Background of the Invention

1 . Field of the Invention

The present invention relates to safely disposing of medical waste, particularly needles and the like, in a manner which minimizes

the danger of transmission of infectious diseases. More specifically,

this invention is directed to a disposal system and, especially, to such a system which comprises a receptacle for contaminated medical products of the type which comprise a hub, the products also typically including a needle, the system additionally comprising a holder which cooperates with the products so as to cause a product mounted to the holder may be automatically detached from the holder and deposited

within the receptacle. Accordingly, the general objects of the present

invention are to provide novel and improved methods and apparatus of

such character.

2. Description of the Related Art

A wide variety of blood collection/fluid injection devices are

used by the health care industry. These devices include a hollow bored member, hereinafter a "hub", for transferring fluid materials via a

cannula, hyopodermic needle or via the hub itself thereby providing a connective conduit for the fluid path. The hub may be tapered, and/or

may be externally threaded or may have some other external

configuration to faciliate and provide attachment means. These hub

based devices include hypodermic syringes and blood collection/fluid injection systems. While hypodermic syringes normally have a fluid chamber integrally formed with the needle holder, blood collection /fluid

injection systems typically include a needle holder having a hub

detachably mounted thereon so that a needle is disposed at one end of

the holder and a fluid collection tube may be inserted in the other end of the holder.

For both economic and safety reasons a wide variety of

venipuncture devices have been developed. Economic factors have

favored designs having associated holders which allow hub removal

whereby reuse of the holder is permitted . Safety concerns, however, have pointed away from the use of such devices because the hub removal procedure creates an increased risk of inadvertent contact

between the health care worker and a patient's bodily fluids and,

particularly, an accidental needle stick. In recent years, increased

concern about the transmission of infectious diseases, such as HIV and HBV, has renewed interest in developing safer methods and apparatus

for disposing of infectious medical waste. Most of the development

efforts to date have been directed toward simplifying the process of

removing a hub from a holder while simultaneously minimizing .the health care worker's contact with the "sharp" which is affixed to or integral with the hub. In particular, these efforts have been directed

toward improving both hub retaining mechanisms and complementary

hub removing means which are integrated with sharps disposal

receptacles.

Sharps receptacles designed for removing a standard externally

threaded hub from a holder typically possess a hollow base portion, for

receiving the detached devices, and a cover having various shaped

slots, known in the art as unwinder apertures, for engaging a hub during needle removal. To dispose of a previously used hub with attached needle using a conventional sharps receptacle, a health care worker must carefully position the hub in the appropriate slot and then grip and

rotate the holder to unthread the hub so that it and the attached needle may fall through the slot into the underlying body of the receptacle.

When using these devices, it is often difficult to tell when the hub has been fully unwound from the holder. Since the health care worker may

be simultaneously performing other tasks, there exists a serious danger that a hub may "hang-up" and the associated needle inadvertently

contact an unsuspecting health care worker. A further deficiency of

prior art devices of the type being discussed stems from the lack of any

product misuse prevention features. For example, the use of hubs which only appear to be compatible with a given unwinder slot may cause a malfunction. Where the hub is attached to a double-ended

needle, i.e., a cannula, a further danger arises after the hub is

disengaged from a holder because the hub may remain lodged in the

slot, causing exposure of the upstanding posterior end of the cannula. In such a case, the user must physically handle the hub to remove it from the slot and permit the cannula hub assembly to drop into the

sharps receptacle.

Aside from hub-engaging unwinder slots, other medical "sharps" removal schemes have been developed. These include the use of sharps receptacles having movable jaws which engage the standard

externally threaded hub of a needle assembly. Such devices allow a

user to unthread the hub/needle combination from a holder by (1 ) inserting the hub into a sharps box having such jaws; (2) operating the jaw mechanism to lock the hub; (3) rotating the holder to unthread the hub from the holder; and (4) releasing the locking mechanism to allow the now threadably removed hub and needle combination to fall into the

sharps container base. While some sharps disposal containers of this

nature can effectively remove threaded hubs, with associated needles

or cannulas from holders, they are typically complex and costly devices, the complexity having a deleterious effect on reliability. Additionally,

such sharps receptacles still require the health care worker to follow a

relatively lengthy and complex manual hub-unwinding procedure. As

with less complicated devices having unwinder slots, these receptacles

periodically suffer from the problem of incomplete hub unwinding. Finally, safety is again compromised by the lack of any means for

preventing operator misuse.

