Needle and hub assembly with needle contacting member

A needle assembly includes an elongate cannula having a first end, an opposite end and a sidewall therebetween. The cannula includes a lumen therethrough defining a cannula longitudinal axis. A hub having a proximal end, a distal end and a passageway therethrough defining a longitudinal axis is provided. The passageway includes an enlarged first portion at the distal end, a second portion adjacent to the first portion and a third portion adjacent to the proximal end. The cannula is positioned in the hub so that the opposite end is within the second portion and the first end projects outwardly from the distal end of the hub. The second portion includes a proximally located ledge for establishing the most proximal position of the cannula in the passageway and an inwardly projecting flange, located distally from the ledge, for contacting and holding a cannula with sufficient force to prevent the cannula from falling out of the hub. The annular flange and the ledge interact with the cannula so that the angular relationship between the cannula longitudinal axis and the hub longitudinal axis can be varied and the cannula movably held in a selected angular relationship. Adhesive is provided in the volume described by the first portion for holding the cannula fixedly in the selected angular relationship with respect to the hub.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a needle assembly and more particularly 
concerns an improved needle assembly for use with or as part of a 
hypodermic syringe or other fluid transferring device. 
2. Description of Related Information 
Hypodermic needle assemblies, including a cannula and a hub, are oftentimes 
removably attached to syringes for performing a variety of tasks such as 
the administration of medication to patients and into devices and for the 
withdrawing of fluid samples from patients and from fluid sources. In some 
cases the cannula is attached directly to the syringe barrel, thus 
eliminating the hub. Further, many fluid delivery tube sets, fittings and 
stopcocks have a standard luer or locking luer fitting so that needle 
assemblies may be used in a variety of drug delivery systems such as in 
intravenous (IV) therapy and in a variety of fluid handling laboratory 
setups. Needle assemblies are also used for blood collection and in 
industrial applications such as dispensing liquids. 
A fundamental requirement for a cannula and hub assembly, and an assembly 
of a cannula and a syringe barrel, is that the resulting assembly be 
capable of holding the cannula so that it is firmly connected to the hub 
or syringe and cannot be easily removed therefrom. Also, the cannula 
should be substantially aligned with the longitudinal axis of the hub or 
syringe barrel and not projecting angularly therefrom. An important 
negative consequence of a misaligned cannula occurs in the manufacturing 
process because the sharp cannula tip can be extensively damaged by 
engaging the inside wall of the rigid needle shield when the needle shield 
is placed over the cannula to engage the hub. Proper alignment between the 
cannula and the hub and/or syringe barrel is important to help the user 
properly guide the cannula into the patient's body during injection when 
reshielding the cannula. Further, the manufacturing process used should 
not create particles or debris in the lumen of the cannula which may later 
be injected into the patient presenting a potential health hazard. 
From a manufacturing process point of view, it can be undesirable to 
provide a hub which has a cannula receiving bore which is smaller than the 
outside diameter of the cannula. It is believed that, unless dimensional 
tolerances are carefully controlled, forcing the hollow cannula through a 
smaller bore, especially with a plastic hub, allows the fine edges of the 
cannula to potentially skive plastic material from the hub inside diameter 
wherein this material may be later injected into the patient. Also, the 
forced assembly of a cannula and hub presents quality problems during mass 
production because of the difficulty in controlling the forces involved. 
The forces required for cannula insertion may be large enough to bend or 
buckle the cannula, or drive the cannula too far into the hub or through 
the hub. This is especially true when many cannula hub assemblies are 
being processed at the same time. Finally, placing a cannula in a long 
cannula receiving bore may result in the cannula being at an angular 
orientation with respect to the hub and/or barrel. This angular 
orientation is the result of molding tolerances and cannot be adjusted if 
a more optimal angular relationship is required. 
