Abstract:
A manual baler for compressing thin plastic sheeting for efficient recycling including downwardly extending fingers on the compression plate that serve to gather and retain the plastic sheeting during compression and a latch and twine threading system for holding the bale in compression while allowing ties to be wrapped around the bale to retain it in a compressed state.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional application 61/677,360 filed Jul. 30, 2012 and hereby incorporated in its entirety by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a baler for compressing loose material into compact bales and in particular to a baler that can facilitate the recycling of voluminous thin plastic sheeting. 
         [0003]    Thin plastic sheets and films find increasing use in modern commerce. Plastic “stretch film” may be wrapped around shipped items to stabilize, secure, and protect those items. Hospitals used large volumes of so-called “blue wrap” as part of the sterilization process of hospital instruments. Plastic films and grocery bags are used extensively in modern supermarkets. 
         [0004]    After use, these thin plastic films become unwanted waste that is difficult to recycle. A common solution is to collect loose plastic film material into “gaylord” containers (boxes approximating a 42 inch cube); however, such containers present signficant storage problems in themselves and are costly to ship, substantially consuming the recycling value of the contained material in shipping costs. 
         [0005]    On site powered baling units can be used to increase the density of such waste film for shipping, but baling units may be impractical for sites with dispersed waste generation locations necessitating a transport of loose film to the baler or the use of multiple baling units at additional cost. In facilities where space is limited, such as hospitals, large powered baling units are impractical. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a compact manual baler that is easily located at or moved between different waste generation locations to compress loose plastic film into recyclable bales. The baler provides multiple features to allow efficient handling of thin plastic sheet including a compression plate with downwardly extending flexible fingers that reduce jamming of the compression mechanism by plastic film slipping between the compression plate and the walls of the baler and a mechanism for holding the bale in compression while restraining ties are put in place. 
         [0007]    Specifically, the present invention provides a manual baler for forming bales from material. The baler provides a container having sidewalls extending upward about a base to define a volume opening upward to receive material. The container has at least one displaceable sidewall to allow removal of the material through a side opening created by displacement of the sidewall. A compression plate is attached to a lever having a first and second end, the first end pivotally communicating with the container so that the compression plate may be compressed downward into the volume by manual movement of the second end to compress the material in the volume. A catch is provided for retaining the compression plate in downward extension against upward forces by the material as well as at least one vertical slot in the displaceable sidewall allowing twine to be tied around a bale of compressed material under compression in the container with the sidewall undisplaced followed by displacement of the sidewall to remove the bale. 
         [0008]    It is thus a feature of at least one embodiment of the invention to provide a baler that can accommodate the elastic nature of thin plastic wraps causing them to recoil after compression both because of the elastic quality of the plastic and entrained air. The catch and slots allow tying of the bale while it is in compression. 
         [0009]    The catch may automatically engage when the lever is in a full downward stroke position and may be manually disengaged. 
         [0010]    It is thus a feature of at least one embodiment of the invention to provide a manual system that may be readily operated by a single individual. Automatic engagement of the catch allows the operator to use both hands on the lever to fully compress the material. 
         [0011]    The lever may be attached to a spring biasing the lever and compression plate in an upward position. 
         [0012]    It is thus a feature of at least one embodiment of the invention to provide an ability to park the compression plate in an upward position so as not to interfere with access to the opening of the container permitting the container to be loaded with thin plastic sheet or the like. 
         [0013]    The compression plate may attach to the lever by means of a strut extending between a top surface of the compression plate and the lever to attach to the lever between the first and second ends. The strut may pivot so that the compression plate may be removed from above the volume of the container. 
         [0014]    It is thus a feature of at least one embodiment of the invention to allow the compression plate to be pulled forward for superior access to the container for loading the container. 
         [0015]    When the compression plate is biased in an upward position, an upper rear surface of the compression plate may interlock with a front sidewall edge of the container preventing upward movement when the compression plate is removed from above the volume to a front of the container. 
         [0016]    It is thus a feature of at least one embodiment of the invention to secure the compression plate against inadvertent interference with the loading of the container. 