A similar style of disposal system, which has both increased

safety and a simplified hub removal procedure, includes a sharps

receptacle with an electric hub-unwinding mechanism. Sharps

receptacles of this nature allow a health care worker to simply insert a holder having a hub/needle combination received therein into an

aperture whereby the hub is unthreaded from the holder by means of an

electric motor. Deficiencies associated with these mechanical sharps

disposal systems include the facts that the receptacles are ( 1 ) very expensive to build and maintain; and (2) not easily transportable because they require some kind of electric power supply. Further, while incomplete hub unwinding is less of a problem with these systems, none of these power driven systems include any type of

operator misuse prevention feature.

Finally, sharps disposal systems have been proposed wherein the sharps disposal container cooperates with a custom hub holder to effect needle release. Some of these proposed disposal systems are

allegedly compatible with cannula assemblies having an externally

threaded hub. While such a system would theoretically increase the

safety of the "sharps" removal procedure, a rather complex series of

steps would be required to achieve removal. Thus, increased safety is achieved at the expense of simplicity of operation. One proposed system for use with a custom holder requires that an adapter be placed

on the hub, the hub of a cannula assembly for example, in order to

make the cannula assembly compatible with the holder. The need for a hub adaptor obviously results in a cost increase. Finally, neither the holder nor the sharps container of the proposed systems have any

means to prevent a health care worker from using them with other,

potentially incompatible, devices. Thus, safety is again sacrificed by the lack of operator misuse prevention features.

Co-pending U.S. Pat. App. No. 08/580,322, filed on December

28, 1995, is directed to an improved holder for a fluid collection and/or injection system. That application has been assigned to the assignee of the present invention and the information disclosed therein is hereby incorporated by reference. The holder shown and described in application 08/580,322 possesses an actuation mechanism at one end

of the holder. The actuation mechanism enables the mounting of the externally threaded hub of a cannula assembly on the holder and the maintaining of the attachment of the cannula assembly to the holder

during use. Initially, the threaded hub will be threadably engaged by the

actuation mechanism of the holder in the same manner as the

hub/needle combination would be installed in any other medical device holder which accepts a threaded hub. Upon operation of an external

actuator of the actuation mechanism, the hub is released from the actuation mechanism whereby the hub/needle combination will fall from

the holder under the force of gravity. In one embodiment of the holder,

the actuator is in the form of a push-button which is capable of being

depressed by the operator's finger. Thus, this medical sharps holder configuration offers both compatibility with standard threaded hubs and

a safe and simple means of removing a hub, particularly a hub which is

integral with a cannula or needle, from the holder. However, while the

holder of the co-pending application represents a substantial advance

in the sharps disposal field, some methods and apparatus of safely

disposing of used hubs from such a holder are beyond the scope of the incorporated application. Thus, some aspects of the sharps disposal

system of the present application represent improvements on the holder shown and described in the incorporated application.

Summary of the invention

It is an object of the present invention to provide a sharps disposal system which will permit simple, safe and effective disposal of

hubs, and particularly hubs integrated or associated with needles and

cannulas.

Another object of the invention is to provide a sharps disposal

system comprising a holder for releasably engaging a hub and a

cooperating sharps receptacle which is capable of permitting more

precise and reliable single-handed remote disposal of a standard threaded hub or hub/needle combination.

It is yet another object of the present invention to provide such

a disposal system which permits more precise and reliable detachment

of a standard threaded cannula assembly, i.e., an externally threaded

hub and associated cannula, from a holder by simply placing the holder

into a complementary structure of a sharps disposal receptacle.

