Connector for liquid transfer device

A transfer instrument (50), consisting of a prefilled disposable syringe, comprises a container (51) containing the liquid to be injected, a piston (52), and a piston rod (53) attached to the bottom of a capsule (54) with a tubular tip (58). This tubular tip has an inner surface (62) in the shape of a truncated cone to admit an insert (66) and an outer surface (64) in the shape of a truncated cone with a taper of 6%, capable of receiving a standard cap (59) fitted with a needle (60). A throat (73) is provided at the periphery of the insert (66) to permit the flow of the injection liquid and to obviate the need for a large dead volume.

BACKGROUND OF THE INVENTION 
The present invention concerns a connector for adapting a tip to a liquid 
transfer device, particularly one for the transfer of liquid medicine. 
Different means for connecting tips to liquid transfer devices are already 
known. One of these is described in U.S. Pat. No. 4,596,561, in which the 
transfer device is a prefilled single-dose hypodermic syringe and the tip 
is a needle connected to a cover adapted to a needle-holding ferrule 
disposed at the end of the syringe body. 
One critical problem posed by these devices is that of unused contents, 
i.e., the quantity of medication remaining in the syringe after injection. 
The problem is particularly acute when the device is provided with a 
connector with a standard truncated Luer cone body of exterior dimensions 
approaching a 4 mm diameter and with a divergence of 6% along a length of 
from 7 to 10 mm. These exterior dimensions are necessary to allow the 
device to be attached to the standard female tips associated with such 
various elements as needles, multi-track valves, catheters, etc. In known 
manner, this standard truncated connecting device currently called the 
"conical Luer 6% connecting device" has a central conduit for the passage 
of liquid. Furthermore, it is known to be technically impossible to 
produce such a tip efficiently by means of thermoplastic injection molding 
when the central conduit has a relatively narrow ferrule, as the walls of 
the cone body then become proportionately too thick, thereby slowing down 
the injection cycle of the thermoplastic material considerably so that the 
cooling period for the material must be greatly increased to avoid 
shrinking. 
To achieve a ferrule of the Luer type with a central canal diameter of the 
order of 0.4 mm, so as to result in relatively small amount of unused 
contents, the walls of the cone body should be a minimum of about 1.8 mm 
thick. This considerable thickness would require the synthetic material to 
undergo a lengthy cooling phase, during which bubbles would tend to form. 
Therefore, it would be nearly impossible to adhere to the parameters fixed 
by international norms for truncated male Luer 6%-type ferrules. 
This is the reason that injection-manufactured disposable syringes 
presently in commerical use have a Luer ferrule axially transvered by a 
central conduit with a diameter of the order of 3 mm, thereby permitting 
the walls to be thinner, of the order of 0.5 mm. This technological and 
economic imperative has the unfortunate result of leaving a larger 
quantity of unused contents inside the axial conduit of the ferrule. 
This problem of unused contents has been approached and partially resolved 
by a device described in European Pat. Application published as No. 47042. 
The unused contents created by the relatively large dimensions of the 
axial conduit disposed inside the needle-holding ferrule of the syringe is 
partially overcome by insertion, during the final operation, of a 
truncated element connected to the piston extremity. However, this system 
does not resolve the problem of the standard unit described above, known 
as the Luer 6% truncated unit. In practice, when a truncated female 
element is adapted to a truncated male Luer 6% ferrule, a space always 
remains between the base of the female element and the extremity of the 
male ferrule, thereby affording little control over the amount of unused 
contents, a situaton which is both bothersome and dangerous, although 
useful in certain cases to serve as a viewing chamber for observing the 
passage of the liquid. 
U.S. Pat. No. 4,240,425 proposes a unit which almost completely eliminates 
the problem of unused contents in injection syringes by providing on the 
one hand, a connecting device comprising a hollow tubular ferrule and on 
the other hand, a needle-bearing flange of essentially complementary shape 
adaptable to the said ferrule. The disadvantage of the this system resides 
in the fact that said needle-holding flange does not correspond to 
standard construction and therefore prevents replacement of the 
specialized needle by a standard needle if for some reason the special 
needle cannot be used. Actually, if a standard needle comprising a Luer 6% 
flange is placed in the ferrule of this syringe, the problem of unused 
contents described above surfaces again, and the patient is not injected 
with the prescribed dose of medication. 
