Automatic needle cover

An automatic needle cover is mounted onto the base of a hypodermic needle on a syringe and leaves the needle exposed for initial use, such as for withdrawing blood or the like. A releasable tab is either cut or released, and a resilient support arm pushes a protective cap out past the end of the needle, to cover the end of the needle and prevent an accidental pricking of the user's skin. The contents of the syringe can drip freely out of the cap, or if desired, the cap can be braced against a depression in a rubber stopper of a container, to thereby facilitate realigning the hole in the cap with the needle, so that the needle contents can be discharged into the container. The protective cap is made so that it moves laterally to insure covering the point of the needle so that the point will not accidentally protrude.

BACKGROUND OF THE INVENTION 
1. Field of the Invention. 
The present invention relates to protectors for the points of needles used 
on hypodermic syringes. 
2. Description of the Prior Art. 
In the prior art, various needle protectors have been advanced. U.S. Pat. 
No. 4,725,267 discloses a needle sheath that moves forward over the needle 
tip on a sleeve. An end cap tilts when the sheath or cap carrying support 
is extended so the needle tip engages a corner of the cap for protecting 
the tip against causing a scratch. The tilting cap is carried by a spring 
or accordion pleated tube which extends along the length of the needle 
under the spring load when the needle protection is actuated. 
U.S. Pat. No. 4,139,009 shows a needle assembly with a retractable needle 
cover, that extends over the point of the needle and which must be slid 
out of the way when the needle is to be used. The needle opening in the 
cover is always aligned with the needle, so that any retracting force on 
the cover will cause the cover to move back and the needle point will be 
exposed so that it can puncture or scratch a finger accidentally. Thus, 
the cover does not adequately protect against an accidental scratching. 
U.S. Pat. No. 4,693,708 shows a needle guard device incorporated into a 
syringe assembly which includes a sleeve or shield that can be locked in 
position to provide coverage when extended out over the needle. The sleeve 
can be locked in place. 
U.S. Pat. No. 4,747,837 also discloses a slidable cover on a syringe body 
that can be extended and latched to cover the needle point after the 
syringe has been used. A large sleeve covers the needle, and it has an 
opening at its outer end adjacent the needle tip. If the sleeve becomes 
unlatched, the needle would easily be exposed. 
U.S. Pat. No. 4,758,231 discloses a casing for a syringe assembly that can 
be pulled out over the needle after use and has locking ribs to hold the 
cover extended, but if the locks are dislodged the needle easily slides 
out through the opening in the end of the sleeve that is used for 
protection. The latches used for holding the shield in the outer position, 
can be any one of a number of different latches. A full-length tubular 
member is necessary, which is quite large, and requires positive manual 
operation. 
The activity of the prior art shows the need for a simple, low cost and 
easily operated needle guard that will provide for safety against 
accidental scratching or puncturing of the skin. 
SUMMARY OF THE INVENTION 
The present invention relates to an automatic protective device for a 
hypodermic needle and syringe. A resilient (spring loaded) folding support 
arm is attached (preferably integrally molded) to the hub of the needle 
and carries an inverted cuplike cap which includes a base or end wall 
having an opening through which the needle initially extends. The arm and 
cap are made to be easily released without any manipulation once the 
sterile package is opened and the hypodermic needle is removed. The cap 
and arm can be made separate from the needle base and held in place with a 
friction fit. 
The needle can be inserted into a vein and blood drawn, and while the 
needle is still i position, a tear away tab or other release latch 
(including a cutting of the retainer) can be maneuvered with one hand to 
release the latch or retainer and the cap. When the needle is withdrawn, 
the inverted cap will slide out along the needle because of the spring 
loading from the folded support arm. The cap end or base wall member is 
joined along a circumscribing corner to a cylindrical side wall. The end 
wall is formed at a slant relative to the outer end portion of the folding 
arm. When the base wall of the cap is extended out beyond the end of the 
needle, the needle tip slips into the interior of the cap and the cap 
moves sideways so the needle slips over to the corner of the cap where the 
end wall and side wall join. The needle is then offset from the opening in 
the end wall of the cap and is protected by the side and end walls of the 
cap from accidentally scratching or sticking a finger. In this position, 
the support arm and cap have to be positively manipulated in order to 
realign the hole in the cap with the needle point. The hole in the base or 
end wall of the cap is a relatively loose fit around the needle so it can 
be easily manipulated. 
Thus, protection against accidental exposure of the needle end is achieved. 
