Abstract:
A lifter is disclosed which allows for an improved operating envelope of the faceplate. The lifter utilizes a motor having 210 degrees of rotation and lifting arms of a unique geometry to rotate a faceplate from a retracted position below and substantially behind the lifter baseplate to a dumping position above and substantially behind a lower hopper edge for the purpose of dumping refuse carts into a refuse collection vehicle. This dumps refuse further into the vehicle hopper, which minimizes the number of packing cycles required on a collection route. A faceplate is attached to the motor using two lifting arms. The faceplate has a fixed upper hook and a sliding, retractable lower hooking mechanism. This sliding hook feature makes the lifter more compact when retracted and improves ground clearance when the lifter is mounted on the rear of a rear-loading refuse collection vehicle. Longer lifting arms may be substituted to allow for use of the lifter with a side-loading refuse collection vehicle.

Description:
RELATED APPLICATIONS  
       [0001]    This application makes reference to, claims priority to, and claims the benefit of U.S. Provisional Patent Application Serial No. 60/455,546, entitled “Refuse Collection Cart Lifter With An Improved Range Of Rotation” (Attorney Docket 14893US01), filed Mar. 18, 2003, the complete subject matter of which is hereby incorporated herein by reference in its entirety. 
     
    
     
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    [Not Applicable] 
         [MICROFICHE/COPYRIGHT REFERENCE] 
         [0003]    [Not Applicable] 
         BACKGROUND OF THE INVENTION  
         [0004]    The present invention relates to refuse container lifting devices, and in particular to refuse cart lifting devices. Refuse containers are often quite heavy, and therefore refuse collection vehicles are generally equipped with refuse container lifting devices to assist the vehicle operator when emptying the refuse containers. However, a refuse collection vehicle may encounter several different types of refuse containers on a given collection route, and the differences in these refuse containers often require the use of separate lifting devices. For example, large commercial refuse containers, or dumpsters, are typically emptied by tipping the container over the edge of the vehicle hopper using a variety of lifting devices, including tipper bars and cable and winch arrangements.  
           [0005]    Refuse carts are relatively light refuse receptacles constructed from various plastics and other synthetic materials. Features of refuse carts may include for example hinged covers, locking covers, wheels, and handles in various locations and configurations. Capacities generally range for example from 30 gallons to 95 gallons. Refuse carts typically encountered in residential areas are emptied using a refuse cart lifter capable of engaging the refuse cart, lifting it, and inverting the refuse cart to empty refuse into the vehicle hopper.  
           [0006]    Many prior refuse cart lifters presented a wide profile and thus protrude from the refuse collection vehicle so as to interfere with the emptying of commercial dumpsters when they are tipped over the edge of the vehicle hopper. Protruding cart lifters also created a hazard for the rear-loading refuse collection vehicle driver when backing up, and the side-loading refuse collection driver when navigating narrow roadways, such as alleys. Some lifter designs have addressed this problem by locating the lifter off to the side of or even completely beneath the refuse collection vehicle hopper. Others attempted to reduce the profile of the refuse cart lifter to address the lifter protrusion issue.  
           [0007]    Another problem in the refuse cart lifter industry is that cart lifters typically hang down from the refuse collection vehicle, and therefore reduce the vehicle&#39;s ground clearance, particularly on uneven ground. Thus, some lifter designs include a retracted position where the lifter is angled underneath the refuse collection vehicle hopper, rather than hanging straight down.  
           [0008]    Yet another issue involves refuse compaction cycles. Prior cart lifters continuously dump refuse into the portion of the vehicle hopper closest to the refuse cart lifter because these lifters cannot empty the refuse cart a substantial distance into the hopper when dumping. The refuse therefore quickly accumulates near the refuse cart lifter, which requires the vehicle operator to stop collecting carts and compact the refuse to prevent interference with the next lifter dumping cycle. Thus, a lifter that empties refuse carts further into the refuse collection vehicle hopper would decrease the amount of time and energy spent compacting refuse between refuse cart dumping.  
