US2578812A - Injection syringe - Google Patents

Description

Dec. 18, 1951 p, KQLLSMAN 2,578,812

INJECTION SYRINGE Filed Dec. 20, 1947 INVENTOR. P HC/L KOLLSMQN A. ATTORNISY Patented Dec. 18, 1951 UNITED STATES "PATENT OFFICE INJECTION SYRINGE Paulliolls'man, New York, N. Y.

Application December 20, 1947, Serial No. 792,991

This invention relates to improvementsin devices for hypodermic or intra-muscularinjection of'medicinal compositions. The inventionprovides, among other improvements, asyri'nge which is extremely simple to operate, onesingle manipulation of the syringe being sufficient to apply it to the-patient, insert the'needleand eject the medicinal" composition therefrom.

The'simple construction and mode of operation of'thesyring'es embodying the'present invention makes these syringes particularly suited for self administration of medicinal composi tions by the patient himself. The peculiarcon struction proposed by the invention. renders syringes embodying the inventive features Tprac tically fool-proof? in that the: constructiontnoti only compels correct application ot the' syringe and: proper control of the" depth of? insertion of the needle, but" also insur'essterility of all the important parts of the syringes up" tothe" very; moment-of use.

The invention also provides a-formaof syringe" whichserves as an amp'ule: for storing. aprecis termined volume of amedicinal compositicn' from which the composition? may be discharged into body tissue without-previous transfer from aseparateampule or tosa separatesyringe.

These and numerous other features, advan tages and objects ofthe'invention will appear more fully from the detailed. description-which follows accompanied by drawings showing, for thepurposeof illustration, preferred embodi mentsof the invention. The invention also con sists in certain new and original features of construction and combination of elements hereinafter set-forth and claimed. Although'the features characteristic of this inventionwh-ichare believed. to be: novelwill be particularly pointed out in the claims appended :hereto; theinvention itself, .its objects and advantages, andthe man-- her in which it may be carried outmay be better understood. by referring to thefollowing-description takenin connection with the accompanying drawings-forming a partof it in which Figure 1 is across-sectional. view of arsyringe' embodying the invention, a section being-takenon' line l| of Figure 2';

Figure 2 is aplan view ofthesyringe shown in section in Figure 1;

Figure 3 is a side view, partly in section, of

the modified'form of syringe;

Figure 4 is'a" section taken on lined-4 in Figure 3;

Figure dis a member having rooves. therein into which a movable" stop may be inserted;

Figure 6 is a perspective'viewof astop member atta'chableto the plunger shown in Figure {and Figure 7 is a fractional side view, partly in section, of a form of sealing plugadapited" to fractional side-view of a plunger 7 Claims. (Cl. 128220) i names for convenience.

I ture from the principles of the invention and that the invention maybe appliedto other structures than the ones shown.

The" subject matter of" this applicationis related to the-subject matter-of co-pending applications directed to devices of the general type disclosed herein.

Applicationserial No. 792,992, filedDecember 29, 1947,- discloses and claims a syringe designed for one-time useand so arranged'th'at it cannot be reused.

Application Serial No. 792,993, filed December 20, 1947, discloses and claims a tubular needle seal for a syringe which prevents contaminationof the necd-le'and is blow-off proof in thatit will not-blow off if the syringe fiuidissubjected to a sudden rise in pressure, for example by dropping the syringe.

Application Serial No. 792,994, filedDecember 20, 1947, discloses and claims-a syringe having anarrow visible andv optically enlarged passage leading to the inner-end. ofthe needle to facilitate observation, and expulsion of, gas bubbles in the syringe chamber.

Application Serial No. 792,995, filed December 29, 1947, discloses and claims an improved form of non-creeping plunger seal.

The syringe shown in Figures 1. and. 2 comprises a barrel II in which a plunger IZis-telescopically movable. The plunger I2 is tightly sealed with respect to the interior surface l3 cf:

the barrel by a gasket M which rests. in a groove l5 of the plunger and frictionally engages thev interior surface 13 of the barrel l I.

