Non-reusable syringe with automatically actionable protective needle cover

Disclosed is non-reusable syringe with automatically actionable protective needle cover. The invention consists of a syringe which locks the plunger in place after full injection, rendering it unusable. In addition an automatic needle cover is provided which aides as a clamping device and prevents pricking or leaking of a needle. The means of operating the needle cover also allows the needle to be visible for injection.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is in the field of hypodermic syringes used to inject 
and aspirate liquid material from a patient. More particularly, this 
invention is directed to render a syringe non-reusable syringe with an 
engageable retractable cap for the entire needle. 
2. Description of the Prior Art 
Hypodermic syringes with attached needles are used for the administration 
of medication and for the withdrawal of material from a patient. These 
syringes are generally disposable which presents two problems, one is the 
possible reuse of a syringe and the other and greatest danger is the 
possibility of being pricked by the needle when handling the syringe. 
These two concerns are particularly important because the needle and or 
the syringe may be contaminated and spread disease, such as hepatitis and 
acquired immune deficiency syndrome (AIDS). 
The known non-reusable syringes can easily be reused. In addition often 
times needles need to be visible for injection. Some devices provide for a 
shield where the needle is recessed to prevent possible pricking; however, 
these devices do not provide for a seal directly over the needle whenever 
the needle is not in use and the neddle is not visible for proper 
injection. The apparatus of U.S. Pat. No. 4,795,432 to Karczmer does 
provide a cap at the end of its shield assembly; however, this not only 
prevents pricking but it also prevent multiple exposure of the needle tip 
which is sometimes necessary, especially when withdrawing blood for 
testing. The inventions of U.S. Pat. Nos. 4,507,118 to Dent and 4,767,413 
to Haber provide caps but the syringe needle is designed to pass through 
these caps. Once the needle passes through the caps in these patents, the 
caps are no longer act as a complete seal to prevent any leakage. 
SUMMARY OF THE INVENTION 
In light of the above discussed devices, the present invention provides for 
a less costly syringe that when full injection has been accomplished the 
syringe is non-reusable. This syringe cannot be easily altered to yield a 
reusable syringe. In addition, the present invention is provided with a 
shield assembly that contains a permanent cap, one that easily returns to 
its sealed position, so that whenever the syringe is not in use not only 
is the needle shielded but it is also capped. The present invention 
prevents not only the possibility of pricking but also prevents any 
possibility of leaking. 
Accordingly, it is an object of the present invention to provide a 
non-reusable syringe. 
It is another object of present invention to provide a non-reusable syringe 
with an engageable retractable cap which reseals the needle and prevents 
pricking and leaking.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1-4 show an apparatus for injecting into or withdrawing substances 
from a patient in the form of a hypodermic syringe. 
The syringe 20 includes a tubular cylinder 22 with curved brackets 24, near 
the end of the cylinder. Within the cylinder 22 is the shaft 28 which at 
one end has a plunger 30 that fits snugly within the head of the syringe 
32. The outer rim 26 of the plunger 30 curve inward when aspirating or 
injecting material, FIGS. 1 and 2. The curved brackets 24 of the cylinder 
22 are placed at a greater distance than the fully extended plunger rim 
26. 
When the plunger 30 is in a fully injected (extended) position, FIG. 3, the 
head of plunger 30 forces the rim 26 to invert and push outward below the 
brackets 24 of the cylinder 22. 
The shaft 28 and plunger 30 in FIG. 3 are now locked into position. The 
preferred embodiment is to have the brackets 24 and rim 26 made of metal, 
the advantage being that is is difficult to remove or file down. In 
addition, the preferred material of the plunger 30 is rubber. Removal of 
the metal rim 26 from the rubber plunger 30 would leave holes in the 
rubber plunger 30 and thereby rendering the syringe useless. 
A second embodiment, FIG. 4 shows the shaft 46 with a curved rubber plunger 
44 and a locking spring 48 through the rubber plunger 44. The rubber 
plunger 44 fits snugly within the cylinder 40. The locking spring 48 is 
not at it's fully extended position when the plunger 44 is located above 
the depressions 42 of the cylinder 40. 
