Technical Field This invention relates generally to methods and apparatus for collecting and treating medical waste materials, and more particularly to methods and apparatus for decontaminating and rendering infectious solid and soft medical waste items handleable, and to medical waste collection stations providing a plurality of medical waste containers which may be filled sequentially.

Background Art There are many medical facilities, large and small, where there is a need for improved medical waste collection and disposal. It is particularly desirable to collect medical waste at the site of its creation and to decontaminate the medical waste promptly and effectively without exposure of personnel to the medical waste.

Medical waste collection stations have been provided in hospitals, clinics, doctors' offices and other health agencies for the collection of medical waste as it is generated. Such medical waste collection stations have in the past included but a single container with a limited capacity for medical waste and have caused inconvenience and exposure to risk when a user, faced with a filled medical waste container, would be unable to dispose of medical waste, such as a used hypodermic needle, at the locale at which it was used. Under such circumstances, the user frequently had to carry the medical waste and used hypodermic needles to other remotely located medical waste containers, thereby exposing himself and others to the possibly infectious and toxic medical waste in violation of safety regulations.

Large and expensive systems for the decontamination and disposal of medical waste have been available for hospital use, but no satisfactory small and affordable system for the collection and decontamination of medical waste has been available for use in such small medical facilities as doctor's and dentist's offices. Medical waste from a physician's or a dentist's office for which safe disposal is needed, includes not just hard items, such as needles, syringes and vials, but also soft and fibrous items, such as bandage material, tongue depressors and rubber gloves. The existing prior art decontamination equipment, in a size suitable for portable, desk-top or counter-top use in a small medical facility, cannot suitably handle such a variety of materials although it is desirable to avoid the necessity of sorting such medical waste before decontamination and disposal.

A number of other problems attend the use of currently available medical waste collection and treatment systems. Overfilling of collection containers is a common problem and programs for the periodic replacement of medical waste containers frequently results in under-utilization of container capacity. With many wall-mounted collection stations it is difficult to determine the fill status of the container and to insert medical waste into the container. Undesirable handling of contaminated medical waste is required in collecting and decontaminating medical waste in even large medical facilities, such as hospitals, and no small, affordable and effective medical waste collection and treatment system exists for small medical facilities.

Disclosure of the Invention

The invention provides a method and apparatus for the collection and treatment of contaminated medical waste, including such solid items as syringes and needles, glassware, tubes, vials, culture plates and specimens, and disposable scalpels, and such soft and fibrous materials as gloves and masks. This invention permits the collection of such medical waste at the point and at the time of its generation in a container, which cannot be pierced or torn by the solid waste and in which the waste can be subsequently transported, pulverized and disinfected for easy disposal on site.

The invention eliminates repeated handling of the medical waste and the associated danger of the inadvertent transmission of infectious diseases resulting from the handling of such waste. The invention permits these substantial safeguards to be enjoyed by those personnel working in doctor's and dentist's offices and smaller clinics, which often do not have access to proper medical waste processing facilities, without unnecessary expense and duplication of apparatus.

The apparatus of the invention provides a separate portable processing chamber, with an integral means to treat medical waste, that can be used at locations remote from its power unit for the collection of medical waste and then moved to the remote location of the power unit to drive the waste- treatment means within the chamber for pulverizing and decontaminating the medical waste within the chamber without danger to medical or operating personnel.

The apparatus of the invention comprises a separate waste collection and processing assembly including a closable chamber for the collection,

pulverization and decontamination of medical waste. A rotating waste treatment system is preferably carried within the chamber by bearings spaced on a supporting cylinder that is carried by the chamber bottom around a centrally located aperture through which the rotating system is driven. The rotating waste treatment system includes a plurality of pivotable blades that are carried by a rotating hub and have a configuration which, in cooperation with the chamber walls, provides effective disintegration, pulverization and blunting of solid waste and cutting and mincing of soft and fibrous waste, and the circulation and decontamination of the medical waste within the separate chamber. An inner surface configuration of the chamber provides surfaces coacting with the rotating blades to destroy the waste material and effectively directs the waste during its destruction and decontamination. Furthermore, the separate chamber is self-cleaning and provides collection means from which the destroyed and decontaminated waste material may be easily poured. The rotating hub assembly of the apparatus of this invention includes a ring that extends outwardly from the rotating hub from its lower end to prevent soft and fibrous waste from being carried under the hub. The rotating hub assembly can also be provided with a pair of slots formed in its outer surface in which the blades are pivotally attached. The slots preferably include a blade impingement surface adjacent the pivotal blade mounting, and extend away from the blade impingement surface in the direction opposite the rotation of the hub so that the blades can pivot partially within the hub in response to slow moving and stationary objects and are prevented from pivoting forwardly in the direction of rotation past

their mountings by the forward blade impingement surface of the slot. The rotating hub assembly further includes a container-breaking surface comprising a spike or tooth member, equipped with a metal or carbide tip, protruding upwardly and outwardly adjacent the top surface of the hub. In a preferred embodiment, the blades are pivotally secured within the slots formed in the outer surface of the rotating hub assembly by a rotatable axle pin extending downwardly through a bore provided through the hub assembly and a corresponding opening provided in the proximal end of the blade. The axle pin is secured in and prevented from removing itself from within the bore by a fastener. In a preferred embodiment, a plurality of baffle means on the interior sidewall are located and adapted for more effective treatment of differing portions of the medical waste. In the preferred embodiment, one abutment bar is located at a first selected height above the floor of the chamber to preferentially act on non-soft medical waste adjacent the top of the chamber during operation, and a plurality of abutment bars are disposed along the interior sidewall of the chamber at a second selected height, which is lower than the first selected height, to preferentially act on, in cooperation with the cutting blades, soft and fibrous medical waste adjacent the bottom floor of the chamber during operation. In addition, a radially extending surface can be provided in the waste treatment chamber sidewall which is positioned to direct waste material at the lower abutment bars for destruction by the coaction of the abutment bar surfaces and the pivotable blades of the rotating waste treatment assembly.

A further alternative hub can be provided with an outer, generally frustoconical surface, an outwardly extending ring adjacent the lower edge of the hub member and curved fins extending outwardly from the opposite sides of the outer surface of the hub and from near the top of the hub to the lower ring. This alternative hub may be used to replace the rotating hub assembly and, in operation, effect the complete cleansing and decontamination of the soft medical waste.

Preferred apparatus can also include means for supporting and retaining the waste treatment assembly and any materials expelled from the waste processing chamber during operation, and for vibrationally isolating the waste treatment assembly and driving motor from the apparatus enclosure.

