Patent Publication Number: US-9834377-B1

Title: Lifting arm assembly for automated side loader used on refuse collection vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present utility application relates to and claims priority to U.S. Provisional Patent Application Ser. No. 62/092,056 filed Dec. 15, 2014, which is herein incorporated by reference in entirety. 
    
    
     FIELD 
     The present disclosure relates generally to an extendable and retractable automated side loader used in refuse collection, and more particularly, pertains to a lifting arm assembly of the automated side loader. 
     BACKGROUND 
     To increase the efficiency of refuse collection, many refuse collection companies use automated refuse loaders that lift a filled refuse container, and then dump the contents of the refuse container into a refuse collection vehicle. Such automated refuse loaders can service a significantly higher number of customers in a given time period when compared with manually placing refuse into the refuse collection vehicle. This increased efficiency can result in substantially lower refuse collection costs. 
     Some refuse collection vehicles utilized a cantilevered lifting arm assembly that lifts the refuse container and then dumps the refuse container into a refuse collection vehicle. Such mechanical lifting arm assembly may be mounted on the side of a refuse collection vehicle to permit refuse to be collected as the refuse collection vehicle is driven along a road. 
     One known type of lifting arm assembly used in automated side loaders relies upon chains wrapped around an axle with one end affixed to the axle, and another end anchored to a static frame and held in tension to induce rotation in a sliding frame that lifts a gripper arrangement. Such design as been found to be problematic because the chains require frequent adjustment to maintain the proper level of tension. In addition, the linkage geometry used in this type of known design leads to occasional spillage of refuse from the waste container being lifted and dumped into the refuse collection vehicle, and requires greater forces than desired to induce the rotation needed during emptying of the waste container. 
     Through research and experimentation, the inventor has determined that a need exists to design and construct a lifting arm assembly to better facilitate the efficient grasping, lifting and unloading of a waste container relative to a refuse collection vehicle and to overcome problems of prior art designs. 
     SUMMARY 
     In one example, the present disclosure relates to a lifting arm assembly movable between a grabbing position and a tipping position. The lifting arm assembly includes a static frame provided with a roller arrangement, and a dynamic frame mounted for vertical movement relative to the static frame. A grabber structure is provided with a pair of grabber arms configured for movement between a closed position and an open position. A linkage arrangement is provided having a first end pivotally connected to the dynamic frame, and a second end pivotally attached to the grabber structure. The first end includes a set of teeth arranged in meshing engagement with the roller arrangement on the static frame. Movement of the dynamic frame relative to the static frame causes pivoting of the linkage arrangement resulting in lifting movement of the grabber structure along a curvilinear path between the grabbing position and the tipping position. 
     In a further example, the present disclosure relates to a lifting arm assembly movable between a grabbing position and a tipping position, and adapted to be used in securing, lifting and emptying a waste container into a refuse collection vehicle. The lifting arm assembly includes a static frame adapted to be secured to an extendable and retractable movement mechanism mounted on the refuse collection vehicle. The static frame is provided with a roller arrangement. A dynamic frame is slidably mounted for vertical movement within the static frame. A grabber structure is provided with a pair of grabber arms configured for movement between a closed position and an open position, and is adapted to engage the waste container. A drive arm arrangement has a first end pivotally coupled to the dynamic frame, and a second end pivotally joined to the grabber structure. A control link has a first end pivotally attached to the dynamic frame, and a second end pivotally secured to the grabber structure. A first extendable and retractable piston cylinder is mounted in the static frame for