Garbage truck lifting mechanism
The present invention is directed to the field of garbage trucks and, more particularly, to apparatus for lifting garbage containers and dumping them into the hopper of a side-loading garbage truck.BACKGROUND OF THE INVENTION
Not too many years ago, people burned garbage in open containers in their backyards. Pollution laws, however, in recent years have virtually outlawed such practice throughout the nation. As a result, most garbage today is picked up and hauled to central landfills or other disposal sites.
A variety of garbage truck designs are presently known in the garbage collection industry. Such trucks include front loading, back loading and side loading types. The front loading type include mechanism for lifting a container over the cab before dumping it into the box behind the cab. Back loading types usually have a trough at the back of the box for receiving garbage. The garbage is usually manually lifted into the trough or deposited therein with a loader. In any case, the back loading type usually have a wall for moving the garbage out of the trough and compressing it forwardly into the box.
The present invention is directed to side loading garbage trucks. A number of designs are known. For example, one design allows a person to mount a step and deposit a can of garbage in a trough between the cab and box of the truck. A conveying mechanism then moves the garbage from the trough into the box. Another design has a single arm mechanism between the box and the cab which extends to grab a round container and lift it to the top of the box for deposit of the garbage therein. Still another design uses a pair of arms pivoted near the top of the box and located along the side of the truck to grab opposite sides of a container and lift the container straight upwardly and then over the box to deposit garbage therein.
Most relevant to the present invention is a truck and container system wherein the side of the box of the truck powers down and becomes a hopper into which garbage may be dumped. On pivoting the side upwardly, the garbage is moved into the box. Although garbage may be manually lifted and deposited in the side hopper, the truck is usually used in combination with a container which has its own hydraulic lift mechanism for lifting the container from a base, rotating the container and dumping the garbage contents into the side hopper of the truck. Energization for the hydraulic system comes from a make and break connection between the container hydraulic assembly and the hydraulic system of the truck. Although the system is workable, it is expensive. Each container must have its own hydraulic lift assembly. Furthermore, use of the system requires proper positioning of the truck so that when the side is powered down, it is located properly to receive garbage from the container after it is lifted and rotated for dumping. Also, the operator must take the time to connect the hydraulic lift assembly of the container to the hydraulic system of the truck for each container encountered.
The present invention eliminates the need for separate lift assembles for each container by disclosing an appropriate lift assembly for attachment to a side hopper of the truck.SUMMARY OF THE INVENTION
The present invention is directed to container lift apparatus for a garbage truck wherein the truck has a box and mechanism for pivoting a side of the box between open and closed positions. The box side in the open position forms a hopper for receiving garbage. The side is movable with the pivoting mechanism to the closed position thereby moving the garbage from the hopper to the box. The container lift apparatus includes an arm and mechanism for pivotably attaching the arm to the hopper. The container lift apparatus also includes an hydraulic piston and cylinder assembly having one end attached to the hopper and a second end attached to the arm at a location spaced from the axis of the arm attaching mechanism. The apparatus further includes mechanism for controllably energizing the hydraulic piston and cylinder assembly. In addition, the container lift apparatus has mechanism, attached to the arm, for holding the container whereby such mechanism holds the container as the hydraulic assembly rotates the arm to lift the container and dump garbage from the container into the hopper.
In another embodiment, the container lift apparatus includes a pair of spaced apart arms. The arms are pivotably attached to the hopper. A pair of hydraulic piston and cylinder assemblies each has one end attached to the hopper and a second end attached to one of the arms. The assemblies function to powerably rotate the arms. A pair of legs rotate downwardly from a stored position next to the hopper to provide stabilizing structure to prevent the truck from tipping when a particularly heavy garbage container is lifted.
Each arm includes a wide-angled, V-shaped slot. The slots in the arms are approximately equally spaced from the rotational axis of the arms and are, thus, aligned with one another with respect to the rotational axis. The slots have closable lock assemblies for opening to receive rods attached to a garbage container. The lock assemblies close and lock to hold the rods of the container in the slots. A strong back structure including a pair of downwardly extending legs attached to the arms and a cross member extending between the legs rotates with the arms to form a lift structure for the garbage container. A hook member is attached to the cross member and functions to catch a protuberance attached to the container when the container slides as it is rotated during lifting so that the rods attached to the container move from one end of the slots to the other.
The present invention is particularly advantageous since it provides a single lift mechanism attached to the truck for lifting and depositing in the side hopper of the truck garbage from a plurality of containers. That is, each container need not have its own lift mechanism in the fashion taught by the art.
In addition, the present invention is advantageous since during the lifting of a container, the container slides so that the rods attached to the container move from one end of the slots in the arms to the other. In so doing, the container is jolted, and the garbage therein is loosened in order to obtain a complete dump from the container.
Other advantages of the present invention include a lower retaining mechanism to prevent the garbage container from flipping away from the cross member lift assembly into the hopper. Also, stabilizing legs are provided to support the weight of the container and its garbage at the long moment arm relative to the center of the truck whereby the truck is prevented from tipping.
These advantages and other objects obtained by this invention are further explained and may be better understood by reference to the drawings and descriptive matter which follow. A preferred embodiment of the invention is illustrated and then described in detail.BRIEF DESCRIPTION OF THE DRAWINGS