues, the syringe may be aspirated and the injection achieved all as aforementioned.

In the form of structure shown in Figs. and 11 a needle assembly which may correspond precisely to that shown in Fig. 8, or in other figures, can be employed. However, in this instance a tube or sleeve 77 of metal is inserted into the neck bore in the position occupied by the previously described sleeve. Underlying the tube or sleeve 77 is a C-ring 78 also preferably of metal and normally constricted in the manner shown in Figs. 10 and 11. It is obvious that as initial projection of the piston occurs in this form of apparatus the forward end of this hub will enter the space defined by ring 78. It will cam against the ring to expand the same. Under continued projection spring 78 will override the hub body and snap into position to the rear of the same. In this manner the entire needle assembly will again be properly supported against effective movement with respect to the barrel.

As shown in Figs. 12 and 13 the barrel or anipule 79 may have an outer end wall 80 adjacent the entrance end of its neck bore. This wall is furnished with an off-center opening 81. The needle is furnished with a hub which has a tapered forward end 82 terminating in a shoulder and an extension 83 formed with a transverse bore 84 in communication with the bore of the cannula, The stopper 85 is formed with an off-center recess in'its forward face. Therefore, the parts may be coupled and projected through their initial stroke. In that projection it may be desirable to rotate stopper 85 so that its recess aligns with opening 81. In any event the tapered forward portion 82 of the hub assembly passes through opening 81 until its shoulder extends beyond the forward surface of wall 80. Under these circumstances the tapered portion 82 engages with the seal 86 formed preferably of rubber and in view of the fact that the length of portion 82 is preferably in excess of the neck bore, this seal will be flexed and function in somewhat the order of a spring or a resilient stop limiting the forward movement of the needle assembly. With such an arrangement and after the forward portion 82 of the hub is in position, a relative rotation of the latter as carried by stopper 85 will result in the shoulder intervening this portion overriding a surface of wall 80 as particularly displayed in Fig. 13. Under these conditions a subsequent retraction of the needle assembly will not occur.

As shown in Fig. 14, barrel 87 may be provided with a tapered surface 88 terminating in a shoulder 89 defining the entrance of the neck bore. Needle 90 carries a retaining member which, as shown in Fig. 15, includes a circular body 91 formed of resilient metal having a diameter less than that of the barrel bore and provided with upwardly extending and divergent arms 92 terminating in retaining portions 93. The spacing between these portions of the arms should be greater or at least equal to the diameter of the neck bore. Obviously, as the needle assembly is projected arms 92 will ride into engagement with the surface 88 and be flexed towards each other. This will continue until retaining portions 93 override the shoulder 89. At that moment the arms will snap outwardly as in Fig. 14. Simultaneously, body 91 will have shifted from its normally flat condition shown in dot-and-dash lines in that figure to a flexed condition as illustrated in full lines. This will have resulted because the distance between fingers 93 and the body 91 is less than that necessary for the body to have been accommodated within the barrel bore without being in forcible engagement with surface 88. Therefore, this part of the needle assembly is maintained under a condition of tension. Together with the support afforded be tween the parts at the outer end of the barrel and the needle such support is adequate to maintain the needle substantially rigid with the barrel.

Precisely the same form of structure is shown in Fig. 16 excepting that in the latter figure the inwardly tapered bore surface 95 does not terminate in an immediately adjacent shoulder portion 89. Rather, such a portion 96 is provided adjacent the outer end of the neck bore. The metallic disk-shaped body 97 included in what might be termed the hub assembly has relatively long arms 98 formed in it and extending in generally axial and outward directions. These arms terminate in fingers 99. Therefore, as the parts are shifted, the fingers ride over surface 95, through the bore of the neck and finally reach a position adjacent the shoulder or ledge 96. At that moment body 97 is in the flexed condition shown in Fig. 16. Now as that body is slightly more flexed, fingers 99 will clear ledge 96 and spring outwardly. This again will firmly support the parts.

Various additional alternate forms of structure may also be resorted to. Thus, in Fig. 18 the inner surfaces adjacent the end of the barrel bore and the neck may correspond to the surfaces heretofore described in connection with Fig. 14 and identified under the numerals 1 88 and 89. The needle, however, in this instance includes as part of its hub assembly and as shown in Fig. 19, a. cross-shaped member which is formed of metal and includes spring arms 1%. Spaced below the latter is the body of a metallic disk 101 having resilient properties. Obviously, as the parts are shifted to the position shown in Fig. 18 arms 1% will flex downwardly to override surface 88 and snap into position above shoulder 89'. Simultaneously, disk 101 will be flexed to maintain the parts under a condition of tension mounting.

In Fig. 20 the neck bore is modified to be tapered throughout its entire length as at 102. Adjacent its inner end this bore is defined by a rib or flange 103 formed integrally with the bore of the barrel. The hub assembly in this instance merely includes a flexible disk 1194. As the parts are rammed home this disk, moving with the needle, will override the flange or protuberance 103 and will come to lie above, the same as in Fig. 20. The opening defined at the upper end of the neck bore will be adequate to accommodate the diameter of the needle. Therefore, in conjunction with the disk 104 the needle assembly will be braced so that, in effect, it will be rigid with the end of the barrel.