It is still another object of the present invention to provide a

medical sharps disposal system which is of simple, durable construction and is economical to manufacture.

Another object of the present invention is to provide a sharps

disposal receptacle having a safer means for removing a hub from a cooperating needle holder than has characterized the prior art.

Still another object of the present invention is to provide a sharps

disposal receptacle having an operator misuse prevention feature.

These and other objects and advantages of the present invention are achieved in one embodiment by providing a holder with an actuation mechanism capable of detachably mounting a hub, and particularly the

standard threaded hub of a needle assembly, onto the holder and a

sharps disposal receptacle having a cover with an automatic release

structure for engagement with and operation of the actuation

mechanism of the holder.

In a preferred embodiment of the present invention, the actuation

mechanism of the holder component of the sharps disposal system

includes an actuator element, extending outwardly from, and slidably mounted to, the body of the holder. The actuator element is operably

associated with other components of the actuation mechanism such

that the actuation mechanism is normally biased to a position capable

of engaging the external threads on a hub having a cannula extending

therethrough for fluid transfer purposes. The actuator element includes

a release structure guide channel extending through at least a portion

of the actuator element which projects laterally outwardly from the

holder body. This channel is oriented substantially parallel to the axis of the holder body and possesses a sloped face. Upon operation of the

actuator element, the hub of an engaged needle assembly becomes

detached from the actuation mechanism and the hub and needle are free to fall as a unit from the holder under the force of gravity. The holder includes an end cap for maintaining the actuation mechanism in the holder. The end cap includes a guide channel-access recess aligned

with actuator element channel for permitting access to the sloped face

of the guide channel.

A system in accordance with the present invention also includes a sharps disposal receptacle. In a first embodiment, this receptacle has a hollow base (or, alternatively, body) for receiving medical waste therein and a receptacle cover for covering the open end of the base.

The cover includes an automatic release (also referred to as "auto-

release") structure which is designed to cooperate with the holder such that a standard threaded hub will be detached from the holder upon the

establishment of operative engagement between the automatic release

structure and the actuator element of the holder. The automatic release

structure includes, in the embodiment being described, an aperture

located between, and at a spaced distance from, a pair of holder guide walls which extend from the cover of the sharps receptacle. The guide

walls guide one end of the holder between the inner surfaces of the

guide-walls such that the hub of a hub/needle combination received within the holder may pass through the aperture. A shoulder on one of

the guide walls is sized and shaped to pass through the channel-access

(or, alternatively shoulder-access) recess of the end cap and mate with the sloped face of the channel in the actuator element of the holder. Thus, as the holder moves downwardly, the shoulder imparts linear motion to the actuator element. This, in turn, imparts motion to the hub engaging components of the actuator mechanism, and the, now detached, hub and needle combination passes through the aperture and into the base of the sharps receptacle.

In accordance with a second embodiment of a sharps receptacle for use in practice of the invention, the automatic release structure

includes an aperture located between, and at a spaced distance from,

a plurality of uniformly spaced elevated protrusions. Any pair of these

protrusions may function as the guide structure for the holder while a

third protrusion functions as the release actuation structure. As a holder is contacted by the guide structure, and then moved downwardly, the actuation protrusion imparts linear motion to the actuator element of the holder. This, in turn, imparts motion to the hub

engaging components of the actuator mechanism, and the now

detached hub, typically with a needle affixed thereto, passes through

the aperture and into the base of the sharps receptacle.

A sharps receptacle in accordance with the present invention

preferably also includes novel means for manually unwinding a hub from

a holder. Such a sharps receptacle also has an oversized aperture for

inserting various other types of medical waste into the base of the sharps receptacle. Finally, a sharps receptacle in accordance with the invention is additionally provided with plural lids for selectively opening and closing the various apertures in the cover of the receptacle.