Cannula and hub assemblies wherein adhesive is used to bond the cannula to 
the hub may also present problems where the hub structure allows the 
adhesive to nearly contact the open proximal end of the cannula because if 
the adhesive flows into the cannula lumen there is a potential for 
clogging the cannula. Also, attempting to apply adhesive deeply into the 
space between hub and loosely fitting cannula presents quality control 
problems because the process becomes sensitive to the viscosity, 
temperature and delivery pressure of the adhesive. 
U.S. Pat. No. 3,186,408 to Jacob teaches a cannula and hub assembly wherein 
the cannula mounting portion of the hub has a greater inside diameter than 
the outside diameter of the cannula so that the space therebetween can be 
filled with adhesive. Jacob does not appear to provide structure to assure 
the alignment of the cannula with the hub. The Jacob design, 
theoretically, allows the adhesive to cover all of that portion of the 
cannula which is within the hub and potentially to enter the lumen of the 
cannula. 
U.S. Pat. No. 3,472,227 to Burke teaches an improved cannula hub assembly 
wherein the proximal end of the cannula is physically engaged in the hub, 
in an interference or frictional fit, to maintain the relative position 
between the cannula and the hub. This interference would appear to prevent 
adhesive from passing through to the proximal end of the cannula. Although 
Burke provides structure to prevent the undesirable entry of adhesive into 
the cannula, the structure of Burke neither eliminates the potential for 
skiving hub material into the cannula lumen nor provides a positive stop 
to position the cannula within the hub. Burke also appears to provide a 
structure which will not allow for the angular alignment of the needle 
after it is positioned within the hub. 
Burke, in U.S. Pat. No. 3,523,533, teaches a three piece needle hub 
assembly which has a snap in limit stop provided to contact the proximal 
end of the cannula while distally placed inwardly positioned ribs engage 
the cannula upon insertion. After assembly, adhesive is apparently 
injected between the ribs to fill the cavity in the hub. Here, Burke's 
design allows potential for skiving of hub material and provides potential 
for adhesive to enter the proximal end of the cannula. Further, the 
additional snap in limit stop adds to the complexity of the cannula hub 
assembly and increases the number of dimensional tolerances which can 
negatively affect the alignment of the cannula and the hub, without 
provision for changing the alignment of the cannula in the hub after 
assembly and before application of adhesive to the structure. 
Burke, in U.S. Pat. No. 3,523,532 teaches another three-piece cannula nd 
hub assembly which is functionally similar to the above mentioned U.S. 
Pat. No. 3,523,533 to Burke, except that the third component is snapped in 
from the distal end of the hub rather than from the proximal end. Here 
again, there is the potential for skiving hub material into the lumen, and 
also potential for entry of the adhesive into the lumen of the cannula. 
U.S. Pat. No. 3,430,627 to Kitaj illustrates a typical cannula syringe tip 
assembly wherein the syringe tip contains a bore which is larger than the 
outside diameter of the cannula providing a space for adhesive to be 
introduced. The structure illustrated in the Kitaj patent does not provide 
structure for the alignment of the cannula with the syringe barrel and 
does not appear to eliminate the possibility of adhesive entering the 
proximal end of the cannula. 
U S. Pat. No. 4,581,024 to Swenson teaches a needle assembly to eliminate 
potential problems regarding skiving by providing a hub with a passageway 
which is larger than the needle. Swenson's passageway is enlarged at the 
distal end of the needle hub so that the adhesive used to assemble the 
needle to the hub is positioned at the end of the passageway opposite to 
the open proximal end of the cannula to minimize the possibility of 
adhesive entering the cannula lumen. Swenson's needle assembly, however, 
does not allow the controlled adjustment of the angular alignment between 
the needle cannula and hub. 
The prior art teaches a wide variety of structures of cannula and hub 
assemblies. However, there is still a need for a simple, straight forward, 
reliable, easily fabricated needle assembly which provides needle hub 
structure which allows adjustment of the angular alignment between the 
needle cannula and the hub while providing structure which eliminates or 
minimizes the potential for adhesive entering the cannula lumen and 
structure which is less prone to skiving or scraping hub material during 
the assembly process. 