           [0009]    A final issue involves maintenance of the lifter. Elevated hydraulic loads associated with some lifters correspond to increased wear and strain on cart lifter systems. Also, some lifter motor designs are readily susceptible to damage from contaminants present in the hydraulic system and eventually require complex repairs or rebuilding that can typically only be performed at the manufacturer&#39;s facility. Finally, many lifters use bearings that require regular greasing.  
           [0010]    Thus, a need exists in the refuse collection industry for a residential refuse cart lifter that possesses a slim profile, provides improved ground clearance, decreases the amount of time and energy spent compacting refuse between the emptying of successive refuse carts, provides needed lifting capacity at lower hydraulic pressures, requires little maintenance, and is easy to repair or rebuild at the end user&#39;s facility.  
         SUMMARY OF THE INVENTION  
         [0011]    The present invention relates to a refuse cart lifter that allows for an improved operating envelope of the lifter faceplate. The improved operating envelope results from a wide range of rotation of the lifter faceplate in combination with a unique lifter arm design. This yields a refuse cart lifter that is capable of being retracted when not in use for increased ground clearance, while dumping refuse further into the refuse collection vehicle hopper than prior lifters. This added dumping range increases the efficiency of refuse collection because a vehicle operator does not have to operate the vehicle&#39;s packing blade as frequently, resulting in savings in time and energy.  
           [0012]    The presently preferred version of the refuse cart lifter utilizes a motor to rotate a lifting arm and faceplate  210  degrees for the purpose of dumping refuse containers into a receptacle. It is preferable to use a dual rack and single pinion hydraulically actuated unit as the motor due to its thin profile and superior lifting capacity at lower hydraulic pressures. This motor design also is preferable due to its open gear design, which makes it less susceptible to damage from contaminants in the hydraulic fluid system, and for the ease with which the lifter can be repaired or rebuilt at the end users facility. This actuator is based on the same design disclosed in U.S. Pat. No. 4,773,812, which is hereby incorporated by reference.  
           [0013]    The faceplate is attached to the motor using two lifting arms having a unique design that is capable of directing the faceplate substantially into the vehicle hopper when used with a motor having a wide range of rotation. The faceplate has one fixed saddle and one retractable lower hooking mechanism, or sliding latch. This allows the lifter to be more compact in its home (retracted) position and improves ground clearance when mounted on the rear of a rear loaded refuse collection vehicle. The sliding latch feature is based on the design that is disclosed in U.S. Pat. No. 5,308,211 and related patents, which are hereby incorporated by reference.  
           [0014]    Other design features include the use of composite bearing materials in exposed bearing areas, such as the bearings that form a part of the sliding latch guide, to make the unit more maintenance free by eliminating the need for regular greasing. Also, longer lifting and latch arms may be utilized to allow for mounting the lifter on the side of a side-loading refuse collection vehicle.  
           [0015]    The present lifter faceplate extends partially underneath the refuse collection vehicle in the retracted position, and therefore does not protrude significantly outward of the refuse cart lifter motor. The slim profile of the lifter motor and the retracted position of the faceplate function to preclude interference with the dumping of large commercial containers over the lifter. Thin bumpers may also be mounted to the vehicle to protect the lifter as large commercial containers are dumped into the hopper.  
           [0016]    To empty a residential refuse cart into the hopper of the refuse collection vehicle, the lifter commences an emptying cycle. During the emptying cycle, the lifter motor rotates the lifter faceplate from a retracted position partially beneath the vehicle such that a fixed saddle engages the refuse cart. As the lifter continues to rotate, the cart is lifted in a sweeping arc motion towards the hopper. Meanwhile, a sliding latch gradually engages a lower lifting point on the refuse cart to prevent the loss of the cart into the hopper as the cart is emptied. To prevent unwanted movements of the sliding latch during operation, a sliding latch guide can be incorporated, which includes bearings to reduce friction while sliding. At the end of the emptying cycle, the cart is positioned significantly inward of the outer hopper edge.  
