WO1993016746A1

WO1993016746A1 - Hypodermic needle shield

Info

Publication number: WO1993016746A1
Application number: PCT/US1993/001764
Authority: WO
Inventors: Barbara J. Osborne; Richard W. Slawson
Original assignee: Osborne Barbara J; Slawson Richard W
Priority date: 1992-02-27
Filing date: 1993-02-26
Publication date: 1993-09-02
Also published as: AU3780293A; US5312347A

Abstract

A detachable needle assembly is provided with a needle shield supported for telescoping movement on the needle hub (14d), with the sliding-fit surface on which the shield (50d) moves being separated by a majority of the cross-section of the hub from the feed passage through the hub, or with the shield being movable over an end portion of the hub on which a cover cap is supported prior to use.

Description

HYPODERMIC NEEDLE SHIELD

This invention relates to "safety" syringes designed to be safely used and discarded with little or no danger to the nurse or other person handling the syringe and attending to its use- There is a manifest need for safety syringes, as evidenced by a number of patents directed to the problem in recent years. Various proposals for providing a sheath extendible from the barrel of a syringe are set forth in the following U.S. patents:

Haber et al. Re. 33,585

Sampson et al. 4,573,976

Wanderer et al. 4,693,708 Spencer, Treesa A. 4,702,738 Spencer, John E. 4,723,943

Haber et al. 4,892,523

Haber, Terry 4,915,702

Page et al. 4,943,282

Juhasz, Paul R. 5,061,251

In U.S. Patent 4,840,185 to Hernandez, a shield is provided on the barrel of the vacuum tube holder which itself forms an extension of the syringe barrel. In U.S. Patent 4,861,338 to

Mathiesen et al. , a needle shield is a continuation of the syringe barrel, and the needle holder is turned by the syringe plunger to advance and retract the needle. In U.S. Patent 4,976,701 to Ejlersen et al. , a double ended needle is shielded by a cap fixed to the "cartridge 11, 14, 15" by an

"intermediate member" having a "rear part 23" and a

"front part 24", or the cap 65 is threaded on the cartridge jacket 50, so that essentially the shield is an extension of the cartridge barrel. In U.S.

Patent 4,923,283 to Hogan, in which the needle is

SUBSTITUTESHEET used in a tubing arrangement rather than with a syringe, a needle shield slides down the flexible tubing and over the needle.

The increasing incidence of AIDS and the presence of other serious infectious diseases has driven the effort to provide an acceptable safety syringe that is practical — a safety device of simple design, one which is convenient to use, requires little or no training, and may be installed for use in a manner consistent with existing widely practiced techniques.

The present invention provides such a device. The present invention provides a device whose manner of use will be self-evident and natural to nurses and other medical workers. The invention provides a device which may be used without modification of syringes already widely in use.

An accepted and widely used hypodermic syringe design uses detachable needles which are supplied in sterile packages and are adapted to be attached to any one of a number of sizes of syringe barrels by a standard coupler or end connection provided at the distal end of each syringe. A commercial example is the "Leur -Lok" needle sold commercially Becton Dickinson & Company. The syringe-associated coupler members for receiving the needles may be constant or standard in size for various sizes of syringes, so that one of the detachable needles can be attached to a syringe of any size.

A feature of the present invention is the provision of a retractable shield associated with such detachable needles for hypodermic syringes. The association is such that the shield and detachable needle together provide a self-contained

SUBSTITUTESHEET assembly or package that is independent of the syringe to which the needle is mounted. The arrangement may be such that the installation or attachment of the needle to the syringe is accomplished in a manner that is identical or similar to the way detachable needles are presently attached, so that a health care worker will use easy and familiar practices to attach the shielded needle to the syringe.

The objects and advantages of the invention will become clearer from the following description of specific embodiments, and from the accompanying drawings, in which:

FIG. 1 is a somewhat schematic cross- sectional view of a detachable needle assembly contemplated by the invention shown locked in shield-extended position and further shown in association with a partially enclosing plastic shell or cover.

FIG. 2 is a similar view of the same device coupled to a syringe and with the plastic shell or cover removed. As shown, the shield is still locked in shield-extended position.

FIG. 3 is a similar view showing the needle shield of FIG. 2 in retracted position.

FIG. 4 is a side elevation taken from the plane of line 4-4 in FIG. 2.

FIG. 4A is an end view of only the shield elements shown in FIG. 4 (the needle hub elements shown in FIG. 4 are omitted) taken from the plane of line 4A-4A in FIG. 4.

FIG. 5 is a somewhat schematic cross- sectional view of another detachable needle assembly contemplated by the invention shown locked in shield-extended position and further shown in association with an all-enclosing plastic shell or cover. FIG. 5 omits any showing of the helical grooves associated with the illustrated needle hub.

FIG. 6 is a similar view of the same device as shown in FIG. 5 coupled to a syringe and with the plastic shell or cover removed and the driver partly rotated from the locked position of FIG. 5 to the point where the driver is about to start moving downwardly in the shield-retracting direction.