The present invention offers enhanced safety characteristics relative to prior art devices and methods. This increase in safety is

partially due to the simple operation of the auto-release feature of the

sharps disposal system. To dispose of a used hub/needle or hub/cannula combination with the present invention, the health care worker simply orients a holder with an engaged hub above the auto-

release structure of the sharps disposal receptacle and then places the

holder into the auto-release structure. As the actuator channel of the

holder actuator element engages the shoulder on one of the guide walls or one of the protrusions, the hub previously mounted in the holder becomes detached and drops into the base of the sharps receptacle.

In some embodiments of the present invention, overall safety is

further enhanced by the inclusion of user misuse prevention features.

For example, misuse prevention is achieved in the present invention by

forming the sharps receptacle with an automatic release structure which

unambiguously mates with and exclusively operates the actuation

mechanism of a companion holder. Similarly, the configuration of the

holder prevents actuation of the actuation mechanism by any other sharps receptacle. Therefore, system safety is enhanced by minimizing the possibility that a health care worker will cause incomplete needle

release by attempting to use experimental combinations of system components.

Some embodiments of the present invention also include a sharps

receptacle with a novel unwinder aperture which is incapable of inadvertently being used to tighten the hub of a hub/needle combination to a holder.

Another significant advantage, relative to various prior art

methods and devices for disposing of standard threaded medical sharps,

offered by the present invention is an optimal combination of reduced

cost and efficient usage.

Brief Description of the Drawings

The present invention will now be described with reference to the

accompanying drawings wherein like numerals represent like structures and in which:

Figure 1 is a perspective view of a first embodiment of a sharps

disposal system in accordance with a first embodiment of the present

invention;

Figure 2 is a perspective view of the needle holder of the embodiment of Figure 1 ;

Figure 3 is a top plan view of the sharps disposal receptacle of

Figure 1 ;

Figure 4 is a partial cross-sectional view of the top of the sharps receptacle of Figure 3, taken along line 4-4 of Figure 3, Figure 4 also schematically showing the holder of Figures 1 and 2;

Figures 5A and 5B are respectively enlarged partial top plan and cross-sectional side elevation views of the top of the receptacle which show details of the unwinder aperture;

Figure 6 is a view similar to Figure 1 which depicts a sharps

disposal receptacle in accordance with a second embodiment of the

invention; and

Figure 7 is a partial top plan view of the receptacle of Figure 6,

Figure 7 showing details of the auto-release structure of the receptacle.

Detailed Description of the Disclosed Embodiment

Referring to the drawings, and particularly Figure 1 , a sharps

disposal system, indicated generally at 10, includes a holder 80 and a

sharps disposal receptacle 20. Although not a part of system 10, an

externally threaded hub 83, having a needle affixed thereto, is shown detachably mounted to needle holder 80. Sharps receptacle 20 includes

a generally hollow base 30 for receiving contaminated sharps . Base 30

is a unitary structure and is provided with a cover 40. Each of base 30

and cover 40 have been individually injection molded to an appropriate thickness using a puncture resistant and leak-proof material such as

polypropylene. Base 30, in a preferred embodiment, has a medical

waste receiving capacity of approximately one quart. Referring jointly

to Figures 1 , 3 and 4, cover 40 includes a first lid 42, a second lid 46, an unwinder aperture 50, an oversized aperture 49, and an auto-release structure which has been indicated generally at 60. Auto-release structure 60, in accordance with a first embodiment, includes first and

second guide walls, 61 and 65 respectively, extending substantially perpendicularly from cover 40 and positioned in spaced relation to a needle passage aperture 64. As may best be seen from Figures 3 and 4, a generally rectangular shoulder 69 extends from one side of second

guide wall 65. As illustrated in Figure 1 , holder 80 has been positioned

relative to auto-release structure 60 such that, upon downward

movement of holder 80, shoulder 69 and first and second guide walls

61 , 65 will orient needle holder 80 so that the needle affixed to hub 83 will extend through aperture 64.