SUMMARY OF THE INVENTION 
The present invention proposes to overcome all the foregoing disadvantages 
by realizing a connecting device of the type described, permitting use of 
tips with supports which conform to the norms imposed by the Luer 6%-type 
design principle, as well to resolve the problem of unused contents, 
particularly critical for injectable medication, especially with an 
extremely low volume of active substances. 
To this end, the connecting device according to the invention is 
characterized by the fact that it comprises a tubular ferrule connected to 
the apparatus for liquid transfer, and an adapter connected to the tip, 
said ferrule having a central cavity and said adapter being associated 
with an insert disposed to engage within said central cavity, and by the 
fact that said insert comprises at least one longitudinal peripheral 
groove disposed to define, with the interior wall of the ferrule, a canal 
for the passage of the liquid to be transferred. 
According to a first embodiment of the device, the insert and the adapter 
form a unit. 
According to a second embodiment of the device, the insert is independent 
of the adapter. 
The central cover of the tubluar ferrule preferably comprises a truncated 
interior wall whose generatrices converge towards the transfer apparatus. 
The tubular ferrule preferably comprises an exterior truncated wall whose 
generatrices diverge towards the transfer apparatus. To enable use of a 
standard adapter conforming to the norms imposed by the Luer 6% design 
principle, the divergence of the truncated exterior wall of the tublar 
ferrule is preferably 6%. 
According to a particulary advantageous embodiment of the connecting 
device, the tip is a trocar comprising a first portion with a truncated 
extremity, an intermediate portion and a second portion with a conical 
extremity, the said first portion of the extremity consisting of the said 
insert engaged in the central cavity of the tubular ferrule, the second 
intermediate portion having an exterior diameter greater than that of the 
wide end of the central cavity, and the three portions of said trocar 
being traversed by a longitudinal peripheral groove at least partially 
defining the canal for passage of the liquid to be transferred. 
The intermediate portion of the trocar is disposed to contact the free 
extremity of the tubular ferrule. 
According to another advantageous embodiment of the connecting device 
described, the tip is an injection needle, and the adapter comprises a 
bell-like cover disposed to adapt tightly over the tubular ferrule and 
holds the said injection needle. The insert, preferably independent of 
said cover, advantageously comprises a first truncated end portion engaged 
in the central cavity of the tubular ferrule, an intermediate portion and 
a second end portion engaged in the interior cavity of the said 
bell-shaped cover. 
In this case, the shape of the second portion of the insert extremity is 
preferably designed so that it occupies only a portion of the free space 
within the interior cavity of the bell-shaped cover, so as to form a 
transparent control chamber for viewing the passage of the liquid through 
the cover wall. 
Likewise, in this case, the intermediate portion of the insert is 
preferably disposed to contact the free end of the tubular ferrule and the 
interior wall of the said bell-shaped cover. 
According to one preferred embodiment of the device, the tip is a nasal 
spray dispenser consisting of a rounded end portion formed at the 
extremity of an insert situated inside the tubular ferrule, and the canal 
for passage of the liquid to be transferred opens at the base of the 
rounded tip portion between the walls of the insert and those of the 
tubular ferrule. Said passageway preferably comprises a portion of the 
extremity forming an angle of from 30 to 90 degrees, and preferably 
approximately equal to 60 degrees, in relation to the tubular ferrule 
surface and/or to the insert in the area of the canal opening. 
According to a first advantageous embodiment, the tip comprises a projected 
body within which there is mounted an insert defining, with the interior 
wall of said body, a passageway for the liquid, and said body comprises a 
stop means with a projection at a predetermined distance from the channel 
opening disposed to determine the depth for applying the liquid in the 
nasal cavities. 