FIG. 7 is a similar view showing the needle shield of FIG. 6 in fully shield-retracted position but not yet locked therein.

FIG. 8 is a cross-sectional view of only the driver elements shown in FIG. 7 (the coupler elements, hub elements and shield elements shown in FIG. 7 are omitted) taken from the plane of line 8-8 in FIG. 7.

FIG. 8A is a view on an enlarged scale of a small portion of FIG. 8.

FIG. 9 is a somewhat schematic cross-, sectional view of a third detachable needle assembly contemplated by the invention shown affixed to a syringe and shown while still in shield-extended position but just after it has been unlocked from that position and is about to be moved to shield- retracted position.

FIG. 9A is a broken cross-sectional view taken from the planes of staggered line 9A-9A in FIG. 9.

FIG. 10 is a view similar to FIG. 9 showing the same needle assembly in shield-withdrawn position but not yet locked in that position.

FIG. 11 is a view taken from the plane of line 11-11 in FIG. 9A. FIG. 12 is a diagram of the guide groove and groove follower of the illustrated embodiment, showing three locked positions of the groove follower.

FIG. 12A is a view on an enlarged scale of a small portion of FIG. 12.

FIG. 13 is a somewhat schematic cross- sectional view of a detachable needle assembly illustrative of the prior art, shown attached to a syringe but prior to removal of a plastic shell or cover associated with the detachable needle.

FIG. 13A is an end view of only the hub elements shown in FIG. 13 (the coupler elements and plastic shell or cover elements shown in FIG. 13 are omitted) taken from the plane of line 13A-13A in FIG. 13.

Drawings are referred to above as being somewhat schematic because no attempt has been made to portray mold draft angles, reinforcing ribs, precise relations as to relative wall thicknesses, and like details which persons skilled in the art of injection molding or other appropriate manufacturing methods may utilize as a matter of routine design.

For a better understanding of the invention, detachable needles of the prior art will first be described. These may be of the type illustrated by the detachable needle generally indicated by the reference numeral 10 in FIG. 10. The detachable needle 10 includes a needle proper 12 and a needle hub 14. The needle is anchored to the hub and extends coaxially from the distal end of the hub. An open mouth 16 in the proximal or lower end of the hub provides inlet means for fluids passing through the hub. The mouth 16 also forms a bore 20 extending upwardly to a taper or seat 22 for

SUBSTITUTE SHEET receiving a hollow male coupler member 24 which has a central passage 28. The seat 22 provides interior annular socket means for the male coupler member 24. The member 24 is integrally formed as part of the coupler generally indicated by the reference numeral 30. The coupler 30 is a standardized fitting or coupler member fixed to the end of syringe barrel 32. The syringe barrel may have any one of a number of standard diameters, ranging from as small as approximately the diameter of fitting 30 itself up to four or more times the diameter of fitting 30.

The hub 14 also has a radially extending flange means comprising a pair of radially extending flanges 26 adapted to threadedly engage the interior threads 34 of fitting 30. When the flanges 26 are turned down in the threads 34, the male coupler member 24 is tightened into the seat 22, and the central passage 28 is sealingly connected to the hub passage 23 which leads to the needle 12.

A plastic shell or cover 40 is provided which may have a slightly tapered fit (not shown) on the hub 14 such that the cover 40 is spaced above the needle when seated as far as possible on the hub in the position shown in FIG. 13. In practice, this shell or cover is usually immediately removed when the detachable needle is coupled to a syringe, but the cover is included in FIG. 13 for completeness. Prior to use, and prior to being coupled to a syringe, the assembly as so far described (of course excluding the coupling 30 and syringe barrel 32) may be supplied in a sterile flexible package or envelope (not shown) .

When the detachable needle is to be used, the user removes the sterile assembly from its sterile packaging, grasps the shell or cover 40 in the vicinity of the hub 14, and connects the assembly to a syringe 32 by inserting the flanges 26 into the threads 34 of the syringe coupler 30 and twisting the hub to tighten the flanges down in the threads until the male member 24 of the coupler is received tightly in the seat 22. When the detachable needle is tightly coupled to the syringe, the plastic shell or cover is removed by twisting and pulling it off the hub.

When the worker grasps the cover 40 in the vicinity of the hub 40, sterility at this location on the cover is destroyed, but that is of no consequence, since sterility of the detachable needle and of the interior passages between the syringe and the needle tip is preserved.

If the needle 12 is not covered following use, it presents an obvious risk to health care personnel and others required to handle or dispose of the used devices. Following use, the needle 12 may be re-covered with the cover 40 (which, inconveniently, has to have been saved when originally removed) by applying the cover over the "front" or distal end of the needle. Doing so involves moving the cover in the proximal direction while the cover is closely adjacent the needle tip and, moreover, involves moving the cover over the needle from beyond the needle tip, thereby presenting a substantial risk of a needle prick to a possibly harried and distracted health care worker.