In the illustrated form of syringe, the rear surface I6 of the plunger forms a movable wall of a chamber ll adapted to contain acharge of medicinal fluid confined between the barrel H and the plunger l2.

A hollow injection needle l8, preferable of substantially constant outer diameter, is mounted in the plunger i2 and communicates with the chamber ll through a hollow passage. l9 extending through the plunger. The needle l8 projects from the front end surface 20 of the plunger a distance 11 equal to the depth to which the needle is to be inserted into the body tissue. Preferably the exposed length of the needle :2 is made equal to or smaller than the outside diameter of the plunger I2 so as to compel application of the syringe by placing the needle substantially at right angles to the surface of the skin of the patient.

The front end surface 20 is substantially fiat and comprises an area large enough to provide sufficient resistance for ejection of the medicinal composition from the syringe without causing discomfort to the patient by reason of excessive local pressure.

The plunger may be provided with adjustable stop means to permit step-by-step discharge of the contents of the syringe. In the form of syringe shown in Figures 1 and 2, the outside surface of the plunger I2 is provided partially or entirely with a shallow thread 2| engaged by an internally threaded ring 22 whose back surface 23' cooperates with a front surface 24 on the barrel I I and forms an adjustable stop limiting the depth to which the plunger I2 may be telescoped into the barrel II.

A graduation 25 formed on a fiat surface 28 of the plunger I2 and suitably calibrated in volumetric units permits accurate adjustment of the ring 22 on the plunger I2 so that an desired fractional volume may be discharged from the syringe. The graduation 25 cooperates with and is read against the front surface 2'! of the ring 22.

The syringe shown in Figures 1 and 2 is primarily designed for filling with a medicinal fluid composition at the plant or laboratory of the producer, the volume of the fluid being suflicient for a single injection or a series of injections by operating the syringe in repeater fashion with the aid of the adjustable stop ring 22 as hereinbefore explained. After initial filling, the syringe is sealed by placing over the needle I8 a sealing plug 28 preferably of rubber or any other suitable material to prevent discharge of the fluid therefrom in the event the syringe is accidentally subjected to telescoping force and to maintain the front end of the syringe sterile.

Small air bubbles accidentally trapped in the chamber I1 during the filling of the syringe may easily be removed by placing the filled syringe in an upright position thus causing the bubbles to rise and collect near the passage I9. Collection of the bubbles is facilitated by the conical shape of the rear surface It of the plunger as shown in the drawings. Slight telescoping movement of the plunger I2 with respect to the barrel I I forces the bubbles out through the passage I 9 and the needle I8.

The syringe shown in Figures 1 and 2 is used as follows. After removal of the sealing plug 28 from the injection needle I8, the device is ready for immediate use. It is applied to the body of a patient by grasping it at the barrel H which provides a finger grip surface or portion 28. The point of the needle I8 is placed on the patients skin and pressure is then exerted in the direction of the needle I 8 to insert the needle into the body tissue. This force does not cause any discharge from the syringe because in the initial state in which the plunger gasket I8 is stationary with respect to the barrel surface I3 the friction therebetween is relatively great and is equivalent to a multiple of the force required for inserting the needle to its full length.

The needle l8 penetrates the tissue until the front end surface 28 of the plunger comes to rest on the patients skin whereafter the force erted at the barrel is opposed by an equal pressure exerted by the skin against the front surface 20. This is sufiicient to overcome the friction of the gasket I l, and the barrel II then moves telescopically over the plunger causing the fluid to be discharged through the passage I9 and the needle I8 into the patients body tissue. The discharge continues until either the plunger reaches its end position in the barrel or until the adjustable ring 22 engages the front surface 24 of the barrel in the case of partial discharge.

After complete discharge of the fluid from the syringe, the syringe is discarded. The low production price and the difiiculty of removal of the plunger from the barrel due to its peculiar construction discourages attempts of re-using it.

