Abstract:
A lid for a medical waste container which receives sharps waste such as hypodermic needles. The lid has a closure hinged to the lid by a flexible strap and movable between first and second recesses in the lid. The first recess is closed and simply receives and retains the closure when the lid is open for depositing waste. The second recess has an opening through which waste can be deposited into the container. A temporary locking mechanism retains the closure in the second recess by a snap fit but allows the closure to be lifted from the second recess to open the container. A permanent locking mechanism, when actuated, locks the closure in the second recess permanently so that the container is sealed for autoclaving and cannot be reopened.

Description:
FIELD OF THE INVENTION 
     This invention relates to a lid for a container which receives medical waste. The container is particularly intended to receive the barrels and needles of syringes. 
     BACKGROUND OF THE INVENTION 
     After medical syringes have been used, e.g. to take fluid samples from patients, or to inject medication into patients, the syringes must be disposed of. In some cases the syringe is disposed of as a complete unit, while in other cases the needle may be unscrewed from the barrel of the syringe, and the two components may be disposed of separately (although in some cases, they are still disposed of in the same container). Because of the presence of the sharp needles, this type of waste is commonly referred to in the medical profession as “sharps” waste. 
     Sharps waste can be hazardous to persons who may come in contact with such waste, since the needles may be and frequently are contaminated with dangerous biological materials. Therefore sharps waste must be disposed of, usually by a physician or a nurse, in a safe container where it is unlikely to cause injury while it is awaiting removal from the physician&#39;s office for permanent disposal. 
     BRIEF SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a lid for a container for medical waste, which lid is convenient and relatively safe to use. 
     In one aspect the invention provides a lid for a medical waste container, said lid comprising: 
     (a) a closure hinged to said lid and movable between a first closed position and a second open position; 
     (b) first and second recesses in said lid for receiving said closure when said closure is in its first and second positions respectively; 
     (c) said first recess being closed and serving only to house said closure when said lid is to be open for depositing said waste; 
     (d) said second recess having an opening therein to allow waste to be deposited therethrough into said container; 
     (e) said closure and said second recess including at least one cooperative locking mechanism for retaining said closure in said second recess, to close said opening in said second recess. 
    
    
     Further objects and advantages of the invention will appear from the following description, taken together with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a perspective view of a lid according to the invention, with the lid spaced above a container; 
     FIG. 1A is a partial view of a snap fit pivot for the handle of the FIG. 1 lid; 
     FIG. 2 is a top view of the FIG. 1 container; 
     FIG. 3 is a top isometric view of the FIG.  1 : lid, with the closure in “open” position; 
     FIG. 4 is a bottom isometric view of the FIG. 1 lid, with the closure in temporary closed position; 
     FIG. 5 is a bottom isometric view similar to that of FIG. 4 with the closure in permanent closed position; 
     FIG. 6 is a top view of the closure for the FIG. 1 lid, with the permanent locking mechanism omitted; 
     FIG. 7 is a side view of the FIG. 6 closure; 
     FIG. 8 is an isometric view of the FIG. 6 closure; 
     FIG. 9A is a top partial view of the FIG. 1 lid, with the closure in “open” position and showing section lines for FIG. 9B; 
     FIG. 9B is a section taken along lines  9 B— 9 B of FIG. 9A; 
     FIG. 9C is a n enlarged view of detail A of FIG. 9B; 
     FIG. 10A is a top view of the FIG. 1 lid and showing section lines for FIG. 10B; 
     FIG. 10B is a section taken along lines  10 B— 10 B of FIG. 10A; 
     FIG. 10C is an enlarged view of detail A of FIG. 10B; 
     FIG. 11A is a top view of the FIG. 1 lid with the closure in “closed” position and showing section lines for FIG. 11B; 
     FIG. 11B is a section taken along lines  11 B— 11 B of FIG. 11A; 
     FIG. 11C is an enlarged view of detail A of FIG. 11 B; 
     FIG. 12A is an exploded isometric view of the closure for the FIG. 1 lid and showing in particular a portion of the permanent locking mechanism; 
     FIG. 12B is a top isometric view of the FIG. 12A closure; 
     FIG. 12C is a bottom isometric view of the FIG. 12A closure; 
     FIG. 13A is a top view of a button forming part of the permanent locking mechanism for the FIG. 12A closure; 
     FIG. 13B is a side view of the FIG. 13A button; 
     FIG. 13C is a top isometric view of the FIG. 13A button; 
     FIG. 13D is a bottom isometric view of the FIG. 13A button; 
     FIG. 14A is a top view of a washer for the permanent locking mechanism for the FIG. 12A closure; 
     FIG. 14B is a side view of the FIG. 14A washer; 
     FIG. 14C is a top isometric view of the FIG. 14A washer; 
     FIG. 14D is a bottom isometric view of the FIG. 14A washer; 
     FIG. 15 is a bottom sectional view of the FIG. 1 lid showing the temporary locking mechanism and showing the permanent locking mechanism in its open condition; 
     FIG. 16 is an enlarged view of detail A of FIG.  15  and showing the temporary locking mechanism; and 
     FIG. 17 is a top view of an alternative opening design for the FIG. 1 lid. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference is first made to FIG. 1, which shows a medical waste container  10  bearing a lid  12  having a handle  14 . As shown, the lid  12  is of generally square configuration (although it can, of course, be round, elliptical or of other outline), with an upper surface  15 , a lower encircling perimeter wall  16  and an upper encircling perimeter wall  18  inset slightly from the lower wall  16  and joined to the lower wall by a ledge  20 . As seen from the inside of the lid  12  (FIGS. 4,  15 ), an extension  22  of the upper wall  18  extends downwardly inside and parallel to the lower wall  16 , forming a channel  24  which receives the upper edge  26  of the container  10 . 