If the needle is to be detached from the syringe following use, the user must either proceed while the needle is still exposed by grasping the hub and twisting it in order to back the flanges 26 out of the threads 24, thereby risking a prick from the exposed needle during such backing-out, or must re-cover the needle in the manner previously described, with the attendant risk of pricking at that stage.

The invention presents a needle which may be safely shielded before and after use by shield means which is conveniently manipulated solely from the proximal end of the needle assembly, thus avoiding direct exposure to the needle tip or any need to grasp parts located beyond the needle tip. At the same time, the present invention may be used in place of the detachable needles of the prior art with little or no modification of the practices of the prior art in using needles of that general type, and without modification of existing syringes used with detachable needles.

An embodiment of the invention is shown in FIGS 1-4. A detachable needle generally indicated by the reference numeral 10a (FIG. 3) includes a needle proper 12a and a needle hub 14a. The hub 14a is somewhat elongated and preferably of generally cylindrical configuration. The needle 12a is anchored to the hub 14a and extends coaxially from the distal end of the hub. An open mouth 16a (FIG. 1) in the proximal or lower end of the hub provides inlet means for fluids passing through the hub. The mouth 16a also forms a bore 20a extending upwardly to a taper or seat 22a for receiving the hollow male coupler member 24 associated with a standard coupler 30 of the type previously described. The seat 22a provides interior annular socket means for the male coupler member 24.

The hub 14a also has radially extending flange means comprising a pair of radially extending flanges 26a adapted to threadedly engage the interior threads of fitting 30. The flanges 26a and

SUBSTITUTESHEET sear 22a comprise means for screw-down connection with the standard coupler 30. When the flanges 26a are turned down in the threads, the male coupler member 24 is tightened into the seat 22a, and the central passage 28 of the male coupler member is sealingly connected to the hub passage 23a which leads to the needle 12a.

The detachable needle assembly 10a is provided with a shroud or shield 50a which is slidingly supported on the hub 14a for telescoping movement between needle-covering or shield-extended position seen in FIGS. 1, 2 and 4 and needle- exposing or shield-retracted position seen in FIG. 3. It is to be noted that all points of support of the shroud 50a on the hub 14a are themselves supported entirely via the engagement of the screw- down connection means of the detachable needle assembly with the syringe-mounted locking means 30, and that such telescoping support is self- established by the detachable needle assembly and does not depend to any significant degree, or to any degree whatsoever in the illustrated embodiment, on structural support or interaction of the shroud with any elements associated with the syringe 32. Thus, the telescoping support of the needle shroud 50a on the needle hub 14a is a substantially self- established attribute of the detachable needle assembly 10a.

Suitable detent, guide and tab means may be provided to hold the shroud in its extended or retracted position, to guide its movement between extended and retracted positions, and to allow it to be conveniently manually actuated from the proximate end of the detachable needle assembly. In the illustrated example, a longitudinal groove 52a (FIG. 4) is formed in the outer wall of the needle hub 14a. The longitudinal groove 52a is joined at its outer end to a short lateral groove 54a terminating in a slight depression 56a. The longitudinal groove 52a is joined at its inner end to a short lateral groove 58a terminating in a slight depression 60a.

The shroud 50a is preferably of hollow cylindrical shape as shown, and is the illustrated example has a pair of slits 62a extending from its lower or proximal end. The slits 62a define a spring tab 64a. A groove follower or detent projection 66a is formed on the inner side of the spring tab 64a near its free end. The dimensions of these parts are such that the spring tab 64a is slightly spring-loaded when the detent projection 66a is positioned in the depression 56a or 60a, and is spring-loaded to a slightly greater extent when the detent is positioned in the longitudinal groove 52a or in one of the short lateral grooves 54a or 58a.

As best seen in FIG. 4A, the shroud or shield 50a is also provided with an integral control tab 68a which is spaced above and bridges the end of the spring tab 64a in such a manner as not to interfere with the springing action of the tab 64a.as best shown in FIG. 4A.

The construction as so far described may be supplied in a plastic shell or cover 40a (FIG. 1) . The cover may be enlarged at portion 42a to allow its removal past the control tab 68a. The filleted corners at the top end of the cover may snugly fit against the extended shroud or shield 50a, as shown in FIG. 1. The construction as thus far described may be contained in a flexible sterile package (not shown) . When the detachable needle of FIGS. 1-4 is to be used, the user removes the sterile assembly from its sterile packaging, grasps the cover 40a in the vicinity of the top end of the hub 14a, and connects the assembly to a syringe 32 by inserting the flanges 26a into the threads of the syringe coupler 30 and twisting the hub to tighten the flanges down in the threads until the male member 24 of the coupler is received tightly in the seat 22a. When the detachable needle is tightly coupled to the syringe, the plastic shell or cover is removed by twisting and pulling it off the shroud or shield 50a, leaving the needle in covered or protected condition as illustrated in FIGS. 2 and 4.

