Patent Abstract:
The present invention discloses a waste disposal apparatus including a container having a first end and a second end. A tubing cassette for supplying tubing is mounted proximate the first end of the container. A first sealing member and a second sealing member are moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing members, and a closed position, wherein the first and second sealing members can be activated to create a seal in the tubing. The first and second sealing members are guided by guide pins that travel along stepped channels for moving the first and second sealing members between the open and closed positions, and for pulling the tubing and waste packages through the waste disposal apparatus.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a waste disposal apparatus and, more particularly, to an apparatus particularly suited for the sanitary and odorless disposal of waste such as soiled diapers. 
     2. Description of the Related Art 
     There are a number of systems for disposing of waste materials such as soiled diapers. The systems are often touted as a convenient way to dispose of such waste materials and reduce or eliminate any odor that may emanate from the materials. An example of such systems is U.S. Pat. No. 5,147,055 which discloses a diaper container that includes an activated charcoal filter to retain and absorb orders within the container. 
     European patent application No. 0005660, the contents of which are incorporated by reference herein, describes a device for disposing kitchen refuse in packages enclosed by flexible tubing derived from a tubular pack of tubing surrounding a tubular guide. The device includes a tube sealing mechanism. The tubing passes from the pack over the top of and then down the guide to a position beneath the guide where it has been closed by fusion to provide a receptacle within the guide means. When this receptacle is full of refuse, a lever is manually operated to actuate an electromechanical apparatus including clamping and fusion devices that travel round closed tracks to perform the four-fold task of drawing the receptacle down below the tubular guide, fusing the tubing walls together to seal the top of the receptacle, sealing the tubing walls together to provide the closed base of the next receptacle and dividing the tubing by heat at a location between these two fusion locations to separate the filled package. There are a number of disadvantages with this device including the need for latches to prevent the wheels extending from the heating elements from inadvertently returning up the central track portions (as opposed to following the outer track portions as they should. A further disadvantage is that the heating element must be at least the width of the tube in order to seal the tube all the way across thereby preventing, for example, the escape of odors from the waste. 
     Another device for use in disposing of diapers is disclosed in U.S. Pat. No. 6,370,847 to Jensen, et al., and U.S. Pat. No. 6,516,588 to Jensen, et al., the contents of which are incorporated by reference herein. The devices disclosed include tube sealing mechanisms. These related patents disclose a sealable diaper-disposal system that includes a container body  44 , a tubular core  63  in which flexible tubing  62  is stored, and a pair of heating elements  76  and  78 . The tubing  62  extends between two sealing members  76  and  78  that are operable to move toward each other to seal across the width of the tubing  62  and away from each other to allow the tubing  62  to be pushed into the lower portion of the container body  44 . A disadvantage of the Jensen system is that the soiled diaper must be pushed into the device beyond the tubular core  63  and the separated sealing members  76  and  78  so the sealing members can seal the tubing  62  to form a closed package with diaper enclosed. A further disadvantage is that the heating elements  76  and  78  must be at least the width of the tubing  62  in order to seal the tubing all the way across. 
     Another popular approach to disposing of such diapers has been with a device using a tube twisting mechanism to form a pouch about the diaper. As an example, see the disclosures of U.S. Pat. Nos. 4,869,049, 5,590,512, 5,813,200, the contents of all of which are incorporated by reference herein. 
     The U.S. Pat. No. 5,813,200 discloses a device for disposing of soiled diapers in twisted packages. The device has a container body with a hinged base, a hinged lid, and an upward cylinder secured within the container body. A tubular core rests on a portion of the upward cylinder to allow rotation there between. A flexible tube or sleeve rests on a portion of the tubular core with the tubing being circumferentially pleated as stored. Springs are fixed to the container and project radially inward to engage a package formed from the tube. The springs are equally spaced around the interior of the container to hold the package during the forming of a twist in the tube. 