     An outwardly extending ridge  30  encircles the outer wall  32  of the container  10  and serves as a stop to position the lid  12  accurately on the container. 
     Short projections  34  near the top of the container (above ridge  30 ) protrude through openings  36  in the lower lid wall  16  to provide a snap fit when the lid is placed on the container, ensuring that the lid  12  will remain in position on the container. 
     The handle  14  is hinged to the upper wall  18  by snap-fit stub pivot shafts  38  (FIG. 1A) which protrude into closed wells  40  in the lid upper surface  15 . The handle  14  permits a user to lift the container, with reduced risk of encountering a needle which may have thrust through the wall of the container body. However the container body and lid are both preferably formed from a strong material such as polypropylene, which is highly resistant to being penetrated by a needle tip. 
     The container  10  tapers slightly inwardly in a downward direction, so that a number of containers  10  can be nested for storage prior to use. However as an added precaution to prevent weakening of the containers when they are nested, each container  10  contains two pairs of internal ridges  42  (FIG.  2 ), one pair at each of two opposed corners, extending from the container bottom partway up the inner wall  43  of the container as shown. Each container also has four slightly protruding external pairs of legs  44  at its bottom outer surface, one pair at each corner. When the containers  10  are nested, the legs  44  encounter and are stopped by the inner ridges  42 , preventing an inner container from being forced too far into an outer container and thereby weakening the outer container. Instead, during nesting, the containers stack with the bottom of one container spaced from the bottom of the container in which it is nested. 
     The lid  12  includes a closure  46  having an integral flexible strap  48  protruding from one end of the closure. (See also FIGS. 6-9) The strap  48  is pivotally mounted to the lid upper surface  15  at pivot mounting  50  (which is a conventional plastic hinge) so that the closure  46  can move between an open position  54 A (FIG. 3) and a closed position  54 B (FIG.  1 ). In the closure&#39;s open position  54 A, the closure  46  is housed in a recess  56  in the lid upper surface  15 . The recess  56  includes a recessed outer portion  58  (FIG. 1) shaped to accommodate the closure  46 , and a further recessed central portion  60  which receives and accommodates the closure locking mechanism (to be described), so that the upper surface of the closure  46  is approximately flush with the lid upper surface  15 . An extension  62  of the recess outer portion  58  receives a finger tab  64  extending from the closure  46  at the opposite end from the strap  48 . 
     The recess  56  is shaped and dimensioned to accommodate the closure  46  relatively snugly, preferably with enough friction to prevent the closure from “flopping” loosely, but with sufficient tolerance to allow a small lifting force applied by a finger on the tab  64  to lift the closure  46  from the recess  56 , (bending strap  48  upwardly at this time) and then swinging the closure to its closed position  54 B. The recess extension  62  is sufficiently larger than the finger tab  64  on the closure to allow a finger to be inserted under the extension tab  62  to lift the closure for a movement to its closed position  54 B. The recess  56  is “closed”, i.e. it has no openings from its upper to its lower surface. 
     The lid  12  also contains a second upper recess  68  (FIG.  3 ), located at the closed position  54 B. Recess  68  has the same shape as the first upper recess  56 , including an extension recess  70  for the finger tab  64 . However the second recess  68 , instead of containing a central recess like recess  56 , instead contains an opening  72  through which syringe needles and barrels and complete syringes may be deposited into the waste container  10 . The opening  72  is of convenient size for this purpose and may for example be between one and two inches wide at its widest portion, and between two and three inches long. In a preferred embodiment the opening  72  was approximately 1.40 inches wide at its widest dimension and was approximately 2.27 inches long at its longest dimension. 