When the health care worker grasps the cover 40a in the vicinity of the top end of the hub 14a, sterility at this location on the cover is destroyed, but as is similarly true of the detachable needles of the prior art described above, that is of no consequence, since sterility of the detachable needle and of the interior passages . between the syringe and the needle tip is preserved.

It is noteworthy that the manipulations used to connect the detachable needle of the invention to a syringe are very similar to, if they do not exactly duplicate, the manipulations used to connect the detachable needles of the prior art which are described above. Health care workers already familiar with the use of detachable needles require little or no training before they can proceed with confidence to properly connect the detachable needle of the convention. Also to be noted is the fact that the invention can be used with the same syringes as have been used with the

_SUB_STITUTE SHEET detachable needles of the prior art, without any modifications of such known types of syringes.

When the detachable needle 10a is supplied and is in the condition shown in FIG. 1, the detent projection 66a is positioned in the depression 56a and the shroud 50a is locked against retraction. After the detachable needle 10a is coupled to a syringe and the cover 40a is removed, the needle may be exposed by pushing the control tab 68a with a finger to move the detent projection 66a out of the depression 56a and into the short lateral groove 64a. This move will encounter a resistance due to the fact that the depression 56a is slightly deeper than the groove 64a, but the resistance can be overcome with firm finger pressure on the control tab 68a to torque the shield 50a and start the motion. Once the detent projection 66a is in the groove 54a it is moved along that groove with relatively little resistance by continuing the torquing of the shield 50a until the projection 66a reaches the upper or distal end of the longitudinal groove 52a. The control tab 52a is then finger- pulled longitudinally to move the projection 66a downwardly from the distal to the proximate end of the groove 52a, again with relatively little resistance. This of course pulls the entire shroud 50a to retracted or needle-exposing position. The shroud can then be locked in retracted position by lightly torquing the shroud by finger pressure on the control tab 68a to move the detent projection 66a along the short lateral groove 58a and into the depression 60a.

While the foregoing description of the retracting motions is very detailed, the motions themselves are simple and can be performed in a straightforward and simple manner using a single finger or using the thumb and index finger to manipulate the control tab 68a in a manner that is obvious to the user, or is easily learned if not self-evident.

After the needle has been used, the shroud 50a can be extended to needle covering position by reversing the motions just described. The shroud is released from its locked retracted position by finger-applied torquing pressure sufficient to force the detent projection 66a out of the depression 60a against a resistance that is due to the fact that the depressions 60a is deeper than the longitudinal groove 58a leading from the depression. The remainder of the motion is the reverse of that previously described and should be self-evident.

It is noteworthy that all manipulations described are performed, so to speak, from the "back" or proximate end of the needle assembly, and the fingers never move past the needle tip, or anywhere close to the needle tip, and never move from a point beyond or in front of the needle tip, but are at all times well away from and "behind" the needle tip.

Another embodiment of the invention is shown in FIGS 4-8. A detachable needle generally indicated by the reference numeral 10b (FIG. 7) includes a needle proper 12b and a needle hub 14b. The hub 14b is somewhat elongated and preferably of generally cylindrical configuration. The needle 12b is anchored to the hub 14b and extends coaxially from the distal end of the hub. An open mouth 16b (FIG. 5) in the proximal or lower end of the hub provides inlet means for fluids passing through the hub. The mouth 16b also forms a bore 20b extending upwardly to a taper or seat 22b for receiving the hollow male coupler member associated with a standard coupler 30 of the type previously described. The seat 22b provides interior annular socket means for the male coupler member.

The hub 14b also has radially extending flange means comprising a pair of radially extending flanges 26b adapted to threadedly engage the interior threads of fitting 30. When the flanges 26b are turned down in the threads, the male coupler member is tightened into the seat 22b, and the central passage of the male coupler member is sealingly connected to the hub passage 23b which leads to the needle 12b.

The detachable needle assembly 10b is provided with a shroud or shield 50b which is slidingly supported on the hub 14b for telescoping movement between needle-covering or shield-extended position seen in FIGS. 5 and 6 and needle-exposing or shield-retracted position seen in FIG. 7. In the illustrated example, the sliding telescoping support of the shroud 50b on the hub 14b is not by direct contact between the members 50b and 14b, but is via an intermediate driver member 70b, most clearly seen in FIG. 8, which will be more fully described below. It is to be noted that all points of support of the shroud 50b on the hub 14b (via the driver member 70b) are themselves supported entirely via the engagement of the screw-down connection means of the detachable needle assembly 10b with the syringe- mounted locking means 30, and that such telescoping support is self-established by the detachable needle assembly and does not depend to any significant degree, or to any degree whatsoever in the illustrated embodiment, on structural support or

SUBSTITUTESHEET interaction of the shroud with any elements associated with the syringe 32. Thus, the telescoping support of the needle shroud 50b on the needle hub 14b is a substantially self-established attribute of the detachable needle assembly 10b.