         [0017]    The manual baler may further include tabs on an outer surface of non-displaceable sidewall opposite the displaceable sidewall for retaining twine attached to the tabs to loop over an upper edge of the non-displaceable sidewall into the volume and out of the slots. 
         [0018]    It is thus a feature of at least one embodiment of the invention to provide a simple one person tying of the bales by providing a way of holding loose ends of tying twine or the like during the baling process. 
         [0019]    The second end of the lever may have handlebars extending substantially perpendicularly from the second end to be grasped by hands of a user facing the baler. 
         [0020]    It is thus a feature of at least one embodiment of the invention to encourage effective two-handed compression techniques by operators of the baler. 
         [0021]    The compression plate may attach to the lever by means of a telescoping strut communicating between a top surface of the compression plate and the lever between the first and second ends, the telescoping strut including a lock holding either of two extension lengths against compression to allow steps of compaction of the plastic material with the telescoping strut in each of the two extension lengths. 
         [0022]    It is thus a feature of at least one embodiment of the invention to accommodate the substantial compression required of loose thin film plastic while limiting the lever to a mechanically advantageous range using successive extensions of the strut. 
         [0023]    The manual baler may further include a pair of wheels positioned at a lower edge of a given sidewall opposite the displaceable sidewall and a handle positioned at an upper edge of the given sidewall to be grasped to tip the container to rest solely on the wheels for transportation. 
         [0024]    It is thus a feature of at least one embodiment of the invention to provide a baler that may be readily transported to locations in which thin plastic sheet or the like accumulate. 
         [0025]    The compression plate may include on its lower face abutting the material in the volume, multiple downwardly extending fingers sized to deform and draw plastic sheet material at an interface with the compression plate away from the walls of the container during compression of the material. 
         [0026]    It is thus a feature of at least one embodiment of the invention to accommodate the tendency of thin plastic sheeting to slip between a compressing plate and a sidewall of the container, jamming the same. 
         [0027]    The fingers may extend at least one-half inch downward. 
         [0028]    It is thus a feature of at least one embodiment of the invention to provide for a compression plate adapted for use with thin plastic film 
         [0029]    The fingers may be an elastomeric material. 
         [0030]    It is thus a feature of at least one embodiment of the invention to provide fingers that better engage and retain the plastic film during the compression process. 
         [0031]    These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a perspective view of a manual baler according to the present invention having a manually operated lever communicating by means of a strut to a compression plate fitting within a container, the container having a front sidewall door shown in an open position for removing a bale; 
           [0033]      FIG. 2  is a perspective view of the compression plate and the strut showing the latter&#39;s telescopic construction and showing film-retaining fingers extending downward from the bottom of the compression plate; 
           [0034]      FIGS. 3   a  and  3   b  are simplified side elevational cross-sections of the manual baler of  FIG. 1  showing two stages of compression of a bale with the strut in a first short and second longer position; 
           [0035]      FIG. 4  is a fragmentary perspective view of an upper end of the container of the manual baler of  FIG. 1  with the lever, strut, and compression plate and supporting elements removed to better show tabs on a rear wall for supporting baling twine or the like to be threaded downward into the container and out of the slots in the front door of the container; 
           [0036]      FIGS. 5   a  and  5   b  are simplified elevational views similar to  FIGS. 3 , the first showing the compression plate in a stowed position for insertion of material into the container and the positioning of the twine prior to that insertion and the second showing additional compression of the material after threading of the twine around the bale and then continued compression while the twine is tied with the lever in a latched downward position; 
           [0037]      FIG. 6  is a fragmentary side view of the compression plate in the stowed position and showing an interlocking between a front lip of the container and the rear lip of the compression plate retained by upward biasing of a spring (not shown in  FIG. 6 ); 
           [0038]      FIG. 7  is a fragmentary detail side view of the lever as latched to a front edge of the container, for example, in the position shown in  FIG. 5   b;    
           [0039]      FIG. 8  is a fragmentary rear view of the container with the lever removed for clarity showing wheels and a handle allowing ready transportation of the container; 
           [0040]      FIG. 9  is an exploded perspective view of the container of the manual baler of  FIG. 1 , with the handle removed for clarity, showing installation of a baling bag allowing the manual baler to have additional use in compressing conventional loose materials that are difficult to bale such as aluminum cans; and 
           [0041]      FIG. 10  is a figure similar to that of  FIG. 2  showing an alternative compression plate suitable for use with cans, this compression plate promoting dimpling and then buckling of the can material. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0042]    Referring now to  FIG. 1 , a manual baler  10  following the teachings of the present invention may generally provide a container  12  having tour planar walls  14  including a left sidewall  14   a,  a rear wall  14   b,  a right sidewall  14   c  and a front wall  14   d  each extending upward from corresponding edges of a lower rectangular base  16  and joined at vertical edges to define a volume  18  therebetween. 