According to a second advantageous embodiment, the tip is a dropper, and 
the insert is provided with a flat element disposed at its upper 
extremity, said flat element comprising an opening extending the liquid 
passageway disposed between the said insert and the tubular ferrule. This 
tip is preferably surmounted by a cover consisting of a convex interior 
portion designed to let the cover open for passage of the gas inside the 
distributor and to seal it tightly. Said cover may comprise a base 
associated with an anti-bacterial agent.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a device 10 for liquid transfer essentially comprising a 
receptacle 11 containing, for example, a liquid to be transferred into 
another receptacle holding a liquid or solid substance, such as, for 
example, a lyophilisate. Said other substance may be in a vessel or holder 
stoppered by a membrane to be pierced by a trocar 12 which comprises the 
tip associated with the transfer device. Said transfer device further 
comprises a piston 13 attached to the end of a shaft 14 attached, for 
example, by ultrasonic soldering or any other appropriate means, to the 
base of a capsule 15 having at its free end a tubular ferrule 16 with the 
said trocar 12 inside. A membrane filter 17 is mounted between the base of 
capsule 15 and shaft 14. The latter is hollow and has a pipe 18, generally 
cylindrical and equipped with an axial peripheral groove 19 forming with 
the interior wall of shaft 14 a longitudinal channel to allow liquid to 
flow through said shaft towards filter 17. 
Tubular ferrule 16 (tubular end part) 16 comprises a central cavity 20 
defined by a truncated interior wall 21 extending, at its end adjacent the 
base of capsule 15, into an annular cylindrical wall 22. Truncated wall 21 
has generatrices which converge towards the transfer device. Exterior wall 
23 of tubular ferrule 16 is also truncated, but its generatrices diverge 
towards the transfer device. Exterior wall 23 preferably has a 6% 
divergence to conform to international norms for Luer 6% design. 
Trocar 12 comprises at least a first truncated portion 24 designed to be 
situated inside tubular ferrule 16. This portion comprises a lateral 
truncated surface with a conic section equal to that of interior wall 21 
of tubular ferrule 16. It further comprises an intermediate portion 25, 
generally cylindrical, with a diameter greater than the interior diameter 
of the widest portion of the central cavity of tubular ferrule 16. While 
the diameter of intermediate portion 25 could be the same or smaller than 
the exterior diameter of tubular ferrule 16, the advantage of the larger 
diameter lies in reducing the risk of erroneously attaching a standard 
needle to a transfer device containing a substance requiring dilution 
before injection. Finally, trocar 12 comprises a third conical portion 26 
designed to allow a membrane or cover to be pierced with a recipient for 
the liquid to be transferred, initially held in receptacle 11. 
In the example shown, truncated portion 24 of the trocar extends into a 
cylindrical ring 27 defining an annular shoulder 28 with portion 24 to 
engage in the cylindrical opening defined by cylindrical wall 22 and 
disposed in the base of tubular ferrule 16 and across the base of capsule 
15. 
In this exemplary embodiment, the tip is a trocar, whose function has been 
described above. The adapter connected to the tip consists partly of the 
point or conical portion 26 of said trocar. The adapter is attached to the 
previously mentioned insert and these two elements are connected to form 
one element which is the truncated portion 24 of the trocar extending into 
cylindrical ring 27. 
So that the liquid which has passed through filter 17 may flow towards the 
point of the trocar 12, cylindrical ring 27, truncated element 24, 
intermediate element 25 and conical element 26 of the trocar comprise a 
longitudinal peripheral groove 29 cooperating with walls 22 and 21 
respectively disposed in the base of capsule 15 and inside tubular ferrule 
16 to form a very narrow channel which allows liquid to flow but prevents 
formation of unused contents, which is very important for the transfer 
device concerned. 
A protective cover 30 may be fitted over trocar 12 and attached by known 
means to capsule 15, which has an appropriate opening 31 in its base. 
Cylindrical ring 27 comprises a retaining means cooperating with shoulder 
28 to hold trocar 12 in place and to seal intermediate portion 25 tightly 
against the free end of tubular ferrule 16. Because of this, 
impermeability is perfectly assured at this level. 
The same construction principle is used to create longitudinal conduit 19, 
thereby reducing the unused contents in the transfer device to an absolute 
minimum, that is, the volume of residual liquid after the transfer 
operation. 
FIGS. 1A, B and 1C are a cross-section views showing the geometry of the 
different parts of the trocar taken along lines 1A--1A, 1B--1B and 1C--1C, 
respectively. 
FIG. 2 shows a device for liquid transfer 50 in the form of a disposable 
single- or multiple-dose syringe. Said syringe essentially comprises a 
receptacle 51 for the injectable medication, a piston 52 engaged at the 
end of receptacle 51 and mounted on an essentially cylindrical shaft 53 
attached, for example by ultrasonic soldering, to the base of capsule 54 
comprising two flanges 55 for holding the syringe. Shaft 53 is hollow and 
has a generally cylindrical passageway 56. A filter 57 is located at the 
base of capsule 54. Said capsule extends into a tubular ferrule 58 
consisting a needle-holding tip disposed to receive a bell-shaped cover 59 
holding a needle 60. Before use, a protective cover is mounted on the end 
of capsule 54 to keep the needle in a sterile environment. 
Tubular ferrule 58 has the same shape and dimensions as tubular ferrule 16 
described with reference to FIG. 1. Its inside surface 62 is essentially 
truncated and extended by annular cylindrical wall 63 at its lower end. 
Its outside surface 64 is also truncated with a 6% divergence to allow 
attachment to a standard needle holder, so that it conforms to standard 
Luer 6%-type design. Cover 59 has a 6% interior divergence and adapts 
perfectly to tubular ferrule 58. 
Passageway 56, located inside tubular shaft 53, prevents formation of too 
large a quantity of unused medication. The medication, which passes 
through piston 52 by means of a conduit (not shown), flows axially through 
a longitudinal channel defined by a groove disposed in the periphery of 
the tip of passageway 56 and by the interior wall of hollow cylindrical 
shaft 53. For the same reason, that is, to limit the amount of unused 
contents, i.e., the amount of medication remaining in the syringe after 
injection, an insert 66 is engaged within the truncated cavity defined by 
tubular ferrule 58. This insert essentially comprises a first truncated 
portion 67 completely engaged within tubular ferrule 58, an intermediate 
portion 68 in contact on the one hand with the annular surface of the end 
of tubular ferrule 58 and on the other hand with the interior wall of 
cover 59 holding needle 60, to form a sort of impermeable seal between 
these two components. The insert comprises a third portion 69 shared and 
dimensioned to only partially fill the remaining portion of the interior 
cavity of cover 59, so as to form a viewing chamber exposing the 
medication at the moment of injection through the transparent or 
semi-transparent wall of cover 59. The lower extremity of the first 
truncated portion 67 of insert 66 comprises a cylindrical element 71, the 
purpose of which is to form a retaining means to hold the insert in 
position within tubular ferrule 58. A groove 73 is disposed on the 
periphery of insert 66 to allow flow of the liquid which has passed 
through filter 57 and to lead into the viewing chamber communicating with 
the lower extremity of needle 60. 
FIGS. 2A, 2B and 2C, which illustrate cross-sections taken along lines 
2A--2A, 2B--2B and 2C-2C, respectively, show the shape of cover 59, of the 
upper portion 69 of insert 66, of the intermediate portion 68 of said 
insert, of the lower portion 67 of insert 66 and finally of passageway 73. 
In this case, insert 66 is an independent piece forcibly engaged inside 
tubular ferrule 58 and designed to limit the amount of unused contents, 
that is, the residual amount of injectable medication after using the 
syringe, while permitting use of standard needles of Luer 6%-type design. 
FIG. 3 shows a variation of the device shown in FIG. 1. A conventional 
syringe 80 with a piston 81, affixed to an end of the shaft of piston 82, 
is provided with a tubular ferrule 83 identical to that describe with 
reference to FIG. 1. This ferrule receives trocar 84, identical in every 
respect to that described above. In this drawing, trocar 84 has been used 
to perforate membrane 85. 
FIG. 4 shows a syringe 80, identical to that of FIG. 3, comprising piston 
81 affixed to the end of a shaft of piston 82 and provided with a tubular 
ferrule 83. A cover 86 holding needle 87 is attached to this ferrule, both 
identical in every respect to cap 59 and needle 60 shown in FIG. 2. An 
insert 88 is situated inside the ferrule of extremity 83. The devices of 
FIGS. 3 and 4 demonstrate that the truncated ferrule described above, 
capable of accommodating a standard Luer 6%-type design, may be adapted to 
any known transfer device. 