The driver member 70b is preferably generally of cylindrical shape as shown and is rotatably mounted on the hub 14b. The driver 70b has a main barrel portion 72b, and a finger wheel 73b. A longitudinal slot 74b and short lateral slots 76b and 78b are formed in and extend through the wall of the barrel portion 72b. The short lateral slot 76b is slightly narrowed at an intermediate point by slight projection 77b as best seen in FIG. 8A. The short lateral slot 78b is similarly slightly narrowed at a similar intermediate point by a similar slight projection whose location is indicated in FIG. 8 by the reference numeral 79b. This latter projection is not illustrated in a separate figure corresponding to FIG. 8A. As shown, the longitudinal slot 74b may extend to the distal or upper edge of the main barrel portion 72b to allow for assembly of the parts. Another similar set of slots is formed in the wall of the main barrel portion 72b diametrically opposite the illustrated slots 74b, 76b and 78b.

Suitable detent, guide and tab means may be provided to hold the shroud in its extended or retracted position, to guide its movement between extended and retracted positions, and to allow it to be conveniently manually actuated from the proximate end of the detachable needle assembly. In the illustrated example, a pair of helical grooves is formed in the outer wall of the needle hub 14b. In the drawings, only one of these helical grooves can be seen along its lengthwise extent. This groove is labelled with the reference number 80b and can be seen to extend along and partially around the hub 14b.

The shroud 50b is preferably of hollow cylindrical shape as shown, and is the illustrated example has a pair of integrally formed follower fingers 80b extending radially inwardly a short distance at a location near the lower or proximate end of the shroud. Each of these fingers extends through one of the slots 74b, 76b, or 78b (depending on the position of the parts) or through one of the counterpart slots at the diametrically opposite side of the hub, and into the helical groove 80b or its counterpart on the opposite sidewall of the needle hub 14b.

The construction as so far described may be supplied in a plastic shell or cover 40b (FIG. 5) . The cover may be enlarged at portion 42b to cover the finger wheel 73b and extend past the entire detachable needle assembly. The filleted corners at the top end of the cover may snugly fit against the extended shroud or shield 50b, as shown in FIG. 1. The construction as thus far described may be closed by an end cover 46b attached around the bottom rim of the cover 40b by pressure- sensitive adhesive and provided with a lift tab 48b. This assembly may provide a sterile self-contained package without the need for any additional packaging in a sterile flexible envelope or the like.

When the detachable needle of FIGS. 5-8 is to be used, the user grasps the lift tab 48b and removes the end cover 46b. The user then grasps the

SUBSTITUTE SHEET cover 40b in the vicinity of the top end of the hub 14b, and connects the assembly to a syringe 32 by inserting the flanges 26b into the threads of the syringe coupler 30 and twisting the hub to tighten the flanges down in the threads until the male member of the coupler is received tightly in the seat 22b. When the detachable needle is tightly coupled to the syringe, the plastic shell or cover is removed by twisting and pulling it off the shroud or shield 50b, leaving the needle in covered or protected condition as illustrated in FIG. 6.

If the cover 40b and end cover 46b are the only packaging for the adjustable needle, the entire exterior of this packaging is not sterile. Even so, sterility of the detachable needle and of the interior passages between the syringe and the needle tip is preserved when the assembly is manipulated and coupled to a syringe in the anticipated and natural manner described above.

It is again noteworthy that the manipulations used to connect the detachable needle of the invention to a syringe are very similar to, if they do not exactly duplicate, the manipulations used to connect the detachable needles of the prior art which are described above. Again, health care workers already familiar with the use of detachable needles require little or no training before they can proceed with confidence to properly connect the detachable needle of the invention. Also again to be noted is the fact that the invention can be used with the same syringes as have been used with the detachable needles of the prior art, without any modifications of such known types of syringes.

When the detachable needle 10b is supplied and is in the condition shown in FIG. 5, the

SUBSTITUTE SHEET follower finger 82b is positioned at the closed end of the short lateral slot 76b, and the diametrically opposed finger is positioned equivalently in its a short lateral slot diametrically opposed to the slot 76b. The shroud 50b is thereby locked against retraction since the follower fingers are not free to travel lengthwise of the hub. After the detachable needle 10b is coupled to a syringe and the cover 40b is removed, the needle may be exposed by pushing the finger wheel 73b to move driver member 70b and therefore move the sides of the short lateral slot 76b past the follower finger 82. (The same relative movement occurs between counterpart elements at the diametrically opposite side of the assembly.) This movement will encounter a resistance because the slight projection 77b must pass the follower finger 82b (the same thing happens with respect to the diametrically opposite counterparts) , but the resistance can be overcome with firm finger pressure on the finger wheel 73b to torque the driver member with enough force to compress or deform the slight projection 77b (and its diametrically opposite counterpart) sufficiently to allow the motion to continue. Once the slight projection at each side of the assembly is cleared, the motion can be continued with relatively little resistance.