Such means can include a support plate to carry the waste treatment assembly, its driving motor and the base support for the waste treatment assembly, a pair of isolating straps to carry the support plate from the machine frame and a plurality of vibration absorbing mounts for carrying the support plate on the isolating straps. The base support for the waste treatment assembly can include means to engage the waste treatment assembly to prevent its rotation and can be formed to contain any spillage therefrom.

This invention further provides a multi-container medical waste collection station, that permits sequential access to and filling of multiple medical waste containers and provides notice when a medical waste container at a medical waste collection station is ready to be emptied. This embodiment of the invention provides first means for supporting a plurality of medical waste containers, each of which has an opening permitting the insertion of medical

waste, and second means, carried by the first means, for sequentially providing access to the openings of the medical waste containers, one after the other. Preferably, the second means comprises a movable element with a plurality of positions, each position of the movable element allowing access to the opening of one of the medical waste containers and preventing access to the openings of the others. Furthermore, in preferable embodiments of the invention, the first means carries indicia and the second means is operatively associated with the indicia to provide notice when one or more of the medical waste containers is ready,to be emptied.

A preferred medical waste collection station provided by this embodiment of the invention can comprise a station enclosure, as said first means, capable of supporting and enclosing at least two medical waste containers arranged side by side, with at least two waste containers being supported by the station enclosure with open tops below and adjacent a top opening of the enclosure. The station enclosure carries a movable means or element, as said second means, adjacent its top opening for limiting access by user to the open top of the single medical waste container through the top opening of the station enclosure. The movable means is movably carried by the station enclosure to provide a plurality of positions with each position providing access to a different single waste container and otherwise blocking access to the remaining waste containers. The movable means is preferably a cover slidably carried by the station enclosure at its top opening and slidable between its plurality of positions, each position of the movable cover closing a portion of the top opening of the station enclosure except over the

open top of a single waste container. In a preferred embodiment including two medical waste containers, the movable cover extends partially over the open top of the station enclosure, is engaged by a spring carried by the station enclosure and includes a latch portion extending downwardly from the movable cover. The movable cover is urged by the spring into a first position where it extends over one of the waste containers and exposes the open top of the other waste container and is movable to a second position where its latch portion is engaged, e.g. by a part of the first means or the top of the other container, to retain the movable cover in the second position and expose the open top of the one waste container. In this preferred embodiment, the station enclosure carries indicia exposed by the movable cover when the movable cover is in the second position.

In the invention the first means may be provided with a hypodermic needle-engaging surface adjacent the open top of one or more medical waste containers to engage a hypodermic needle and permit its disengagement from a syringe by a user and its insertion into an adjacent medical waste container without handling by the user. Other features and advantages of the disclosed embodiments and methods of the invention will be apparent from the drawings and more detailed description of the invention that follows.

Brief Description of the Drawings

Fig. 1 is a pictorial view of a portable waste treatment device of the invention;

Fig. 2 is an enlarged fragmentary vertical section through a portion of the cabinet taken at line

2-2 in Fig. 1 and viewed in the direction of the arrows and showing some interior details;

Fig. 3 is a fragmentary section taken at line 3-3 in Fig. 2 and viewed in the direction of the arrows; Fig. 4 is a section taken at line 4-4 in Fig. 2 and viewed in the direction of the arrows;

Fig. 5 is an end view of a blade taken at line 5-5 in Fig. 4 and viewed in the direction of the arrows; Fig. 6 is a perspective view of a strainer plug used in the practice of the invention;

Fig. 7 is a perspective view of a further embodiment of a rotating hub assembly of this invention; Fig. 8 is a top view of the rotating hub assembly of Fig. 7;

Fig. 9 is a perspective view of an alternative rotating hub provided in this invention;

Fig. 10 is a perspective partially cut-away view of a further embodiment of a medical waste treatment assembly provided by this invention;

Fig. 11 is an enlarged partial perspective view of the means by which the cutting blades of the processing chamber of Fig. 10 are secured to the rotating hub assembly;

Fig. 12 is an enlarged partial cross section of the point of attachment of the pivoting cutting blades to the rotating hub assembly of Fig. 11;

Fig. 13 is a top view of the inside of the cabinet of one embodiment of the invention to show the means to support and retain the waste treatment assembly and to handle any materials expelled from the waste treatment chamber during operation; and

Fig. 14 is a partial cross-sectional view of Fig. 13.

Fig. 15 is a perspective view of a medical waste collection station of the invention;

Fig. 16 is an exploded perspective view of the medical waste collection station of Fig. 15; Fig. 17 is a perspective view of the medical waste collection station of this invention in use with one of the containers filled with medical waste;

Fig. 18A and 18B are schematic side views illustrating how the medical waste collection station of Fig. 15 may be opened to gain access to the medical waste containers carried therein;

Fig. 19A-19D illustrate various embodiments of the indicia means of the invention;

Fig. 20 is an enlarged partial side cross section of the upper portion of the medical waste collection station of the invention showing the means by which the slidable cover of the depository assembly can be secured; and

Fig. 21 is an enlarged partial side cross section of the upper portion of a medical waste collection station of the invention showing an alternative means by which the slidable cover can be secured.

Description of the Preferred Embodiment For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would

normally occur to one skilled in the art to which the invention relates.

Referring now to the drawings in detail, and particularly Fig. 1, a floor-mounted, mobile unit 11 includes a main cabinet 12 mounted on the top of a cart 13 which is movable along the floor 14, being supported on four casters 16, one at each corner. Referring now to Fig. 3, and regardless of whether a mobile cart 13 or a stationary counter top is the site for the present invention, it will include a support 17 which, in the illustrated embodiment, is rectangular in shape, framing a central opening 18 in which the waste treatment device is mounted according to the present invention. For this purpose, a rectangular frame 19, typically metal, is provided with an outwardly extending perimetrical flange 21 (Figs. 2 and 4) and is mounted on the support 17 and may be secured to it in any suitable manner. The portions of frame 19 and flange 21 that are at the front of the machine are designated 19F and 2IF.

Frame 19 has a gusset 22 welded to it at each of the four corners of the frame. An isolation strap 23 having a front end 23F and rear end 23R is mounted to the frame gussets 22 at their respective ends by means of isolator couplings 24. An identical strap 25 and mounting arrangement is provided at the opposite side of the frame 19.

A motor mount plate 26 is mounted on top of the two straps, with four fasteners 27 securing each side of the plate to each of the two straps 23 and 25. In the illustrated example, the fasteners are socket head cap screws with nuts. This motor mount plate is generally U-shaped as shown best in Fig. 2. The motor 28, having a standard C-face 29, is fastened to the bottom center of the plate 26 by four socket head

cap screws 31. The motor shaft 32 extends up through a central aperture 33 in plate 26 and is provided with a slinger ring 34 immediately above the plate 26. The motor shaft has a standard square keyway to receive a standard square key 37 in coupling 38 to which the key is secured by set screw 39. The upper end of the coupling 38 is provided with a 1/2 inch square cross section at 41.