The auto-release structure in accordance with a second

embodiment may be seen from Figures 6 and 7. This alternative auto-

release structure, indicated generally at 60', includes three protruding

posts 66, 67, 68 extending substantially perpendicularly from cover 40 and positioned in a circular, evenly spaced relation to needle passage

aperture 64. The height of posts 66 - 68 is sufficient to establish an

operative relationship with the holder activation mechanism. As

illustrated in Figure 6, holder 80 has been positioned relative to auto- release structure 60' such that, upon downward movement of holder 80, two posts 66, 67 will guide and orient the holder 80 so that the needle affixed to hub 83 will extend through aperture 64. The third

post 68 will engage the needle release mechanism. Three possible orientations of holder 80 onto posts 66, 67, 68 will result in actuation of the release mechanism.

An enlarged perspective view of holder 80 is shown in Figure 2.

As illustrated therein, holder 80 consists of a body 81 , an actuation mechanism 82 and an end cap 90. End cap 90 is used to retain

actuation mechanism 82 in holder 80 and is itself retained in holder 80

by flanges 89. End cap 90 includes an aperture which permits hub/needle combinations to be inserted into actuation mechanism 82.

Additionally, end cap 90 includes a recess 92 at one end thereof. As

shown, recess 92 is generally rectangular.

Actuation mechanism 82 includes an actuator 84 and which is

normally biased outwardly, with respect to body 81 , to the position

shown in Figure 2. In this position, a guide channel 85 in the actuation

mechanism is, at its deepest point, substantially aligned with the base of recess 92 in end cap 90. Channel 85 has a constantly and smoothly

decreased depth and, in part, is defined by a pair of facing side walls 86

and 88, which are preferably in alignment with the side walls of recess

92. Channel 85 also includes a sloped face, i.e., a cam surface, 87 which slopes away from the axis of holder body 81 . As shown in

Figure 2, both end cap 90 and actuator 84 possess a bevelled outer surface at one end thereof which assists with appropriate alignment of the needle holder during venipuncture. While end cap 90 is preferably fixedly attached to holder 80, actuator 84 is slidably mounted to holder

80 for reciprocal movement in a direction generally perpendicular to the axis of body 81 . The various other components of actuation mechanism 82, and their interaction with a hub 83 (see Fig. 1 ), are described in greater detail in above-referenced co-pending U.S. Patent

Application No. 08/580,322.

As shown in Figure 2, when actuator 84 is in the outward

position, actuation mechanism 82 is biased to a hub engaging position. In this position, a standard threaded hub, for example a hub integrate

with a needle to form a hub/needle combination, can be threaded into

actuation mechanism 82 and firmly supported by holder 80. Upon

movement of actuator 84 toward the axis of body 81 , hub 83 detaches from actuation mechanism 82 such that, if holder 84 were inverted from

the Figure 2 orientation, hub 83 and the associated needle would be

free to fall from holder 80 under the influence of gravity.

Also as shown in Figure 2, channel 85 preferably extends through

a relatively small central region of actuator 84 so that actuator 84 can

be, optionally, operated by using a finger. The extension of end cap 90

outwardly in substantial alignment with actuator 84 minimizes the

possibility of inadvertent operation of actuator 84 whereby the rigid

support for hub 83 would be disrupted at an inopportune moment. Similarly, end cap 90 cooperates with actuator 84 to ensure, as will be

discussed in more detail below, that hubs are automatically detached from holder 80 only by the action of the complementary auto-release structure of sharps receptacle 20 (Fig. 1 ).

Referring to Figure 3, a top plan view of sharps receptacle 20 of

system 10 is shown. Cover 40 of receptacle 20 includes a generally cat's-eye shaped unwinder aperture 50. Undulating portions 52 and 54,

of generally sinusoidal shape, are included in the opposite elongated

sides of the perimeter of aperture 50 as shown. The central region of

aperture 50 is sized and shaped to comfortably receive a hub of a needle/hub combination, such as hub 83. As a result of movement of

the hub either to the left or to the right from the insertion position, i.e.,

movement away from the central region of aperture 50, the undulating portions 52 or 54 will engage the hub and impede counter-clockwise rotation thereof. This engagement allows an operator to manually

unthread hub 83 from holder 80. Thus, using unwinder aperture 50, a health care worker has the option of manually unscrewing hub 83 from

holder 80 in the conventional manner. The positioning undulating portions 52 and 54 as shown in Figure 3 precipitates the advantage that

undulating portions 52 and 54 will only mechanically engage a hub as the hub is unwound, i.e., rotated in the counter-clockwise direction,

from a holder. Thus, a health care worker cannot inadvertently over¬ tighten a hub to a holder when attempting to unwind the hub from the holder.