When the barrel portion has been turned sufficiently to bring the far wall 75b of the longitudinal slot 74b into contact with the follower finger 82b (and to bring the diametrically opposite counterparts into the same relation) , the parts are in the position shown in FIG. 6. As the finger wheel 73b continues to be turned, the follower finger, now positioned in the longitudinal slot and under continuing pressure from the wall 75b, is constrained to move downwardly along the associated helical groove 80b (as is its diametrically opposite counterpart) thereby causing the shroud 50b to retract (and twist) from the position shown in FIG. 6 to the position shown in FIG. 7. At this position, the follower finger 82b is juxtaposed with the open end of the lower short lateral slot 78b. (The same is true of the diametrically opposite counterparts.) Continued turning of the finger wheel 73b moves the sides of the slot 78b past the finger 82b, resistance caused by the slight projection 79b is overcome, and the movement is continued until the end of the slot 78b is reached. (The same is true of the diametrically opposed counterparts.) This provides an end stop to the turning movement of the driver 70b in the shield- retracting direction. The needle assembly is now locked in shield-retracted or needle-exposed condition.

Again, while the foregoing description of the retracting motions is very detailed, the motions themselves are simple and can be performed in a straightforward and simple manner using a single finger or using the thumb and index finger to turn the finger wheel in a manner that is obvious to the user, or is easily learned if not self-evident. The action is similar to the retracting action of a common lipstick or chapstick, and will therefore "feel" familiar to almost everyone.

After the needle has been used, the shroud 50b can be extended to needle covering position by reversing the motions just described. The shroud is released from its locked retracted position by finger-applied torquing pressure in the direction opposite to that of the pressure applied during retraction. Sufficient pressure is applied to clear the slight projections 79b (and to do the same with the diametrically opposed counterparts) . The remainder of the motion is the reverse of that previously described and should be self-evident.

It is again noteworthy that all manipulations described are performed, so to speak, from the "back" or proximate end of the needle assembly, and the fingers never move past the needle tip, or anywhere close to the needle tip, and never move from a point beyond or in front of the needle tip, but are at all times well away from and "behind" the needle tip.

Another embodiment of the invention is shown in FIGS. 9-12. A detachable needle generally indicated by the reference numeral 10c (FIG. 10) includes a needle proper 12c and a needle hub 14c. The hub 14c is of sufficient diameter so that its lower skirt portion is capable of fitting over the standard locking means 30, as seen in FIGS. 9 and 10. This has the advantage of minimizing the ratio between the overall length of the assembly and the maximum length of telescoping movement between the hub and a shroud to be carried on the hub. In other words, for a given designed degree of telescoping movement, lengthwise compactness of the assembly is maximized

As shown, the hub 14c is preferably of generally cylindrical configuration. The needle 12c is anchored to the hub 14c and extends coaxially from the distal end of the hub. An open mouth in the proximal or lower end of the hub provides inlet means for fluids passing through the hub. The mouth also forms a bore 20c extending upwardly into a

SUBSTITUTESHEET taper or seat 22c for receiving the hollow male coupler member 24 associated with a standard coupler of the type previously described. It will be noted that the hollow male coupler member 24 is shown as relatively shorter than in the earlier figures; this shorter male member shown in FIGS. 9 and 10 is believed to more accurately reflect typical relative dimensions of the parts of prior-art standard couplers. From a disclosure standpoint this should be of no significance, since it will be noted that the longer relative dimension shown for the male member of the standard coupler in the first two illustrated embodiments merely affects the longitudinal locations of the seats 22a or 22b, whose longitudinal location obviously can be readily chosen to properly seat male members of the standard length, whatever that may be.

The hub 14c also has radially extending flange means comprising a pair of radially extending flanges 26c adapted to threadedly engage the interior threads of fitting 30. When the flanges 26c are turned down in the threads, the male coupler member is tightened into the seat 22c, and the central passage 28 of the male coupler member is sealingly connected to the hub passage 23c which leads to the needle 12c.

To save material and weight, the hub 14c is preferably of generally hollow construction as shown, and may be provided with internal stiffening ribs or buttress ribs 15c.

The detachable needle assembly 10c is provided with a shroud or shield 50c which is slidingly supported on the hub 14c for telescoping movement between needle-covering or shield-extended position seen in FIGS. 9 and 11 and needle-exposing or shield-retracted position seen in FIG. 10. It is to be noted that all points of support of the shroud 50c on the hub 14c are themselves supported entirely via the engagement of the screw-down connection means of the detachable needle assembly 10c with the syringe-mounted locking means 30, and that such telescoping support is self-established by the detachable needle assembly and does not depend to any significant degree, or to any degree whatsoever in the illustrated embodiment, on structural support or interaction of the shroud with any elements associated with the syringe 32. Thus, the telescoping support of the needle shroud 50c on the needle hub 14c is a substantially self-established attribute of the detachable needle assembly 10c.

