Abstract:
The invention provides an incinerator adapted for disintegrating metal needles and lancets such as are used in the medical profession. An incinerator is provided that includes first and second electrodes, each having a contact edge spaced apart in an overlapping relationship to one another. The second electrode is rotated relative to the first electrode so as to define a tapered gap between the contact edges. A controlled power source is selectively interconnected to the first and second electrodes, with both being supported by a housing. The housing defines an opening adjacent to the electrodes for receiving metal, such as hypodermic needles, interveinous needles, lancets, etc., to be incinerated by the electrodes. In another embodiment of the invention, a residue collection drawer is slidably mounted within the housing adjacent to the electrodes so as to capture residue from the incineration. An electrode broom is movably mounted within the housing or the drawer, adjacent to the gap between the electrodes, so as to be movable against the contact edges thereby to remove a build-up of debris resulting from incineration.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention generally relates to waste disposal devices, and more particularly to devices for disposing of needles associated with hypodermic syringes, lancets and the like.  
         BACKGROUND OF THE INVENTION  
         [0002]    With the ever increasing need to prevent the spread of infectious diseases, there has been a growing emphasis on the safe handling and disposal of medical waste and particularly the needles utilized with hypodermic syringes. It is extremely important to protect medical personnel and others who are required to administer hypodermic injections from inadvertent or accidental “stick” injuries. This protection is also required by those who must dispose of medical waste by-products, including the hypodermic syringes and needles, from accidental “stick” injuries which can occur by the improper or accidental handling of such waste products.  
           [0003]    In an effort to provide increased safety and prevent the spread of infectious disease, small incinerating devices have been developed in recent years which are specifically designed for destroying hypodermic syringe needles and the like. Most of these incinerating devices have been designed to be portable, and most operate on conventional 110 volt AC outlet current so that the units may be plugged into a conventional outlet. With these, and other, prior art devices, a needle may be destroyed immediately after its use by inserting the needle, while still attached to the hypodermic syringe, into the incinerating apparatus where heat or electricity is utilized to thermally neutralize biohazardous materials, and melt or disintegrate the needle. Some examples of such prior art incinerators are found in U.S. Pat. No.: 4,628,169 to Ching-Lung; U.S. Pat. No. 4,877,934 to Spinello; U.S. Pat. No. 4,965,426 to Colombo; U.S. Pat. No. 5,075,529 to Kudo; U.S. Pat. No. 5,091,621 to Butler; U.S. Pat. No. 5,138,125 to Salesses; U.S. Pat. No. 5,282,428 to Grevill, et al.; U.S. Pat. No. 5,288,964 to Walker, et al.; U.S. Pat. No. 5,300,752 to Elmerick, et al.; U.S. Pat. Nos. 5,336,862 and 5,468,928 to Yelvington; U.S. Pat No. 5,551,355 to Haines et al.; U.S. Pat. No. 5,710,404 to Descent; U.S. Pat. No. 5,852,267 to Yanobu; U.S. Pat. No. 5,868,709 to Champion, et al.; and U.S. Pat. No. 5,877,469 to Truesdale, et al.  
           [0004]    In many of these prior art incinerators, a pair of electrodes are engageable by a needle inserted into the incinerator housing. An electric arc is established through the needle, destroying the needle at temperatures of 1,000 degrees or higher, with the disintegration occurring substantially instantaneously. In some of the prior art incinerators, small fans are utilized to exhaust the by-products of combustion to the ambient atmosphere. To prevent the release of airborne contaminants or pathogens, which may remain in the gaseous material, some prior art devices utilize a filter element to filter the air before it is exhausted from the incinerator apparatus.  
           [0005]    Unfortunately, prior art needle incinerating units have not met with acceptance by practitioners in the health care industry. For one thing, incinerating devices have not proven to be sufficiently capable of ensuring that all exhaust from the incinerating devices is purified to prevent smoke, toxins, trace metal contaminates, and airborne pathogens from being discharged to the atmosphere. many healthcare professionals do not want to place any type of incinerating apparatus within an enclosed area where people may be exposed to the exhaust.  
           [0006]    Another disadvantage in prior art needle incinerators is the need to adjust the incinerator electrodes or contacts depending upon the type of needle which is to be destroyed. In many prior art incinerators, the electrodes for contacting the needle are fixed relative to one another or flexible relative to one another, so as to ensure contact with varying lengths of needles. In other prior art devices, gauges or dedicated entrance ports are utilized to accommodate different diameter needles. Also, prior art needle incinerators have not been adequately designed to cooperatively destroy needles associated with differing sizes of hypodermic syringes.  
           [0007]    One other disadvantage associated with most prior art needle incinerators is the inability to clean electrodes without disassembly. In particular, after several needles have been disintegrated, a residue forms on the edges of the electrodes which degrades the performance of the disintegration process, and often provides a load on the battery that causes the battery to discharge. If left uncleaned, this build-up of combustion by-products, residue and debris may render the incinerator inoperative.  
           [0008]    In view of the foregoing, there is a need to increase the operating performance, safety characteristics, self-cleaning treatment characteristics, and adaptability of needle incinerators.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides an incinerator adapted for disintegrating metal needles and lancets such as are used in the medical profession. In one embodiment of the invention, an incinerator is provided that includes first and second electrodes, each having a contact edge spaced apart in an overlapping relationship to each other. The second electrode is rotated relative to the first electrode so as to define a tapered gap between the contact edges. A controlled power source is selectively interconnected to the first and second electrodes, with both being supported by a housing. The housing defines an opening adjacent to the electrodes for receiving metal, such as hypodermic needles, interveinous needles, lancets, etc., to be incinerated by the electrodes.  
           [0010]    In another embodiment of the invention, a residue collection drawer is slidably mounted within the housing adjacent to the electrodes so as to capture residue from the incineration. An electrode broom is movably mounted within the housing or the drawer, adjacent to the gap between the electrodes so as to be movable against the contact edges thereby to remove a build-up of debris resulting from incineration. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiment of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein:  
         [0012]    [0012]FIG. 1 is a perspective view of a needle incinerator formed in accordance with the invention;  
         [0013]    [0013]FIG. 2 is a top view of the needle incinerator shown in FIG. 1;  
         [0014]    [0014]FIG. 3 is a cross-sectional view of the needle incinerator shown in FIGS. 1 and 2, as taken along lines  3 - 3  in FIG. 2;  
         [0015]    [0015]FIG. 4 is a plan view of the bottom wall of the needle incinerator shown in FIG. 1;  
         [0016]    [0016]FIG. 5 is a schematic representation of one wiring and circuit arrangement used in connection with the present invention;  
         [0017]    [0017]FIG. 6 is a perspective view of a negative incineration contact and a positive incineration contact that are used in connection with the electrode assembly of the needle incinerator, with surrounding structures removed for clarity of illustration;  
         [0018]    [0018]FIG. 7 is a side elevational view of the negative incineration contact and positive incineration contact shown in FIG. 6;  
         [0019]    [0019]FIG. 8 is a cross-sectional view of the needle incinerator, as taken along lines  8 - 8  in FIG. 2;  
         [0020]    [0020]FIG. 9 is a top view of the needle incinerator shown in FIG. 1, but with a top portion of a housing removed for clarity of illustration;  
         [0021]    [0021]FIG. 10 is a perspective view of a cleaning assembly formed in accordance with the present invention, with the surrounding structures of the needle incinerator removed for clarity of illustration; and  
         [0022]    [0022]FIG. 11 is a perspective view of the cleaning assembly similar to FIG. 10, but including a negative incineration contact and a positive incineration contact that are used in connection with the electrode assembly of the needle incinerator, with the surrounding structures of the needle incinerator removed for clarity of illustration. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “horizonal,” “vertical,” “up,” “down,” “top” and “bottom”, “back” and “front”, as well as derivatives (thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship.  
         [0024]    Referring to FIGS.  1 - 3 , a needle incinerator  5  formed in accordance with a preferred embodiment of the invention comprises a housing  8 , a power and control assembly  10 , an electrode assembly  12 , and a cleaning assembly  14 . More particularly, housing  8  includes a top wall  20 , a bottom  22 , sidewalls  24 , a front opening  26 , and a back wall  28  which are all arranged to define an interior void space or chamber  29  within housing  8 . Housing  8  is preferably formed from a durable dielectric material, such as one of the well known engineering polymers, e.g., polyhalo-olefins, polyamides, polyolefins, polystyrenes, polyvinyls, polyacrylates, polymethacrylates, polypropylene, polyesters, polystyrenes, polydienes, polyoxides, polyamides and polysulfides and their blends, co-polymers and substituted derivatives thereof. Chamber  29  is sized and shaped to house power and control assembly  10 , electrode assembly  12 , and a cleaning assembly  14 . Front opening  26  provides access for cleaning assembly  14  to be placed adjacent to a portion of electrode assembly  12 , as will hereinafter be disclosed in further detail.  
         [0025]    Top wall  20  defines an opening  33  which provides access to electrode assembly  12 . Opening  33  is the main aperture for inserting needles into needle incinerator  5  for incineration. Opening  33  is preferably circular, often with a radius of between 0.3 and 1.0 inches, and preferably about 0.6 inches. A semi-spherical indentation  34  is defined along an edge of housing  8  between top wall  20  and a sidewall  24  so that needle incinerator  5  can be carried with ease. Indentation  34  may be formed on both sides of housing  8  (FIGS. 2 and 8). Clips  35  are connected in the corners of bottom  22 , and function to attach a top portion of housing  8  to bottom  22  (FIG. 4). Connection brackets  36  are positioned on the inner surface of sidewalls  24  to engage clips  35 . An annular enclosure seal  38  is positioned around the perimeter of bottom  22 . Enclosure seal  38  prevents dust and vapors from entering or exiting housing  8  through the interface of the housing top portion and bottom  22  when the housing fully assembled and operating.  
         [0026]    Referring to FIG. 4, four holes  39  are defined in the corners of bottom  22 . The primary function of holes  39  is to mount four rubber grommets (not shown) to act as feet for needle incinerator  5 . A secondary function is to provide a port for the insertion of dowels (not shown) to unlock connection clips  35  from the connection brackets  36  and thereby release housing top portion and bottom  22 .  
         [0027]    Power and control assembly  10  is positioned within chamber  29  of housing  8 , and includes a power source  40 , a momentary action switch  42  and control electronics system  44 . In a portable embodiment of the invention, direct current electrical energy is provided to electrode assembly  12  from a battery or batteries  46  located within a rear portion  47  of chamber  29 . Alternatively, when alternating current is drawn from, e.g., conventional wall outlet and a plug arrangement, a transformer (not shown) is provided within rear portion  47  of chamber  29  to convert the alternating line current to direct current for use with electrode assembly  12 . A power jack  45  is provided, and designed to sit flush with a sidewall  24  of housing  8 . Power jack  45  accepts a plug (not shown) from a standard wall plug-in AC/DC adapter for recharging of battery  46 . The choice of battery  46  or transformer is determined by the specific range of needles to be regularly incinerated with needle incinerator  5 . For example, a needle incinerator  5  designed to incinerate 20 to 30 gauge needles may use a 6 Volt, 5 Amp-hour battery to accomplish the incineration.  
         [0028]    It will be understood that other ranges of gauges of needles may be incinerated with the present invention with a proper choice of battery capacity and electrode assembly.  
         [0029]    Momentary action switch  42  preferably comprises a plunger-type actuator  48  to actuate the switch, and is electrically interconnected between power source  40 , electrode assembly  12 , and control electronics system  44 . When plunger-type actuator  48  is fully depressed, momentary action switch  42  is closed, thereby allowing current to flow to electrode assembly  12 . When plunger-type actuator  48  is fully extended, momentary action switch  42  is open, thereby stopping the flow of any current to electrode assembly  12 . Operation of a portion of cleaning assembly  14  actuates momentary action switch  42 , as will hereinafter be disclosed in further detail.  
         [0030]    Control electronics system  44  includes an operations display  50 , a display drive circuit  53 , and a battery recharge protection circuit  56 . More particularly, operations display  50  comprises at least three incinerator status indicators positioned on the surface of top wall  20 . The at least three incinerator status indicators may include a “Ready” status indication light  60 , a “Charge” status indication light  62 , and a “Clean” status indication light  64 . Status indication lights  60 , 62 ,  64  are preferably light-emitting diodes (LED) each having a different color. For example, “Ready” status indication light  60 , may be green to notify the user of needle incinerator  5  that the device is ready to incinerate a needle, and that there is sufficient power available from battery  46  to do so. “Charge” status indication light  62  may be a yellow (amber) LED to notify the user that battery  46  has a lower than needed charge and is in need of recharging. “Clean” status indication light  64  may be a red LED and, when on, notifies the user that there is a potentially harmful material lodged in an active portion of electrode assembly  12 . During operation of needle incinerator  5 , status indication lights  60 , 62 ,  64  will often flicker or go out due to a drop in voltage from battery  46 . When incineration is complete, one of the three lights will display to indicate to the user the status of needle incinerator  5 . In the event that all three lights remain off after incineration, an under-voltage condition in battery  46  is indicated, at which time battery  46  can no longer be recharged and requires replacement.  
         [0031]    Referring to FIG. 5, main circuit board  68  contains the circuitry components that drive status indication lights  60 , 62 ,  64  and the circuitry components that monitor and protect battery  46  during operation of needle incinerator  5  and recharging of battery  46 . Circuit board connection clips  69  are used to attach main circuit board  68  to the inside of top wall  20  of housing  8 . Main circuit board  68  is often split into two sections comprising display drive circuit  53  and battery monitoring and recharge protection circuit  56 , and includes the appropriate passive and active electronic components and interconnection circuitry for driving status indication lights  60 , 62 , 64  and for monitoring the load placed upon battery  46  during operation and recharging, which devices and circuitry are conventional and well known to those of ordinary skill in the art.  
         [0032]    For example, recharging lead wire  72  interconnects power jack  45  to battery recharge protection circuit  56 . Recharging lead wire  73  interconnects battery recharge protection circuit  56  to positive terminal  83  of battery  46 . LED drive circuit wire  74  interconnects battery  46  to LED drive circuit  53 . Main lead wire  75  interconnects battery  46  to the positive terminal of momentary action switch  42 . Incineration contact wires  76 , 77  interconnect momentary action switch  42  and battery  46  to electrode assembly  12  so as to form a complete circuit. Recharging wire  78  interconnects battery  46  to power jack  45  to complete the circuit. LED drive wire  79  interconnects drive circuit  53  to battery  46  so as to complete the circuit. Battery terminal  81  is the connection site for the lead wire  75  which interconnects battery  46  to momentary action switch  42  so as to complete the circuit. Battery terminal  82  interconnects lead wire  77  to electrode assembly  12  to the power source so as to complete the circuit. Terminal  84  of momentary action switch  42  interconnects electrode assembly  12 , via lead wire  76 , to momentary action switch  42  so as to complete the circuit.  
         [0033]    Referring to FIGS. 3, 5, and  6 - 8 , electrode assembly  12  comprises a negative incineration contact  100 , a positive incineration contact  102 , and an incineration chamber cowl  106 . More particularly, negative incineration contact  100  is formed from a highly conductive metal, such as copper or a copper alloy, and includes a substantially straight and elongate mounting arm  110  having a through hole  112  defined along its length and a needle engagement plate  115  positioned at one end. Through-hole  112  is sized to receive a portion of a mounting bolt or the like  116  for securely fastening negative incineration contact  100  to a bulkhead  118  positioned within a front portion of chamber  29  of housing  8 . Needle engagement plate  115  comprises a substantially flat surface defining a needle contact edge  119 , and is preferably formed from H&amp;H 72/28 silver alloy, silver solder mounted to copper.  
         [0034]    Negative incineration contact  100  is mounted to bulkhead  118  so that the longitudinal axis of mounting arm  110  is oriented substantially parallel to sidewalls  24  of housing  8 , with needle contact edge  119  of needle engagement plate  115  disposed substantially under opening  33  in top wall  20  of housing  8 . In this position, needle engagement plate  115  is oriented at an angle of between about 12 degrees to about 25 degrees, and preferably at an angle of about 17 degrees, relative to the longitudinal axis of mounting arm  110 . This angled orientation of needle engagement plate  115  allows any needles entering electrode assembly  12 , via opening  33 , and encountering needle engagement plate  115  at an angle of incidence that causes the needle to stub on its surface, to be redirected toward needle contact edge  119  of needle engagement plate  115  and positive incineration contact  102  where the incineration of the needle is effected.  
         [0035]    Positive incineration contact  102  is formed from a highly conductive metal, such as copper or a copper alloy, and includes a substantially straight and elongate mounting arm  125  having a through hole  128  defined along its length, a downwardly bent end portion  131 , and a needle engagement plate  135  fastened to a top surface of end portion  131 . Through hole  128  is sized to receive a portion of a mounting bolt or the like  141  for securely fastening positive incineration contact  102  to a bulkhead  143  positioned within a front portion of chamber  29  within housing  8 . Needle engagement plate  135  comprises a substantially flat surface defining a needle contact edge  147 , and is preferably formed from H&amp;H 72/28 silver alloy, silver solder mounted to copper.  
         [0036]    Positive incineration contact  102  is mounted to bulkhead  143  so that the longitudinal axis of mounting arm  125  is oriented substantially parallel to sidewalls  24  of housing  8 , with needle contact edge  147  of needle engagement plate  135  disposed substantially under opening  33  in top wall  20  of housing  8 . In this position, needle engagement plate  135  is oriented at an angle of between about 35 degrees to about 50 degrees, and preferably at an angle of about 45 degrees, relative to the longitudinal axis of mounting arm  125 , and also rotationally oriented at an angle of between about 2 degrees and about 6 degrees, and preferably at an angle of about 4 degrees, relative to a vertical axis directed coaxially through opening  33  in top wall  20 .  
         [0037]    Advantageously, this combination of angular positions of positive incineration contact  102  provides a tapering gap  150  between needle contact edge  119  and needle contact edge  147 . In other words, gap  150  defined between needle contact edge  119  and needle contact edge  147  is skewed such that it is narrower at one end (approximately between 0.018 and 0.024 inches) and wider at the other end (approximately between 0.028 and 0.035 inches). This feature provides a user with the capability to incinerate a large range of gauge sizes of needles, inasmuch as, larger gauge needles can be incinerated near the wider end of gap  150  and smaller gauge needles can be incinerated near narrower end of gap  150 .  
         [0038]    Incineration chamber cowl  106  is sized and shaped to enclose an upper portion of electrode assembly  12 , adjacent to negative incineration contact  100  and positive incineration contact  102 . Two or more clips  35  are used to connect incineration chamber cowl  106  to housing  8 . Use of clips  35  allows for easy installation and service of electrode assembly  12 .  
