Abstract:
The present invention relates to a tamper resistant lid for a container and a method for sealing a container. The method for sealing a container includes providing a tamper resistant lid having a centre axis; an outer member; an inner member; the outer member and the inner member each include an outer surface and an inner surface wherein at least a part of the outer surface of the inner member is substantially adjacent at least a part of the inner surface of the outer member, the inner member having a thread; and at least one stop member preventing the inner member from rotation with respect to the outer member, placing the tamper resistant lid onto a container; rotating the outer member in a first direction to allow the thread of the inner member to connect to a thread of a neck element of the container; and disabling the at least one stop member by applying a designated force after the inner member has been connected to the container, so that the outer member can be freely rotated with respect to the inner member to thereby prevent removal of the tamper resistant lid from the container.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a tamper resistant lid for sealing an opening of a container while at the same time, providing a tamper resistant lid which substantially prevents access to the container by preventing the lid from being removed from the container after it has been connected thereto. 
       BACKGROUND OF THE INVENTION 
       [0002]    Hospitals, care centers, and the like, generally tend to use more and more disposable medical devices in their daily operation. Disposable medical devices are used as they generally require no post use sorting, sterilization or washing facilities. Instead, as their name suggests, they can simply be disposed. The amount of medical waste, such as used needles, contaminated medical devices, e.g. infusion sets or the like, is thus growing. Although there are several advantages with disposable items, medical waste generally tends to require considerations during and after disposal. 
         [0003]    A nurse taking a blood sample using a needle, places the needle in a safe environment, i.e. an environment which has a limited access. The limited access after use prevents staff from unnecessary exposure and the risk there from. Sealable containers are frequently used for this purpose. Generally such sealable containers are made from stainless steel, aluminum or a similar metal, and after being filled with medical waste, the containers are simply sealed using an ordinary screw lid. The sealed containers can thereafter be brought to an incinerator for destruction or optionally for sterilization before going to a recycle plant or a land fill. 
         [0004]    However, during use, e.g. as the sealed containers are moved to their end station, persons handling the sealed containers are exposed to the risk of accidentally opening the sealed container, or for any other reason, the sealed container would be opened or break. As such there is a constant need to improve the methods and devices used for sealing containers, and especially for sealing medical waste containers. 
       SUMMARY OF THE INVENTION 
       [0005]    It is an object of the present invention to at least partly solve or reduce the effects of the drawbacks mentioned above. More specifically they are at least partly solved or reduced by a tamper resistant lid for a container according to the present invention. The lid exhibits a centre axis and comprises an outer and an inner member. The outer and inner members each comprise an outer and inner surface wherein at least a part of the outer surface of the inner member is substantially adjacent at least a part of the inner surface of the outer member. The outer and inner members are further substantially prevented from displacement along the centre axis with respect to each other. The inner member comprises connection means enabling a connection to the container by means of rotating the outer member in a first direction. The lid comprises at least one stop member preventing the inner member from rotation with respect to the outer member. The at least one stop member(s) is/are adapted to be controllably disabled with a designated force after the inner member has been connected to the container, so that the outer member can be freely rotated with respect to the inner member to thereby prevent the removal of the lid from the container. 
         [0006]    The present invention provides for a tamper resistant lid which enables an improved handling in terms of safety and work environment. The tamper resistant lid effectively reduces the risk of accidentally opening sealed containers, while permitting a secure sealing of the container. 
         [0007]    In an embodiment according to the present invention, the at least one stop member can be adapted to be disabled with a designated rupture force. The designated rupture force can be imparted to the at least one stop member by moving the outer member, with respect to the inner member, or by moving the at least one stop member itself in a designated direction or a first direction. Generally, the at least one stop member is moved with respect to the outer member. In this way, the at least one stop member can be disabled by rupturing the at least one stop member, and/or optionally the at least one stop member can be disabled by being removed. 