vertically moving the dynamic frame within the static frame. The first piston cylinder has a base end fixed to the static frame, and a rod end joined to the dynamic frame. A second extendable and retractable piston cylinder is mounted on the grabber structure for moving the grabber arms between the opened and closed positions. The first end of the drive arm arrangement is formed as a sprocket having a plurality of teeth arranged in meshing arrangement with the roller arrangement on the static frame. Actuation of the second piston cylinder is adapted to cause the grabber arms to engage the waste container, and actuation of the first piston cylinder causes vertical movement of the dynamic frame within the static frame such that the control link and the drive arm arrangement are pivoted resulting in movement of the grabber structure along a curvilinear path between the grabbing position and the tipping position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 a    is a side perspective view of a refuse collection vehicle equipped with an automated side loader including a lifting arm assembly of the present disclosure shown in a retracted position; 
         FIG. 1 b    is a view similar to  FIG. 1 a    showing the lifting arm assembly in an extended grabbing position; 
         FIG. 1 c    is a view similar to  FIGS. 1 a  and 1 b    showing the lifting arm assembly in a tipped dumping position; 
         FIG. 2  is a bottom perspective view of the lifting arm assembly in a lowermost position; 
         FIG. 3  is an exploded perspective view of the lifting arm assembly; 
         FIG. 4  is an isolated detail view of a grabber structure of the lifting arm assembly showing a pair of grabber arms in a closed position; 
         FIG. 5  is another isolated detail view of a grabber structure showing the grabber arms in an open position; 
         FIG. 6  is a fragmentary top perspective view of the lifting arm assembly taken from the rear thereof; 
         FIG. 7  is a front perspective view of the lifting arm assembly, shown in  FIG. 2  in the lowermost position with the grabber structure in a closed position; 
         FIG. 8  is a side view of  FIG. 7 ; 
         FIG. 9  is a front perspective view of the lifting arm assembly in the position of  FIG. 7  showing the grabber structure in the open position; 
         FIG. 10  is a side view of  FIG. 9 ; 
         FIG. 11  is a front perspective view of the lifting arm assembly in a partially raised position; 
         FIG. 12  is a side view of  FIG. 11 ; 
         FIG. 13  is a front perspective view of the lifting arm assembly in an uppermost position with the grabber structure in the closed position; and 
         FIG. 14  is a side view of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings,  FIGS. 1 a , 1 b  and 1 c    illustrate a refuse collection vehicle  10  equipped with an automated side loader  12  including a lifting arm assembly  14  in accordance with the present disclosure. 
     The refuse collection vehicle  10  includes a vehicle cab  16  and a chassis  18  having a vehicle body  20  mounted thereto. The vehicle body  20  is configured with a forward receiving hopper  22  for collection of waste materials, such as from curbside waste containers, and a rearward storage compartment  24  for compacted waste. The automated side loader  12  is constructed with the lifting arm assembly  14  for securing, lifting and tipping waste containers filled with refuse into the receiving hopper  22 . The automated side loader  12  is mounted on a side of the refuse collection vehicle  10 , and typically includes an extendable and retractable movement mechanism  26  connected to the lift arm assembly  14  for laterally extending and retracting the lifting arm  14  between a waste container  28  and the side of the refuse collection vehicle  10 . The lifting arm assembly  14  is provided with an outwardly facing, shield-like chute  30  which engages against an outer surface of the waste container  28  when it is desired to empty refuse therefrom. 
     Referring now to  FIGS. 2-6 , and in particular to  FIG. 3 , the lifting arm assembly  14  is basically comprised of a static frame  32 , a fluid actuated lift piston cylinder  34 , a dynamic sliding frame  36 , a pair of spaced apart sprocket arms  38 ,  40  defining a drive arm arrangement, a control link  42 , and a grabber structure  44  defined by a grabber frame  46 , a fluid actuated grabber piston cylinder  48  and a pair of grabber arms  50 ,  52  which are movable between a closed position and an open position. 