The detent and guide means provided for the shroud 50c includes a guide groove consisting of guide groove segments 91c-96c formed in the shroud 50c as best seen in FIGS. 11 and 12. The groove 91c-96c receives a groove follower or detent projection 90c formed on the inner side of the shroud 50c. The follower is triangularly shaped, as most clearly seen in FIG. 12A. Barb-like projections 97c are formed in the sidewalls of grooves 92c, 94c and 96c at stations P, Q and R, respectively. The barb-like projections are small and the plastic or plastics forming the parts is somewhat yielding, so that the follower 90c can be forced past the barb-like projections in one direction against the resistance presented by the wedging action between the angled faces of the barb¬ like projections on the one hand and the angled faces of the follower on the other hand. However, reverse movement is prevented by a locking action between the flat barb faces and the flat face of the follower 90c. When the follower 90c is at station P as shown in FIG. 12A, it is releasably restrained against forward (leftward) movement by wedging engagement with the leftward barb-like projections on either side of the groove 92c, and is locked against rearward (rightward) movement by locking engagement with the rightward barb-like projections on either side of the groove 92c.

This detent and guide means as so far described is duplicated at diametrically opposite sides of the needle assembly 10c, and it is to be understood that the foregoing and following description applies to the detent and guide means at each side, although the elements at only one side may be referred to. For the most part, the views in the drawings are taken in such a way that the detent and guide means at only one side of the needle assembly 10c can be seen in the drawings.

The user manipulates the shroud 50c by using one or more fingers to engage or grasp it, preferably at the proximal skirt or lower end of the shroud. Such skirt portion constitutes the finger- engageable means for retracting and advancing the shroud. To encourage grasping at the lower end, and to improve finger traction, the lower end or skirt of the shroud may be knurled, or may be coated or covered, or may otherwise be provided with anti-slip means (not shown) .

The construction as so far described may be provided in a sterile pack, with the parts factory-positioned in the position shown in FIGS. 11 and 12A. The groove segment 91c allows insertion of the follower 90c in the guide groove system as part of the assembly procedure. The follower 90c is inserted and the shroud is partly turned to snap the

SUBSTITUTESHEET follower past the first pair of barb-like projections encountered at station P, but not past the second pair.

When the detachable needle of FIGS. 9-12 is to be used, the user removes the sterile assembly from its sterile packaging, grasps the shroud 50c in the vicinity of the lower skirt portion, and connects the assembly to a syringe 32 by inserting the flanges 26c into the threads of the syringe coupler 30 and twisting the hub to tighten the flanges down in the threads until the male member 24 of the coupler is received tightly in the seat 22a. In the course of this tightening, if the twisting forces are sufficient, the follower 90c may come unlocked from the position shown in FIG. 12A and advance to the exiting end (left end) of the groove 92c where it will engage the far wall of groove 92c, whereupon all twisting force on the assembly will be applied to tightening down the hub-to-coupler connection. This is the position of the parts seen in FIGS. 9 and 9A.

When the health care worker removes the needle assembly 10c from its sterile package and handles it, sterility on the exterior of shroud 50c and hub 14c may be destroyed, but sterility of the detachable needle and of the interior passages between the syringe and the needle tip is well protected by the container-like configuration of these two elements.

It is again noteworthy that the manipulations used to connect the detachable needle of the invention to a syringe are very similar to, if they do not exactly duplicate, the manipulations used to connect the detachable needles of the prior art which are described above. Again, health care

SUBSTITUTESHEET workers already familiar with the use of detachable needles require little or no training before they can proceed with confidence to properly connect the detachable needle of the invention. Also again to be noted is the fact that the invention can be used with the same syringes as have been used with the detachable needles of the prior art, without any modifications of such known types of syringes.

After the detachable needle 10c has been attached, the user uses his or her fingers to pull the shroud from the position of FIGS. 9 and 9A to the position of FIG. 10. The user then turns the needle assembly in the same advancing direction as previously used to advance the follower in the groove segment 94c until station Q is reached and the follower snaps past the first set of burr-like projections at that station to reach a condition similar to that shown in FIG. 12 in which the follower 90c is releasably restrained against forward (leftward) movement by wedging engagement with the leftward barb-like projections on either side of the groove 94c, and is locked against rearward (rightward) movement by locking engagement with the rightward barb-like projections on either side of the groove segment 94c (not readily visible on the scale of the drawings, or not visible at all) . The shroud is thus releasably held against further twisting movement in the advancing direction, and is locked against retrograde movement. Also, the shroud is positively locked against movement in the extending or needle-exposing direction by engagement with the upper wall of the groove segment 92a.

After the needle has been used, the shroud 50c can be extended to needle-covering position by twisting the shroud in the advancing direction with sufficient force to overcome the wedging resistance of the remaining pair of barb-like projections in the groove segment 94c, so that the follower wedges past them and reaches the lower end of the groove segment 95. The shroud 50c is then extended to cover the needle whereupon the follower reaches the top end of the groove segment 95c. The shroud is then twisted to advance the follower into groove segment 96c and past a first (and only) pair of barb-like projections 97c (not readily visible on the scale of the drawings, or not visible at all) on the opposite side walls of that segment, at which time the follower is locked at final station R and the shroud is irreversibly locked in extended position.