Now referring to Figs. 22 and 23, the numeral 105 indicates the body of a syringe barrel having a reduced neck portion b. The outer end of the latter is defined by an inwardly extending flange 107. In Fig. 22 the detent or latching structure for the hub of the needle assembly is embodied in a member which seals the bore of the neck. That member may include an outer perforable head portion 108 and a cylindrical body 109 which defines a receiving and retaining chamber. The entrance to the latter is characterized by inwardly tapered or conical surfaces 119. The member is conveniently formed of polyethylene. The needle 111 is secured to a hub having a for ward tapered surface 112 and a rear extension 113. The latter is received within and bears against the ribs 75 or other spacing surfaces formed in the recess of stopper'73 as in Figs. 8 and 9.

Accordingly, extension 113 resting within that recess will project with the stopper causing the pointed end of the needle which initially rested within the bore extending below cap portion 108, to perforate the diaphragm portion of that cap. Surfaces 112 of the hub will cam against surfaces 110. The seal being formed of a flexible plastic, the parts will shift until the forward end of the hub bears against the inner face of the chamber with the latch portions of the stopper beyond surfaces 110 riding into locking engagement with the enlarged hub portion at the upper end of extension 113. Thus, the needle will be properly supported. The piston-stopper may now be retracted and a procedure as aforedescribed may be followed.

Substantially the same structure may be followed in Fig. 23 in which body 114 defining chamber 116 may have its lower end tapered inwardly to furnish a camming and latching surface 115. This of course engages with parts of the hub assembly as previously traversed. Body 114 has its outer end bored and this bore is closed by a stopper preferably formed of rubber. That stopper includes an outer head 117, providing a diaphragm portion for puncture by the needle portion with little danger of plug-cutting resulting as the needle is projected. The plug of the stopper includes a bore 118 initially housing the outer end of the needle and the inner end of the plug terminates in a flange 119, overlapping correspondingly contoured portions of body 114 to prevent a separation of the parts. The operation of this assembly will obviously parallel the operation as described in Fig. 22.

If it is desired to employ a syringe barrel of the type previously described in connection With Fig. 1, then a structure such as is present in Figs. 24 and 25 may be resorted to. In those figures, the numeral 119 designates the body of the barrel which is formed at its forward end with a reduced or grooved neck portion terminating in a bead 120. As in Fig. 24, a stopper is employed'wh'ich may again be formed of polyethylene, styrene, etc., and which includes a head 121 retained against displacement with respect to the body 120 by a metallic ring' or strip of foil 122 which overlaps these parts. The plug ofthe stopper is recessed to provide a chamber 123" continued in the form of a reduced bore for reception of the needle point which may perforate a diaphragm portion of the head 121 beyond the same. At its lower end, the chamber is defined by an entrance involving sloping surfaces 124 corresponding to the surfaces and in Figs. 22 and 23 and having the same functional cooperation with the parts ofthe needle assembly.

Likewise, the stopper shown in Fig. 25 may be similarly formed to include a chamber 123 and cam surfaces 124 beyond which are furnished latch portions. However, in this case, the head of the stopper is bored as at 125 through to its outer surface. Beyond that surface and the retaining ring 127, a perforable sealingdisk 126 is positioned. This, of course, is penetrated as previously brought out by the needle upon the latter being projected.

Referring to Figs. 26 and 27, a barrel 128 is shown which includes a reduced neck portion and, as in the former figure, with a recess or well 129 in its outer end. Through the bore of this barrel, a stopper 130, having piston characteristics, is projected by, for example, an actuator 131. This stopper is also formed with a recess on its outer face. Received within the latter is the base of a tubular section 132 of polyethylene or similar material. The rear or inner end of this tube is conveniently notched as'at 133. The upper end of the tube presents an outwardly extending flange, the periphery of which embraces a sloping face 134. The bore of tube 132, at a point short of that flange, conveniently includesadetent portion 135. Between this and a shoulder 136, the bore ofthe tube is enlarged. In that space it receives the hub 137 of a needle 138.