     The static frame  32  is constructed from a pair of C-shaped channels  54  connected to a bottom plate  56  and a rear backward plate  58 . Wear plates  60  are provided along the entire lengths of oppositely facing inside surfaces of the C-shaped channels  54 . A series of vertically aligned spaced apart rollers  62  are provided between the outside surface of each C-shaped channel  54  and an elongated L-shaped channel  63 . The L-shaped channels  63  are attached to the backward plate  58  and are spaced from the C-shaped channels  54  as seen best in  FIG. 6 . The lift piston cylinder  34  is designed to be mounted within the static frame  32  and to provide powered vertical movement ultimately lifting and tilting the grabber structure  44  as will be better understood below. The lift piston cylinder  34  has a casing  64  with a base end  66  which extends through an opening in the bottom plate  56  between spaced apart ears of a bottom cylinder mount  68  at which location it is fixed by a suitable retainer. The lift piston cylinder  34  has a rod eye  70  mounted on a rod  72  which is vertically extendable and retractable relative to the casing  64 . 
     The dynamic sliding frame  36  is slidably received and retained within the static frame  32 , and is configured to rearwardly receive the lift piston cylinder  34  such that the rod eye  70  is suitably connected between spaced apart ears of a top cylinder mount  74 . The sliding frame  36  has a pair of forward side plates  76  which provide upward pivotal mounting positions for the sprocket arms  38 ,  40  and the control link  42 . 
     More specifically, tubular extensions  78  projecting laterally from the side plates  76  form passages  80  that are aligned with openings  82  in upper ends  84  of the sprocket arms  38 ,  40 . The upper ends  84  are formed as sprockets with a number of spaced apart teeth  86  which are radially spaced from the opening  82 . Valleys  87  are formed on each side of the teeth  86  for receiving the rollers  62 . An axle  88  is passed through the aligned extensions  78 , passages  80 , and openings  82  to define an upper pivotal mounting for the sprocket arms  38 ,  40  which are held pivotally mounted to opposite sides of the side plates  76  of the sliding frame  36  by placing axle caps  90  on opposite sides of the axle  88 . With the upper ends of the sprocket arms  38 ,  40  pivotally mounted to the sliding frame  36 , the teeth  86  will be in meshing engagement between the rollers  62  provided on the sides of the static frame  32 . 
     Bottom ends  92  of the sprocket arms  38 ,  40  have aligned apertures  94  which receive a pivot pin  96  that extends across tube  98  connecting spaced apart side plates  100  on the grabber frame  46 . The pivot pin  96  defines a lower pivotal mounting for the sprocket arms  38 ,  40  which are held pivotally mounted to the grabber frame  46  by placing axle caps  102  on opposite ends of the pivot pin  96 . 
     The side plates  76  of the sliding frame  36  are also provided with collars  104  in communication with holes  106  aligned with a passageway formed through a cross tube  108  formed on the upper end of the control link  42 . A pivot pin  110  is passed through the aligned collars  104 , holes  106  and the cross tube  108  to define an upper pivotal mounting for the control link  42 . Set screws may be screwed into the collars  104  against the pin  110  to maintain the upper pivotal mounting of the control link  42 . A lower end of the control link  42  has a cross tube  112  which is positioned between inwardly facing collars  114  provided on side plates  100  of the grabber frame  46 . A pivot pin  116  is passed through the aligned cross tube  112  and collars  114 , and held in place by using set screws screwed into the collars  114  against the pin  116 . The pin  116  thus defines a lower pivotal mounting for the control link  42 . 
     As best seen in  FIGS. 3, 4 and 5 , the grabber frame  46  has a lower pivot plate  118  provided with a collar  120  to which a base end  122  of the grabber piston cylinder  48  is pivotally mounted. A rod end  124  of the grabber piston cylinder  48  is pivotally connected to one side of a first grabber pivot  126  on the grabber arm  52 . The grabber pivot  126  and the grabber arm  52  are pivotally mounted to the grabber frame  46  about a pivot pin  128  suitably retained such as by a set screw. The grabber arm  50  has a grabber pivot  130  which is pivotally mounted to the grabber frame  46  by a pivot pin  132  suitably held in place, such as by a set screw. A link  134  has one end  136  pivotally attached to one side of the grabber pivot  130 , and another end  138  pivotally connected to the other side of the grabber pivot  126 . Such arrangement enables movement of the grabber arms  50 ,  52  between opened and closed positions when the grabber piston cylinder  48  is actuated. The grabber arms  50 ,  52  are provided with respective face plates  140 ,  142 . In addition, the grabber frame  46  includes a face plate  144  to which the chute  30  is attached. It should be noted that in  FIGS. 2-4, 6-8 and 11-14 , the grabber arms  50 ,  52  are shown in an extreme closed position such that the arms  50 ,  52  overlap. However, in practical use, the closed position is defined by the engagement of the arms  50 ,  52  with the side surfaces of a waste container  28 . 