Figures 5A and 5B show the unwinder aperture 50 in greater

detail. The opposite, narrow ends 90 and 91 of aperture 50 interconnect, and thus define the ends of, a pair of opposed aperture

sides 95, 96. Sides 95 and 96 are in the form of substantially equal

radii arcs. The central portions of arcuate sides 95 and 96 are spaced

sufficiently to permit the free passage of hubs, such as hub 83, therethrough. The undulating portions 52 and 54 are located between

the central or free drop portions of the aperture defined by arcuate sides 95 and 96 and respective of the ends 90 and 91 . Each undulating

portion is located opposite from a smoothly curved wall. As may clearly

be seen in Figure 5B, top 40 is provided with regions of increased thickness which extend at least part way about the periphery of aperture 50, these enlarged width portions increasing the strength of

the top.

As shown in Figure 3, top 40 also includes oversized aperture 49

for receiving assorted infectious medical waste such as hypodermic

syringes, winged infusion sets and catheters of appropriate size. While aperture 49 is shown as being generally rectangular, it can, of course,

also be any one of many other shapes as long as aperture 49 is

sufficiently large to easily receive the aforementioned medical products.

Aperture 49 may have a notch along one side thereof to facilitate

disposal of waste products have standard Luer fittings or adapters. Once these products have passed through aperture 49, second lid 46 may be used to seal aperture 49 and prevent inadvertent spillage of infectious medical waste.

Second lid 46 is pivotably mounted to one end of cover 40 via a

second hinge 48. Second lid 46 is preferably integrally formed with

cover 40 and second hinge 48 is preferably sized and shaped to provide a durable, yet flexible, hinge for repeated usage. Thus, to provide access to oversized aperture 49, second lid 46 is pivoted away from

aperture 49. Similarly, aperture 49 can be closed by pivoting second

lid 46 toward cover 40. For allowing temporary closure, second cover

46 may have any suitable means, such as detents, which snap-fit into complementary elements on cover 40. Aperture 49 can be permanently

closed by pivoting second lid 46 toward cover 40 and slipping a lock-

tab 47 into a lock-slot 47'. This would be done, for example, once the

infectious medical waste has substantially filled sharps receptacle 20.

Cover 40, as noted above, also includes auto-release structure 60. Structure 60 preferably includes needle passage aperture 64

disposed between, and in spaced relation to, guide walls 61 and 65 or

posts 66 - 68. As can be seen from Figure 3, which is a further

showing of the receptacle of Figure 1 , first guide wall 61 is preferably generally arc-shaped and second guide wall 65 is preferably generally U-shaped. The concave portions of first and second guide walls 61 and

65 face one another and are sized and shaped to receive one end of

holder 80. Needle passage aperture 64 is preferably large enough to

easily pass hub 83, but small enough to prevent holder 80 from passing therethrough. First guide wall 61 has a concave inner surface 62 which faces inner surface 66 on second guide wall 65. Further, as clearly

shown in Figure 4, first guide wall 61 has a chamfered edge 63 which

extends downwardly and inwardly from the top of guide wall 61 .