The outwardly turned front and rear flanges 26F and 26R, respectively, of the motor mount plate support the main cabinet 12. The cabinet has a front wall 12F, and a rear wall 12R and is molded in one piece of fiberglass reinforced plastic with a generally centralized tub portion 42 which is generally rectangular in configuration as shown by the front and rear walls 43F and 43R, respectively, and the sidewalls 43 in Fig. 4. The floor 43B of the tub is secured to the outwardly extending flanges 26F and 26R of the motor mounting plate by four fasteners 44 through each of the flanges, these fasteners typically being socket head cap screw and nut assemblies.

A hollow bulb gasket 46 is secured to the inside of the cabinet outer shell around the entire perimeter of the lower edge 47 of the shell. This gasket 46 lightly but sealingly engages the top surface of the support 17 entirely around the perimeter of the cabinet. However, it does not provide support for the cabinet since that is supported by the motor mount plate supporting the bottom 43B of the cabinet tub portion.

The flask assembly 51 of the present invention includes a flask lower housing 52 and flask top housing 53, both of which are symmetrical about the central axis 54. The flask lower housing has an outwardly turned upper circular flange 52U supporting

an O-ring 56 which supports the circular bead at the bottom of the flask top housing. The top and lower housings are fastened together by over-center lever operated spring clamps 57 such as are available from Dzus Fasteners of West Islip, New York 11795. The bottom of the flask lower housing has four circularly spaced feet 58 which are received in sockets 59 in the floor 43B of the cabinet tub portion. These feet support the flask assembly in the cabinet tub. They also prevent the flask assembly from rotating in the tub.

An impeller assembly 61 is mounted in the flask assembly. It is located and supported by a bearing mount cylinder 62 which is welded to the bottom of the flask lower housing at 63 around the central opening 64 in the flask bottom. This bearing mount cylinder receives the lower ball bearing assembly 66 and the upper ball bearing assembly 67. The inner race of each of these ball bearing assemblies fittingly receives outer cylindrical surfaces of the impeller shaft 68 which has an octagonal internal spline or socket at 69 received on the square upper end of the coupler 38. The upper portion of the impeller shaft has a sleeve 71 pressed thereon above the inner race of the upper bearing 67. This serves to engage a lip seal 72 which is secured in the outer race receiving bore of the impeller bearing mount cylinder 62. The upper end of shaft 68 is threaded at 73 and threadedly receives thereon the top 74 of the impeller which extends from the top down to the slinger flange 76 at the bottom and which is immediately above the bottom of the flask lower housing.

The cylindrical wall 77 of the impeller has two additional circular flanges above the slinger flange 76. These are the blade support flange 78 and

the blade hub cover flange 79. Two blades 81 are mounted in the annular groove 82 between the flanges 78 and 79 and pivotally secured in place by the pins 83 which are shoulder bolts screwed into the flange 78. The shape of these blades can be observed in Fig. 4 and Fig. 5. The blades are driven in the clockwise direction of arrow 86 in Fig. 4. Although the hub area of the blade is rectangular as shown in Fig. 5, the blade is tapered beginning at a line 87 (Fig. 4) to provide a sharp leading edge 88 while the trailing edge of the blade 89 is the full height of the hub area of the blade. The blade is preferably made of steel but tungsten carbide may also prove suitable. A "baffle" bar 91 is mounted on the inside upstanding cylindrical wall of the flask lower housing and extends up from near the bottom to a top edge 92. Thus, it presents a 90° angle edge 93 facing the materials as they are driven around by the impeller blades moving in the clockwise direction of arrow 86. Due to the inclination of the lower face of the blades 81 downward from the front or leading edge toward the rear or trailing edge, as the blades 81 rotate the trailing edge of each is closer to the bottom of the flask than is the sharp leading edge. This drives the waste materials downward and thus assures that they will be aggressively treated by the baffle bar 91 during operation.

A removable flask cap 96 is provided in the central opening 97 at the top of the frustoconical surface of the flask top housing. This cap 96 has a tapered wall 98 so as to be manually insertable to the point of a snug fit, but can be readily removed manually, if desired, by means of the outwardly directed circular flange 99 at the top of the cap.

The cabinet is provided with a lid 101 which is hinged to the upper rear wall 12R of the cabinet by adjustable hinges 102 such as the 500 Series marketed by Southco, Inc. of Concordville, Pennsylvania 19331. These hinges are adjustable so that the lid can be raised at the front end edge in the direction of arrow 102a and can remain in virtually any position up to vertical. The underside of the lid has an inwardly projecting bulge 103 therein which, when the lid is closed, engages the flask cap 96 and assures that the cap will remain securely closed in place on the flask top housing. A bulb gasket may be provided around the perimeter of the cabinet lid to seal against the cabinet top during operation. Referring to Fig. 6, a strainer cap 112 is shown.

It is similar to cap 96, having a tapered wall 113 and perimetrical top flange 114 but, instead of a solid bottom, the bottom 116 is a screen. It may also have a handle tab 117 at the top flange. Referring again to Figs. 1 and 2, a control group 104 is provided on a boss 106 at the front of the cabinet and includes a momentary contact "ON" switch 107, and "EMERGENCY STOP" switch 108, and a pilot light 109 illuminated when the operating cycle is in progress. These are associated with suitable electrical circuitry to control the motor as desired. The circuitry is not shown herein as it may be conventional and well within the skill of the art. Referring again to Fig. 4, a pair of T-type handles 111 may be provided on the side of the flask lower housing for a purpose which will be described now.