Manipulation can be done by placing the end of a container that has an 
outer cover on it and in which the blood sample in the syringe (or other 
syringe contents) is to be injected, such as a rubber stopper vial sold 
under the trademark Vacutainer against the cap and then moving the syringe 
and needle. The realignment is easily and positively done so that the 
needle can be exposed and inserted through the stopper to discharge the 
syringe contents into the vial. 
When the cap is braced against a resilient structure such as a rubber 
stopper of a bottle or tube, the hole in the cap can be realigned without 
touching either the needle or the cap with the fingers. The user can see 
the entire length of the needle because the assembly is very short 
axially. This helps in insertion into a patient. The arm and cap are made 
so that the needle tip will be automatically covered without further 
manipulation upon removal of the needle from the skin after use. 
The inverted cup that is used as a protector has to have a cover forming 
end wall that extends transversely of the needle and which shifts over the 
point of the needle when the needle slips out of the normal hole through 
which the needle extends. The folding support arm moves in an arc and 
tends to tilt the end cap as it extends so there is misalignment of the 
needle and the needle opening in the end cap at the extended position of 
the cap. The needle then will not accidentally slide through the hole. 
The protector can easily be molded, and simply attached to the needle hub 
or support at the base of the syringe in a number of ways. The cap also 
can be separately made and loosely attached to the support arm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A hypodermic syringe indicated generally at 10 comprises a standard 
cylindrical barrel 11 which may be formed of a transparent plastic, and 
which is a hollow cylinder having an end wall portion 12 on which a needle 
attaching sleeve 13 of suitable design is mounted. The needle attaching 
sleeve 13 can be molded to the barrel at the time of manufacture, and 
suitable means of any desired type can be made to support the hypodermic 
needle 14 at the outer end of the needle attaching sleeve. A syringe 
plunger 15 has a piston member on the interior of the barrel 11 and can be 
slid outwardly along the interior of the barrel to draw fluids or blood in 
through the hypodermic needle 14 (which has a sharp, open point). The 
plunger also can be moved inwardly to discharge the barrel contents 
through the needle. 
A needle guard assembly indicated generally at 20 is shown installed on the 
molded hub 19 of the needle, adjacent the needle attaching sleeve 13, and 
can be attached to the needle in any suitable way; preferably it will be 
molded in place. The guard assembly also can be cemented or frictionally 
attached in place. The needle guard assembly comprises a resilient or 
spring loaded folding support arm 21 that has a base end 22 which is the 
portion of the guard attached to the needle hub in a suitable manner. The 
arm 21 includes a spring loaded elbow type hinge joint 23 approximately 
midway between the base end 22 and an outer end 25. The elbow hinge 
divides the arm into too arm sections 21A and 21B. The intermediate ends 
of the arm sections 21A and 21B are joined together at the elbow joint 23. 
The arm outer end 25, as shown, has an opening 26 therein of a size to 
permit the needle 14 to slide therethrough. 
The outer end 25 of the arm 21 has an inverted cuplike cap 30 molded 
thereon, and as shown, the cap 30 has a base or end wall 31 and a 
generally cylindrical outer side wall 32 circumscribing the end wall and 
molded integrally with the end wall at a corner junction. The side wall 32 
is formed so that the end wall 31 defines a lane that is inclined with 
respect to he general plane of the arm section 21B at outer end portion 
25. The cap more or less "cants" in relation to the outer end 25 of the 
arm 21. 
The end wall 31 has a central or axial opening 33 through which the needle 
14 can extend, and as shown when the arm 21 is folded or retracted as seen 
in FIG. 1, the needle 14 passes through both the opening 26 and the 
opening 33. The outer end 25 of the arm defines a plane support member 
that is inclined with respect to the central axis of the needle in 
retracted position, and when in released position, the outer arm section 
21B moves in an arc outwardly and the outer end portion inclines relative 
to the axis of needle. The arm section extends outwardly from the needle 
and inclines in direction back toward the barrel 11. 
The outer end 25 of the arm 21 is retained in a retracted position with 
respect to the base portion 22 against the arm resilient force (or spring 
load at hinge 25) tending to urge the outer end 25 toward the outer end of 
the needle through a suitable cuttable or releasable latch or retainer 
indicated at 38. As shown, the retainer 38 can be a tear away tab or ear 
made with a weakened junction for tearing it away, much like the tabs on 
plastic milk bottle caps. If desired, the latch can be a molded ear 39 
(see FIG. 3), which has an aperture 40 that fits over a small projection 
or knob 41 which is molded onto the outer end 25 of the arm 21. The latch 
should be low cost and simple to operate. It can be any desired type. 