The cylinder 40 has internal depressions 42 which run along the cylinder 
with its deepest point of depression near the end of the cylinder 40. The 
depressed area 50 must be slightly greater than the distance between the 
plunger 44 head and the locking spring 48 which is located in the middle 
of the plunger 44. 
When the plunger is fully extended, beyond the internal depressions 42, the 
locking springs 48 push toward the wall of the cylinder 40 in the 
depressed area 50. The extended springs 48 prevent the plunger 46 from 
being pulled from the fully extended position. 
Like the metal rim 26 of FIG. 3, removal of the locking springs 48 would 
damage the rubber plunger 44 and make it impossible to retain fluid in the 
syringe. 
In order that a non-reusable syringe may not be a threat to society, the 
needle of the syringe must likewise be rendered safe. FIGS. 5-7 show the 
preferred embodiments of a non-removable cap for a needle. The cap may be 
attached to a needle that is permanently affixed to a syringe or it may be 
attached separately. 
The preferred material used for the cap 82 is a rigid, clear plastic. The 
cap consists of two half cylinders 60 and 62. Each half cylinder having 
either a rubber male 64 or female 66 fitting to assure a tight closure 
around a sterile needle 70. On each end of the cylinder halves 60 and 62 
are extension tabs 72 and 74. 
At the base of the needle 70 the preferred embodiment is a rubber lower 
seal 76 to ensure fit with rubber ports of medication 78. 
Pressure is exerted on the tabs 72 and 74 which forces the cylinder halves 
60 and 64 to open exposing the needle 70, FIG 6. Releasing the pressure 
from extension tabs 72 and 74 automatically reseals the cap 82, FIG. 7. 
The advantage of the above described embodiment in FIG. 7, is that when 
medication is being administrated for a period of time, the pressure is 
released from the extension tabs 72 and 74 and the half cylinders 60 and 
62 of the cap act as a clamp which ensures that the needle will not easily 
slip out of position and even if it should the cap would automatically 
close over the end of the needle 70 and the needle 70 would not be a 
threat to anyone in the vicinity. 
Another variation of FIGS. 5-7 would be to have a spring device 82 as seen 
in FIG. 7a rather than the extension tabs 72 and 74. Pressure can be 
exerted on the spring devices 82 which would force the cylinders 60 and 62 
to open. The spring devices 82 can be locked in place so that the needle 
is fully visible for injection or may be relased once the needle is 
positioned on tubing so as to form a clamp. 
FIGS. 8-10 illustrates a variation of the needle protector cap assembly 
(cap and shield assembly) with a preferred embodiment that is made of a 
rigid cylinder 90 of clear plastic with an inner 92 and outer 94 wall that 
extends beyond the needle tip 96. The outer wall 94 extends slightly 
beyond and around the inner wall 92, forming a lip 98 over the inner wall 
92, FIG. 9. The outer wall also has a opening (not shown) that runs 
partially along the side of the shield to allow a lever 100 to be pushed 
down alongside. 
The cap 102 of the preferred shield assembly is made of rubber. The cap 102 
as can be seen in FIG. 9 is in two sections 104 and 106. Each section has 
either a rubber male or female fitting to assure a tight closure around a 
sterile needle. One cap section 104 is firmly affixed to the end of the 
cylinder 90. The other section 106 is attached to the lever 100 through 
tension means 108. When the lever 100 is pushed towards the base 110 of 
the needle 96 the cap section 100 easily slides between the outer 94 and 
the inner 92 wall. 
When the lever 100 is released the retracted cap section 100 returns to its 
closed position FIG. 10. The lip 98 allows the cap 100 to return to its 
proper closed position. The advantages of such an embodiment is that the 
needle is always in a recessed position so that injury as the result of 
pricking can be avoided, when pressure is released from the lever 100 the 
needle is either resealed or when medication is being administrated the 
cap acts as a clamp which ensures that the needle will not easily slip out 
of position during administration. This embodiment is also advantageous 
for Y ports or for Heparin locks. 
A shield assembly in which both sections of the cap 136 and 138 are 
retractable is demonstrated in FIG. 11. In this embodiment the shield 
assembly 120 is defined by a double walled thickness cylinder. The outer 
wall 122 extends beyond and over the inner wall 124 forming a lip 126. The 
sharp end of the needle 139 is recessed within the cylinder 120. 0n 
opposite sides of the cylinder there are two tracks (not shown) cut out of 
the outer wall 122 to allow the levers 128 and 130 to slide alongside the 
cylinder 120. 