     The device disclosed in U.S. Pat. No. 5,813,200 is used to form a series of packages enclosing objects. The top of the flexible tubing is pulled upwards and tied into a knot. The closed end formed by the knot can then form the bottom of a package with the sidewalls formed by the tubing. The object is inserted and rests against the tubing near the knot. A rotatable interior lid is put into place and rotated such that the unused tubing and the tubular core rotate with respect to the package that is being formed. The package being formed does not rotate because it is held in place by friction between it and springs. Thus a package is formed between the knot and a first twist. Subsequently, objects are disposed and twisted in a like manner to form discrete packages with twists between them. 
     Devices such as that disclosed in U.S. Pat. No. 5,813,200 are a convenient way of disposing of soiled diapers. A disadvantage of the system is that the twists between packages may become unraveled, thereby allowing groups of diapers to collect within the tubing, which makes emptying the container more difficult. Further, the twists do not create a continuous, complete seal and, therefore, may allow odor to escape from a package. Increasing the twists between packages may eliminate the above disadvantages, however, this requires the use of additional tubing. 
     From the above it can be understood by those having ordinary skill in the art that there are a number of disadvantages associated with prior art waste disposal devices using flexible tubing to form packets for disposal of waste materials. It is clear that a device is needed that will eliminate the disadvantages described above. Such a device should be relatively economical to purchase and operate, ensure that the seals between packets are complete and cannot come undone, and be easy to operate. 
     SUMMARY OF THE INVENTION 
     The inventors of the present invention disclose a waste disposal apparatus including a container having a first end and a second end; a tubing cassette for supplying tubing, the tubing cassette mounted proximate the first end of the container; a first sealing member having ends and a second sealing member having ends, the first and second sealing members mounted to the container with their lengths in parallel relationship, positioned between the tubing cassette and the second end of the container, and moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing members, and a closed position, wherein the first and second sealing members can be activated to create a seal in the tubing; a first pair of guide pins each mounted to an end of the first sealing member and biased to move away from each other; a second pair of guide pins each mounted to an end of the second sealing member and biased to move away from each other; a first pair of channels between which the first sealing member is positioned and in each of which one of the first pair of guide pins travels as the first sealing member moves between the open position and the closed position; and a second pair of channels between which the second sealing member is positioned and in each of which one of the second pair of guide pins travels as the second sealing member moves between the open position and the closed position. 
     The inventors further disclose a waste disposal apparatus including a container having a first end and a second end; a tubing cassette for dispensing tubing, the tubing cassette mounted proximate the first end of the container and rotatable in relation to the container, said dispensed tubing being operationally positioned with respect to the container such that a twist can be formed in the tubing to form a receptacle closed on a first end, into which waste material may be placed; a retention means positioned between the tubing cassette and the second end of the container for preventing rotation of a tubing receptacle filled with waste material when the tubing cassette is rotated; and a first sealing member and a second sealing member mounted to the container between the tubing cassette and the second end of the container and moveable between an open position, wherein tubing from the tubing cassette can pass between the first and second sealing means, and a closed position, wherein a twist formed in the tubing can be sealed. 
     The inventors further disclose a method for disposing of waste material including the steps of providing a length of tubing having a first sealed portion of the tubing at a location along its length and an open end of the tubing; inserting waste material through the open end of the tubing until it contacts the first sealed portion of the tubing to form a waste package; retaining the waste package such that the waste package does not rotate in relation to the open end of the tubing; rotating the open end of the tubing such that a twist is formed in the tubing between the open end of the tubing and the waste package; and sealing at least a portion of the twisted tubing to form a second sealed portion. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       A more complete appreciation of the invention and the advantages thereof will be more readily apparent by reference to the detailed description of the preferred embodiments when considered in connection with the accompanying figures, wherein: 
         FIG. 1  is a side elevation view of an apparatus for packaging waste in individual packages distributed along a length of flexible tubing; 
         FIG. 2  is a perspective view of the sealing mechanism shown in  FIG. 1 ; 
         FIG. 3  is an exploded view of the sealing member housing and associated components shown in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the sealing member housing and associated components shown in  FIG. 2 ; 
         FIG. 5  is a side elevation view of a tube sealing mechanism in a start/end position; 
         FIG. 6  is a side elevation view of a tube sealing mechanism in a partially lowered position; 
         FIG. 7  is a side elevation view of a tube sealing mechanism in a lowered position; 
         FIG. 8  is a side elevation view of a tube sealing mechanism in a partially raised position; 
         FIG. 9  is a side elevation view of a tube sealing mechanism in a raised position just after the heating elements meet; and 
         FIG. 10  is a side elevation view similar to  FIG. 1 , wherein an inner lid is rotated to twist one end of the flexible tubing material that contains waste prior to sealing the twisted area with a tube sealing mechanism. 
