Abstract:
A refuse receptacle lifter is disclosed which is movable between a retracted and a dumping position for lifting and inverting refuse receptacles of the type including spaced apart upper and lower engagement surfaces. The lifter may include an actuator with a rotary output shaft, a lift arm attached to the rotary output shaft, an upper engagement member carried at least in part by the lift arm, a first actuator arm pivotally mounted to the lift arm and a second actuator arm pivotally mounted to the base. The actuator arms are attached to an extension assembly that carries a lower engagement member. Upon rotation of the output shaft, the upper engagement member is moved between a lower retracted position and a raised position and the lower engagement member is moved between a retracted position and an extended position, for lifting and inverting a refuse receptacle.

Description:
[0001]     This application claims the benefit of Provisional Application Ser. No. 60/280,795 filed Apr. 2, 2001, and incorporates by reference the aforesaid application. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates generally to lifters for mounting on refuse collection vehicles or on fixed or portable refuse collection stations, or for use in other settings.  
         [0003]     Incorporated by reference herein are also (1) co-pending U.S. patent application Ser. No. 09/731,946 by the inventors Ramiro Arrez and Carlos Arrez, filed Dec. 7, 2000, (2) Provisional Application (Ser. No. 60/271,860) by the same inventors which was filed on Feb. 27, 2001, entitled “Retractable Lifter for Refuse Container,” and related regular U.S. application Ser. No. 10/081,654, filed Feb. 22, 2002, (3) U.S. Provisional Application (Ser. No. 60/280,091) by the same inventors filed on Mar. 30, 2001, entitled “Damage-Resistant Refuse Receptacle Lifter,” and (4) U.S. Provisional Application (Ser. No. 60/280,092) by the same inventors filed on Mar. 30, 2001, entitled “Damage-Resistant Refuse Receptacle Lifter with Face Plate.” 
         [0004]     It is now a well known practice to employ refuse container lifters for automatically lifting and dumping large residential refuse collection containers or carts. Such lifters are typically, although not exclusively, mounted on the rear of refuse collection trucks, adjacent to the refuse hopper. Although such refuse container lifters are available in a variety of shapes and configurations, there remains a continuing need for improved, more reliable and less costly lifters.  
         [0005]     More particularly, there continues to be a need for lifters that can be mounted at various heights and still reliably engage and lift refuse collection containers or carts. For example there is no single standard height for refuse collection vehicles or stations, and mounting height of the lifter (above ground level) may differ from one installation to another. Further, collection routes often involve travel along alleys or roads that have depressions, pot-holes or shoulders that cause frequent and unpredictable variations in the height of the lifter above the road surface. Similarly, the height of the refuse collection container itself may vary according to road surface conditions or according to the manufacturer or model of collection container.  
         [0006]     Accordingly, it would be desirable to have a lifter that functions well in dumping collection containers in some, if not all, of these circumstances, and it is an object of this present invention to provide such a lifter.  
         [0007]     Accordingly, it is a further object of the present invention to provide such an improved lifter suitable for dumping refuse collection carts or containers, and which may be employed in rear loader, side loader, front loader, and other applications. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS AND VIEWS  
       [0008]      FIG. 1  is a perspective view, partially removed, of a rear-loading refuse collection truck including two lifters in accordance with the present invention.  
         [0009]      FIG. 2  is an enlarged perspective view of a typical residential refuse container used with the lifter of the present invention. Although shown using a larger scale than  FIG. 1 , the refuse container actually is suitable for being loaded and dumped by either one of the lifters shown in  FIG. 1 .  
         [0010]      FIG. 3  is a perspective view of the lifter of  FIG. 1  embodying the present invention and illustrated in a lowered or retracted position.  
         [0011]      FIG. 4  is a perspective view of the lifter of  FIG. 3  in an intermediate position between the lowered or retracted position of  FIG. 3  and the raised or dumping position of  FIG. 5 .  
         [0012]      FIG. 5  is a perspective view of the lifter of  FIG. 3  in a raised or dumping position.  
         [0013]      FIG. 6  is a side view of the lifter of  FIG. 3 , showing the lifter mounted at one vertical height and in progressive positions between a lowered or retracted position and a raised position for dumping a container or cart.  
         [0014]      FIG. 7  is a side view of the lifter of  FIG. 3 , showing the lifter mounted a larger vertical height than in  FIG. 6  and in progressive positions between a lowered or retracted position and a raised position for dumping a container or cart. 