SUMMARY OF THE INVENTION 
The needle assembly of the present invention includes an elongate cannula 
having a first end, an opposite end and a sidewall therebetween. The 
cannula includes a lumen therethrough defining a cannula longitudinal 
axis. A hub includes a proximal end for engaging fluid transfer apparatus, 
a distal end and a passageway therethrough defining a hub longitudinal 
axis. The hub passageway includes an enlarged first portion at the distal 
end, a second portion adjacent to the first portion and a third portion 
adjacent to the proximal end. The first portion, second portion and third 
portion are in fluid communication. The cannula is positioned in the hub 
so that the opposite end is within the second portion and the first end of 
the cannula projects outwardly from the distal end of the hub. The second 
portion of the passageway includes a proximally located ledge for 
establishing the most proximal position of the cannula in the passageway. 
The second portion also includes inwardly projecting holding means, 
located distally from the ledge, for contacting and holding the cannula 
with sufficient force to prevent the cannula from falling out of the hub 
when the needle assembly is positioned in any static orientation while 
allowing the cannula to pivot with respect to the holding means. The 
holding means and the ledge interact with the cannula so that the angular 
relationship between the cannula longitudinal axis and the hub 
longitudinal axis can be varied and the cannula movably held in a selected 
angular relationship with respect to the hub. Adhesive is provided in the 
volume described by the first portion and the portion of the cannula 
sidewall within the first portion for holding the cannula fixedly and 
immovably in the selected angular relationship with respect to the hub. 
Another embodiment of the instant invention includes a syringe assembly 
comprising a hollow barrel having a chamber for retaining fluid. A distal 
end of the barrel includes a barrel passageway therethrough communicating 
with the chamber. A stopper is slidably positioned in fluid tight 
engagement inside the barrel. The stopper is adapted to engage a plunger 
rod to facilitate its operation. The stopper is capable of moving fluid 
from the chamber through the passageway upon its movement toward the 
distal end and capable of facilitating the drawing of fluid into the 
chamber through the passageway upon its movement away from the distal end 
of the barrel. An elongate cannula having a first end, an opposite and a 
sidewall therebetween is provided. The cannula has a lumen therethrough 
defining a cannula longitudinal axis. Hub means at the distal end of the 
barrel includes a proximal end, a distal end and a passageway therethrough 
defining a hub longitudinal axis. The passageway includes an enlarged 
first portion at the distal end, a second portion adjacent to the first 
portion and a third portion adjacent to the proximal end and in fluid 
communication with the barrel passageway. The first portion, second 
portion and third portion are in fluid communication. The cannula is 
positioned in the hub means so that the opposite end is within the second 
portion and the first end projects outwardly from the distal end of the 
hub means. The second portion includes proximally located ledge for 
establishing the most proximal position of the cannula in the passageway. 
The second portion also includes inwardly projecting holding means, 
located distally from the ledge, for contacting and holding the cannula 
with sufficient force to prevent the cannula from falling out of the hub 
means when the syringe assembly is positioned in any static orientation 
while allowing the cannula to pivot with respect to the hub means. 
Adhesive is provided in the volume described by the first portion and the 
portion of the cannula sidewall within the first portion for holding the 
cannula fixedly and immovably in the selected angular relationship with 
respect to the hub means.

DETAILED DESCRIPTION 
While this invention is satisfied by embodiments in many different forms, 
there is shown in the drawings and will herein be described in detail 
preferred embodiments of the invention with the understanding that the 
present disclosure is to be considered as exemplary of the principles of 
the invention and is not intended to limit the invention to the 
embodiments illustrated. The scope of the invention will be measured by 
the appended claims and their equivalents. 
