Patent Application
20070166136
The present invention generally relates to lifters for refuse collection containers and, more specifically, to lifters for lifting, tilting and dumping residential-style refuse containers and the container engagement members, such as hooks and stops thereon for engaging the refuse container.
Refuse container lifters have been used for many years in a wide variety of settings. They have, for example, been mounted on refuse collection trucks, both rear and side load trucks. They have been mounted on larger multi-cubic yard refuse containers and they have been used in stationary refuse loading stations. An example of one successful refuse container lifter may be found in U.S. Pat. No. 6,929,441 to Arrez et al. Despite the wide variety of lifters being offered for sale, there continues to be need for lifters that have improved reliability and/or function; that are suitable for a variety of applications on trucks, containers or stationary refuse collection stations; that may be more efficiently manufactured at reduced cost and/or that minimize or reduce the scratching or denting or other damaging of the refuse container, which is typically made of relatively thin plastic material, during lifting, tilting or dumping.
In one aspect of the present invention, a container engagement member for mounting on a refuse container lifter, comprises a first portion for mounting to the lifter and a second portion which extends from the first component to permit engagement with an engagement surface on the refuse container which is to be lifted during the lifting. At least the second portion comprises a container engaging surface of polymeric material which serves to reduce damage to the container.
The polymeric material may comprise a polyolefin, such as polyethylene, and preferably has a high molecular weight such as, at least about 2 million, and more preferably at least about 3.1 million, and still more preferably, at least about 4.2 million. Also the engagement member is preferably constructed essentially entirely of polymeric material and is of one piece construction.
These and other objects, features and advantages of the present invention will more clearly understood through a consideration of the following drawings and detailed description.
In the course of this description, reference will frequently be made to the attached drawings in which:
The collection truck illustrated in
For dumping smaller, residential style containers, the refuse collection truck shown in
Before turning to a more detailed description of the lifter 40, reference is made to
A lifter 40 embodying the present invention is perhaps best seen in
The illustrative lifter 40 embodying the present invention includes a rotary hydraulic motor or actuator 54, at least one lift arm and actuator arm generally at 56, and a container carriage, generally at 58. The hydraulic motor 54 has a generally horizontal rotary actuator shaft (not shown) that extends through at least one end of the motor, and preferably through each end of the motor. The motor 54 may be of any suitable design. The motor 54 is attached, as by welding or bolting, to a mounting or base plate 62 or it may be attached to the base plate or sill 32 in a manner to permit rapid and easy removal from or mounting to the base plate or sill.
For lifting the container carriage 58, a lift arm 64 is attached to the actuator shaft of the hydraulic motor 54, and preferably a lift arm 64 is fixed to each end of the shaft. The other ends of the lift arms 64 are attached, as by welding, bolting or other attachment, to the carriage. For inverting the carriage, an actuator arm 66 is pivotally mounted at 68 to the base plate 62 at a location beyond the end of the motor actuator shaft. Each actuator arm 66 is pivotally mounted to a bracket 70 that is welded or otherwise attached to the base plate 62. The axis of rotation at the pivot 68 is displaced from and located above the axis of rotation of the motor actuator shaft. The other end of each actuator arm 64 is pivotally attached to the carriage.
In the illustrated embodiment the carriage includes an upper cross member 72 that carries an upwardly facing container engagement member or upper hook 74 that serves to hook under the uppermost lift bar 52 on the refuse container 42 as the lifter is moved from the retracted to the extended position. Each end of the upper cross member 72 is welded or otherwise attached, directly or indirectly, to a lift arm 64 so that as the lift arm is rotated by the hydraulic motor 54, the cross member 72 is also raised or lowered.
Each side of the carriage in the illustrated embodiment includes two relatively movable or telescoping members 76 and 78. These members could be provided separately from the carriage, but making them part of the carriage reduces the number of parts and thus the material and labor costs. Inner telescoping member 76, as illustrated, is a solid cylindrical steel rod, and is attached directly or indirectly to the end of the lift arm 64 as, for example, by welding. Outer telescoping member 78, as illustrated, is a steel sleeve or tube pivotally attached to the end of the actuator arm 66. A lower cross member 80 of the carriage extends between and is attached to each of the outer telescoping members 78. The lower cross member 80 includes a downwardly facing lower container engagement member such as stop 82 for engaging over the lowermost lift bar 53 of the refuse collection container 42. The stop could also be in the shape of a downwardly facing hook or other shape without departing from the present invention and could be movable between a retracted and extended position.