Each cap section 136 and 138 is attached to tension means 132 and 134 which 
is attached to corresponding lever 128 and 130. When pressure is exerted 
upon the levers 128 and 130 the cap sections 136 and 138 pull back between 
the inner 124 and outer walls 122 of the cylinder. Upon releasing the 
levers 128 and 130, the cap sections 136 and 138 automatically return to 
the sealed position. 
The advantage of both cap sections 136 and 138 being retractable is that a 
more uniform clamp can be attained when administrating medications. 
Another for a retractable cap as described above can be seen in FIGS. 12 
and 13. This embodiment has the permanent cap consisting of either one or 
two sides of corrugate-like tubing 160 that is joined to the lever 168 
through tension means 170. The lever 168 slides between the outer 172 and 
the inner 174 wall of the cylinder 162. The cylinder 162 is affixed to the 
syringe and is made of clear plastic. At the base of the needle 166 there 
is a spring apparatus 164. The spring apparatus 164 is nesseccary to 
create a firm pressure seal around a port to prevent pulling our to 
needle. When the lever 168 is pulled back, the corrugated-like tubing 160 
folds back and exposes the needle 166 for insertion, FIG. 13. When the 
lever 168 is released the corrugated tubing 160 springs back and forms a 
seal around the needle 166 port, FIG. 12. A dual retractable cap as 
described above can be similarly employed. 
The permanent cap illustrated in FIG. 14 is a cap 140 that can be hinged 
150 onto the cylinder 142. When the needle 144 is to be used the cap 140 
can be released from the cylinder while it is still attached on one side 
150 of the cylinder 140. While the needle 144 is in use the cap 140 can be 
fastened alongside the cylinder 146. When through with the needle 144 the 
cap 140 can be released and fastened at its closed position 148. 
There are instances where the length of the needle must be exposed for use, 
such as when medication is being administered directly into a patient or 
body fluid is being withdrawn. This being the case a shield assembly is 
necessary that retracts entirely along the length of the needle. 
A retractable cap and shield assembly is demonstrated in FIGS. 15 and 16. 
The cap 180 is made of a rubber substance and the sides of the assembly 
(cylinder) 182 is made of a more clear durable plastic. The cap sections 
184 and 186 have a rubber male--female fitting and are attached to the 
levers 188 and 190 through tension means 192 and 194. As the cap sections 
184 and 186 are pulled back they retract into compartments 196 and 198 
along the outer wall 200 of the assembly on either side of the needle 204. 
Once the cap sections 184 and 186 are in the in the compartments 196 and 
198, additional pressure of the tension means 192 and 194 causes the outer 
wall 200 of the durable plastic assembly to retract over the inner wall 
202 of the assembly, thereby exposing the needle 204, FIG. 16. When the 
needle 204 is exposed, the levers 188 and 190 can be locked in place in 
grooves 206 and 208 along the side of the inner wall 202 of the assembly. 
When the levers 188 and 190 are released the assembly automatically 
reseals over the needle 204, FIG. 15. 
Another variation of the above described shield assembly is seen in FIGS. 
17 and 18. The cap sections 220 and 222 are made of rubber and are 
attached to corrugated-like tubing 224 which is attached to levers 226 and 
228 through tension means 230 and 232. When pressure is applied to the 
levers 226 and 228 the rubber cap sections 220 and 222 are retracted until 
they are stopped against the wall of the corrugated-like tubing 224, FIG. 
17. Additional pressure on the levers 226 and 228 causes the 
corrugated-like tubing 224 to fold back at the base of the needle 240, 
FIG. 18. Once the desired needle 240 exposure is attained the levers 226 
and 228 can be secured in the grooves 234 and 236 along the clear plastic 
wall 238 of the assembly. When the levers 226 and 228 are released the 
assembly automatically reseals over the needle 240, FIG. 17. 
While the foregoing invention has been described with references to its 
preferred embodiments, it should not be limited to such embodiments since 
various alterations and modifications will occur to those skilled in the 
art. For example, the plastic and rubber materials used could be replaced 
by equally effective materials. All such variations and modifications are 
intended to fall within the scope of the appended claims.