     
    
    
     It is notable that similar items depicted in the figures may be given the same item number (e.g., all guide pins are identified with item number  42 , all stepped channels are identified with item  48 ), and similar items depicted in the figures that are not specifically numbered may be referred to by the same item number (e.g., all inner channels are referred to as item  94 ). 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A waste disposal apparatus is disclosed for disposing of waste materials such as soiled diapers. The apparatus has improved features over prior art devices including, for example, tube twisting and sealing mechanisms that ensure the seals between packages are airtight, compact, and facilitates automation of the sealing process. Also disclosed are attributes that reduce the complexity of such mechanisms and reduce the cost to manufacture and assemble the same. 
     Referring to  FIG. 1 , an apparatus in accordance with an embodiment of line present invention is illustrated at  10 . The apparatus  10  includes a cylindrical container  12  having a removable cover  14  at the top of the cylindrical container  12  and an access door  15  at the bottom of the cylindrical container  12 . The removable cover  14  has an opening covered by a hinged lid  16 . The apparatus  10  further includes a tube twisting mechanism  18  and a tube sealing mechanism  20 . Specific embodiments these mechanisms arc described herein below, however, various other mechanisms that may be employed to obtain advantages (e.g., improved seals between waste packages, more economical heating element configuration) of the invention as discussed in detail herein. Exemplary tube twisting mechanisms are disclosed in U.S. Pat. No. 6,128,890 and U.S. Publication No. US 2002/0162304, the contents of all of which are incorporated by reference herein. Exemplary tube sealing mechanisms are disclosed in U.S. Pat. Nos. 6,065,272 and 6,370,847, the contents of all of which are incorporated by reference herein. 
     Tube twisting mechanism  18  includes a channel-shaped flange  22  that is located inside of and fixed to the cylindrical container  12 , a tubing cassette  23  resting on the channel-shaped flange  22 , and an inner lid  28  mounted to the tubing cassette  23 . The tubing cassette  23  has a tubular core  24  and a continuous length of flexible tubing  26  stored in within the tubular core  24 . An exemplary tubing cassette is disclosed in U.S. Pat. No. 4,934,529, the contents of which are incorporated by reference herein. When the inner lid  28  is rotated it causes the tubing cassette  23  to rotate in relation to the channel-shaped flange  22 . Flexible tubing  26  is shown to extend from the top of the tubing cassette  23 , over the inner lid  28 , and through the center of the tubular core  24  of the tubing cassette  23 . Waste packages  29  are shown formed at the free end of the flexible tubing  26  within the cylindrical container  12 . A flat flange  30  extends from the cylindrical container  12 . A plurality of retention means, for example, retention springs  32  are attached to the flat flange  30  and retain or hold a waste package  29  stationary while the inner lid  28  is rotated to twist the flexible tubing  26 . As used herein, the term “retention means” shall include any retention device for retaining a waste package  29  stationary while the flexible tubing  26  is rotated. The term shall include, for example, retention devices as disclosed in U.S. Pat. Nos. 4,869,049, 5,590,512, 6,170,240, 6,128,890, 6,370,847, JP 592039015 (P2000-247401 A), and U.S. Patent Publication No. US 2002/0162304, the contents of all of which are incorporated by reference herein. 
     Tube sealing mechanism  20  includes a sealing member housing  36  in which a first sealing member  38  and a second sealing member  40  are housed. As described in more detail herein below, the first and second sealing members&#39;  38  and  40  are configured to heat a twist created in the tubing  26  by the tube twisting mechanism  18 . Guide pins  42  extend from the first and second sealing members  38 ,  40 , protrude through longitudinal openings  44  in the sealing member housing  36 , protrude through the upper ends of guide links  46 , and engage with stepped channels  48 . The stepped channels  48  are formed in base plates  49  which are attached to the cylindrical container  12 . 