As a result of the relatively movable arrangement between members 76 and 78, and the displaced axes of the pivot 68, the spacing between the upper and lower cross members 72 and 80 varies depending on the rotational position of carriage. As the rotary actuator 54 rotates counterclockwise, the carriage moves from the fully retracted position to an intermediate position. The displaced axes of the pivot 68 and motor actuator shaft causes the actuator arm 66 to push against the outer member 78, causing it to slide downwardly relative to the inner member 76, and increasing the spacing between the upper hook 74 and the lower stop 82. The upper hook 74 and lower stop 82 extend into the recessed area 50 of the container and are located between the lift bars 52 and 53, with the upper hook 74 engaging under and beginning to lift the upper lift bar 52 of the refuse collection container 42, and the lower hook being located above lower lift bar 53 of the refuse container 42.
As the lifter 40 continues to rotate upwardly, the upper hook 74 lifts the refuse container, and continued upward rotation of the lifter also results in the actuator arms 66 continuing to push the lower stop 82 away from the upper hook so that the lower stop 82 engages over the lower lift bar 53 of the collection container 42. At that position the weight of the container has generally shifted such that the lower bar 53 of the collection container rests against the lower stop 82 of the lifter 40. At this point, the distance between the upper hook 74 and lower stop 82 is such as to effectively capture the refuse collection container 40 on the lifter so that the refuse container cannot fall from the lifter as it is being lifted and dumped. More specifically, the upper hook 74 and lower stop 82 are spaced apart nearly the same distance that the upper and lower lift bars 52 and 53 of the refuse container 42 are spaced apart, so that the container cannot shift enough that either lift bar can be removed from its respective hook or stop. The relative motion of the upper hook 74 and lower stop 82 is reversed as the lifter rotates back toward the retracted position, with the inner and outer members 76 and 78 sliding or telescoping together, drawing the cross members 72 and 80, and their respective upper hook 74 and low. stop 82 closer together for release of the container.
As noted earlier, the container carriage, with relatively movable upper hook 74 and lower stop 82, could be a separate assembly operatively attached to the relatively movable members 76 and 78 for moving the hooks. In the illustrated embodiment the relatively movable members 76 and 78 are directly attached, respectively, to the cross members 72 and 80, which tends to reduce cost and simplify construction.
In addition to the lower stop 82, the lower cross member 80 also preferably mounts a pair of rollers 84 to protect the wall of the container as it is lifted, tilted and dumped. As noted earlier, the upper hook 74 and lower stop 82 extend into the recessed area 50 of the collection container and the rollers 84 serve to support the container wall to minimize gouging by the lower hook or damage to the container as the lower hook moves downwardly during rotation of the carriage.
In addition, to further reduce gouging or other damage to the plastic container in accordance with the present invention, the upper hook 74 and/or lower stop 82 have a container engaging surface of polymeric material.
The construction and operation of the lifter 40 together with various modifications are described in detail in the aforementioned U.S. Pat. No. 6,929,441, the content of which is incorporated herein by reference.
The present invention is directed to an improved upper hook 74 and/or lower stop 82 on the lifter 40 as previously described.
Referring to
Referring to
In the present invention, container engagement members such as the upper hook 74 and/or lower stop 82 are preferably formed entirely of a very hard, but low abrasion polymer. Such polymer minimizes the wear during use on the upper hook 74 and/or lower stop 82 while facilitating. engagement and disengagement of the upper hook and/or lower stop with the lift bars 52 and 53 on the container 42, and it also minimizes any possibility of scratching or gouging of the container 42 during use.
A preferred polymer for the upper hook 74 and/or lower stop 82 is a very high molecular weight polyolefin, preferably high density polyethylene, and more preferably, of an ultra high molecular weight polyethylene. The molecular weight of the polyethylene is preferably at least about 2 million, more preferably at least about 3.1 million, and most preferably at least about 4.2 million. Such polyethylenes include GAR-DUR® which is available from Garland Mfg. Company, Saco, Me.
Although the engagement members are preferably formed essentially entirely of polymeric material, forming a one-piece construction as illustrated above that may be molded, the engagement members may also be of multi-component construction. For example, the engagement members may have a core of steel or other high strength material entirely or partially coated with a suitable polymeric material so that the container contacting surface of the engagement member is of polymeric material to reduce container damage. Alternatively, the engagement member may be made of steel or other high strength material and only the portion that is likely to contact or damage a container may be of polymeric material or may be coated or covered with the desired polymeric material.
It will be understood that the preferred embodiment of the present invention which has been described is merely illustrative of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