Figure 3 illustrates a modified form of syringe comprising a barrel 38 within which a plunger 3| is telescopically movable. The plunger may be made from tubular round stock. It is slotted at 32 and an elastic plug 3| is inserted between the slotted plunger portions to provide sufficient frictional engagement of the plunger with the interior surface 33 of the barrel. The plunger may have an enlarged finger operable grip portion 34 and may be provided with graduations 35 readable against the back surface 36 of the barrel.

A movable seal or piston 31, preferably separate from the plunger 3| is telescopically movable in the barrel and forms a seal of the fluid chamber 38 against the plunger 3|.

An injection needle 39 is mounted in the front end 40 of the barrel by means of a taper plug 40' and communicates with the interior of the chamber 38. Since the seal 31 is not attached to the plunger, it cannot be removed from the barrel by withdrawal of the plunger. Refilling of the syringe is thus discouraged by the difliculty of removing the seal from the barrel.

Air or gas bubbles accidentally trapped in the chamber 38 may be removed by placing the syringe in an upright position causing the bubbles to collect at the conical end surface 46 of the chamber 38. Slight movement of the plunger 3| then expels the bubbles through the needle 39. Experience has shown that movable seals or pistons 31 of elastic material have a tendency slightly to creep back at the rim portion after the pressure by the plunger on the seal is released. Such creeping of the seal 31 may cause a small air bubble to be drawn into the chamber through the needle. Creeping of the seal 31 is prevented by frictional fit of the plunger 3| with in the barrel 30. The elastic plug 3| which forces the slotted ends of the plunger 3| apart and against the wall 33 of the barrel provides sufficient friction to check any creeping of the seal, the frictional force being greater than the elastic force of deformation of the seal 31 at the rim portion tending to move the seal back slightly.

The syringe shown in Figure 3 is likewise designed for one-time use to be filled at the laboratory or factory. It may be sealed by an appropriate sealing plug 28 for shipment and storage in sterile condition until the time of its use.

When the syringe of Figure 3 is to be used, the sealing cap 28 is removed from its needle 39 and the front end 40. The syringe is grasped by the finger operable portion 34 of the plunger 3| and is placed on the patients skin. No fluid is expelled from the syringe during the insertionof the needle since the resistance of the needleto insertion is not sufiicient to overcome the fricasses-12- tion. of the movable seal 31. After the needle 39;- is completely inserted intor the tissue,,further movement of the piston 3l is'opposedby reaction of'the-skin against the front end 40- of theebarrel. Iihisresistance is sufficient to overcome thefrictional resistance of the movable seal 31 and liquid is now forced-out throughthe-needle 39.

A- modified form of stop means for theplunger [2 or 3! of the syringes of Figures 1 and 3 is shown in Figures 5 and 6. The plunger is provided with a plurality, of circumferential grooves 41' into which a movable stop 48 fits. The stop 48 is preferably made'of plastic sheet material and has a jaw shaped portion 49 adapted frictionally to-engage any of the groovesufl'l in: the plunger. Attachment of the stop 48 limits-the freedomv of telescoping movement of the piston 12 or." 31, respectively; the. end of the pre-set stroke being reached when the stop" abuts the end. surface 24' or 36 of the barrel, respectively.

Figure 7 illustrates an. alternate'form of plug construction for thene'edle H3 or 3.9: Asealing plug; 511' is: attached to thefrontaend of theneedle and seals-it. Priorto use of the syringe, the front surface- 52 of the plug 5! is; sterilized and the plug 5121s. not removedbut the needle I8v or 39 is forced through the. plug causing the'plugto move against the. front surface. 2ll-or 40: of the plunger or barrel [2 or 30 respectively, as: indicatedinbrokenlines in Figure 7. In this position,.the:,plug 51 forms astoplimitingthefdepth to which" the needle may be inserted into the body'tissue.

The inventionthus provides a syringe which,

becanseiof its simplicity, is. inexpensive to. manufacture by modern mass: production methods; The. cost of the syringe. is so small as to make one-time use and; discarding after use more profitable. than re-use of the syringe involving inspection, sterilization'andreJ-filling. Syringes embodying the present invention: are extremely simpletooperate andimay be used by the patient with far greater ease and convenience and safety than conventional'forms of syringes since no accurate gauging of' the depth of insertion of the needleis required and since the operation of syringes embodying the invention is consid erably simpler than the operation of conventional syringes.