In the example of FIG. 5, the connecting device 90 is designed for use as a 
nasal spray, that is, to apply medication to the nasal membranes. As 
before, it comprises a tubular ferrule 91 with a central axial opening 
within which insert 92 is engaged. The central opening of tubular ferrule 
91 is slightly conical. The lower portion of the insert to be engaged 
within the opening has the same shape. The upper extremity of insert 92 
has an essentially spherical, rounded form to contact the membranes 
without risk of hurting them. A conduit 94 is disposed between the 
interior wall of tubular element 91 and the exterior wall of insert 92 to 
ensure the flow of liquid initially held in the recipient (not shown), to 
which the connecting device 90 is attached. This channel, essentially 
parallel to the axis of the lower portion of the insert, deviates and 
forms an angle of about 60 degrees in the area of its upper extremity. 
This inclination allows the medication to be applied directly to the 
mucous membranes and ensures ready absorption of the active product. 
FIG. 6 shows another embodiment of a nasal spray device which is in some 
respects a combination of the device shown in FIG. 2 with that of FIG. 5. 
Actually, this connecting device 100 comprises a tubular ferrule 101, 
inside of which there is an insert 102 essentially identical to insert 66 
of the device of FIG. 2. The nasal spray device per se comprises a body 
103 encasing tubular ferrule 101 which fits into insert 102. This tubular 
body comprises a central opening which is largely stoppered by a second 
insert 104, essentially identical to insert 92 shown in FIG. 5 and which 
has, between the inside wall of body 103 and the exterior wall of the said 
second insert 104, a lateral canal 105 essentially identical in shape and 
function to passageway 94 of the device of the preceding drawing. At its 
base, body 103 is provided with a flange 106 comprising a stop means whose 
function is to determine the depth at which the nasal spray is inserted 
into the nose, that is, the area where the medication will be applied. 
This depth is determined in such a way that the area for applying the 
medication corresponds to the optimal absorption area of the nasal mucous 
membranes. 
FIG. 7 shows another connecting device 110 used as a dropper. In this 
example, insert 111, situated inside of tubular ferrule 112, is surmounted 
by a flat element 113 provided with a peripheral notch 114 communicating 
with the longitudinal canal 115 defined by the interior wall of tubular 
ferrule 112 and by the wall of an axial notch disposed in insert 111. 
FIGS. 8 and 9 expand upon the device shown in FIG. 7 with the addition of a 
tightly sealing cover 116. In FIG. 8, the cover 116 is in the open 
position for decompression, i.e., evacuation of the air inside the 
distributor body in the direction of arrow D. In FIG. 9, cover 116 is 
shown in the closed position to ensure tight sealing of distributor 
channel 115. To achieve this, the interior lateral wall of cover 116 
comprises an annular protrusion 117 which, because of the relative 
elasticity of the material, can be moved over flat element 114 surmounting 
insert 11 to contact the exterior wall of tubular ferrule 112 beneath said 
flat area. The base 118 of the interior cavity or cap 116 may be treated 
with an anti-bacterial agent, or may contain a small anti-bacterial plate 
to permanently disinfect the area where the liquid flows through the 
dropper. This arrangement is particualrly advantageous in a dropper system 
designed for numerous uses, where each use places the dropper in contact 
with the environment and contaminates it. Between uses, the storage period 
activates the anti-bacterial substance and thus systematically 
decontaminates the contaminated portion. 
It is understood that the present invention is not limited to the 
embodiments described, but may be modified and undergo various changes 
obvious to one skilled in the art. Thus, the shape and dimensions of the 
various components of the droppers or nasal spray applicators, as well as 
of the protective cover and finally the anti-bacterial agent, may be 
modified according to need or requirements imposed by either use or 
manufacture. 
In the case of the nasal spray, the parameters, the stop means, the slope 
of the channel extremity and its diameter may be modified according to the 
type of medication to be administered and its viscosity. The position of 
the flange of the stop means shown in FIG. 6 further depends upon the 
location of the optimal absorption area in the nasal mucous membranes. In 
the case of the dropper, the exterior shape of the insert may be adapted 
to the desired use for the dropper. The intention is to apply a calibrated 
drop in the eyes, on the body surface, in the mouth or even into a 
receptacle for dilution with water or other liquid for absorption. The 
fundamental advantage of such a dropper, mounted on a piston distributor, 
is that the evacuation of the drop is controlled by piston action. Unlike 
conventional droppers, there is no reabsorption of gas inside the 
distributor body and therefore no risk of contaminating the medicated 
solution inside the distributor.