Mode of Operation

The flask assembly is removable from the main cabinet by simply lifting the cabinet lid and lifting the flask assembly out of the cabinet by use of the T-handles, one in each hand. The flask assembly can be easily lifted off the coupler and moved to whatever site location is convenient for depositing medical waste material therein, which is typically wherever such material is being generated. Of course, if the unit is mounted on a moveable cart as in Fig. 1, the cart can be simply pushed to the site without removing the flask assembly from the cart. With the top cap 96 pulled out of the top of the flask assembly, the waste material can be simply dropped into the flask assembly through the opening 97. The opening has a sufficient diameter, four inches, for example, to readily receive syringes, bandage material, rubber gloves, culture plates and vials, for example. Such waste materials can be dropped directly into the opening 97 as they are produced, or they can be put into another container and then transferred later to the flask. For example, as a bandage is removed from a subject, the bandage materials can be placed directly into the flask. When the flask assembly has been filled to a level about even with the top of the flask lower housing or bowl 52, and if the flask assembly is separate from the main cabinet, it can then be returned to the main cabinet and placed on the cabinet tub bottom with the four feet 58 aligned within the pockets 59. Simultaneously the impeller shaft socket is received on the coupler square 41. Water is then poured through the top opening 97, a pouch of decontaminant is added, and the top cap 96 is installed and the cabinet lid is closed. The start switch 107 is then pushed past the lid and may

thereupon be locked by an automatic electrically operated lid latch (not shown) . The motor is now energized which drives the impeller, which in turn drives the blades in a clockwise circular path as shown by reference arrow 86 in Fig. 4 around the impeller axis. As the blades are driven, they begin to cut-up the waste material in the housing.

Although the materials provide some resistance to the action of the blades, the combined effects of the sharp leading edges 88 of the blades and of centrifugal force keep the blades deployed in a substantially radially outward, extending direction to continue to cut up the waste material. As this occurs, the slinger flange 76 at the bottom of the impeller assembly keeps the material moving outwardly and upwardly around the curved outer portion 55 of the flask lower housing wall 52. Thus, the material is kept moving in a path outward and upward along the wall and then back down into the cutting path of the blades. In addition, the presence of the vertical block (baffle) 91 provides an abutment which, to materials moving in the clockwise direction, presents a relatively sharp edge. Baffle 91 also inhibits the free circular flow of material around the inner wall of the flask lower housing, tending to knock or direct the material back into the cutting path of the blades. Thus, the baffle 91 facilitates the destruction of sharp items and facilitates the cutting and tearing of soft materials. The processing continues as long as desired until it is either stopped by expiration of the "run" period of an automatic timer, or is manually stopped by pushing the emergency stop pad 108 to simply end the desired cycle. The pilot light serves as an indicator that a cycle is in process. This light may remain on

for several minutes after the processing is complete in order to indicate to the operator that it is not yet time to open the lid because, among other possible reasons, the contents may not have yet settled. When the pilot light goes out, the operator can then open the lid, grip the T-handles, pull the flask assembly out of the tub of the main cabinet, and transport the flask to a sink. The cap 96 is then removed and replaced by the strainer 112 in the opening 97. Then the flask assembly is inverted in the sink, and the decontaminant solution, together with any other liquids which were contained in the waste material are drained into the sink. Then the flask assembly is righted and moved over to a solid waste receiver bucket or bag or the like, and the processed waste materials are dumped into the receiver for subsequent disposal in a conventional waste container.

As an alternative procedure, instead of using the strainer, the flask assembly can be dumped, liquids and solids simultaneously, into a disposable bag containing a liquid-absorbent gel compound. In this scenario, the flask is righted and ready for return to the waste generation site for collection of more waste.

With a machine built according to the present invention, in addition to the mincing action on materials, needles are bent and blunted as they are driven into the baffle 91. If it is ever desired to do so, the flask can be washed out without taking it apart, just as one could wash out a vase or bowl. If ever desired, such as for servicing interior components, the flask upper and lower housing can be separated by releasing the spring clamps 57. After servicing, they can be re-assembled, clamped together,

and the flask assembly can be returned to the waste generation site for use again as described above.

As an example, the chamber-forming flask components can be made of spun stainless steel. Many of the more dense components, such as the impeller bearing mount cylinder, the impeller shaft, and the impeller itself, can be stainless steel investment castings. For a flask assembly that will hold and process approximately one-two gallons of medical waste materials in their final processed state, a drive motor of two horsepower is useful to complete a processing of that much material within a two to three minute cycle. A rotational speed of about 3450 rpm is advisable for effective destruction of the solid and soft medical waste identified above. Examples of suitable decontaminant solutions are a one ounce package of "A-33" dry decontaminant powder as marketed by Airkem Professional Products of St. Paul, Minn, and an Iodophor disinfectant compound sold by Ecolab, Inc. at Minneapolis, Minnesota under their trade name

"Mikroklene". Dumping of treated waste from the flask can be into a plastic bag of appropriate size and at least 3 mm. membrane, and preferably an eight gallon, double ply plastic bag, which contains a polymeric absorbent powder which develops a gel as it absorbs the liquid. The bag preferably has a drawstring for convenient handling and can be placed in a conventional trash or garbage container. Although the description refers to a one-gallon flask or chamber, it should be appreciated that the present invention can be applied to larger or smaller size apparatus. A further preferred impeller hub assembly 261 suitable for use with this invention is shown in isolation in Figs. 7 and 8. Impeller hub assembly 261 is located and supported within the flask housing in

identical fashion as impeller assembly 61 shown and described in relation to Fig. 2. Hub assembly 261 is formed with an upper portion 263, a middle portion 265, and a lower portion 267. Hub assembly 261 further includes a ring 285 disposed at the lowermost portion 267 to prevent soft medical waste from being carried under hub 261 while it rotates. Upper portion 263 preferably includes an inclined wall 277 and lower portion 267 preferably includes a cylindrical or vertical wall 284. An annular shoulder 279 is disposed normally to the axis of rotation of hub 261 and an inclined frustoconical wall 282 is disposed in middle portion 265 interconnecting shoulder 279 and vertical wall 284. A pair of blades 281 (only one blade is shown in

Fig. 7) are pivotally mounted to the hub 261 at diametrically opposed locations on the sides of the hub 261 adjacent its lower portion 267 within recessed slots 290 provided in wall 284. Blade 281 is identical to blades 81 shown and discussed above.

Blades 281 are pivotally secured by pins 283 formed by shoulder bolts extending through a receiving hole (not shown) provided near the inner or proximal end of the blade 281 and screwed into the lower surface 292 of slot 290. Bolts 283 are received in a recessed area 283' provided in the middle portion 265 of hub 261.

As shown in Fig. 8, slots 290 are formed in the sidewall 284 of hub 61 and extend inwardly toward the center of hub 261. Slots 290 include first forward impingement surfaces 293 and a second rear impingement surfaces 291. When the hub 261 is rotating in the direction shown by reference arrow 286 (clockwise) , the pivotal blades 281 are urged to pivot outwardly along path 281' by centrifugal force to the extended position shown in Fig. 8. The blades 281 are

prevented from pivoting forwardly in the direction of rotation (arrow 286) substantially past a reference line 281a extending radially outwardly from their pivotal mountings by the forward impingement surface 293 engaging the leading edge of blade 281. Upon contact with stationary or more slowly moving waste material, the blades 281 can pivot rearwardly along reference path 281' where they can be partially received within slots 290 and the following edge of blade 281 impinges upon the second rear impingement surface 291 of slot 290.