The invention obviously is not restricted. to. the particular embodiments herein shown and described. Numerous modifications, additions, omissions, substitutions'and other changes may be made without departing from the spirit and the essence of the invention, as defined in the claims appended hereto. All'such changes will be apparent to persons skilled in art familiar with the disclosure of the invention anddo-not involve av departure from the spirit and the teachings. of the invention.

What is claimed is:

1. An injection syringe comprising, in combination, a barrel member; a plunger. member telescopically fitting into said barrel member'and forming, a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of said members having a'substantiallyflat front end surface of substantially continuous curvature and free from projections, said'surface bein of a diameter substantially equal to that of said one member for engaging and restingagainst the body portion of a patient into whichthe fluidis to be injected, the -other member being adapted to be manually grasped member; sealing meansfor sealing.- the plungermember. with. respect to. the barrel member; a hollow injection needle fixedly mounted in said one membercommunicating withsaid chamber, said needle projecting from said front end surface and being of uniform thickness from said surface to the needle point, said surface by resting against the body portion of the'patient determining the depth to which the needle is insert'able, said other member having a finger grip portion'for manual operation of the syringe by pressure: exertedat said finger grip portion inithedirection of v said needle, causing insertion of said needle until said: end surface comes to rest against the patients body" and thereafter causing injection of said. fluidv through said needle by telescoping" movement of said members by reason of the resistanceto such pressure by said one memberbearing against the patients skin.

2; An injection syringe comprising, in combination, a barrel" member; a plunger member telescopically fitting into saidba'rrel member and forming" a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of saidmembers' having a substantially flat front endsurface of substantially continuous curvature and free from projections, said surface being of a diameter substantially equal to that of said" one member for engaging and resting against, the-body" portion of a patientinto which the fluid is to beinjected; the other member being adapted to be manually grasped fol-"telescoping movement relatively to said one member; sealing means for sealing the'plunger member with'respe'ct-to the'barrel member; a hollowunjectioir needle fixedly mounted in said one'memb'er communicating with said chamber, said"needle projecting from said front end surface and being of unifiirmv 'diameter'from said surface to the needle point, said surface by resting-against the bodyportion of the patient determiningthe depth to which the needle is insertable, said other member having a: finger grip portion formanual-operation of the syringe by pressure in the direction of the needle causing insertion of said. needleuntil said end surface comes'to restagainst the patients body and thereafter causing injection of said fluid throug-hsaid needle by the telescoping movement of-said member by reason of the resistance to'such pressure by saidone'member bearing against thep'atientsskin; and adjustable stop means-onsa-id plunger'member; said stop means bearing against saidbarrel member for limiting the extenttowhich the plunger member may be'movedinto said' barrel member.

3; An" injection syringe comprising, in combination, a barrel-member; a plunger member telescopically-fitting into-said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid'; sealingmeans'for sealingthe plunger member with respect-to the barrel member; a hollow injection'n'eedle mounted in one of said members cominunicating'with said chamber, said-needle projecting from the front end surface of said one member; said 'other-member-having a finger grip portion-for manual operation of the syringe by pressure'inthedirectionof the needle; and a pierceable sealingplu'gon'said'needi'e, sa-i-d plug havingv a thickness-less than thelength of the needle;'saidf'plugbeing-adaptedto 'seal the point or the=needie'-and adapted to be pierced and slid ior telescoping movement relatively to said one ll along said needle against said front end surface upon exertion of pressure at said finger grip portion in the direction of said needle, whereby said plug forms a stop limiting the depth to which the needle may be inserted into body tissue.

4. An injection syringe comprising, in combination, a barrel member; a plunger member having a threaded outer surface telescopically fitting into said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of said members having a substantially flat front end surface of a diameter substantially equal to that of said one member for engaging and resting against, the body portion of a patient into which the fluid is to be injected, the other member being adapted to be manually grasped for telescoping movement relatively to said one member; sealing means for sealing the plunger member with respect to the barrel member; a hollow injection needle fixedly mounted in said one member communicating with said chamber, said needle projecting from said front end surface; an internally threaded ring on, and adjustable with regard to, the threaded plunger surface, the end of said barrel member forming an abutment stop for said rin to determine the depth to which said plunger member may be telescoped into said barrel member, said front end surface of said one member forming a stop limiting the depth to which said needle is insertable, said other member having a finger grip portion for manual operation of the syringe by pressure exerted at said finger grip portion in the direction of said needle, causing insertion of said needle until said end surface comes to rest against the patients body and thereafter causing injection of said fluid through said needle by telescoping movement of said members by reason of the resistance to such pressure by said one member bearing against the patients skin.

5. An injection syringe comprising, in combination, a barrel; a plunger telescopically fitting into said barrel and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid, said plunger having a graduation extending longitudinally of the plunger, said plunger further having a passage therethrough leading from said chamber to the front end of the plunger, said front end having a surface adapted to rest against the body portion of a patient into which the fluid is to be injected; sealing means for sealing the plunger with respect to said barrel; a hollow injection needle mounted on said plunger communicating with said passage, said needle projecting from said front end surface, the front end surface forming a stop limiting the depth to which said needle is insertable, said barrel having a finger grip portion for manual operation of the syringe by pressure exerted at said finger grip portion in the direction of said needle, causing insertion of said needle until said end surface comes to rest against the patients body; and stop means adjustably attachable to said plunger, said stop means operating with said barrel for limiting the extent to which the plunger may be moved into said barrel.

6. An injection syringe comprising, in combination, a barrel member; a plunger member telescopically fitting into said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of said members having a substantially flat front end of a diameter substantially equal to that of said one member for engaging and restin against, the body portion of a patient into which the fluid is to be injected, the other member being adapted to be manually grasped for telescoping movement relatively to said one member; sealing means for sealing the plunger member with respect to the barrel member; a hollow injection needle mounted in said one member communicating with said chamber, said needle projecting from said front end surface and being of uniform diameter from said surface to the needle point, said surface by resting against the body portion of the patient determining the depth to which the needle is insertable, said other member having a finger grip portion for manual operation of the syringe by pressure exerted at said finger grip portion in the direction of said needle, causing insertion of said needle until said end surface comes to rest against the patients body, whereby the depth of insertion of said needle is positively limited.

7. An injection syringe comprising, in combination, a barrel member; a plunger member telescopically fitting into said barrel member and forming a variable volume chamber therewith adapted to contain a charge of medicinal fluid, one of said members having a front end surface adapted to engage, and rest against, the body portion of a patient into which the fluid is to be injected, the other member being adapted to be manually grasped for telescoping movement relatively to said one member; sealing means for sealing the plunger member with respect to the barrel member; a hollow injection needle mounted in said one member communicating with said chamber, said needle projecting from said front end surface a total distance less than the outside diameter of said one member, the projecting portion of said needle being of substantially uniform outside diameter, said front end surface being adapted to rest against the body portion of the patient to determine the depth to which the needle is insertable, said other member having a finger grip portion for manual operation of the syringe by pressure exerted at said finger grip portion in the direction of said needle, causing insertion of said needle until said end surface comes to rest against the patients body, whereby the depth of insertion of said needle is positively limited.

PAUL KOLLSMAN.

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

UNITED STATES PATENTS Number Name Date 446,125 Schirmer Feb. 10, 1891 509,676 Pilling et a1 Nov. 28, 1893 1,499,952 Spahlinger July 1, 1924 1,555,282 Hein Sept. 29 1925 1,817,003 Hein Aug. 4, 1931 1,848,711 Hall Mar. 8, 1932 2,388,323 Henderson Nov. 6, 1945 2,394,687 Hein Feb. 12, 1946 2,408,323 Lockhart Sept. 24, 1946 2,409,656 Austin Oct. 22, 1946 2,410,351 Lockhart Oct. 29, 1946 FOREIGN PATENTS Number Country Date 51,542 Switzerland Mar. 1, 1910

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