Similarly, second guide wall 65 has a generally U-shaped chamfered

edge 73 extending downwardly and inwardly from the top of guide wall 65. First and second chamfered edges 63 and 73 function as guides to insure proper orientation of holder 80 when holder 80 is initially inserted

into auto-release structure 60. Upon further downward movement of

holder 80, shoulder 69, which is preferably of uniform rectangular cross-section passes through recess 92 (Fig. 2) of end cap 90 thus positioning guide wall inner surfaces 62 and 66 adjacent the outer

surface of holder 80. Since shoulder 69 only extends up to the bottom

chamfered edge 73, release of actuation mechanism 82 only begins at this point. Upon further downward movement of holder 80, shoulder

69 enters actuator channel 85. This keyed alignment between shoulder

69 and channel 85 further ensures appropriate and exclusive operation

between auto-release structure 60 and holder 80. Still further downward movement of holder 80 forces the top edge shoulder 69 to

ride along sloped face 87 of channel 85 whereby actuator 84 is cammed toward body 81 of holder 80 in a direction which is substantially perpendicular to the axis of holder body 81 . This camming action may be achieved, after contact is established between

shoulder 69 and face 87 of actuator channel 85, by imparting a rocking motion to holder 80. The holder thus does not have to be moved axially

with respect to aperture 64 but, rather, needs merely to engage guide wall surface 62 to permit the hub release action to be initiated . The

inward movement of actuator 84 causes actuation mechanism 82 to

detach a hub 83 previously mounted to holder 80. Thus, hub/needle

combination is free to fall through needle passage aperture 64 into

sharps receptacle base 30 under the force of gravity.

Central needle passage aperture 64 is preferably large enough to easily pass hub 83, but small enough to prevent holder 80 from passing

therethrough. In the embodiment of Figures 6 and 7, positioned jn a circular spaced relation to needle passage aperture 64, three protruding

posts 66, 67, 68 extend substantially perpendicularly from cover 40.

The height of these posts is sufficient to operatively engage the holder

activation mechanism. The width of each of posts 66, 67, 68 is sufficiently narrow to pass through recess 92 of end cap 90, into

actuator channel 85. This keyed alignment between the posts 66, 67,

68 and the channel 85 further ensures appropriate and exclusive

operation between the auto-release structure 60 and holder 80. As

illustrated in Figure 7, holder 80, shown in hatching, has been positioned relative to auto-release structure 60 such that, upon downward movement of holder 80, two posts 66, 68 will guide and orient the holder 80 so that hub 83 will extend through aperture 64 while the third post 67 enters channel 85 and contacts the hub

actuator 84 on its sloped cam surface 87.

Similar to second lid 46, first lid 42 is pivotably mounted to cover

40 via first hinge 44. First lid 42 can be used to selectively open and

close both needle passage aperture 64 and unwinder aperture 50 by rotation about first hinge 44. For allowing temporary closure, first

cover 42 may have any suitable means such as detents which snap-fit

into complementary elements on cover 40. As with second lid 46, first

lid 42 includes a lock-tab 43 which is sized and shaped to engage lock-

slot 43' to permanently seal needle passage aperture 64 and unwinder

aperture 50. Lid 42 is preferably integrally formed with cover 40 and hinge 44 is sized and shaped to provide a durable, yet flexible, hinge for

repeated usage.

Cover 40 is preferably permanently affixed to base 30 (Figure 1 )

at a rim 41 in snap-fit fashion. Cover 40 is engaged by base 30,

preferably at rim 41 , with sufficient strength that cover 40 cannot be removed from base 30 without causing substantial damage thereto.

Cover 40 and base 30 are individually injection molded from a suitable

plastic material. These components may, however, vary in certain

respects. For example, base 30 is preferably formed of a red opaque

material. By contrast, cover 40 is preferably formed of either a translucent or transparent material. This allows health care workers to monitor the amount of accumulated waste material inside sharps

receptacle 20. Medical waste level monitoring may be further assisted

by the presence on base 30 of a fill-line (not shown) extending around

the surface of base 30. Thus, by forming cover 40 of translucent material, and by the inclusion of a fill line on base 30, a health case worker may easily determine when sharps receptacle 20 is sufficiently

full. When sharps receptacle 20 has become sufficiently full with waste

material, a health care worker may permanently seal sharps receptacle

20 by closing covers 42 and 46 and slipping lock-tabs 43 and 47 into

lock-slots 43' and 47' respectively. Thereafter, the sealed sharps receptacle 20 can be discarded in an appropriate manner as a single

unit. It should be noted that, since guide walls 61 and 65 preferably

extend upwardly from cover 40, more medical waste may be received within base 30 relative to prior art sharps receptacles having release

mechanisms located within the interior of the sharps receptacle. Thus,

the present invention more efficiently utilizes the space available for

receiving medical waste.