         [0008]    In cases where the at least one stop member is arranged to fixedly connect the outer and the inner member of the lid, the at least one stop member can be ruptured by subjecting the at least one stop member to a designated rupture force, thereby enabling the outer member to be freely turned, i.e. rotated, with respect to the inner member. Alternatively, or additionally, at least one of the stop members can be adapted to be in working cooperation with the inner member. The at least one of the stop members can be in the form of a removable protrusion member, cooperative with a groove on the inner member for example. 
         [0009]    According an embodiment to the present invention, at least one stop member is controllably disabled by a designated force in a designated direction. The designated direction can be in the same direction as the first direction. This is advantageous as a user simply continues the rotational motion, when screwing the lid onto e.g. a container, to disable the at least one stop member. Optionally, the designated direction can be in the direction of the centre axis (X). This can be advantageous in cases where a user want to make sure that a container is to be closed, but not disabling the at least one stop member. This can be done as the lid is threaded onto e.g. a container, while the at least one stop member is disabled by moving e.g. the outer member, with respect to the inner member in a direction substantially perpendicular to the first direction along which the lid is screwed onto a container. A user does thereby not risk disabling the at least one stop member(s) accidentally. 
         [0010]    The at least one stop member can be arranged at many different locations depending on the desired designated direction for disabling the at least one stop member. Suitable locations are substantially between the inner and outer members or between the inner and outer members, as this is a simple yet effective way of preventing the outer member from motion with respect to the inner member, thereby enabling the lid to be screwed on a container, while afterwards disabling the at least one stop member. Optionally, the at least one stop member can be arranged between the inner surface of the outer member and the outer surface of the inner member. 
         [0011]    In an embodiment according to the present invention, the at least one stop member can extend around the centre axis, e.g. as a ring or a polygonal, continuous or discontinuous around the centre axis. If there is a plurality of stop members, they can be positioned symmetrically around the centre axis for distributing the required designated rupture force required to disable the stop members. Optionally, if there is only one stop member, the stop member can in itself be arranged symmetrically around the centre axis, preferably between the inner and outer members. This will provide a good rupture surface between the outer and inner members after disabling the stop member. The inner and the outer members will not be inclined to reengage each other, thus not enabling the outer member to move the inner member. This advantage is also prominent if the at least one stop member is arranged to intersect the centre axis, i.e. is positioned between the inner and outer members and at the centre of the circular base of the inner and outer members. 
         [0012]    The at least one stop member can be adapted to be controllably disabled by removal from the outer member. It/they will thus be prevented from interacting with the inner member to stop the inner member from being turned with respect to the outer member. According to one embodiment of the present invention, the at least one stop member can be removed by imparting a designated rupture force to the at least one stop member. In this embodiment, the at least one stop member is fixedly attached to the inner and/or the outer member before being removed by the imparted rupture force. 
         [0013]    In an embodiment according to the present invention, the inner member, outer member and the at least one stop member can be integrally formed in one piece of material, e.g. by form molding or similar. Optionally, the outer and inner members are formed from separate pieces of material. The at least one stop member can be integrally formed by one piece of material with either the inner member and/or the outer member. 
         [0014]    The present invention further relates to an assembly of a medical waste container and the tamper resistant lid as described herein. The assembly specifically relates to all the different embodiments described above and below, and as outlined in the claims. The present invention also relates to the use of a tamper resistant lid as described herein, or according to any of the claims, for sealing a medical waste container. 
         [0015]    The present invention also relates to a method for sealing a container using a tamper resistant lid as described herein. The method comprises the steps of;
       providing the lid;   screwing the lid onto the container;   disabling the at least one stop member.       
 
         [0019]    The method enables the sealing of a container which sealing effectively prevents the container from being reopened. 
         [0020]    The at least one stop member can be; one stop member, two stop members, three stop members, four stop members, or more. In some embodiments it can be advantageous to have 2-50 stop members, 5-40 stop members or optionally 10-30 stop members. According to an embodiment of the present invention, the stop member or the plurality of stop members can be formed by a pin, e.g. press fitted, which is arranged between the inner and outer member. 