         [0043]    A lower portion of the front wall  14   d  operates as a door that is hinged at one vertical edge to be displaced from the volume  18  by swinging open to allow removal of a compressed bale (to be discussed below) through that opening. The front wall  14   d  may be latched in a closed position by means of a latch elements  17   a  at a font edge of right sidewall  14   c  joining with corresponding latch elements  17   b  on a corresponding edge of front wall  14   d.    
         [0044]    The container  12  provides an opening at an upper end  20  to allow the insertion of material downward into the volume  18  from that end  20 . As shown in  FIG. 1 , during a compression process, that opening may be blocked by a generally rectangular compression plate  22  extending horizontally within and between the walls  14  and movable vertically into and out of the volume  18 . 
         [0045]    The compression plate  22  is attached near a center of its upper side to the lower end of a strut  24 , for example, by welding the strut  24  extending perpendicularly upward from the compression plate  22 . The upper end of the strut  24  may be pivotably attached to a lever  26  between the ends of the lever  26 , the latter of which is positioned above the compression plate  22 . 
         [0046]    The lever  26  may extend from the rear of the container  12  forward over the front wall  14   d.  At its rear end, the lever  26  is attached at pivot  28  to a support  30  attached to the container  12  at a center of an upper edge of rear wall  14   b  opposite front wall  14   d  when that rear wall  14   b  is in a closed position. 
         [0047]    A front end of the lever  26  extends forward beyond the front wall  14   d  (when the front wall  14   d  is in the closed position) to attach to a set of handlebars  32  extending laterally (that is horizontally and perpendicularly to the extent of the lever  26 ) on either side of the second end of the lever  26 . The handlebars are configured to be grasped, for example, by a left and right hand of the user facing the container  12  from its front. By raising or lowering the handlebars  32 , the user may raise or lower the compression plate  22  with the mechanical advantage provided by the lever being determined by the relative distance between the location of the pivot  28  and the strut  24  and the distance between the strut  24  and the handlebars  32 . Generally this former distance is much smaller than this latter distance to provide approximately 2:1 or greater mechanical advantage. 
         [0048]    Each of the above-described components may be constructed, for example, of steel plate and steel tubing as context would require to provide a rugged assembly that may withstand forces anticipated in the baling action to be discussed. 
         [0049]    Referring, now to  FIG. 2 , the strut  24  may provide for a telescoping construction in which an outer upper rectangular tube  34  of the strut  24  fits concentrically around a lower rectangular tube  36  of the strut  24  so that the latter may slide within the former in a straight line restrained against rotation. One or more holes  38  are cut across the axis of tube  36  to align at different relative extensions of tube  36  within tube  34  with a corresponding hole  40  into tube  34 . The relative position of tube  36  with respect to tube  34  may be held in either of the least two extension lengths  44  by a pin  42 , for example, retained by a mechanical detent (such as a spring-loaded ball) on the pin  42  interacting with an inner surface of the holes  38 . Indicia  45  may be stamped or cut on one outer face of the inner tube  36  so that the indicia  45  align with a port  48  cut in a corresponding face of tube  34  to be displayed there to indicate the particular length  44  selected. 
         [0050]    A lower surface of the compression plate  22  supports a series of downwardly cone-shaped extending elastomeric fingers  46  with the base of the cones abutting and attached to a lower surface of the compression plate  22 . In one embodiment, the fingers  46  may extend downward by approximately 1-2 inches. Referring momentarily to now to  FIG. 3   a , in operation of the manual baler  10 , the fingers  46  serve to make initial contact with a bolus of loose plastic sheet material  49  as the compression plate  22  is lowered on the sheet plastic material  49  previously introduced into the container  12 . While the inventors do not wish to be bound by a particular theory, it is believed that the fingers  46  both prevent migration of the material of the plastic sheet material  49  such as would promote its jamming between the compression plate  22  and the inner walls of the container  12  and, by deforming the upper surface of the plastic sheet material  49 , draw that upper surface inward away from the walls of the container  12  facilitating compaction without jamming. Placement of the fingers  46  and their number may be adjusted for different materials by observation. The plastic sheet material  49  may, for example, be polyethylene stretch wrap or polypropylene hospital blue wrap typically having a gauge from 50 to 80 for stretch wrap (0.5-0.8 mils). 
         [0051]    Referring to  FIGS. 1 ,  2 , and  3   a , the telescoping action of the strut  24  may be used to provide for two stages of compression of the sheet plastic material  49  allowing the motion of the lever  26  to be constrained within a range of convenient and efficient operation by an operator. In the first stage of compression, the length of the strut  24  is reduced to its smallest extent and sheet plastic material  49  compressed by a first amount, for example, achieved with successive introduction of material into the container  12  and compression with the lever  26 , the latter pulled fully down. Referring now to  FIGS. 2 and 3   b , the strut may then be adjusted by removal of the pin  42  and extension of tube  36  to increase the length of the strut  24  so that pulling of the lever  26  to its full downward position, as shown, provides greater compression of the sheet plastic material  49 . 
         [0052]    Referring again to  FIGS. 3   a ,  5   a , and  6 , the lever  26  may extend slightly past the pivot  28  behind the rear of the container  12 , to attach to a gas spring  50  (or hydraulic damper) that may serve to pull down on the rear end of the lever  26  projecting beyond the pivot  28  to bias the handlebars  32  upward and hence to bias the compression plate  22  upward. With this upward bias, the lever  26  will be stably raised fully and compression plate  22  will be parked out of the container  12  with its lower rear edge adjacent to the outer upper edge of front wall  14   d  above the door portion of the front wall  14   d.  Referring momentarily to  FIGS. 1 and 4 , the upper edges of the sidewalls  14  of the container  12  may be folded outward to provide a rim  52 . As shown in  FIG. 6 , a front portion of the rim  52  associated with the upper portion of the front wall  14   d  may hook with a second rim  53  surrounding the periphery of the compression plate  22 , the two held engaged by the upward force of the compression plate  22  as transmitted through the lever  26  from the gas spring  50 . In this parked position of the compression plate  22 , material may be freely added to the interior volume  18  of the container  12  without interference from the compression plate  22 . 
         [0053]    Referring to  FIGS. 4 and 5   a , portions of the rim  52  associated with the rear wall  14   b  may include two guide slits  54  extending inward from outer peripheral edge of the rim  52  and having a separation substantially equal to a separation of corresponding vertical door slots  57  in the door portion of front wall  14   d.  These door slots  57  extend substantially a full height of the door portion of the front wall  14   d  with the exception of short upper and lower margins of the door required to retain door integrity. Ends of twine  56  or other bale-tying material may be attached to each of two tabs  58  extending outward from a rear surface of the rear well  14   b  aligned with but just below the guide slits  54 . 
         [0054]    Referring still to  FIGS. 4 and 5   a , a remainder of the length of the twine  56  is then guided upward through the guide slits  54  and downward along the inner surface of the rear wall  14   b  across the base  16  and out through the door slots  57 . After positioning of the twine  56 , and with the compression plate  22  in the parked position described above, loose sheet plastic material  49  may be inserted into the container  12  for the first stages of compression previously described with respect to  FIG. 3   a  above. 
         [0055]    After this first stage of compression, the compression plate  22  may be raised and the ends of the twine  56  removed from the tabs  58  and threaded through the upper ends of the door slots  37  of the door portion of front wall  14   d  over the top of a bolus of the material  49 . As shown in  FIG. 5   b , the second stage of compression may be undertaken with the strut  24  in its extended position and the twine  56  between the bolus of material  49  and the compression plate  22 . 
         [0056]    Referring now also to  FIG. 7 , at this point, a full downward stroke of the lever  26  brings together catch element  60  on lever  26  and catch element  62  on the rim  52  of the front wall  14   d  which engage, holding the lever  26  down against the gas spring  50  (shown in  FIG. 3   a ) and the elastic recoil of the material  49 . The latch formed of catch elements  60  and  62  may automatically engage when the lever  26  is in the full downward position. This automatic engagement may be by spring biasing (not shown) of either of the catch elements  60  and  62  according to methods well known in the art. After automatic engagement, the catch elements  60  and  62  may be released by manual operation of lever  64 , for example, on catch element  60 . 
         [0057]    As so compressed and held, the opposite ends of each length of twine  56  extending through the slots  57  above and below the bolus of material  49  may be tied together to retain the material  49  in its compressed state in a bale. Referring again to  FIG. 1 , after these ends of twine  56  are tied together, the catch elements  60  and  62  may then be released and the door portion of the front wall  14   d  may be opened and the bale removed, the door slots  57  allowing free passage of the tied twine  56  holding material  49 . 
         [0058]    A portion of the base  16  may extend forward from the container  12  beneath the closed position of the front wall  14   d  so that it may be held against a floor, for example, by the user&#39;s foot during the bale extraction process stabilizing the container  12  by preventing it from following with the removed bale. It will be appreciated that the latching provided by catch elements  62  and  64  shown in  FIG. 7  may be engaged for a period of time after each compression to allow the compressed material  49  to “set” prior to adding more material so that the previously compressed material  49  does not re-expand substantially when the compression plate  22  is retracted upward. 
         [0059]    Referring now to  FIG. 8 , wheels  70  may be attached to a lower outer edge of rear wall  14   b  by means of short axle stubs  72  in turn supported by pillow flanges  74  welded to the back of rear wall  14   b.  The short axle stubs  72  are generally parallel to the lower edge of the rear wall  14   b  and coaxial but do not extend the full width of the rear wall  14   b  eliminating possible damage or misalignment of a full axle. The wheels  70  allow the container  12  to be tipped backward by means of a handle  76  placed, for example, near the upper rear edge of rear wall  14   b.  In this way the manual baler  10  may be freely wheeled from location to location and may be placed, for example, in a closet for storage in between use. 
         [0060]    Referring now to  FIGS. 9 and 10 , the manual baler  10  of the present invention may find additional use in the compression and baling of conventional items. For example, aluminum cans  78  may be compressed in the container  12  by first placing a square bottomed plastic hag  80  as a liner in the container  12 . A square bottom plastic bag  80 , as is understood in the art, is generally seamed to conform in a relaxed but opened state to a rectangular volume  18  thus to resist tearing under the forces of compressed material pressing the bag  80  outward because the material of the bag  80  is fully supported against the walls of the container  12  and the base  16 . 
         [0061]    The process of compression for other materials such as cans  78  may be substantially the same as described with respect to  FIGS. 3   a  and  3   b  but for the addition of the plastic bag  80  and may include or not include the use of twine as shown in the previous discussion pending on the inherent elasticity of the compressed material. For compression of conventional materials, the compression plate  22  may be replaced with the compression plate  82  having for example, rigid teeth  84  in the form of a rectangular corrugation that serves to produce points of high pressure on the cans that promote their dimpling and buckling for better compression. The replacement is done easily by removing the compression plate  22  and attached tube  36  by releasing pin  42  (shown in  FIG. 2 ). 
         [0062]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0063]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0064]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.