Adverting to FIGS. 1-6, an improved needle assembly 20 includes an elongate 
cannula 21, a hub 22 and bonding material such as a quantity of adhesive 
23 for joining the cannula and the hub. Needle assembly 20 may be used 
with a hypodermic syringe assembly 25 which typically includes a hollow 
barrel 27, a resilient stopper 28 and a plunger rod 29. Barrel 27 has an 
interior chamber 31 for retaining fluid. A tip 32 extends from the distal 
end of the barrel and contains a tip passageway 33 therethrough 
communicating with chamber 31. 
For the purposes of the description of the present invention, the term 
"distal end" is meant to refer to the end furthest from the person holding 
the syringe, whereas the term "proximal end" is meant to refer to the end 
closest to the holder of the syringe. 
Stopper 28 is slidably positioned in fluid tight engagement inside the 
barrel. Stopper 28 engages rigid plunger rod 29. In this embodiment, the 
stopper contains an internal thread (not shown) which engages an external 
thread (not shown) on the plunger rod. It will be apparent to one skilled 
in the art that numerous constructions can be used to join a stopper in a 
plunger rod and that the arrangement described herein is exemplary of 
these many possibilities. Also, it is within the purview of the instant 
invention to include a one piece plunger rod stopper assembly. The plunger 
rod is accessible outside of the proximal end of the barrel and is 
provided to move the stopper along the barrel to force fluid into or out 
of the chamber through tip passageway 33. Specifically, the stopper is 
capable of moving fluid from the chamber through the passageway upon its 
movement toward the distal end of the barrel, and the stopper is capable 
of facilitating the drawing of fluid into the chamber through the tip 
passageway upon its movement away from the distal end of the barrel. 
Elongate cannula 21 includes a first end 34, an opposite end 35 and a 
sidewall 37 therebetween. The cannula includes a lumen 38 defining a 
cannula longitudinal axis 39. 
Hub 22 includes a proximal end 40 for engaging fluid transfer apparatus, a 
distal end 41 and a passageway 43 therethrough defining a hub longitudinal 
axis 44. Passageway 43 includes an enlarged first portion 45 at the distal 
end, a second portion 46 adjacent to the first portion and a third portion 
47 adjacent to the proximal end of the hub. First portion 45, second 
portion 46 and third portion 47 are in fluid communication. The cannula is 
positioned in the hub so that opposite end 35 of the cannula is within 
second portion 46 and first end 34 of the cannula projects outwardly from 
the distal end of the hub. 
Second portion 46 of the hub passageway includes a proximally located ledge 
means for establishing the most proximal position of the cannula in the 
passageway. In this embodiment, ledge means includes a ledge 49 having a 
cannula contacting surface 50 projecting inwardly in a plane substantially 
perpendicular to hub longitudinal axis 44. Although the ledge in this 
preferred embodiment is a continuous annular structure having a planar 
cannula contacting surface it is within the purview of the instant 
invention to include ledges of various structures including discontinuous 
and ledges having non-planar cannula contacting surfaces such as a 
frusto-conically shaped ledge which will be described hereinafter in an 
alternative embodiment. Contact between opposite end 35 of the cannula and 
cannula contacting surface 50 of ledge 49 limits the depth to which the 
cannula enters the hub and resists further proximally directed movement of 
the cannula with respect to the hub. 
Second portion 46 also includes holding means, located distally from ledge 
49, for contacting and holding the cannula with sufficient force to 
prevent the cannula from falling out of the hub when the needle assembly 
is positioned in any static orientation while allowing the cannula to 
pivot with respect to the holding means. In this preferred embodiment 
holding means includes an inwardly projecting annular collar 51 having an 
inside diameter which is slightly smaller than the outside diameter of 
cannula 21. The difference between the inside diameter described by the 
annular collar and the outside diameter of the cannula creates an 
interference fit between the cannula and the hub which is sufficient to 
hold the cannula from falling out of the hub even if it is oriented in an 
upside down position with the cannula facing downwardly. Holding means in 
the form of annular collar 51 and ledge means in the form of ledge 49 
interact with the cannula so that the angular relationship between the 
cannula longitudinal axis and the hub longitudinal axis can be adjusted or 
varied and the cannula movably held in a selected angular relationship 
with the hub. 