         [0021]    According to an aspect, an embodiment relates to a tamper resistant lid for a container. The lid comprises a centre axis X, an outer and an inner member. The outer and inner members are further substantially prevented from displacement along the centre axis X with respect to each other. At least a part of the inner member comprises threads enabling a threaded connection to the container by means of rotating the outer member in a first direction. The lid further comprises at least one stop member preventing the inner member from rotation with respect to the outer member. The at least one stop member is adapted to be controllably disabled with a designated force after the inner member has been connected to the container, so that the outer member can be freely rotated with respect to the inner member to thereby prevent removal of the lid from the container. The present invention enables the sealing of a container, while substantially preventing the container from being reopened. 
         [0022]    Suitable materials for the inner and outer members are polymeric materials such as polyethylene, polypropylene, polyurethane, biopolymers, e.g. PPC, polyprophylene carbonate and/or starch, or the like, metals or alloys such as aluminum, alumina, brass, steel, iron or the like. Combinations of the above mentioned materials are of course also possible such as a metal outer member having an inner member made from a polymeric material, such as plastics, e.g. polypropylene. The outer member can advantageously be manufactured from a deformation resistant material such as steel or a thicker plastic material, to prevent or reduce the risk of that the outer member is deformed when subjected to a force. Such force could be imparted when the inner member is rotated by means of the outer member for example. 
         [0023]    The inner member or outer member can be coated with a material to reduce the friction between the inner and the outer member. Optionally a friction reducing material can be positioned, chemically attached with e.g. adhesive or physically retained in position, between the inner and outer member. 
       DEFINITIONS 
       [0024]    It should be noted that although it is said that removal of the tamper resistant lid is prevented after disabling the stop member, the term “prevented” is by no means to be interpreted as impossible to remove. A lid (or a container) can be broken whereafter the lid can be removed. Thus the term “prevented” is to be read as; prevented from removal using reasonable efforts or otherwise normal procedures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The present invention will be described in greater detail with reference to the accompanying figures in which; 
           [0026]      FIG. 1  shows a container and a tamper resistant lid according to one embodiment of the present invention; 
           [0027]      FIG. 2  shows a cross section of the tamper resistant lid shown in  FIG. 1  and; 
           [0028]      FIG. 3   a - 3   b  show a cross section of a tamper resistant lid according to a second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0029]      FIG. 1  shows a medical waste container  1 , hereafter referred to as the container, for storing hazardous waste such as used needles, contaminated medical equipment or the like. The tamper resistant lid  10  can however be used for any container to store hazardous material, goods, or the like. The container  1  can be sealed with a tamper resistant lid  10 , also referred to as “the lid”, according to one embodiment of the present invention. The lid  10  is suitably connected to the container  1  by means of a threaded coupling using threads  2  arranged on a neck element  3  of the container  1 . The container  1  and the lid  10  are depicted with a centre axis X extending through the centre of the container  1  and the lid  10 . When e.g. medical waste, in the form of used needles for example, has been placed in the container  1 , the lid  10  can be threaded onto the neck element  3  to seal the interior of the container  1  from the ambient environment thus preventing access the container  1  and the medical waste. The lid  10  comprises at least one stop member which is adapted to enable the lid  10  to be screwed onto the neck element  3  and, after being connected thereto, disable the lid from being unscrewed from the neck element  3 , to thereby prevent access to the interior of the container  1 . 
         [0030]      FIG. 2  shows a cross section of the tamper resistant lid  10  as shown in  FIG. 1 . The lid  10  comprises an outer member  20  substantially enclosing an inner member  40 . The outer member  20  comprises a circular base  21  having a circular periphery  22 . A circular wall  23  extends around the circular periphery  22 , the circular wall has a proximal end  24  arranged on the circular base  21  and a distal end  25  arranged remotely from the circular base  21 . The outer member  20  further exhibits an outer surface  26  and an inner surface  27 . At least the inner surface  27  can have a smooth surface. At the distal end  25  of the circular wall  23 , a circumferential lock flange  28 , projects towards the centre axis X. The circumferential lock flange  28  is substantially preventing the inner member  40  from movement along the centre axis X in a direction away from the inner surface  27  of the outer member  20 . It should be noted that although the circumferential lock flange  28  is said to prevent the inner member  40  from moving along the centre axis X with respect to the outer member  20 , there can still be a play between the outer and inner members  20 ,  40  permitting a small relative displacement of the outer and inner members  20 ,  40 . 