     An exemplary operation of the lifting arm assembly  14  follows with reference to  FIGS. 1 a , 1 b , 1 c    and  6 - 14 . 
       FIG. 1 a    illustrates the lifting arm assembly in a lowermost retracted position against the side of the refuse collection vehicle  10  with the grabber arms  50 ,  52  in the open position. In the lowermost retracted position, the first or innermost tooth valley  87  on the sprocket arms  38 ,  40  receives the lowermost roller  62  on the static frame  32  as depicted, for example, in  FIG. 9 . When it is desired to empty a filled waste container  28 , the mechanism  26  is laterally extended towards the waste container  28 . At the same time, the lift piston cylinder  64  is actuated to begin moving the sliding frame  36  within the static frame  32  causing an increased meshing engagement of the teeth  86  with a lower group of rollers  62  as the sprocket arms  38 ,  40 , the control link  42 , and the grabber structure  44  are moved forwardly. When the chute  30  engages the waste container  28 , the grabber arms  50 ,  52  are brought into a closed position with the sides of the waste container  28  by actuating the grabber piston cylinder  48  as illustrated in  FIG. 1   b.    
     Continued actuation of the lift piston cylinder  64  results in progressive engagement of the teeth  86  with the middle portion of rollers  62 , as depicted in  FIG. 12 , causing a combined pivoting and lifting movement of the sprocket arms  38 ,  40 , the control link  42  and the grabber structure  44  engaged with the waste container  28 . Such pivoting and lifting movement continues until the teeth  86  engage the uppermost portion of the rollers  62  as seen in  FIGS. 6 and 14  to tip and dump the refuse contents of the waste container  28  into the hopper  22  of the refuse collection vehicle  10  as shown in  FIG. 1   c.    
     Operation of the lifting arm assembly  14  is reversed to return the emptied waste container  28  to its initial position. The grabber arms  50 ,  52  are released from the waste container  28  and the lifting arm assembly  14  is retracted to the position of  FIG. 1 a    after which the refuse collection vehicle  10  can be moved to a different location to repeat the above described operation for emptying a different filled waste container  28 . 
     Thus, it should be understood that the present disclosure relies upon a rolling meshing engagement of the sprocket arm teeth  86  of a linkage and drive arm arrangement  38 ,  40  with rollers  62  on a static frame  32  to provide an effective pivoting and lifting motion used in an automated side loader  12  during refuse collection. The interaction between the static frame  32 , the sliding frame  36 , the sprocket arms  38 ,  40 , the control link  42  and the grabber structure  44  provides an efficient linkage geometry which results in improved stability and structural integrity of the lifting arm assembly  14 , and requires a decrease in the forces previously required to provide cantilevered lifting during refuse collection. The lifting arm assembly  14  is designed to provide rapid and stable emptying of waste containers with a minimum of spillage during the emptying operation, and without any reliance on chains that previously required periodic adjustment. 
     It should be appreciated that certain components of the linkage geometry may be modified as desired. For example, the size of the valleys  87  between the teeth  86  of the sprocket arms  38 ,  40  and the size of the rollers  62  may be altered to provide a different pivoting and lifting motion. The present disclosure contemplates further changes and modifications without affecting the scope of the invention as defined in the claims.