           [0017]    An unloading cycle reverses the emptying cycle and the cart is brought back down to street level in a sweeping arc motion. As the cart descends, the sliding latch gradually disengages the lower lifting point on the refuse cart, followed by the disengagement of the upper saddle and upper lifting point on the refuse cart after the cart reaches the ground. The lifter can then be rotated further until the faceplate returns to the retracted position, substantially under the refuse collection vehicle.  
       
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       [0018]    A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:  
         [0019]    [0019]FIG. 1 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention shown in a retracted position;  
         [0020]    [0020]FIG. 2 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention shown in an intermediate position;  
         [0021]    [0021]FIG. 3 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position;  
         [0022]    [0022]FIG. 4 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown in a retracted position;  
         [0023]    [0023]FIG. 5 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown in an intermediate position;  
         [0024]    [0024]FIG. 6 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position;  
         [0025]    [0025]FIG. 7 is a front view of an exemplary refuse cart lifter in accordance with the present invention shown in a retracted position;  
         [0026]    [0026]FIG. 8 is a front view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position;  
         [0027]    [0027]FIG. 9 is a side view of an exemplary refuse cart adjacent to a refuse cart lifter in accordance with the present invention shown in a retracted position;  
         [0028]    [0028]FIG. 10 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown engaging the upper lifting point of an adjacent refuse cart;  
         [0029]    [0029]FIG. 11 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position engaging the upper and lower lifting points of a refuse cart;  
         [0030]    [0030]FIG. 12 is a perspective view of an exemplary refuse cart adjacent to a refuse cart lifter in accordance with the present invention shown in a retracted position;  
         [0031]    [0031]FIG. 13 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention shown engaging the upper lifting point of an adjacent refuse cart;  
         [0032]    [0032]FIG. 14 is a perspective view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position engaging the upper and lower lifting points of a refuse cart;  
         [0033]    [0033]FIG. 15 is a front view of the rear of a rear-loading refuse collection vehicle showing two lifters in accordance with the present invention mounted to the rear of the refuse collection vehicle;  
         [0034]    [0034]FIG. 16 is a side view of an exemplary refuse cart lifter in accordance with the present invention shown in a retracted position and mounted on a rear-loading refuse collection vehicle;  
         [0035]    [0035]FIG. 17 is a partially cut away side view of an exemplary refuse cart lifter in accordance with the present invention shown in a dumping position and mounted on a rear-loading refuse collection vehicle; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    [0036]FIG. 1 depicts a preferred embodiment of the present refuse cart lifter shown in a retracted position. The motor  60  is affixed to the front side  56  of the baseplate  52 . The motor depicted is a dual rack, single pinion hydraulic actuator capable of 210 degrees of rotation. The rear side  54  of baseplate  52  can be attached to a refuse collection vehicle or a large refuse collection container. Dual lifting arms  76  are attached at a first end  78  of the lifting arms  76  to the rotatable shaft  62  (see FIG. 4) of motor  60 . The second end  80  of the lifting arms  76  are attached to the faceplate  64 . In this view, the inner surface  66  of faceplate  64  is clearly visible, as is the saddle  74 .  
         [0037]    The inner surface  84  of a portion of the sliding latch  82  is also seen. The sliding latch  82  is connected to the baseplate  52  with dual latch arms  88 . A first end  90  of the latch arms  88  is pivotally connected to the front side  56  of baseplate  52 . A second end  92  of the latch arms  88  is pivotally connected to the sliding latch  82 . A pair of sliding latch guides  94  which limit undesirable sliding latch  82  movement in relation to faceplate  64  is also depicted.  
         [0038]    [0038]FIG. 2 depicts a preferred embodiment of the present refuse cart lifter shown in an intermediate position. In this figure, the motor  60  has rotated the lifting arms  76  and swung faceplate  64  to a position essentially parallel to baseplate  52 . Note that latch arms  88  have also swung upwards with the sliding latch  82 , which has yet to slide significantly in relation to faceplate  64  to a point where it would engage a refuse cart due to the geometry of the lifting arms  76  in relation to the latch arms  88 . Also shown in this figure is the location of the upper end  70  and the lower end  72  of faceplate  64 .  