     
    
     DETAILED DESCRIPTION  
       [0015]      FIG. 1  illustrates a typical rear loading refuse collection truck of the type having a pair of sidewalls  20 , a top wall  22 , and bottom wall (not shown) forming a refuse collection body, generally at  24 . A rear load hopper assembly, generally at  26 , is mounted at the back of the collection body and includes sidewalls  28  and a curved bottom hopper wall  30 . The bottom hopper wall slopes upwardly toward a rearward sill or sill edge  32 , over which refuse is dumped into the collection hopper. For convenience, the directions corresponding to the front and rear of the truck will be the same as those used for the present invention. Although the present invention is illustrated on a refuse collection vehicle, its utility is not limited to that application and it may be mounted on stationary or portable refuse collection stations or the like.  
         [0016]     The collection truck illustrated in  FIG. 1  is adapted for dumping residential style containers (as shown for example in  FIG. 2 ). For dumping the residential style containers, the refuse collection truck in  FIG. 1  has two lifters  40  embodying the present invention mounted at the rear, although only one could also be used. Also, the lifter of the present invention is not limited to rear mounting, but may also be side mounted or mounted directly on larger refuse collection containers that are either stationary or movable, for example, by refuse collection vehicle.  
         [0017]     Before turning to a more detailed description of the lifter  40 , reference is made to  FIG. 2 , which shows a typical residential roll out refuse collection container or cart  42  for which the present lifter is intended. The typical container  42  is made of rigid plastic construction, with a body  44  and a hinged lid  46 . A pair of wheels  48  allow the container to be conveniently moved curbside or to another pickup location. The front side of the container includes a generally recessed area  50  to accommodate lifter units on the refuse collection vehicle. For cooperation with such lifters, a pair of parallel, spaced-apart lift bars  52  are firmly secured in the container body in the recessed area  50  and provide upper and lower engagement surfaces (upper and lower lift bars) for engagement by a lifter. Lid  46  is hingedly connected to the body, so that the lid is naturally opened by gravity when the container is inverted for dumping. It should be understood that refuse collection containers of the type shown, are available in a variety of styles and designs, and the present invention is not limited to any particular type style or design of refuse collection container. For example, some refuse carts have molded-in lift surfaces or areas instead of lift bars, and the lifter  40  is suited for those carts as well.  
         [0018]     Turning to  FIG. 3 , each lifter  40  attached to the back of the truck has the same basic construction. Each lifter  40  includes a base or base plate  100  for attachment to the truck, container or lift station. A rotary hydraulic actuator  102  is welded, bolted or otherwise attached to the base, and includes a rotary output shaft  104  extending from at least one and preferably both ends. When mounted on the truck or container, the output shaft extends generally horizontally and has opposed ends that extend through each end of the cylindrical rotary actuator housing. A rotary hydraulic actuator of the type sold by Helac Corporation of Enumclaw, Wash., USA, is preferred, although other types of rotary or other actuators may be used with the present invention.  
         [0019]     A lift or drive arm  106  is fixedly attached, as by a splined connection, to each end of the output shaft  104 , so as to rotate or pivot about the output shaft axis  132  as the output shaft is rotated. There is at least one, and preferably two, lift arms having first and second ends, the first end being attached to the output shaft  104  and the terminal or second ends of the lift arms being connected by a cross member  108 . The cross member mounts a saddle or hook  110  of engaging and lifting the upper bar or lift surface  52  of the refuse container or cart  40 .  
         [0020]     For capturing the cart and holding it when inverted, the lifter  40  includes a lower hook actuation assembly, generally at  112 , for moving a lower hook  114  to a position over the lower bar or engagement area  52 . This actuation assembly includes at least a first actuator arm  116  (and preferably two such arms), that is pivotally attached at a first end to the lift arm  106  at a location intermediate the ends of the lift arm, and a second actuator arm  118  that is pivotally attached at a first end to the base  100  by way of brackets  119 . An identical actuator arm pair is employed on each side of the lifter, and description of one pair will suffice for the other as well.  
         [0021]     More specifically, the first actuator arm is preferably pivotally attached to the lift arm, as seen in  FIG. 4 , between the first end and the mid-point of the lift arm, and near or in the proximity to the first end or to the output shaft  104 .  