         [0039]    Referring to FIGS. 3 and 8- 9 , cleaning assembly  14  includes a residue drawer  160  and a contact broom  163 . Residue drawer  160  comprises four sidewalls  166  and a bottom  168  that together form an open receptacle that is sized and shaped to be slid through front opening  26  of housing  8 , and beneath electrode assembly  12 . A front wall  164  includes a handle  165  formed on an outer surface for grasping during the removal of residue drawer  160  from needle incinerator  5 . The primary function of residue drawer  160  is to collect the waste residue formed as a result of the incineration of a plurality of needles, and provide for the easy disposal of that residue. The secondary function of residue drawer  160  is to support contact broom  163 .  
         [0040]    More particularly, each longitudinally oriented sidewall  166  and bottom  168  include a recessed channel  170  that are sized and shaped to receive corresponding guide rails  173  located on lower portions of bulkheads  118  and  143 , and the inner surface of bottom  22  of housing  8 . Recessed channels  170  and guide rails  173  cooperate when residue drawer  160  is slid into and out of front opening  26  to properly align residue drawer  160 . This is especially important in order to orient contact broom  163  properly so as to clean incineration residue from needle contact edge  119  and needle contact edge  147 . It should be noted that when residue drawer  160  is positioned fully within housing  8 , a sidewall  166  engages and fully depresses plunger-type actuator  48  of momentary action switch  42 , thereby closing momentary action switch  42 , and allowing current to flow to electrode assembly  12  (FIG. 3).  
         [0041]    Contact broom  163  comprises an elongate rod  178  having an abrasive wire, plate, or bristle assembly  179  or any combination of the three fastened on one end. Bristle assembly  179  is sized and shaped to be slid within gap  150 , from its narrowest end to its widest end, and back, so as to scrape and brush residue, debris, etc., from needle contact edges  119 , 147 . Rod  178  is attached to a sidewall  166  of residue drawer  160  by means of clips or bolts  181  so as to project upwardly relative to bottom  168 , with contact broom  163  positioned in spaced relation to residue drawer  160 . In this way, when residue drawer  160  is slid into front opening  26  of housing  8 , and fully positioned and properly aligned with electrode assembly  12 , contact broom  163  is in coaxial aligned relation with gap  150  and spaced away from needle engagement plate  115  and needle engagement plate  135 . This spacial relationship between contact broom  163  and the needle engagement plates is especially important in order to prevent an unwanted electrical short circuit through contact broom  163  during operation of needle incinerator  5 .  
         [0042]    When residue drawer  160  is removed from housing  8 , contact broom  163  moves through gap  150  thereby sweeping needle contact edge  119  and needle contact edge  147 , and thus removing any debris or residue left from an incineration. This is especially important as any metal residue or debris left engaging both needle engagement plate  115  and needle engagement plate  135  would quickly deplete any stored charge in battery  46 , or potentially cause damage to the battery. In addition, the removal residue drawer  160  operates momentary action switch  42 . More particularly, when residue drawer  160  is removed from housing  8 , plunger-type actuator  48  is fully extended, and momentary action switch  42  is opened, thereby stopping the flow of any current to electrode assembly  12 .  
         [0043]    In operation, when battery monitoring and recharge protection circuit  56  senses a build up of debris (by monitoring an increase in load on battery  46  without incineration of a needle) status indication light  64  lights up to notify the user that needle engagement plate  115  and needle engagement plate  135  need to be cleaned. At this point, residue drawer  160  may be removed, and the collected debris and residue discarded. It should be noted that when residue drawer  160  is removed from housing  8 , plunger-type actuator  48  is fully extended, opening the circuit so that no current can flow from the power source to electrode assembly  12 . Also, when residue drawer  160  is removed, contact broom  163  sweeps through gap  150  removing any residue or debris left in the contacts after incineration of a needle. When residue drawer  160  is once again inserted completely into front opening  26 , plunger-type actuator  48  is fully depressed, closing the circuit and allowing current to flow from battery  46  to electrode assembly  12 . This process may be repeated as often as need be.  
         [0044]    It is to be understood that the present invention is by no means limited only to the particular constructions herein disclosed and shown in the drawings, but also comprises any modifications or equivalents within the scope of the claims.