The outer (sharpened) end or point 14A of the needle 14 can be inserted 
into a patient, with the needle protector in retracted position as shown 
in FIG. 1. The length of needle 14 exposed beyond the base wall 31 of the 
cap 30 is sufficient so that it can be inserted into an arm to withdraw 
blood from a vein, for example. The plunger 15 will be drawn out, so that 
the blood sample will be taken from the arm, and before the needle 14 is 
removed, the latch assembly 38 or tear away strip will be released, or 
cut, and the resilient springlike plastic material forming a spring load 
at hinge 23 creates a force which tends to unfold the arm sections 21A and 
21B causing the outer end 25 of the arm to slide along the length of the 
needle 14 toward the outer tip 14A. When the base wall 31 of the cap 
extends beyond point 14A, the needle tip retracts inwardly of the base 
wall 31, and the angle of the axes of the opening 33 and the arc or path 
of movement of the arm section 21B will be such that the needle tip 14A 
will be urged over toward a corner or junction of the walls 30 and 32 of 
the cap 30, along the longer side of the side wall 32, as shown in FIG. 5. 
The needle tip 14A then will rest along the side wall 32 at the corner 32A 
where the side wall 32 joins the base wall 33, and the opening 33 will be 
off to the side of the needle. 
The outer end portion 25 of the arm section 21B forms an inclined plane 
positioned at an angle with respect to the needle axis that is 
substantially equal to but inclined in opposite direction from the angle 
of the arm section 21B when in its retracted position. This means that the 
needle tip 14A will be fully protected and will not b accidentally exposed 
for scratching or pricking the skin of a person. The protective cap will 
remain in place automatically, but when one wants to place the blood 
sample or other contents of the syringe into a container that has a rubber 
cap or stopper indicated at 50 (FIG. 6), the base wall 31 of the cap can 
be braced against a concave surface 51 of the stopper and then he cap slid 
over so that the needle tip 14A passes through the opening 33. The needle 
14 then can be pushed through the rubber cap 50 and the syringe contents 
discharged into the container. 
The cap member can be molded in place along with the folding arm 21, and 
the openings 26 and 33 for the needle also can be molded so that they are 
aligned. These openings are of size to provide clearance. The plane of the 
base wall 33 is canted with respect to the general plane of the arm 
section on which it is mounted. The axes of the holes 33 and the hole 26 
are not aligned, as shown in FIG. 5 but rather are at a desired angle so 
that when the plane of the arm outer end portion 25 inclines with respect 
to the needle as the arm moves outwardly, the opening 33 will move off to 
the side of the needle and the needle point 14A will rest in the corner of 
the cap. 
The cap can have drain openings molded through the side wall adjacent to 
the region where it attaches to the support arm. This will help in seeing 
drips from the needle tip. Also, the cap can be molded separately and 
attached to the arm in a suitable manner. 
In FIG. 7, a modified needle guard assembly 70 is shown. In this form, a 
support arm 71 has a base end 72, which can be mounted on a needle hub in 
a suitable manner. A bellows type or accordian folded spring hinge joint 
73 joins two arm sections 71A and 71B which are joined by the joint 73. 
The arm 71, as molded, has an outer end 75 which is folded back against 
the base end 72 and is originally retained with a short tear-away strip 77 
that has a break or tear line on both the upper and lower sections of the 
arm. 
The arm section 71B has a cap 80 on its outer end which fits over the 
needle as explained before. 
The accordian spring connector or joint 73 urges the cap 80 outwardly on 
the needle so when the guard is to be used, strip 77 is pulled away or cut 
and the arm section 71B will spring outwardly. 
The cap will cover the needle point as previously explained to protect the 
user. 
A tether cord or line 82 can be molded in place between the arm sections 
71A and 71B, or added as a separate line after molding. The tether cord is 
used as a stop to stop extension of the arm section 71B and cap 80 at the 
desired position. The cord prevents the arm section 71 from sliding all 
the way off the needle. 
The action of the cap is as previously explained for protection. 
The protective device thus is fairly simple, and uses a folding spring 
loaded arm which is held with external fasteners in a retracted position 
until the protective device is to be used (after the needle has been 
used). Then the latch is released and the arm will automatically spring 
out to cover the needle point. If desired, the arm 21 can be retained in 
its maximum outward position with suitable latch members. The arm can be 
made so that it will only extend out to the correct position and will not 
extend beyond the needle tip. The arm 21 can be made in sections and 
separately spring loaded so the outer arm section moves outwardly if 
desired. Note also that the contents of the syringe can drip freely out of 
the cap when the needle is held upright. 
Although the present invention has been described with reference to 
preferred embodiments, workers skilled in the art will recognize that 
changes may be made in form and detail without departing from the spirit 
and scope of the invention.