It is to be noted that all twisting manipulations occur in a single turning direction, which is the also the tightening-down direction for the connection between the needle assembly 10c and the locking means 30 on the syringe. This continuous one-way movement in the lock-tightening direction to expose and cover the needle avoids the risk of inadvertently releasing the hub from the locking means, or releasing it before the needle is covered.

Again, while the foregoing description of the retracting and advancing motions is very detailed, the motions themselves are simple and can be performed in a straightforward and simple manner using a single finger or using the thumb and index finger to turn, push and pull the shroud skirt in a manner that is obvious to the user, or is easily learned if not self-evident. It is again noteworthy that all manipulations described are performed, so to speak, from the "back" or proximate end of the needle assembly, and the fingers never move past the needle tip, or anywhere close to the needle tip, and never move from a point beyond or in front of the needle tip, but are at all times well away from and "behind" the needle tip.

While presently preferred embodiments of the invention have been described, additions, deletions, modifications and refinements in the invention can be made without departing from the fair teachings thereof. For example, the shroud- retracting arrangement may be spring-loaded, so that the shroud is retracted by finger pressure which also loads a spring, and the shroud is subsequently extended by release of the spring force. The scope of the invention is intended to be defined by the following claims, and is not intended to be limited to specific details of the foregoing disclosure except to the extent, if any, fairly required by proper interpretation of the claims.

SUBSTITUTE SHEET

Claims

WHAT IS CLAIMED IS:

1. A needle and cover assembly for use with syringes of the detachable needle type comprising an elongated needle hub proper, said hub having proximal and distal ends, inlet means at the proximal end of the hub, a needle anchored to the hub and extending from the distal end of the hub coaxially therewith, passage means in the hub between the needle at the distal end and said inlet means at the proximal end, said hub having at its lower end means for screw-down connection with a syringe-mounted locking means for the hubbed needle, said screw-down connection means including radially extending flange means and interior annular socket means, and a needle shroud permanently associated with said hub and supported thereon for telescoping movement between needle-covering and needle-exposing positions.

2. A device as in claim 1, the points of support of said needle shroud for telescoping movement with respect to said hub being themselves supported substantially entirely via the engagement of said screw-down connection means with syringe- mounted locking means in which such flange means is engaged, whereby said support of said needle shroud for telescoping movement is a substantially self- established attribute of said detachable needle and shroud assembly.

3. A device as in claim 1, finger- engageable means mounted on said hub for powering said telescoping movement at least in the direction toward needle-exposing, shroud-retracted position.

4. A device as in claim 1, finger- engageable means mounted on said hub for powering said telescoping movement at least in the direction toward needle-covering, shroud-extended position.

5. A device as in claim 1, finger engageable means mounted on said hub for powering said telescoping movement in both shroud-retracting and shroud-extending directions.

6. A device as in claim 4, said finger- engageable means being remote from the tip of the needle at all times during shroud-retracting and shroud-extending movement.

7. A device as in claim 1, detent means for releasably holding said needle shroud in needle- covering, shroud-extended position and detent means for releasably holding said needle shroud in needle- exposing, shroud-retracted position.

8. A device as in claim 7 including additional detent means for permanently locking said needle shroud in needle-covering, shroud-extended position when it is extended to said position from the needle-exposing, shroud-retracted position.

9. A detachable needle and shroud assembly for use with syringes of the detachable needle type comprising a needle hub, said hub having proximal and distal ends, inlet means at the proximal end of the hub, a needle anchored to the hub and extending from the distal end of the hub, passage means in the hub between the needle at the distal end and said inlet means at the proximal end, said hub having connection means for connection with needle-locking means on a syringe, and a needle shroud permanently associated with said hub and supported thereon for telescoping movement between needle-covering and needle-exposing positions.

10. A device as in claim 9, the points of support of said needle shroud for telescoping movement with respect to said hub being themselves supported substantially entirely via the engagement of said connection means with syringe-mounted locking means in which such connection means is engaged, whereby said support of said needle shroud for telescoping movement is a substantially self- established attribute of said detachable needle and shroud assembly.

SUBSTITUTESHEET

11. A device as in claim 9, said connection means being turnable in a given turning direction to tighten said connection means in said needle-locking means, guide and detent means for guiding said needle shroud for both needle-covering and needle exposing movement, said guide and detent means accommodating turning of said shroud in said turning direction incident to both said needle- exposing and needle-covering movement.

12. A device as in claim 11, said guide and detent means including means constraining said shroud against turning in the direction opposed to said given turning direction.

13. A device as in claim 9, including detent means for permanently locking said needle shroud in needle-covering position when it is extended to said position from needle-exposing position.

14. A device as in claim 12, said guide and detent means including means for permanently locking said needle shroud in needle-covering position when it is extended to said position from needle-exposing position.