Hub 261 shown in Figs. 7 and 8 can further include means for breaking waste-carrying containers introduced into the waste treatment chamber. Such container-breaking means can comprise a spike or tooth-like member 300 equipped with a carbide metal tip and protruding upwardly and outwardly adjacent the outer edge of top surface 274 of the hub assembly 261. Spike 300 is effective in disintegrating waste- carrying containers made of thin polystyrene.

This invention provides a further alternative hub 361, shown in Fig. 9. The alternative hub 361 may replace the rotating hub assemblies described above when it is desirable to simply wash or decontaminate the soft medical waste with a decontaminant prior to its disposal. Alternative hub 361 includes a generally frustoconical outer surface 363, a pair of fins 367 extending outwardly from the outer surface 363 of the hub 361, and a ring 365 extending outwardly from adjacent the lower edge of the outer surface 363. Ring 365 prevents the soft medical waste from being carried under the rotating hub 361, and also prevents waste materials from sitting idly on the bottom of the chamber during operation and thereby evading the washing and decontaminating action of hub

361. Fins 367 are disposed diametrically on opposite sides the outer surface 363 of hub 361 and partially form spiral-like surfaces 367a from adjacent the top surface 374 of hub 361 to the lower band 365. Each fin 367 has an upper tip 368 extending vertically above the top surface 374 of hub 363 adapted to tear open plastic refuse bags that are commonly used to tote soft medical waste, and to prevent materials from remaining idly on the top surface 374 of hub 361 while in operation. Thus, hub assembly 361 can effect the medical cleansing and disinfecting of soft medical waste.

Reference will now be made to Figs. 10-12 which show an even further embodiment of a waste treatment assembly, or processing flask, 451 and an impeller hub assembly 461 provided by this invention. The flask assembly 451 of this further embodiment includes a flask lower housing 452 and a flask top housing 453, which is arranged atop flask lower housing 452. The flask lower housing 452 has an outwardly turned upper circular flange 452U supporting the flask top housing 453 on a seal member (not shown) , which seals against a circular bead at the bottom of the flask top housing 453. The top and lower housings are fastened together by over-center lever-operated spring clamps 457.

Referring now to Figs. 13 and 14, the bottom of the flask lower housing has four circularly spaced feet 458 (only three of which are shown in Fig. 10) which are received on an annular chamber base plate 590. These feet support the flask assembly 451 on base plate 590 within the cabinet tub 591, and also prevent the flask assembly from rotating or climbing out under torque by pressing against stops 592 while operatively disposed within the cabinet tub. The annular chamber base plate 590 also features outer and

inner liquid containment dams 590a and 590b, respectively, that retain spillage that may occur from the flask 451. The outer edge of the dam 590a extends beyond the opening in the cabinet tub 591a so that leakage into the cabinet tub 591 will fall into the chamber base plate 590. Liquids will drain through drainage tube inlet 593 into drainage tube 594 and be directed by a hose to a collection reservoir at the back of the cabinet. Referring again to Fig. 10, the flask top housing

453 further includes a cap or top 402 positioned atop and fastened via clamps 457' to the top housing 453 enclosing its upper opening. A cap liner 404 is affixed to the underside of cap 402 to prevent waste material from clinging to the underside of cap 402. A plenum-like space 406 is formed between cap liner 402 and liner 404. Cap liner 402 is formed by a gas- permeable material that permits the flask 451 to breath through HEPA valve 408 in response to heated moist air through the entire cap liner 402.

A pair of T-type handles 411 can be provided on the side of the flask lower housing 452 for removal of the flask assembly 451 from the main cabinet 591 by simply lifting the cabinet lid and lifting the flask assembly out of the cabinet by use of the T-handles, one in each hand. The flask assembly can be easily lifted off the coupler and moved to whatever site location is convenient for depositing medical waste material therein typically being generated. An impeller hub assembly 461 is mounted in flask assembly 451 supported by a bearing mount cylinder assembly substantially similar to the manners in which hub assemblies 61, 261, and 361 are mounted to their respective flask assemblies as described above. Accordingly, those details need not be repeated here.

Impeller hub assembly 461 is constructed in a substantially similar fashion to hub 261 shown and described in relation to Figs. 7 and 8 and includes an upper portion 463, a middle portion 465 and a lower portion 467. Hub assembly 461 further includes a ring 485 disposed at the lowermost portion 467 to prevent soft medical waste from being carried under hub 461 while it rotates. Upper portion 463 preferably includes an inclined wall 477 and lower portion 467 preferably includes a cylindrical or vertical wall 484. An annular shoulder 479 is disposed normally to the rotation axis of hub 461 and an inclined frustoconical wall 482 is disposed in middle portion 465 interconnecting shoulder 479 and vertical wall 484. Two blades 481, driven in the direction (clockwise) of reference arrow 486, are mounted in recessed slots 490 formed in wall 484 and each is pivotally secured in place by a pin 483 and shoulder bolt 520, which are discussed in further detail below. Blades 481 are similarly shaped to blades 81, 281 and 381 as described above and their shape can be better observed in Figs. 4 and 5. As noted above, the blades of this invention are preferably made of a steel alloy, such as tool steel. During treatment of medical waste in a rotating pulverizing apparatus such as provided by the invention, it has been discovered that medical waste may be more effectively treated with a plurality of baffle means, each baffle means being located within the chamber and adapted for more effective treatment of differing medical waste. To more effectively treat the hard waste portion (e.g., medical sharps and the like) of the medical waste within the processing chamber, a first baffle means defined by an abutment bar 491 can be mounted on the inside upstanding

cylindrical wall 452a of the flask lower housing 452 above the floor of the housing with its top 492 adjacent the top of the lower housing 452. Baffle bar 491 presents a 90° angle edge 493 facing the materials as they are driven around by impeller blades 481 moving in a clockwise direction (as shown by reference arrow 486) . Baffle bar 491 is disposed in this embodiment higher above the rotating blades 481 than the arrangement of abutment bars 91 shown and described in relation to Figs. 2 and 4. Baffle bar 491 is thus positioned to more effectively blunt and fractionalize the sharps and other non-soft waste traveling with the rotating mass within the chamber during operation. Baffle bar 491 stops rotation of the upper portion of the material within the chamber, allowing the material to fall into the path of the blades 481, enhancing the impact of blades 481 on the medical waste, and more effectively blunting and fractionalizing the non-soft waste. As discussed and shown in relation to Fig. 5 above, the lower face of the blades 481 are inclined downwardly from the front or leading edge toward the rear or trailing edge. Consequently, the trailing edge of each blade is closer to the bottom floor of the flask lower housing than is the sharper leading edge as the blade rotates. This arrangement has a tendency to initially drive the waste materials downwardly. To more effectively treat the soft portion of the medical waste, a second baffle means 500, defined by one or more baffle bars, can be mounted on the inside upstanding cylindrical wall 452a of lower flask assembly 452 adjacent the bottom floor thereof. In a preferred embodiment, six (6) baffle bars 500 can be employed in two groups of three, diametrically opposed to one another in a plane lower