         [0039]    [0039]FIG. 3 depicts a preferred embodiment of the present refuse cart lifter shown in a dumping position, which is the extreme opposite of the retracted position depicted in FIG. 1. In FIG. 3, the motor  60  has further rotated rotatable shaft  62  and attached lifting arms  76  past a vertical position. The resulting angle of the first end  78  of lifting arms  76  away from the back side  54  of the baseplate  52  (or towards the hopper if the lifter is mounted on a refuse collection vehicle—see FIG. 17), combined with the design of the lifting arms  76  that directs the second end  80  of lifting arms  76  even further away from the back side  54  of the baseplate  52  serves to swing faceplate  64  to a position above and substantially behind baseplate  52 . Lifting arm  76  design directs the second end  80  of lifting arms  76  away from the back side  54  of the baseplate  52  by offsetting the second end  80  of lifting arm  76  from the lifting arm using, for example, a curve or an angle in lifting arm  76 . This wide range of rotation of motor  60  and unique geometry of lifting arms  76  facilitates the dumping of refuse further into the refuse receptacle or refuse collection vehicle hopper than otherwise possible using existing lifters.  
         [0040]    Latch arms  88  have also swung upwards with the sliding latch  82 . Although better seen in FIG. 6, the first ends.  90  of latch arms  88  are pivotally attached to the front side  56  of baseplate  52 , while the second ends  92  of latch arms  88  are pivotally attached to sliding latch  82 . Latch arms  88  are of a length and geometry calculated to cause the sliding latch  82  to engage the refuse cart at some point after faceplate  64  moves from the intermediate position depicted in FIG. 2 to the dumping position. A sliding latch guide  94  prevents undesirable movements of the sliding latch, and includes bearings to reduce the sliding friction resulting from the movement of sliding latch  82 . The point at which sliding latch  82  begins to slide away from the lower end  72  of faceplate  64  can be adjusted by varying either the location of the pivotal connection of the latch arms  88  to the front side  56  of the baseplate  52 , or the length and geometry of the latch arms  88  themselves, or both.  
         [0041]    [0041]FIGS. 4 through 6 depict a side view of a preferred embodiment of the present refuse cart lifter shown in the retracted, intermediate and dumping positions, respectively, but this time from a side view. FIG. 4 shows one end of rotatable shaft  62 . In addition, this figure shows that the lower end  72  of faceplate  64  is located below and substantially behind baseplate  52  when the lifter is in the retracted position. The unique geometry of the lifting arms  76  and the latch arms  88  can also be seen. Note the effect of the lift arm  76  geometry as the lift arms  76  are rotated the full 210 degrees to the dumping position in FIG. 6. Also important is the slim profile depicted in this retracted configuration, showing the faceplate  64 , lifting arms  76 , and latch arms  66  located substantially behind the outermost face  61  of motor  60 . This facilitates the emptying of large commercial refuse containers over the refuse cart lifter, thereby enhancing the versatility of the refuse collection vehicle.  
         [0042]    [0042]FIG. 5 depicts a side view of the preferred embodiment of the present refuse cart lifter in an intermediate position. As in FIG. 2, the faceplate  64  is essentially parallel to baseplate  52 . At this point, the movement of the latch arms  88  has not yet caused sliding latch  82  to engage the refuse cart.  
         [0043]    [0043]FIG. 6 depicts a side view of the preferred embodiment of the present refuse cart lifter in the dumping position. Here it can be observed that the relative connection points and geometries of lifting arms  76  and latch arms  88  have caused sliding latch  82  to slide away from the lower end  72  of faceplate  64  as the faceplate  64  moved from the intermediate position shown in FIG. 5 to the dumping position. As discussed in reference to FIG. 3, the unique geometry of the lifting arms  76  coupled with 210 degrees of lifting arm  76  rotation from the retracted position serve to position the upper end  70  of faceplate  64  above and substantially behind baseplate  52 . This facilitates the dumping of refuse further into the receiving refuse container than otherwise possible with conventional lifters.  
         [0044]    [0044]FIG. 7 depicts a front view of the preferred embodiment of the present refuse cart lifter in the retracted position. This view shows the vertical relation of faceplate  64  to the baseplate  52 , with faceplate  64  positioned well beneath baseplate  52 .  