A quantity of adhesive 23 is placed preferably within the volume described 
by the enlarged first portion of the hub passageway and that portion of 
the cannula sidewall within first portion 45 of the passageway. The 
adhesive is provided for holding the cannula fixedly in a selected angular 
relationship with respect to the hub and for preventing the cannula from 
being pulled out of the hub during normal use. The first portion is 
enlarged to provide an adequate volume to hold adhesive. Alternating 
annular grooves 53 and ribs 55 provide structure for engaging the adhesive 
to further improve the joining of the adhesive to the first portion and 
to, increase the structural integrity of the needle assembly. As will be 
apparent to one skilled in the art, there are numerous structures that are 
known to improve the holding power between adhesive and a solid structure 
such as grooves, ribs, and modified surface finishes and that the 
alternating grooves and ribs shown herein are exemplary of these many 
possibilities. 
Hub 22 preferably includes a tapered inside surface 57 which is sized and 
shaped to accept and removably engage tip 32 of hypodermic syringe 25 so 
that there is fluid communication between the interior chamber 31 of the 
syringe barrel through tip passageway 33 and hub passageway 43. Inside 
surface 57 may also accept and removably engage known I.V. tubing 
connectors and other known fluid flow fittings. External outwardly facing 
ribs 58 are provided to removably engage syringe tips or fluid flow 
fittings which contain a locking luer fitting (not shown). The hub also 
includes longitudinal external ribs 59 providing an engagement surface for 
a rigid cannula needle shield (not shown) which is removably positioned 
over the cannula to protect it before use and in some cases after use. It 
is an important feature of this invention that cannula alignment with 
respect to the hub may be controlled so that the cannula tip is less 
likely to be damaged when the rigid shield is installed on the hub. 
A cannula and hub assembly of the preferred embodiment using a 22 gauge 
cannula, 0.028 inch (0.71 mm) outside diameter preferably has a first 
portion having a maximum diameter, at the distal end of the hub, of 
approximately 0.075 inch (1.78 mm) and a length of approximately 0.090 
inch (2.29 mm). The second portion is approximately inch 0.220 inch (5.59 
mm) long with the inside diameter of the groove at annular collar 51 being 
approximately 0.027 inches (0.69 mm) inch. 
During assembly of the preferred needle assembly, the hub is oriented so 
that the distal end faces upwardly. A cannula is inserted, opposite end 
first, into the hub through the first portion and the second portion until 
the opposite end contacts cannula contacting surface of the ledge. As 
previously noted, cannula contacting surface 50 substantially limits how 
far the cannula enters the passageway. At this point the cannula alignment 
with respect to the hub may be satisfactory and within a pre determined 
specified range. However, if the alignment is not within specification the 
cannula may be moved angularly so that it pivots with respect to the 
annular collar while the opposite end of the cannula moves to a different 
position along the cannula contacting surface of the ledge. The 
interaction between the cannula and the hub can be better understood by 
referring to FIGS. 5 and 6. FIG. 5 illustrates a needle cannula 21a having 
a cannula longitudinal axis 39a in alignment with hub longitudinal axis 
44a. FIG. 6 illustrates cannula 21a having its longitudinal axis 39a 
misaligned with hub longitudinal axis 44a at an angle of A. To change the 
orientation from that illustrated in FIG. 5 to that illustrated in FIG. 6 
force is applied to the cannula to cause it to pivot around annular collar 
51a so that opposite end 35a of the cannula moves to a different 
contacting position on cannula contacting surface 50a of ledge 49a in 
second portion 46a. 