than abutment bar 491, only one group of three being shown in Fig. 10. A radially inwardly extending deflector 510 is also mounted on the interior wall 452a for directing waste in a downwardly circulating motion into baffle bars 500 to facilitate its fractionalization and destruction. As shown in Fig. 10, deflector 510 is positioned to direct medical waste materials moving within the chamber to expose it particularly to the co-action of the baffle bars 500 and pivotal blades 481. Deflector 510 can be a ribbon of stainless steel having a thickness on the order of about 3/32 to about 3/16 of an inch and welded or otherwise fastened to the interior sidewall of the chamber in a downwardly extending direction from adjacent the upper portion of sidewall to adjacent the central portion of chamber sidewall 452. In preferred embodiments of the invention, the terminal portion 510a of deflector 510 is located "upstream" of the baffle bars 500 and their cutting edges 502 so that waste materials will, for example, leave the terminal portion 510a of deflector 510 with a high velocity directed at baffle bars 500, which provide a plurality of cutting edges at each of their respective corners 502 located only a small clearance distance from the ends 481a of the blades 481, as indicated in Fig. 10. The co-action of blade ends 481a and the cutting edges 502 of baffle bars 500 more effectively cut and tear soft medical waste material, such as those described above, into small pieces, while abutment bar 491 serves to more effectively fractionalize and dull non-soft medical waste of the type described above into a generally minced state.

The pair of blades 481 (only one blade is shown in Fig. 10) are pivotally mounted to the hub 461 at diametrically opposed locations of the hub 461

adjacent its lower portion 467 within recessed slots 490 provided in wall 484. As shown in Figs. 11 and 16, each blade 481 is pivotally secured by an axle pin 483 that extends through a bore 492a through planar surface 523 and the adjacent portion of hub 461, and through a receiving hole 481' provided in blade 481 near its inner proximal end, and is received at its lower end in a bore 492b formed in the portion of hub 461 adjacent the lower surface 492 of slot 490. Axle pin 483 is secured in place by a shoulder bolt 520 received in a recessed cove area 522 formed in part by planar surface 523 provided in portions 479 and 482 of hub 461 as shown best in Fig. 11. Shoulder bolt 520 includes a skirt 521 that extends partially over an upwardly facing surface 483b of pin 483 to secure the pin within bore 492a. Shoulder bolt 520 is threadably fastened in a threaded bore 524 formed in surface 523 of cove 522. Bore 524 must be located sufficiently near pin-receiving bore 492 so that when pin 483 is in bore 492, the skirt 521 of shoulder bolt 520 extends partially over the top end 483b of pin 483. It is understood that other means of securing pin 483 in bore 492a may prove suitable and are therefore contemplated by this invention. Axle pin 483 is preferably provided with a nipple

483a protruding upwardly above planar surface 523 of cove 522 when pin 483 is disposed within pin-receiving bore 492 to provide means for grasping pin 483 for removal. The portion of hub 461 adjacent its bottom underside surface 461a (Fig. 12) can further include means for dislodging pin 483 in the event one is unable to remove the pin 483 with nipple 483a. Such means can include a bore 461b extending through hub 461 from the underside 461a and opening into pin- receiving bore 492b to allow one to use a punch and

tap the pin 483 out of bore 492a from the underside. Pin 483 can also include a nipple (not shown) extending downwardly from its lower end and through or partially through bore 461b to facilitate the removal of pin 483 by tapping from the underside if desirable. Axle pins 483 are preferably formed from hardened stainless steel to provide a more durable assembly. For example, blades 481 may be formed from steel with a hardness of Re 60 for use with axle pin 483 formed from steel with a hardness of Re 55.

Slots 490 are formed in the sidewall 484 of hub 461 and extend inwardly toward the center of hub 461. As with blades 281 and recessed slots 290 shown in Figs. 7 and 8, each slot 490 includes a first forward impingement surface and a second rear impingement surface. When the hub 461 is rotating in the direction shown by reference arrow 486 (clockwise) , the pivotal blades 481 are urged to pivot outwardly by centrifugal force to an extended position. The blades 481 are prevented from pivoting forwardly in the direction of rotation (arrow 486) substantially past a reference line extending radially outwardly from their pivotal mountings by the forward impingement surface of recessed slot 490. Upon contact with stationary or more slowly moving waste material, the blades 481 may pivot along reference path 481' to be partially received within slots 490, where the trailing edge of the blade impinges upon the second rear impingement surface of slot 490. Hub 461 shown in Fig. 10 can further include a surface for breaking waste-carrying containers introduced into the waste treatment chamber comprising a spike or tooth-like member 530 equipped with a carbide metal tip and protruding upwardly and outwardly adjacent the outer edge of top surface 474

of the hub assembly 461. Spike 530 is effective in disintegrating waste-carrying containers made of polystyrene or other friable material.

The apparatus of this invention includes hub- mounting features permitting the rotating hubs to be interchanged with little effort. As noted, hub assemblies 261, 361 and 461 shown in Figs. 7-12, respectively, can all be interchangeably mounted and employed in the waste treatment apparatus of this invention described above and shown in Figs. 2 and 10. More particularly, as with the apparatus shown in Fig. 2, the apparatus of Figs. 7-12 includes a lower ball bearing assembly 166 and an upper ball bearing assembly 167 spaced several inches apart, and supported by, a bearing supporting cylinder 162, which is welded to the bottom of the flask assembly. The inner race of bearings 166 and 167 carry the impeller shaft 168. This assembly provides a rugged and durable rotatable support of the rotating waste destruction and treatment assembly (which includes pivotal blades 81, 281, and 481, and rotating fenders and surfaces 300, 530) , which must endure intense shock loads during operation. The combination of the pivotable blades, which are pivotally mounted intermediate the upper and lower bearings, and the spaced ball bearing support provided by the impeller shaft provide a waste treatment assembly which can endure the torturous abuse imposed by the combined effects of solid and/or soft medical waste being processed.