         [0045]    [0045]FIG. 8 depicts a front view of the preferred embodiment of the present refuse cart lifter in the dumping position. This view shows the sliding latch  82  extended out from the lower end  72  of faceplate  64 , and faceplate  64  positioned above baseplate  52 .  
         [0046]    [0046]FIGS. 9 through 11 show a side view of the emptying of a refuse cart using a preferred embodiment of the present refuse cart lifter  50 . Initially, an operator would position a refuse cart  104  adjacent to an embodiment of the present refuse cart lifter  50 , as depicted in FIG. 9 (showing a side view of a preferred embodiment of the present refuse cart lifter  50  in the retracted position). The upper lifting point  106  and lower lifting point  108  of refuse cart  104  are also illustrated.  
         [0047]    Once refuse cart  104  is positioned adjacent to refuse cart lifter  50 , refuse cart lifter  50  would be operated to rotate lifting arms  76  to swing faceplate  64  up such that saddle  74  engages refuse cart upper lifting point  106  as seen in FIG. 10. The continued operation of the lifter then causes the upper end  70  of faceplate  64  to swing over and substantially behind baseplate  52 , thereby dumping refuse from the refuse cart far behind baseplate  52  as shown in FIG. 11. In addition, while faceplate  64  is swinging from the intermediate position depicted in FIG. 10 to the emptying position shown here in FIG. 11, the relative geometries of lifting arms  76  and latch arms  88  cause sliding latch  82  to slide out and away from lower end  72  of faceplate  64  and engage refuse cart lower lifting point  108 . This prevents refuse cart  104  from falling into the refuse collection area when saddle  74  is inverted as seen in FIG. 11.  
         [0048]    [0048]FIGS. 12 through 14 depict the same sequence of events as FIGS. 9 through 11 during the emptying of refuse container  104 , but from a perspective view. A preferred embodiment of the present refuse cart lifter  50  is shown in a retracted position adjacent to refuse cart  104  in FIG. 12. FIG. 13 depicts the refuse cart lifter  50  engaging refuse cart upper lifting point  106  after lifting arms  76  have swung faceplate  64  up and away from baseplate  52 . Finally, FIG. 14 shows the refuse cart lifter  50  faceplate  64  swung to the dumping position with both saddle  74  and sliding latch  82  engaging refuse cart  104  at lifting points  106  and  108 , respectively.  
         [0049]    [0049]FIG. 15 depicts dual lifters  50  mounted to a refuse collection vehicle  100 . The refuse hopper  101  is shown, as is lower hopper edge  102 . As discussed previously, when refuse cart lifters  50  are operated to empty a refuse cart  104 , lifting arms  76  will cause faceplate  64  to swing over and substantially inward of lower hopper edge  102 . This can be seen by examining FIGS. 16 and 17, which depict a refuse cart lifter  50  mounted on a rear-loading refuse collection vehicle  100 .  
         [0050]    [0050]FIG. 16 depicts a preferred embodiment of the present refuse cart lifter  50  shown in a retracted position and attached to a refuse collection vehicle  100 . This figure emphasizes the slim side profile of the lifter, which facilitates the dumping of large commercial containers over the refuse cart lifter  50  when in the retracted position. FIG. 17 depicts the refuse cart lifter  50  in a the dumping position, and offers a cutaway view (represented by jagged lines) of the refuse collection vehicle hopper showing the upper end  70  of faceplate  64  angled over the baseplate  52  and extending substantially inward of lower hopper edge  102 . An embodiment of the present refuse cart lifter could also be readily mounted to a side-loading refuse collection vehicle (not shown).  
         [0051]    The words used above are words of description rather than of limitation. Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. It should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.  
         [0052]    For example, a refuse cart lifter in accordance with this invention could utilize a single lifting arm or a single latch arm, or various multiples of each or both. Furthermore, the lifter could be mounted to freestanding refuse containers, intermediate containers, rear-loading refuse collection vehicles, or side-loading refuse collection vehicles. Thus, it should be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims.