US2622595A - Device for hypodermic injections - Google Patents

Description

Dec. 23, 1952 P. KOLLSMAN 2,622,595

DEVICE FOR HYPODERMIC INJECTIONS Filed Dec. 20, 1947 I. H grill/111m ll gym/1171101404;

Fig. 5

INVENTOR. P g UL KOLLSMHN 5),, ATTORNEY Patented Dec. 23, 1952 UNITED STATES PATENT OFFICE DEVICE FOR HYPODERMIC INJECTION 8 Paul Kollsman, New York, N. Y.

Application December 20, 1947, Serial No. 792,992

1 Claim. 1

This invention relates to improvements in syringes for hypodermic or intramuscular injection of medicinal compositions. The invention provides a double purpose syringe which is inexpensive to manufacture and which serves as ampoule for storing a predetermined volume of a medicinal composition. The composition is discharged from the ampoule-syringe directly into body tissue without previous transfer to a separate syringe or other injection device.

The invention also provides a syringe which is extremely simple to operate, one single manipulation of the syringe being sufiicient to apply it to the patient, insert the needle and eject the medicinal composition therefrom. The simple and inexpensive construction proposed by the invention makes it advantageous to discard rather than refill the syringe after discharge of the medicinal composition therefrom.

The invention offers in this connection various structural improvements which make syringes non-refillable whereby unauthorized refilling under non-sterile conditions is guarded against.

These and numerous other features, advantages and objects of the invention will appear more fully from the detailed description which follows accompanied by drawings showing, for the purpose of illustration, preferred embodiments of the invention. The invention also consists in certain new and original features of construction and combination of elements hereinafter set forth and claimed, Although the fea tures characteristic of this invention which are believed to be novel will be particularly pointed out in the claim appended hereto, the invention itself, its objects and advantages, and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of this application in which:

Figure 1 is a cross-sectional view of a syringe embodying the invention, a section being taken on line l--I of Figure 2;

Figure 2 is a plan view of the syringe shown in section in Figure 1;

Figure 3 is a side view, partly in section, of a Figure 5 is a perspective view of a stop member attachable to the plunger shown in Figure 1.

In the following description and in the claims, various details will be identified by specific names for convenience. The names, however, are intended to be generic in their application. Like reference characters refer to like parts in the several figures of the drawings.

In the drawings accompanying, and forming part of this specification, certain specific disclosure of the invention is made for the purpose of explanation of broader aspects of the invention, but it is understood that the details may be modified in various respects without departure from the principles of the invention and that the invention may be applied to other structures than the ones shown.

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

Application Serial No. 792,991, filed December 20, 1947, now Patent No. 2,578,812, dated December 18, 1951, discloses and claims a syringe in which the depth of insertion is automatically controlled and limited, and in which stop means are provided permitting measured partial discharge.

Application Serial No. 792,993, filed December 20, 1947, now Patent No. 2,578,813, dated December 18, 1951, discloses and claims a tubular needle seal for a syringe which prevents contamination of the needle and is blow-off proof in that it will not blow 011 if thesyringe fluid is subjected to a sudden rise in pressure, for example by dropping the syringe.

Application Serial No. 792,994, filed December 20, 1947, now Patent No. 2,578,814, dated December 18, 1951, discloses and claims a syringe having a narrow visible and optically enlarged passage leading to the inner end of the needle to facilitate observation, and expulsion of, gas bubbles in the syringe chamber.

Application Serial No. 792,995, filed December 20, 1947, discloses and claims an improved form of non-creeping plunger seal. The syringe shown in Figures 1 and 2 comprises a barrel l l in which. a plunger 12 is telescopically movable. The plunger I2 is tightly sealed with respect to the interior surface l3 of the barrel by a gasket [4 which rests in a groove l5 of the plunger and frictionally engages the interior surface 13 of the barrel H.

In order to make the syringe unfit for re-use after discharge, the barrel H and plunger l2 are preferably made from a thermo-responsive preferably clear synthetic plastic which at ordinary room temperatures is hard and shape retaining and which, upon heating to sterilizing temperatures, of the order of the boiling point of water, becomes plastic and loses its shape or changes its appearance, for example by turning opaque. This property of the plastic material makes the barrel and plunger unfit for use after an attempt to sterilize them by heating. Sterilization of the needle alone is discouraged by making it.non-. removable.

However, the barrel and plunger may initially. be sterilized by the manufacturer or thepharmaceutical laboratory distributing the filledsyringes by exposing the parts to an atmosphere of sterilizing gas.

In the illustrated form of syringe, the rear-- surface I6 of the plunger forms a movable wall of a chamber I! adapted. to contain a charge of medicinal fluid confined between the barrel H and the plunger I2.

A hollow injection needle 18, preferably of'substantially constant outer diameter, is non-removably mounted in, the plunger 12 and communicates with the chamber H through a hollow passage l'9 extending through the plunger.- The needle 18 projects from the front end surface 20 of the plunger a distance d equalto the depthto which the needle is to be, inserted intothc body tissue.

The front end" surface 20 is substantially flat and comprises an, area large enough t,0 provide suflicient resistance for ejection of themedicinal 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 piston is provided with a plurality of circumferential grooves '21 into which a movable stop 22; fits. The stop 22 is preferably made of plastic sheet material and has a jaw-shaped portion 23 adapted frictionally to engage any of the grooves 2| in the piston. Attachment of the-stop 22 limits the freedom of telescoping movement of the piston l2, the end of the preset stroke being reached when the stop abutsthe end surface 24; of the barrel.

The plunger I2 is suitably calibrated in terms of'volumetric units; This maybe done byapplying scale numerals 25 to the ridges above the respective grooves-for the stop '22. For example, the nuzneral 1.5 indicates that if the stop 22 is placed in the groove 2| below the numeral 1.5, the volume; discharged atthe time the stopabuts the barrel II- is 1.5 volumetric units. Thisarrangement permits any-"desired fractional volume to bedlschargedfrom the syringe.

Refilling of the syringe is mechanically discouraged by making the plunger l2 ofa length Z1 equal to, or slightly-less than, thelength Z2 of the barrel, measured on the, inside so that in fully telescoped position the plunger is completely within the barrel l l and cannot be removed therefromby hand for thepurpose of refilling. The friction which the gasketl 4 provides against the interior surface [3 is sufficient to preventwithsurface 20;

4 drawal of the plunger from the barrel by a needle I8.

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 sufficient for a single injection or a series of injections by operating the syringe in repeater fashion with the aid of the adjustable stop 22 as hereinbefore explained. After initial filling, the syringe is sealed by placing over the end of the needle l8 a sealing plug 28 preferably of rubber or any other suitable material. This plug pressure tightly seals the end of the needle to prevent discharge of the fluid therefrom in the eventthe syringe is accidentally subjected to telescoping force and to maintain the front end of the syringe sterile.

In sealed condition, the syringe serves as an ampoule and is ready for immediate use by removal of the sealing plug 28 and adjustment of the ring 22, if the syringe is equipped with such a ring.

Small air bubbles accidentally trapped in the chamber If 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, l9, Collection of. the,- hubblesis facilitated by the conical shape of the rear surface Hi ofjthe plun er [2' as shown in the, drawings. Slight telescoping movement of theplunger l2 withrespect to the barrel I I forces the bubbles, out through the passage 19 and the needle-1B.-

syringe showninFigurcs 1 and 215 used as follows. After remoyal ofthe sealing plug 28 from the, injection needle E8, the, device is ready for immediate use. It is applied to the body of apatient by grasping it at the barrel l I which provides afinger grip surface or portion 29. The point. of the needle I8 is placed'on the patients shin andpressure is then exerted in the direction of the needle l 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 l 41 is stationary with respect to the barrel surface E3 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 IBpenetrates the body tissue until the front end surface 20, of the plunger comes to rest onthe patients skin, whereafter the force exerted at the barrel is opposed by an equal pressure exerted by the skin againstv the front This is sufiicient to overcome the friction of'the gasket [4 andthe barrel H then moves telescopically over the plunger causing the fluid to be discharged through the passage l9 and the needle i8 intothe patients body tissue. The, discharge continuesuntil either the plunger reaches its end position in the barrel ,or until the adjustable rin 22 engages the frontsurface 2 ofthe barrel in the case of partial discharge.

After completedischarge of the fluid from the syringethe syringe is discarded, The low production price and the difficulty of removal of the plunger from the barrel due to its peculiar construction discourages attempts of re-usingit Figure 3 illustrates a modifiedform of syringe comprising a barrel 3!! Within which a plunger 31 is telescopically movable. The plunger may be made from tubular round stock. It is slotted'at 32 and an elastic plug 35 inserted between the slotted plunger portions tends to force the slotted portions apart 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 a scale 35 readable against the back surface 36 of the barrel.

A movable seal or membrane 31, preferably separate from the plunger 3| is telescopically movable in the barrel and forms a seal of the fluid chamber 38 against the piston 3 I An injection needle 39 is mounted in the front end Q0 of the barrel and extends in the illustrated embodiment with its pointed rear end 4| into the chamber 38 to pierce the center portion 42 of the seal 31 when the seal arrives in its end position. Since the seal 31 is not attached to the plunger, it cannot be removed from the barrel by withdrawal of the plunger. Refillin of the syringe is thus discouraged by the difficulty of removing the seal from the barrel and is further rendered impossible by destruction of the seal once the syringe is fully discharged.