As shown in Figs. 13 and 14, the motor 128 is securely mounted at its upper end to a support plate 126. Support plate 126 can be carried by a plurality of vibration isolator couplings to the machine frame and vibrationally isolated from the walled enclosure.

As shown in Figs. 13 and 14, chamber base plate 590 is carried above support plate 126 by a plurality of tubular spacers 129 and fastened in place by a plurality of bolts 595. As indicated above the chamber base plate 590 includes a pair of stops 592 which are fastened to the upper surface of the chamber base plate 590 to engage the feet 458 of the flask 451. The stops 592 preferably each have a projecting pointed corner 592a which will sink into the elastomeric feet 458 of the flask and, in addition to preventing its rotation, will provide force molding the flask 451 against the chamber base plate 590. Annular chamber base plate 590 has a central opening 130 which permits a driving coupling 138 from the rotating shaft 132 of the driving motor to extend into the keyed opening of the impeller shaft of the particular rotating hub assembly employed with the system. Thus, unlike the embodiment illustrated in Fig. 2, the entire rotational waste treatment assembly and its driving motor are suspended by bracket from the machine frame within the walled enclosure and openable top (Fig. 1) by a vibration isolating structure. There is no mechanical connection between the sidewalls 43 of the centralized tub portion 42, 591 of the enclosure and the annular chamber base plate 590 or any other portion of the waste treatment operating apparatus, as there is in the embodiment of Fig. 2. (Motormount plate 26 of Fig. 2 is thus eliminated.) The opening 592 in the central portion of the apparatus enclosure 591 overlaps the outside dimension of the chamber base plate 590, but is separated by a gap, as shown in Fig. 14, so that the chamber base plate 590 may move with the motor and chamber freely while not contacting the central portion of the apparatus housing 591, so as not to

transmit vibration from the isolated portion of the apparatus to the stationary portion of the apparatus.

Thus, in the apparatus of the invention, vibration and sound can be trapped and deadened in an improved manner within the enclosure for the apparatus, and the operating portion of the waste treatment apparatus including the flask assembly, driving motor and the intervening supporting structure, are isolated from the enclosure by elastomeric sound and vibration deadening elements. The driving motor and waste destruction chamber are thus isolated from the apparatus housing.

Figs. 15-21 show a preferred medical waste collection station 610 of this invention. As shown in Figs. 15 and 16, the medical waste collection station of the invention includes first means 611 for supporting a plurality of medical waste containers 630, 631 and second means 620, carried by the first means 611, for sequentially providing access to the openings 630a, 631a of all but one of the medical waste containers 630, 631 as shown in Figs. 15 and 17.

The second means 620 preferably comprises movable means with the plurality of positions, each position of the movable means 620 allowing access to an opening 630a, 631a of only one of the medical waste containers 630, 631 while preventing access to the others.

In the preferred medical waste collection station in Figs. 15-21 the first means 611 supports the plurality of medical waste containers 630, 631 with their open tops 630a, 631a lying generally in a horizontal plane, and carries the second means 620 over open tops 630a, 631a of the medical waste containers 630, 631. As shown in Figs 15 and 17, the second means 620 can preferably comprise a cover

movably carried by the first means 611 over the horizontal plane generally including the open tops 630a, 631a and providing a plurality of positions, and the movable cover 620 provides access to the open top of a different medical waste container in each of the plurality of positions.

As indicated in Fig. 17, the first means 611 carries indicia 613 and the movable cover 620 is operatively associated with the indicia to provide notice when at least one of the medical waste containers 631 is full and ready to be replaced. As further indicated in Fig. 16 and 18A, the first means 611 includes a flat wall portion 614 which can be fastened to the building wall in an area where medical waste is generated.

In the preferred medical waste collection station 610 of Figs. 15-18, the first means preferably forms a station enclosure 611 capable of supporting and enclosing at least two medical waste containers 630, 631 arranged side by side. More particularly, first means 611 preferably includes, as shown more clearly in Fig. 16, a base portion 611a for carrying containers 630, 631 and their lids 630b and 631b, respectively, a shell portion 611b hingedly carried by base portion 611a, a cover plate 611c carried within a top opening 611d provided in shell portion 611b, and cover 620 slidably carried by plate 611c. If desired, a curved lower base portion or bottom facia 6lie can be included. Shell portion 611b can be lockably secured by a key lock 612a carried thereon and adapted to be received in a lock-receiving slot 612b provided in base portion 611a and is hingedly carried at a pivot axis 611b and is movable, as shown by reference arrow 623, in Figs. 18A and 18B, between an open position (Fig. 18A) and a closed position (Fig. 18B) .

In the open position as shown in Fig. 18A, medical personnel can access and remove the medical containers

630 and 631 carried therein, place the lid on the container (e.g., lid 631b on container 631), and transport the container filled with medical waste to the waste treatment apparatus of the invention. An empty container can then be placed in the collection station base portion 611a. The medical waste containers 630, 631 are supported by the station enclosure 611 with their open tops 630a, 631a below and adjacent to the top opening 611a provided in shell 611b. The second means, or movable cover, 620 is preferably slidably carried by the station enclosure 611 adjacent top opening 611d. The movable second means, or slidable cover, 620 is movable between a plurality of positions on plate 611c, with each position allowing access to a different single waste container 630, 631 through a plurality of separate depository openings 614 and otherwise blocking access to the other of the waste containers 630, 631. In Fig. 15, where the two medical waste containers 630,

631 are supported side by side, with their open tops 630a, 631a lying generally in a plane below the slidable cover 620, the slidable cover 620 is in a position over the open top 631a of container 631 and is slidable to a second position, where it exposes the open top of container 631 while covering the open top 630a of the other medical waste container 630.

Referring now to Fig. 20, in the medical waste collection station 600 of the invention the slidable cover 620 is engaged by a spring 615 which is coupled to and bears against a surface of the station enclosure 611 at one end and against a surface of the slidable cover 620 at the other end and is compressed between the engaged surfaces of the slidable cover 620

and the station enclosure 611 at all positions of the slidable cover. The slidable cover 620 can include a latch 632 extending downwardly from the slidable cover 620 and coupled thereto by a latch pivot post 634, which in turn is carried by a latch yoke 636 affixed to cover 620. Latch pivot post 634 is also coupled to one end of spring 615. The slidable cover 620 is urged by the spring 615 into a first position, at the right as shown in Fig. 15, where it extends over the open top 631a of one waste container 631 and exposes the open top 630a of the other waste container 630. When waste container 630 is filled, as depicted in Fig. 17, a user slides the slidable cover 620 to the left, as indicated by arrow 22 of Fig. 17, to its second position, where the latch 632 engages a stationary post 638 disposed on rear wall 611a, as shown in Fig. 20, to retain the slidable cover in the second position and to expose the open top 631a of waste container 631 through depository opening 614 of plate 611c. While the spring 615 is described as a compression spring, a tension spring can also be used with this invention with slight modification.

As shown in Fig. 17, the station enclosure 611 carries indicia 613 carried by cover plate 611c which is exposed when the second means, or slidable cover, 620 is in the second position (at the left of Fig. 17) . Indicia 613 may be a brightly colored panel in red or yellow or in fluorescent (Da-Glo) colors, and the indicia 613 may be provided with lettering as shown in Fig. 17. The indicia 613 provides notice that when the second means, or slidable cover, 620 is in the second position, the first medical waste container 630 is full and ready to be replaced with an empty container.

Indicia means 613 may take several forms as shown in Figs. 19A-19D. In Fig. 19A, the indicia means may include a flip-up spring steel indicator 613a affixed to plate 611c that is urged to an "up" position as shown in Fig. 19A when cover 620 is moved in the direction of reference arrow 622. In Fig. 19B, the indicia means may include a brightly colored indicator strip or panel 613b as shown and discussed in relation to Fig. 17. In Fig. 19C, the indicia means may include a pop-up indicator flag 613c that is urged to an up position as shown in Fig. 19C when cover 620 is moved in the direction of reference arrow 622. In Fig. 19D, the indicia means can include a pop-up indicator button 613d that is urged to an up position as shown in Fig. 19D when cover 620 is moved in the direction of reference arrow 622.

As noted above, the back wall 611a of station enclosure 611 is preferably flat and provides means, such as slots or other screw fastener openings 611h, permitting the medical waste collection station 610 to be fastened to a building wall at a site of medical waste generation.

A further feature of medical waste collection stations of the invention is that the first means 611 can include surfaces adjacent the open ends of the medical waste containers to engage hypodermic needles and permit their disengagement from syringes and insertion into the medical waste containers without the need for human handling of the hypodermic needle. For example, as shown in the figures, the cover plate 611c of the first means 611 can form hypodermic needle engagement surfaces 616 over the open top, e.g. 631a, of a medical waste container, e.g. 631. The tooling surfaces 616 formed to engage a hypodermic needle can be slots of varying widths providing wrench surfaces

to engage the standardly sized flats at the base of a hypodermic needle. The first means 611 and second means 620 are shaped to permit a user access to the tooling surfaces 616 of the station enclosure 611. Thus, a user may dispose of a used hypodermic needle by inserting the hypodermic needle through the opening formed by tooling surfaces 616 and sliding the hypodermic needle into the tooling surfaces 616 until the needle engages the mating wrench surfaces so formed by the tooling surfaces and thereafter unscrewing or otherwise disengaging the hypodermic needle from the syringe and, with the syringe, pushing the used hypodermic needle from the slot and tool forming surfaces 616 into the waste container 631 below.

As shown in Figs. 15-17, the base portion 611a of the collection station 611 is preferably formed from sheet metal, such as steel, and as shown in Fig. 17, blood and other fluids that may drain from needles and syringes into the bottom of the containers, and other unsightly medical waste are hidden from view so that installation of the collection station in areas accessible to non-medical personnel does not present a distasteful appearance. The hinged shell portion 611b can be, preferably, formed from a strong, thermo-formed clear material, such as Lexan brand thermoplastic. Such a material provides effective structural support for the lock 612a, thus limiting access to containers 630, 631 and their contents to authorized medical personnel. In addition, the transparency of the shell portion 611b permits a user to see when one of the containers is full, as shown in Fig. 17, where the contents of container 630 are visible to a user because the container 630 is full and the user has moved the

second means 620 to a position preventing over-filling of container 630 and opening container 631 to use.

In addition, the upper part of the shell portion 611b, and the cover plate 611c it carries, are forwardly angled at an acute angle, as shown in Figs. 15-21 and most apparent from Figs. 15 and 17. Because the cover plate 611c is carried at a forwardly facing acute angle, a user may readily see both the openings 614 providing access to the containers 630, 631 and the tooling surfaces 616 formed in the cover plate

611c that may be used to separate hypodermic needles from their syringes.

The collection station 600 of this invention can be, thus, relatively attractive, easy to use, and inexpensively made, can provide notice of, and prevent over-filling of, a filled container, can provide additional capacity for medical waste, can limit access to the medical containers and their contents through a locked cover and a restricted, but easily used, opening, and can provide automatic resetting of the means that prevents access to a filled container when the filled container is replaced.

It should be further noted that the invention does not require that the first means form an enclosure for the plurality of medical waste containers as shown and described with respect to Figs. 15-21. The first means need only support the plurality of medical waste containers in operative association with the second means carried by the first means; however, in such instances where the first means forms an enclosure for the medical waste containers, the shell portion 611b of the station enclosure is preferably formed from transparent material permitting a user to visually examine the status, i.e., volume of medical waste material, of

the medical waste containers, which are also preferably formed of transparent material.

It should be noted that the tooling surfaces 616 used to engage a hypodermic needle and disengage said hypodermic needle from a syringe need not be of the slotted configuration shown in Fig. 15-17 but may be formed by a slot in any configuration that is suitable for engaging and holding the flatted surface at the base of a hypodermic needle. For example, wrench forming surfaces may be formed by a slot which narrows gradually to provide a range of substantially parallel opposing surfaces, variably spaced apart at a distance to accommodate the various standard hypodermic needles. In addition, separately formed tools for disengaging a used hypodermic needle may be attached to and carried by the first means 611.

Furthermore, a station enclosure may be provided with other types of removable or hinged walls to permit the insertion and withdrawal of the medical waste containers as needed.

The second means 620 of the invention can take many forms for providing selective and sequential access to the open tops of the plural medical waste containers one after the other(s) . In addition to the slidable cover of the embodiment of Figs. 15-21, the second means 620 can be a rotatable element, with an opening moved from position to position adjacent the open tops of circularly arranged containers, or the second means 620 can form a chute to direct medical waste to a selected one of the medical waste containers, e.g. for separate collection of different kinds of medical waste. In addition, the second means can comprise one or more movable internal valves to direct medical waste to a selected one of the plural

waste containers, or a hinged door, to alternately cover the open tops of the plural waste containers.

Where the description above refers to used hypodermic needles, it should be recognized that not only the metal needle portion but the entire syringe assembly may be safely collected by this invention. In addition, disposable scalpels and other sharp solid medical waste and even soft medical waste may also be collected and safely disposed of. Following the collection of solid medical waste in a medical waste container, the entire container may be carried to and inserted in the waste treatment chamber for the treatment, as shown and described above.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.