     After a syringe or a needle or a syringe barrel has been deposited in the container  10 , but when the container  10  is not yet full, it is usually desired to close the container temporarily (using the closure  46 ), until the next deposit. After the container is full, it is desired to lock the closure  46  permanently in closed position, so that it cannot readily be opened from outside the container. 
     For this purpose the closure  46  includes two locking mechanisms, one of which holds the closure temporarily in closed position  54 B, and the other of which can hold the closure permanently in closed position  54 B. 
     The temporary locking mechanism (see particularly FIGS. 11A,  11 B,  11 C,  16 ) comprises a post  76  which extends downwardly from the lower surface of the closure  46 , near the finger tab  64 , and in a position in which it interferes slightly with the edge  78  of the opening  72 . The lower surface  80  of the post includes a short forwardly projecting tab  82  as best shown in FIG. 10C, so that as the post lower surface  80  (which is formed of polypropylene) encounters the edge  78 , the post is cammed inwardly allowing the tab  82  at the bottom of the post  76  to snap under the edge of the opening  72 , thus holding the closure  46  in closed position by this snap-fit. To open the closure  46 , upward pressure is exerted on the finger tab  64 , thus forcing the thin post  76  to move inwardly and allowing the closure  46  to be opened for a new deposit. 
     For more secure temporary locking, and also for permanent locking, of the closure  46  in closed position  54 B, a locking mechanism  86  is provided (FIGS. 4,  5 ,  12 - 16 ). The locking mechanism  86  includes a circular flat button  88  mounted in a recess  90  in closure  46 .and having a diametrical ridge  92  extending upwardly from the upper surface of the button  88 . The ridge  92  can be grasped to rotate the button  88 . As shown, the ridge  92  extends diametrically slightly beyond the circumference of the button on each side of the button and encounters stop ridges  94 ,  96  (see also FIG. 6) formed on the upper surface of the closure recess  90 , so that the button  88  can be rotated only from the position shown in FIG. 1 or  3  (parallel to the longitudinal axis  98  of the closure  46 ) clockwise to a position 90 degrees from the position shown in FIG. 1 or  3  (at which time the ridge  92  again encounters the stop ridges  94 ,  96  and is prevented from further rotation). Small raised projections  100 . (FIG. 6) (which look like dots) extend upwardly from the bottom upper surface of recess  90  and offer modest resistance to rotation of ridge  92  over them, to prevent button  88  from accidentally being rotated from its unlocked position towards its locked position. 
     The button  88  is secured, by a protruding snap fit pair of integral members  104  (FIG. 13) which extend through opening  106  in the closure recess  90 , and through a washer  108 . Washer  108  is circular and generally of flat disc shape but contains a pair of diametrically opposed protrusions  110  which lie in the same plane as the remainder of washer  108 . A pair of ribs  112  extend diametrically along protrusions  110  to stiffen them. 
     The upper surfaces of the protrusions  110  are sloped as indicated in FIG. 14, to form camming surfaces.  114 . With the closure  46  in its closed position  54 B, then when the button  88  and washer  108  are rotated clockwise, the protrusions  110  move underneath the bottom wall  116  bordering the recess  72 , temporarily securely locking the closure  46  in closed position. If the button  88  and washer  108  are rotated a full  90  degrees from their opened unlocked position, the camming surfaces  114  of the protrusions  110  ride over wedged shaped camming projections  120  (FIG. 14) extending from the bottom wall  116  of the recess  90 , so that the projections  110  then snap into a recess formed between camming projections  120  and stops  122  spaced circumferentially from projections  120 . (The space between projections  120  and stops  122  is slightly greater than the width of projections  110 .) It is now impossible to rotate the button and washer counterclockwise using ridge  92  at the top of the closure  46 , so the closure  46  is now permanently locked in its closed position, and cannot be reopened without destruction of the closure. 
     The sealed container  10  can then be removed and autoclaved for sterilization of its contents, after which the container and its contents can be destroyed or otherwise dealt with in conventional fashion. 
     If desired, and as shown in FIG. 17, the shape of the opening  72  can be changed to provide a serrated portion  124 . The serrated portion  124  can be used to grip a syringe-needle while the physician or nurse is holding the syringe barrel, thus allowing the barrel to be unscrewed from the needle, after which the needle will fall into the container. 
     It will be appreciated that other changes may be made in the container body and lid as described, and such changes and modifications are intended to be included within the scope of the present invention.