Referring again to Figure 4, the cooperation between needle

holder 80 and auto-release structure 60 in the embodiment of Figures 1 and 3 will be described in still greater detail. In Figure 4, cover 40 is depicted in partial cross-section taken along line 4-4 of Fig. 3. Holder

80, by contrast, is shown in side elevation view. As shown in Figure

4, holder 80 has been partially placed into auto-release structure 60 in the direction of arrow A. Channel 85 and shoulder-access recess 92, shown in phantom, are in engagement with shoulder 69 such that actuator 84 has experienced some minimal movement in the direction

of arrow B. In this position, hub 83 has not yet become detached from

actuation mechanism 82. Upon further movement of holder 80 in the

direction of arrow A, end cap 90 will come into abutting relationship

with cover 40 at the bottom of first and second guide walls 61 and 65.

At this time, actuator 84 will have moved in the direction of arrow B,

i.e., channel 85 will have moved to the position where shoulder 69 has reached the end of channel 85. In this position, hub 83 is detached from actuation mechanism 82 and is free to fall from holder 80 into

base 30 of sharps receptacle 20 (Figure 1 ) in the direction of arrow A.

Upon removal of holder 80 from auto-release structure 60 in a direction

opposite of that of arrow A, holder 80 resumes its normal configuration,

as shown in Figure 2, and is ready for reuse. The operation of the embodiment of Figures 6 and 7 is, of course, substantially identical to

the above-described operation of the Figures 1 and 3 embodiment.

It will be readily appreciated by one of ordinary skill that the

present invention incorporates a number of safety features not present in the prior art. First and foremost is that holder 80 and both disclosed

embodiments of auto-release structure 60 are specifically designed for use with one another. For example, end cap 90 of holder 80 effectively

precludes movement of actuator 84 when holder 80 is inserted into non-compatible disposal containers, such as containers of the type having a generally conical opening. Thus, health care workers are effectively prevented from attempting to use holder 80 with

incompatible sharps containers. Similarly, the arrangement of first and second guide walls 61 and 65, or the array of posts 66 - 68, and

rectangular shoulder 69 effectively prevents auto-release structure 60 from being used with other needle holders. Thus, while holder 80 can

be hand-operated, the exclusive compatibility between holder 80 and

auto-release structure 60 ensures that experimental combinations of

components is precluded.

The cooperation between holder 80 and auto-release structures

60 significantly improves the reliability of the hub detachment operation. For example, the sizing, spacing and arrangement of first

and second guide walls 61 and 65 or posts 66 - 68 and rectangular

shoulder 69 ensures that actuator 84 is sufficiently, but not overly, depressed each time holder 80 is fully placed into auto-release structure 60. This ensures proper detachment of hub 83 from holder 80 while

extending the life of holder 80 by preventing over-stressing of actuation

mechanism 82. Similarly, the sizing and location of needle passage

aperture 64 ensures that holder 80 will never pass into or become

lodged in sharps receptacle 20. This arrangement also ensures that a health care worker can easily recognize when the needle detaching procedure has been completed. Similarly, the first and second chamfered edges 63 and 73 in the embodiment of Figures 1 and 3 help ensure proper alignment between holder 80 and first and second guide walls 61 and 65. This feature further enhances the speed and accuracy

of the hub detachment operation. Thus, successful hub detachment is

virtually ensured using the methods and apparatus of the present invention.

Having described two preferred embodiments of the present

invention with reference to the accompanying drawings, it will be

appreciated that various changes and modifications can be effected

therein by one of ordinary skill in the art without departing from the

spirit and scope of the invention as defined in the appended claims.