         [0022]     The other or second ends of the actuator arms are cooperatively attached to an extension assembly, such as a telescoping arrangement, having first and second relatively movable members, such as inner and outer members of a telescoping assembly, generally at  120 . The extension assembly is operable to move the lower hook downwardly, in a direction away from the upper hook, as the lifter rotates from the lower retracted position to the raised and inverted dumping position. More specifically, in the illustrated embodiment, the second end of the first actuator arm is fixed, as by welding or the like, to a steel rod  122  that forms the inner member of the relatively slidable or telescoping arrangement, generally at  120 . The other or second end of the second actuator arm  118  is pivotally fixed to a hollow steel cylinder or sleeve  124  that forms the outer member of the relatively slidable or telescoping arrangement, and slidably receives the steel rod  122  within the bore of the cylinder. As shown more clearly in  FIG. 5  and one or more of the applications incorporated by reference above, the sleeve  124  is slotted to receive the first actuator arm as the rod moves into the sleeve. These parts could, of course, be reversed without departing from the present invention.  
         [0023]     As illustrated, cross member  126  extends between and is attached to each of the cylinders or sleeves  124 . The cross member mounts the lower hook  114  for capturing the lower bar or engagement area  52  of the container  42 . The hook may be spring biased and is flanked by a pair of rollers  128  for protecting the side of the cart or container against damage from the lower hook.  
         [0024]     In operation, the elongated lift arms  106 , which rotate with the output shaft of the actuator, form a fixed radius of rotation for the upper hook. In the retracted position, as seen in  FIG. 4 , the elongated lift arms hang nearly vertically downwardly, and the upper hook is located at the bottom end of the lift arms in proximity to the lower hook. This lower location allows the upper hook to sweep upwardly from a very low position and catch beneath the upper bar  52  or engagement surface of a container, as the lifter is rotated to a raised and inverted position. This is particularly advantageous because it allows to lifter to be mounted at different heights, depending on the particular vehicle or location where mounted, and still be very effective in lifting and dumping containers. As seen, for example in  FIGS. 6 and 7 , the lifter may be mounted at very different heights and still function effectively in lifting and dumping containers, due the very low position of the upper hook when the lifter is in the retracted position.  
         [0025]     The movement of the lower hook is effected by the actuator arms  116  and  118  and the extension or telescoping assembly  120 . The second actuator arms are pivotally attached to the base  100  at a pivot axis  130  spaced above and slightly rearward of the pivot axis  132  of the rotary hydraulic actuator  102 . As a result of the relative spacing of the axes, when the lifter moves rearwardly and upwardly, second actuator arm effectively pushes the sleeve or cylinder  124  and the first actuator arm effectively pulls on the inner rod  122 , such that the second cylinder or sleeve  124  slides downwardly or outwardly along the steel rod  122 , telescoping apart and increasing the distance between the upper and lower hooks  110  and  114  to capture the container or cart by capturing the lower bar or engagement surface  52  under the lower hook  114 .  
         [0026]     The reverse movement takes place during retraction of the lifter. The lift arm are rotated clockwise (as seen in  FIGS. 6 and 7 ), bringing the upper hook to a lowermost position as seen in  FIGS. 3, 6  and  7 , with the lift arms extending vertically downward. The relative spacing between the axes of rotation  130  and  132  cause the rod and cylinder to telescope together reducing the distance between the hooks and raising the lower hook.  
         [0027]     As is apparent from the drawings (e.g.,  FIG. 3 ), when the lifter is in the retracted position the actuator and lift arms are located in a low-profile, nesting arrangement in which the actuator and lift arms extend substantially vertically downward, with the first actuator arm  116  being located between the lift arm  106  and second actuator arm  118 . The lift arm is of sufficient length that when in the retracted position, the upper hook  110  is located just above, or proximal to the lower hook  114 .  
         [0028]     Although the dimensions may vary, the lifter in accordance with the present invention may have a total length (in the retracted position) of about 23⅛ inches, a width of about 21⅞ inches and a depth or thickness of about 6 inches. Such a lifter may be mounted at a height of from about 35½ inches up to about 53½ inches, and still work well in lifting and dumping typical collection carts in containers having an upper lift bar at about 34-35 inches above ground level. With the illustrated features of the present invention, the upper and lower hooks are in proximity when retracted but spaced apart (e.g., 14-15 inches apart) in the dumping position to capture the lift surfaces of the container.  
         [0029]     Because the upper hook rotates upwardly from an extreme lower position, it is able to engage under the upper lift surface in its normal path of travel, and it is unnecessary for the operator to lift or tilt the container in order to engage it properly with the upper hook.  
         [0030]     Although described in terms of the illustrated and preferred embodiments, the present invention is not limited to the exact form or variety shown, and may take such other forms as may be immediately apparent from the above description or which may become apparent only after some study of the above lifter.