         [0031]    The inner member  40  comprises a circular base  41  having a circular periphery  42 . A circular wall  43  extends around the circular periphery  42 . The circular wall  43  has a proximal end  44  arranged on the circular base  41  and a distal end  45  arranged remotely from the circular base  41 . The inner member  40  further exhibits an outer surface  46  and an inner surface  47 . The inner surface  47  exhibits connecting means, such as threads  48 , for providing a threaded coupling with the threads  2  of the neck element  3  of the container  1 . The distal end  45  of the circular wall  43  is in working cooperation with the circumferential lock flange  28  of the outer member  20 , to prevent the inner member  40  from moving along the centre axis X and with respect to the outer member  20 . As is noted, the inner surface  27  of the outer member  20  is substantially adjacent the outer surface  46  of the inner member  40 , however a small play is possible. 
         [0032]    A plurality of stop members  51 ,  52 ,  53  is arranged between the outer member  20  and the inner member  40 , to prevent the inner member  40  from displacement, in this case from rotating, i.e. turning, with respect to the outer member  20 . The shown embodiment in  FIG. 2  shows only three stop members  51 ,  52 ,  53  although the lid  10  is equipped with four stop members. The plurality of stop members  51  , 52  ,  53  are arranged symmetrically around the distal end  45  of the circular wall  43  and attaches the circumferential lock flange  28  of the outer member  20  thereto. As the lid  10  is screwed onto the neck element  3  of the container  1 , the plurality of stop members  51 ,  52 ,  53  are adapted to rupture when being exposed to a designated rupture force, imparted by a user via the outer member  20 . As the plurality of stop members  51 ,  52 ,  53  rupture, the fixed connection between outer and inner members is disabled, and the outer member  20  can be freely rotated with respect to the inner member  40 . As the outer member  20  can be freely rotated with respect to the inner member  40 , but is substantially prevented from displacement along the centre axis X, the outer member  20  substantially encloses the inner member  40  and prevents access to the inner member  40  for unscrewing the inner member  40  from the threads  2  of the neck element  3  of the container  1 . As such, the tamper resistant lid  10  provides a lid which can be threaded onto an appropriate container, and subsequently prevented from being unscrewed from the container, to thereby expose the interior of the container to the ambient environment. 
         [0033]    The play, mentioned above, between the outer and inner members  20 ,  40  permitting a relative displacement of the outer and inner member  20 ,  40 , assists to disable the at least one stop member by permitting the outer member  20  to be imparted with a designated rupture force, e.g. in the direction of rotation or in a direction along the centre axis X. According to an aspect of the invention, the at least one stop member can be specifically configured to withstand a rotational motion while being configured to rupture as a function of a designated force imparted in a direction perpendicular to the rotational motion, and vice versa. According to an embodiment, a user can thus easily attach the lid to the container by a rotating motion and thereafter simply hit the lid with his/hers hand with a motion along the centre axis X to provide the designated rupture force to the plurality of stop members. 
         [0034]      FIGS. 3   a - 3   b  show a cross section of a tamper resistant lid  10 , according to a second embodiment of the present invention. For the sake of simplicity, only a part of the lid  10  is shown. The same references used above are used for the same features. The lid  10  comprises an outer and inner member  20 ,  40 , each respectively comprising an outer and inner surface  26 ,  27 ,  46 ,  47 , and a circular base  21 ,  41  having a circular wall  23 ,  43  extending around the periphery of the circular base  21 ,  41 , as described above with reference to  FIG. 2 . The inner surface  47  of the inner member  40  is equipped with connecting means, such as threads  48 . 