     The lower end of the guide links  46  are pivotally attached by pivot pins  50  to the upper ends of pull bars  51 . The lower ends of the pull bars  48  are pivotally attached by pivot pins  52  to an actuation lever  54 , which is pivotally attached by one end to the cylindrical container  12  by pivot pins  56  and its other end extends through the sidewall of the cylindrical container  12 . A pedal  58  is attached to the end of actuation lever  54  that extends out of the cylindrical container  12 . Pneumatic spring cylinders  60  are connected between the sealing member housing  36  and the cylindrical container  12 . 
     It is notable that the term “waste package” is used broadly herein to describe flexible tubing enclosing waste material and sealed on one end of the package (e.g., the “waste package” formed above the sealing member housing  36  with only one end of the package sealed), or flexible tubing enclosing waste material and sealed on both ends of the package (e.g., the “waste packages”  29  formed below the sealing member housing  36  with both ends of the package sealed). 
     Referring to  FIGS. 1 and 2 , in one embodiment of the invention the first sealing member  38  includes a heating element  62  and the second sealing member  40  includes a backing element  64 . Of course, the first and second sealing element may, in an alternative embodiment, both be heating elements. When the heating element  62  and backing element  64  are in contact, or the closed position, the heating element  62  is sufficiently pressed against the backing element  64  and energized so that a seal forms in the flexible tubing  26 . The sealing in the embodiments of  FIGS. 1 and 2  is performed through thermal heating of the flexible tubing  26 , however, as would be understood by one of ordinary skill in the art, sealing may also be obtained by ultrasonic techniques, application of adhesive to the tubing, activation of adhesive in the tubing material, or other sealing techniques. The heating element  62  is powered through an electrical cord  66  attached to a transformer  68  through a timing switch  70 . The transformer  68  receives power from a standard 115 volt outlet through a standard electrical cord and plug  72 . Alternative power sources may be provided. A magnetically activated proximity switch  74  is mounted to the top of one of the base plates  49 . The proximity switch  74  is connected to the timing switch  70  for activating the switch  70 , which in turn activates the heating element  62  for a predetermined amount of time to seal the flexible tubing  26 . The proximity switch  74  is activated by a magnet  76  that is attached to the top of the sealing member housing  36 . 
     Referring to  FIG. 3 , an exploded view of the sealing member housing  36  of FIG.  2  and associated components is shown. The sealing member housing  36  of such embodiment includes an upper half  80  and a lower half  82 , which are fastened together with fasteners  84 . The first and second sealing members  38 ,  40 , having length approximately equal to “L” (the width of the first and second sealing members  38 ,  40 ) are slidingly assembled between the upper and lower halves  80 ,  82  of the sealing member housing  36 . Springs  86  urge the guide pins  42  out of their mounting holes in the first and second sealing members  38 ,  40 , and toward the bottoms of their respective stepped channels  48 . Springs  88  urge the first and second sealing members  38 ,  40  toward each other. 
     Referring to  FIG. 4 , a cross-sectional view of the sealing member housing  36  and associated components is shown. The first and second sealing members  38 ,  40  are urged toward each other by springs  88 , thereby causing heating element  62  to contact backing element  64 . Backing element  64  is also separately urged by springs  90  against heating element  62 . This arrangement enables more precise adjustment of pressure between the backing element  64  and the heating element  62 , and also compensates for tolerance inaccuracies between the components (e.g., tolerance inaccuracies between the stepped channels  48 ). Alternatively, heating element  62  can be separately urged by a spring (not shown) against backing element  64  (which may or may not be spring loaded) to provide the same advantages. 
     Referring to  FIG. 2 , the stepped channels  48  include ramps and steps to ensure that each pair of guide pins  42  mounted to the first and second sealing members  38 ,  40  travel around the stepped channels  48  in the same direction. It should be readily apparent that all four of the stepped channels  48  include similar features. Considering one stepped channel  48  (the right-hand stepped channel in  FIG. 2 ) and following the path that a guide pin  42  would travel during operation of the tube sealing mechanism  20 , an upper channel  92  has a relatively flat bottom and is about horizontal. When the tube sealing mechanism  20  is activated by a user (e.g., by stepping on pedal  58 , FIG.  1 ), the sealing member housing  36  is urged downward. Consequently, guide pin  42  follows an inner channel  94  downward. Inner channel  94  is tapered inward (i.e., toward the sealing member housing  36 ), thereby causing guide pin  42  to be pressed into the first sealing member  38  against the bias of spring  86 . The inner channel  94  intersects a lower channel  96 . The lower channel  96  is at about the same depth as the upper channel  92 , therefore a step  96  is formed between the inner channel  94  and the lower channel  98 . As the guide pin  42  travels over the step  98 , it snaps outwardly (i.e., away from the sealing member housing  36 ). When the sealing member housing  36  is allowed to travel upward (e.g., by releasing pedal  58 , FIG.  1 ), the guide pin  42  travels upwardly due to the bias of the pneumatic springs  60  against sealing member housing  36 . Because of the step  98  between inner channel  94  and lower channel  96 , and the angle of lower channel  96 , the guide pin  42  follows lower channel  96  to an outer channel  100 . Outer channel  100  is tapered inward (i.e., toward the sealing member housing  36 ), thereby causing guide pin  42  to be pressed into the first sealing member  38  against the bias of spring  86 . The outer channel  100  intersects the upper channel  92 . A step  102  is formed between the outer channel  100  and the upper channel  92 . As the guide pin  42  travels over the step  102 , it snaps outwardly (i.e., away from the sealing member housing  36 ). Thereafter springs  88  urge the first and second sealing members  38 ,  40  toward each other. Guide pin  42  travels in upper channel  92  until it contacts the end of the channel (i.e., at the intersection of the upper channel  92  and the inner channel  94 ). 
     Referring to  FIGS. 5-9 , there is shown sequentially a sealing cycle embodiment of the invention. In such sealing cycle the flexible tubing  26 , any waste contained therein, and any waste package  29  attached thereto are pulled downwardly into the lower portion of cylindrical container  12 ; the first and second sealing members  38 ,  40  are separated to move upwardly past the waste-filled flexible tubing  26 ; the first and second sealing members  38 ,  40  are urged toward each other so the heating element  62  and backing element  64  are in contacting relationship; and the heating element is energized to seal the flexible tubing  26 , thereby forming a waste package  29 . 
     Referring to  FIG. 5 , there is shown yet another embodiment wherein the tube sealing mechanism  20  is in the start position. That is, sealing member housing  36  is shown in a start position, for example, a user has not pressed the pedal  58  downwardly, wherein the pneumatic springs  60  maintain the sealing member housing  36  in the upper position; the first and second sealing members  38 ,  40  are urged toward each other by springs  88 ; the guide pins  42  are positioned in the stepped channels  48  at the intersection of the upper channels  92  and the inner channels  94 ; and the heating element  62  and backing element  64  grip a sealed portion of the flexible tubing  26  between a waste-filled portion of the flexible tubing  26  positioned above the heating element  62  and backing element  64 , and a waste package  29  positioned below the heating element  62  and backing element  64 . 
     Referring to  FIG. 6 , the tube sealing mechanism  20  is shown just after having been actuated, for example, by a user stepping on pedal  58  (FIG.  1 ). That is, the sealing member housing  36  is shown in a partially lowered position, wherein the pneumatic springs  60  are partially compressed; the first and second sealing members  38 ,  40  are urged toward each other by springs  88 ; the guide pins  42  are positioned in the stepped channels  48  in inner channels  94 , partially pressed into the first sealing member  38  and the second sealing member  40  because of tapers in inner channels  94 ; the heating element  62  and backing element  64  grip a sealed portion of the flexible tubing  26  between the waste-filled portion of the flexible tubing  26  positioned above the heating element  62  and backing element  64 , and the waste package  29  positioned below the heating element  62  and backing element  64 ; and the flexible tubing  26 , waste contained therein, and waste package  29  attached thereto are pulled downwardly toward the lower portion of cylindrical container  12 . 