Air or gas bubbles accidentally trapped in the chamber 33 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 3? may cause a small air bubble to be drawn into the chamber through the needle. According to the invention,

creeping of the seal 31 is prevented by frictional fit of the plunger 3! within the barrel 3%. 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 thin center portion 42 of the seal 31 also aids in preventing air from being drawn into the chamber 38. During discharge of fiuid from the chamber 38, the center portion 42 is bulged rearwardly to some extent towards the plunger by reason of the fiuid pressure upon it. When the piston 3| comes to rest and the pressure inside the chamber 38 drops, the center portion 42 of the seal returns to its normal position and in doing so tends to force out an additional small volume of fluid sufiicient to compensate for any creeping of the seal near its rim portion which would tend to draw fluid into the chamber 38.

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 plug 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 M and is placed on the patients skin. Pressure exerted on the plunger forces the needle 39 into the body tissue until the front end 48 of the barrel comes to rest on the patients skin. No fluid is expelled from the syringe during the insertion of the needle since the resistance of the needle to insertion is not sufficient to overcome the friction of the movable seal 31. After the needle 39 is completely inserted into the tissue 6 of the patient, further movement of the piston 3| is opposed by reaction of the skin against the front end M] of the barrel. This resistance is sufficient to overcome the frictional resistance of the movable seal 31 and liquid is now forced out through the needle 39. At the end of the stroke, the pointed rear-end 4! of the needle pierces the thin center portion 42 of the seal and automatically renders the syringe unfit for refilling without removal and replacement of parts.

The invention thus provides a syringe which, because of its simplicity, is inexpensive to manufacture by modern mass production methods. Thecost of the syringe is so small as to make one-time use and discarding after use more profitable than re-use of the syringe.

Safe re-use of a syringe involves inspection, sterilization and re-filling under sterile conditions. Conditions of sterility are difficult to maintain except at establishments specifically equipped for it, for example, laboratories, hospitals and physicians offices.

Syringes, according to the present invention, lend themselves admirably to use by the patient himself, who, but for rare exceptions, has no facilities for the cleaning, sterilization and refilling of syringes, thus opening the doors to dangers of infection. The present invention meets a specific need in providing a syringe which is furnished by a pharmaceutical laboratory ready-filled with a specific volume of medicina1 composition ready for immediate use by the patient. The syringe reaches the patient in sterile condition and requires no filling or transfer of medicinal fluid from one receptacle into another. The novel syringe thus permits maintenance of a degree of sterility by the average patient which he was not heretofore able to maintain. The syringes embodying the principles of the invention are practically fool-proof in use. They are also particularly safe to use by reason of the limitation of the depth to which the needle may be inserted into the body tissue whereby the danger of improper injection or injury due to contact of the injection needle with bone structure of the patient is eliminated. Thus, a degree of safety is provided in the selfadministration of injections which prior to the invention was not regularly attained.

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 appended claim. All uch changes will be apparent to persons skilled in the art familiar with the disclosure of the invention and do not involve a departure from the spirit and the teachings of the invention.

What is claimed is:

An injection syringe comprising, in combination, a barrel; means forming a movable wall in said barrel, said means including a plunger telescopically fitting into said barrel and a plug of resilient material for sealing said barrel towards said plunger, whereby a variable volume chamber is formed in said barrel adapted to contain a charge of medicinal fluid; a hollow injection needle mounted on said barrel communicating with said chamber, said needle projecting from the front end surface of said barrel; said plunger having a plug engaging end portion slotted lengthwise of the plunger; and a resilient Number member for forcing said slotted end portion apart 4, into frictional contact with the barrel wall. 4 PAUL KOLLSMAN. 11 5, 2,388,323 REFERENCES CITED 2,408,323 The following references are of: record in the 21478344 file of this patent:

UNITED STATES PATENTS 10. Number Number Name Date 2 1 4 Re. 16,836 Cook: Dec. 27,. 1927 51 54 446,125 Schirmer Feb. 10, 1891 573,611 509,676 Billing et a1 Nov. 28, 1893 632,383 1,272,742 Weguelin et a1 Ju1y'16, 1918 15 Name Date Rehm Mar. 12, 1929 Morton June 24, 1930 Hall Mar. 18, 1932 Henderson Nov. 6, 1945 Lockhart Sept. 24, 1946 Smith Aug. 9, 1949 FOREIGN PATENTS Country Date Great Britain June 15, 1901 Switzerland Mar. 1, 1910 Great Britain Nov. 18, 1945 Germany July 15, 1936

Images