         [0035]    The outer member  20  comprises at least one stop member  60 , integrally formed with the outer member  20 . The stop member(s)  60  is/are in working cooperation with a groove  63  formed in the outer surface  46  in the circular wall  43  of the inner member  40 . The stop member  60 , while being arranged partly inside the groove  63  of the inner member  40 , as shown in  FIG. 3   a , effectively prevents the outer member  20  from being turned with respect to the inner member  40 , thus permitting the lid  10  to be screwed onto the threads  2  of the neck element  3  of the container  1 , as shown in  FIG. 1 . Optionally the at least one stop member can be integrally formed with the inner member  40  and in working cooperation with a groove or aperture formed in the inner surface  26  of the circular wall  23  of the outer member  20 . 
         [0036]    The stop member  60  is pivotally connected to the outer member  20  at a pivot point  61  and arranged in an opening  64 , i.e. a through aperture, in the circular wall  23  of the outer member  20 . The pivot point  61  permits the stop member  60  to be pivoted away from the groove  63  of the inner member  40 , as indicated by the arrow in  FIG. 3   a , and optionally to be removed from the outer member  20  by fully rupture the connection between the stop member  60  and the outer member  20  at the pivot point  61 . As the stop member  60  is removed from the groove  63 , and removed from the outer member  20 , the outer member  20  can be rotated, i.e. turned, clockwise or counter clockwise around the centre axis X, with respect to the inner member  40 . As the outer member  20  substantially encloses the inner member  40 , the inner member  40  is effectively prevented from being removed for the container  1 , after assembly with the container  1 . A grip member  65 , extends away from the centre axis X, and is arranged on the stop member  60  enabling a user to readily grip and remove or displace the stop member  60 . The shown embodiment can be provided with one or more stop members as just described. Furthermore, the one or more stop members can be interconnected so that they all can be removed with a single pull by a user. 
         [0037]    As can be seen in  FIGS. 3   a  and  3   b , the opening  64  in the circular wall  23  of the outer member  20  further supports the stop member  60  when screwing the lid  10  onto e.g. the neck element  3  of the container  1 . More specifically, the side walls of the opening  64  provide for the support as the stop member  60  is substantially prevented from motion in any direction along the turning direction, i.e. the clock wise or counter-clock wise rotational direction. The stop member  60  is thus snugly fitted in the opening  64  but is still permitted to be removed there from by disabling the stop member  60  in a predetermined, i.e. a designated direction, in this case, away from the outer member  20 . 
         [0038]    According to an embodiment of the present invention, the distal end  45  of the inner member  40  comprises a tilting surface  49  to enable a hook like lock configuration of the inner member  40  with respect to the outer member  20  together with a tilting surface  29 , arranged on the circumferential lock flange  28  of the outer member  20 . In a similar manner, the periphery  42  of the inner member  40  can be provided with a tilting surface to enable a smooth insertion of the inner member  40  into the outer member  20  during assembly of the outer and inner members  20 ,  40 . As is noted, the stop member is also arranged with a tilting surface to simplify the assembly of the inner member  40  with the outer member  20  when manufacturing of the tamper resistant lid  10 . As the inner member  40  is inserted into the inner member  20 , the stop member  60  is pivoted, without rupturing, just enough to be displaced so that the inner member  40  can be inserted into the outer member  20 . As the lid  10 , and the outer member  20  is screwed onto e.g. the neck element  3  of the container  1 , as shown in  FIG. 1 , the stop member  60  will automatically move, or pivot, into the groove  63  of the inner member  40 . The stop member is thus advantageously biased in the direction of the centre axis X. 
         [0039]    As is shown and described with reference to  FIGS. 2 ,  3   a - 3   b,  the at least one stop member  51 ,  52 ,  53 ,  60  can be either fixed or movable. Common for the stop members  51 ,  52 ,  53 ,  60  is however that they all can be disabled. In the shown embodiments, they are disabled by means of imparting a rupture force to the at least one stop member(s)  51 ,  52 ,  53 ,  60 . There are however other ways of disabling the at least one stop members, e.g. the at east one stop member(s) can be removed, if they are removably attached to the lid  10 . Optionally the at least one stop member can be disabled by heat, if using e.g. a heat sensitive adhesive, or dissolved, if using a solvent sensitive adhesive, or by other means. 
         [0040]    It should be noted that even though the claims are directed to a lid for a container, the lid could comprise optional components, such as a membrane.