     Referring to  FIG. 7 , the tube sealing mechanism  20  is shown in a lowered position after having been fully actuated and released, for example, where a user pressed pedal  58  completely downwardly and just released the pedal  58  (FIG.  1 ). That is, the sealing member housing  36  is shown in a lowered position, wherein the pneumatic springs  60  are about fully compressed; the first and second sealing members  38 ,  40  are separating because guide pins  42  are positioned in stepped channels  48  in lower channels  96  moving toward outer channels  100  due to the force exerted by pneumatic springs  60 . Note that guide pins  42  cannot move upwardly into inner channels  94  because of steps  98  (FIG.  2 ). 
     Referring to  FIG. 8 , the tube sealing mechanism  20  is shown in a partially raised position. That is, the sealing member housing  36  is shown in a partially raised position, wherein the pneumatic springs  60  are partially compressed and urging the sealing member housing  36  upwardly; the first and second sealing members  38 ,  40  are separated from each other because the guide pins  42  are positioned in the stepped channels  48  in outer channels  100 , partially pressed into the first sealing member  38  and the second sealing member  40  because of the tapers in outer channels  100 ; and the first and second sealing members  38 ,  40  are sufficiently separated to clear the waste-filled portion of the flexible tubing  26 . 
     Referring to  FIG. 9 , the tube sealing mechanism  20  is shown in a fully raised position. That is, the sealing member housing  36  is shown in a fully raised position, wherein the pneumatic springs  60  are fully extended, maintaining the sealing member housing  36  in the fully raised position; the first and second sealing members  38 ,  40  are urged together by springs  88  because the guide pins  42  had passed over steps  102  in the stepped channel  48  and thereafter followed the upper channels  92  toward the intersection of the upper channels  92  and the inner channels  94 ; the heating element  62  and backing element  64  are in contact and press the upper end of the waste-filled portion of the flexible tubing  26 ; and the magnet  76  causes the proximity switch  74  to activate timing switch  70  to provide electrical power to the heating element  62  for a predetermined amount of time to seal the flexible tubing  26 . Once the timing switch  70  turns off, the heating element  62  will cool and the tube sealing mechanism is ready to begin another cycle. 
     It should be readily apparent to those having ordinary skill in the art that other sealing cycles can be used. For example, the sealing member housing  36  can start in the lower position (e.g., wherein the guide pins  42  are positioned at the intersection of the inner channels  94  and the lower channels  96 ). In such case, the pneumatic springs  60  would be of the type to bias the sealing member housing  36  downward and the guide links  46 , pull bars  51 , and actuation lever  54  would be configured to cause the sealing member housing  36  upward. 
     Referring to  FIG. 10 , a side elevation view similar to  FIG. 1  is shown, wherein a tube twisting mechanism  18  is used to twist flexible tubing  26 . That is, the inner lid  28  is rotated in direction “A” to twist the flexible tubing material  26 , thereby forming a waste package  29  prior to sealing the twisted area  110  with the tube sealing mechanism  20 . A significant advantage of twisting the flexible tubing  26  prior to sealing with the tube sealing mechanism  20  is that twisting makes it possible to use a substantially shorter heating element  62  and backing element  64  (i.e., substantially shorter than length “L”,  FIG. 3 ) since the width of the area to be sealed is only as wide as the twisted area  110 . In addition, twisting the flexible tubing  26  prior to sealing eliminates the need to include a tube cutting mechanism, which have been found to get clogged after repeated use, since the waste packages  29  will lie more randomly in the lower portion of the cylindrical container  12  (the wide, flat seal made between waste packages  29  that have not been twisted tend to cause the packages  29  to stack up). Furthermore, by sealing the twisted areas  110 , the twisted areas will not untwist, thereby preventing the unwanted leaking of odors. Of course, it is not necessary to include a tube twisting mechanism  18  in the present invention. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made therein without departing from the spirit and scope of the invention as defined by the appended claims. For example, components in one figure can be combined with components shown in another figure.

Technology Classification (CPC): 1