It will be understood that contrary to the showing in Fig. 26, stopper 130 is normally retracted as-is also tube 132. The latter carrying the needle assembly, it follows that the point of the needle will be below the sealing layer or disk 13? (conveniently of rubber) at the outer end of the barrel. Therefore with the projection of the stopper, the needle will perforate this seal inthe manner heretofore described. Air Will be expelled from within the barrel interior through the notch 133, the'bore of tube 132 and the lumen of the needle. As the piston stopper 130 is fully projected, the flange portion defined by the inclined perpheral surface 134 will ride into the neck bore of the barrel. In this connection, it will be understood that a certain amount of flexing or distortion of this flange may occur because it is above and accordingly not braced by hub 137. This movement of the parts will continue until the flange rides into the well or recess 129 whereupon it may expand into lockingengagement with the adjacent surfaces. Therefore, a retraction of piston stopper 131) to fill the barrel with medicament will free tube 132 from that stopper. In subsequent projection, the medicament will flow in the same manner as heretofore described in connection with the initial projection of the parts and as the stopper reaches a position adjacent the end wall of the barrel.-

In Fig. 27, the needle may be staked or otherwise suitably secured to a hub portion which inthis -instance merely includes a metallic disk or washer 141. The'latter lies within a recess formed in the forward end'of a tubularbody 142' again, for example, ofpolyethylene. A lip portion 143 may overlie this hub part andthe bore of the tube is constricted asat 144 to furnish a shoulder portion underlying the washer. A seal 145 of rubber or other suitable material is disposed between the outer end of the barrel as in-the case of Fig. 26. Aflange characterized by sloping faces 146 extends from" the outer face of body 142. The neck bore of the barrel is conveniently defined at its entrance end by sloping or rounded surfaces 147. Tube 142 may be provided with a notch 148 in its inner end. That end rides within the recess of a stopper 149 formed of rubber or other suitable material and which stopper is shifted by an actuator 150.

The tube 142 is initially mounted in the socket or recess of the stopper as shown in Fig. 27. That stopper is retracted within the barrel. Accordingly, with the needle assembly carried by the tube, the point of the needle will be below the diaphragm or penetrable layer 145. With projection of the stopper, the needle will be projected by means of tube 142. The sloping surfaces 146 will ride against the sloped portions 147 and this portion of the tube will constrict to pass through the neck bore. Upon this flange of the tube passing beyond the shoulder of the barrel neck defining the lower end of the Wall or recess in that outer end, the flange will expand. Simultaneously, the outer end of the tube will engage the seal 145. Therefore, the needle assembly will be properly mounted and retained. With retraction or aspiration of piston 149, tube 142 and the needle associated therewith, will be freed therefrom; the parts otherwise operating as heretofore described.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously, numerous changes in construction and re-arrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. An assembly of the character described including in combination a syringe barrel having a bore, a neck portion forming a part of the same, said bore being filled with sterile air, a hollow pointed needle housed within said bore, a piston movable within the bore of said barrel, substantially rigid means connecting said piston with said needle to extend the point of the latter through and beyond said barrel as said piston is projected, said needle and rigid means furnishing between them a passage for the flow of air through the lumen of the needle from the bore of the barrel during piston projection, a latch part formed in the bore of said neck portion and including a surface extending at an angle with respect to the axis of the assembly and another latch part secured against movement with respect to said needle to cooperate with said angularly extending surface after the needle has been moved beyond the latter to a predetermined extent.

2. In an assembly as defined in claim 1, a seal disposed in contact with and beyond said neck portion to be perforated by said needle as the latter is projected and means engaging the exterior of said neck portion for retaining said seal in position.

3. A syringe assembly including in combination a barrel, a bored tip extending from the end of said barrel, a piston reciprocal within said barrel, a hollow needle having a pointed outer end, said needle being disposed within said barrel with its outer end adjacent said tip, a hub carried by the needle at its inner end, an extension mounted by said piston and projecting in the direction of said tip, said extension bearing against the hub of the needle to project the same upon said piston being projected and cooperating latch means associated with said hub and the bore of said tip to lock said hub and needle against retraction with respect to said barrel as said hub occupies a position within the bore of said tip.

4. A syringe assembly into which medicament is to be drawn after the parts thereof assume a predetermined relationship, said assembly comprising in combination a barrel having a sealed outer end, a piston adjacent its opposite end, a hollow needle having its body within said barrel and a pointed outer end in proximity to the seal at the outer barrel end, a hub secured to the inner end of the needle, an extension carried by said piston and bearing against surfaces of said hub, the space intervening said piston and sealed barrel end being filled with a sterile gas, said piston being projectible to cause the extension to thrust against said hub and project the point of said needle through and beyond said sealed outer barrel end, a connecting passage existing whereby the sterile air within said barrel discharges through the hub and lumen of the needle as the hub is projected to a position adjacent the outer barrel end and cooperating means at such barrel end and the hub to secure the parts in said predetermined relationship upon said hub and outer barrel ends reaching such adjacent position and during subsequent drawing of medicament into said barrel through the lumen of the needle under retraction of said piston.

5. In a syringe assembly as defined in claim 4, said cooperating means comprising latch parts extending from said hub and the bore face of said barrel to permanently lock said needle in projected position.

6. In a syringe assembly as defined in claim 4, a bored tip of reduced diameter defining the outer barrel end, said hub being projectible into the tip bore and the effective diameter of said hub being such as to supportingly bear against the bore surfaces to maintain said hub in a stable condition therein.

Lockhart Sept. 24, 1946 Scherer et al. Jan. 25, 1949

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