A key feature of the instant invention is that it allows adjusting the 
alignment of the needle cannula with respect to a hub and/or a syringe to 
compensate for manufacturing tolerances and uncontrollable variations in 
the product due to manufacturing variables. For example, if the hub means 
of the instant invention were integrally formed on a syringe barrel it may 
be that the orientation depicted in FIG. 6 would result in a perfect 
alignment of the syringe barrel with the needle cannula. That is, 
variations between the alignment of the hub passageway with respect to the 
syringe barrel may be compensated for by moving the needle within the 
structure taught by the instant invention. 
It should be noted that the short distance of engagement between the 
cannula and the hub in the area of annular collar 51 substantially 
eliminates or reduces the potential for skiving or removing hub material 
while inserting the needle into the hub which is believed to exist in 
needle hub designs having long engagement conduits through which the 
cannula must be forced. Along with the potential for skiving, long 
engaging conduits eliminate the ability to adjust the angular relationship 
between the needle and the hub after initial assembly of the needle and 
the hub before adhesive is applied. Long engagement conduits increase the 
force required for cannula insertion. Such force may be large enough to 
bend or buckle the cannula or drive the cannula too far into the hub or 
through the hub. 
It should be noted that the size of annular collar 51 is exaggerated for 
illustrating the features of the instant invention. A collar projecting 
inwardly in the passageway of the hub having a height of approximately 
0.003 inches (0.076 mm) may be sufficient to achieve the desired result 
and still allow for the effective injection molding of the hub. Even with 
small annular collars the cannula alignment of the cannula longitudinal 
axis with respect to the hub longitudinal axis may be adjusted by about 
plus or minus two degrees which may be sufficient in many instances to 
achieve the desired result. 
After the cannula longitudinal axis is properly aligned with the hub, 
adhesive may be applied to the needle assembly at enlarged first portion 
45. Depending on the holding forces exerted on the cannula by the hub, and 
the viscosity of the adhesive and the manufacturing conditions, the 
cannula may or may not have to be held in alignment with the hub until the 
adhesive has set or cured. The concentration of the adhesive at the distal 
end of the hub, in the enlarged first portion, in the present invention 
allows the effective use of adhesives which must be exposed to specific 
conditions for curing, such as UV curable adhesive, because the adhesive 
is concentrated at a position where it may be readily exposed to the 
curing energy source. The hub of the present invention also facilitates 
the use of fast setting adhesives such as hot melt adhesives, which must 
fill the volume provided in a relatively short period of time, before 
setting. Also, the annular collar further functions to restrict the flow 
of adhesive toward the opposite end of the cannula by occluding a portion 
of the space within the second portion of the passageway outside of the 
cannula. Thus, it can be seen that the present invention provides 
structure for allowing the realignment between the cannula longitudinal 
axis and the hub longitudinal axis during assembly while reducing the 
generation of particles in the cannula lumen during assembly by providing 
minimum contact with the hub and reducing the potential for adhesive 
entering the lumen during assembly. This combination of improvements 
represents a substantial departure from the known prior art. 
Referring now FIG. 7, an alternative embodiment 61 of the instant invention 
is substantially similar to the embodiment of FIGS. 1-4 with the exception 
that a hub 62 is integrally connected with a hollow syringe barrel 63. 
Barrel 63 includes chamber 64 for retaining fluid, a distal end 65 having 
a barrel passageway 67 therethrough communicating with the chamber. Hub 62 
at the distal end of the barrel includes a proximal end 68, a distal end 
69 and a passageway 70 therethrough defining longitudinal axis 71. 
Passageway 70 includes an enlarged first portion 73, a second portion 74 
adjacent to the first portion, and a third portion 75 adjacent to the 
proximal end and in fluid communication with the barrel passageway. First 
portion 73, second portion 74, third portion 75 and barrel passageway 67 
are in fluid communication. As in the embodiment of FIGS. 1-4, second 
portion 74 includes a proximally located ledge 76 projecting inwardly into 
the passageway for establishing the most proximal position of the cannula 
(not shown) in the passageway. The second portion also includes inwardly 
projected annular collar 79, located distally from ledge 76 for contacting 
and holding the cannula with sufficient force to prevent the cannula from 
falling out of the hub when the needle assembly of this embodiment is 
positioned in any static orientation while allowing the cannula to pivot 
with respect to the collar. The cannula (not shown) and bonding means (not 
shown) are substantially identical to those elements as taught hereinabove 
for the embodiment of FIGS. 1-4 and function in the same manner with the 
alternative embodiment of FIG. 7. The features of the instant invention 
are believed to be very desirable in this alternative embodiment because 
it is more difficult to achieve precise alignment of a hub passageway 
which is integrally molded over the long length of a syringe barrel. 
Accordingly, the instant invention provides structure for aligning the 
cannula with a long barrel and compensating for manufacturing variables 
and tolerances to achieve a hypodermic syringe assembly having an 
optimally aligned needle cannula. 
Adverting to FIGS. 8 and 9 wherein an alternative hub 80 embodiment of the 
present invention is illustrated. Hub 80 includes a proximal end 81 for 
engaging fluid transfer apparatus, a distal end 82 and a passageway 83 
therethrough defining a hub longitudinal axis 85. Passageway 83 includes 
an enlarged first portion 87 at the distal end, a second portion 88 
adjacent to the first portion and a third portion 89 adjacent to the 
proximal end. First portion 87, second portion 88 and third portion 89 are 
in fluid communication. 
The second portion includes proximally located ledge means for establishing 
the most proximal position of the cannula (not shown) in the passageway. 
In this embodiment the ledge means includes ledge 100 having a frusto 
conically shaped cannula contacting surface 101 tapered toward the 
proximal end of the hub. This embodiment includes holding means in the 
form of four inwardly directed protuberances 91 projecting into the 
passageway. Each protuberance having a free end 95. The free ends of each 
pair of opposed protuberances are separated by a distance which is smaller 
than the outside diameter of a cannula (not shown) to be used in a needle 
assembly with hub 80. Holding means in the form of protuberances are 
believed to be less tolerance dependent than the annular flange of FIGS. 
1-4. Also, the protuberances in this embodiment allow air to freely escape 
from enlarged first portion 87 while adhesive is being added through the 
distal end of the passageway, thus minimizing the possibility of trapping 
an air bubble in a space provided for adhesive while still helping to 
obstruct the potential path of the adhesive through second portion 88 of 
the passageway. 
In use, the needle assembly of the present invention may be attached to a 
hypodermic syringe which is then filled with liquid medication using known 
techniques. The syringe with needle assembly attached may then be used to 
inject the liquid medication into the patient's body, again, using known 
techniques. In the embodiment where the hub portion is integrally formed 
with the syringe barrel, the present invention may be used in the same 
manner described hereinabove except that it is not necessary to install 
the needle assembly onto the syringe barrel because the cannula is already 
attached to the syringe barrel. 
The hub may be constructed of a wide variety of rigid material such as 
metals, plastics, ceramics and the like. Thermoplastic materials are 
preferred due to their low cost and proven compatibility with many liquid 
medications. A wide variety of materials including metals and plastics may 
be used to fabricate a cannula. However, in most cases a medical grade 
stainless steel is preferred. AA wide variety of adhesives such as hot 
metal adhesive, heat curable adhesive, UV curable adhesive and two part 
epoxy are suitable for bonding the cannula to the hub. It is preferred 
that all elements of the improved needle assembly be sterile when used. 
Accordingly, materials should be selected for compatibility with the 
sterilization process being used. 
Thus, the present invention provides a simple, straight forward, reliable, 
easily fabricated improved needle assembly which provides needle hub 
structure which allows adjustment of the angular alignment between the 
needle cannula and the hub while providing structure which eliminates or 
minimizes the potential for adhesive entering the cannula lumen and 
provides structure which is less prone to skiving or scraping of hub 
material during assembly process and less likely to experience cannula 
point damage when a needle shield is attached.