Patent Publication Number: US-8528769-B1

Title: Lifter apparatus and method

Description:
FIELD OF THE INVENTION 
     This invention relates to a lift apparatus and method for use with structures with a lid. In particular, in accordance with one embodiment, a lift apparatus includes a lift arm connected with the lid and with a lift pivot. A movement arm with a flexible connection with a first end and a second end is provided where the first end of the flexible connection is connected with the lift arm and where the second end of the flexible connection is connected with the movement arm. And an actuator is connected with the movement arm for selected movement of the movement arm and thus the lid. 
     BACKGROUND OF THE INVENTION 
     Many facilities rely on a trash receptacle called a “dumpster” in which to place the trash generated at the facility. A typical dumpster is a metal or plastic box of multiple cubic yardage in size. The dumpster usually has one or more lids commonly mounted on its top and some units have sliding doors to access the interior of the dumpster at a lower level. This lower level access allows trash to be placed into the dumpster without raising the lid(s). Once a dumpster with sliding doors is filled to a level approximately even with the bottom of the sliding doors, however, the trash then has to be placed into the dumpster by raising the lids first. This basic set up of a dumpster has been in use for many years and works but has always presented the problem of having to raise the lid(s) at some point which is not easy to do. 
     To minimize the number of times that a dumpster has to be emptied, the dumpsters are designed to be as large as needed to hold the amount of trash regularly placed in them between scheduled pick ups. Standard dumpster size ranges up to twelve cubic yards. To minimize space taken up by these large dumpsters, they are built tall. Dumpster height can go up to eighty inches high from the ground to the lid. Further, lid length varies up to sixty inches. The combination of lid length, size, weight, and height above the ground make it a significant problem in raising one or more lids high enough to place trash in the dumpster. 
     To make it easier to place trash into the dumpster and to raise the lid(s), some dumpsters are made with sloped tops. This lowers the front height of the lids and allows a person placing trash into the dumpster to possibly lift the lid with one hand and place the trash in with the other hand. If the weight or size of the trash requires both hands, the person placing the trash in the dumpster must first fully open the lids before placing the trash into the dumpster. It is a significant task to raise one or more lids to their fully open position and close them again. That task gets multiplied many times if the lids are filled/covered with water or snow and weigh much more than their normal weight or the wind is blowing and is applying force to the large lid surface area. 
     The task of raising a lid fully open is currently usually done one of two ways. The first way is by hand or by use of a long pole. The second way is by a person climbing on the side of the dumpster and lifting the lid fully open. The second way is unsafe and dumpster manufacturers install decals warning users not to climb on the dumpster for safety reasons. 
     Thus, there is a need in the art for an apparatus and method to safely, easily and economically raise a lid, in particular a lid such as is found in trash receptacles called dumpsters. It, therefore, is an object of the invention to provide a lift for use with lids that is robust and reliable enough to operate effectively with rough use, that can be an economical add on to existing dumpsters or installed as original equipment, that is easy and safe for one person to use and which enables a person to use both hands to position the trash into the dumpster. Further, there is a need that when the trash has been placed into the dumpster, the lid(s) can then be easily closed back to their normal position. Thus, this device has multiple requirements. The device must be easy to use. It must be able to lift heavily loaded snow or water covered lids. Importantly, it must not impede dumpster emptying by the waste hauling company. 
     SUMMARY OF THE INVENTION 
     Accordingly, in a structure with a lid, a lift apparatus, according to one embodiment of the invention, includes a lift arm connected with the lid and with a lift pivot. A movement arm with a flexible connection, with a first end and a second end, is provided in which the first end of the flexible connection is connected with the lift arm and where the second end of the flexible connection is connected with the movement arm. An actuator is connected with the movement arm for selected movement of the movement arm and thus the lid. 
     As used herein, the term “lid” includes all movable coverings usually and normally associated with the term and in the trash receptacle field as known in the art. Such lids may be made of any material such as metal, wood and/or plastic. Plastic lids are light weight but flexible and susceptible to warping or bending if not properly supported as disclosed and described more fully herein. 
     Further, as used herein, the term “actuator” refers preferably to a hydraulic cylinder powered by either manual or electric pumps. Obviously, any appropriate actuator now known or hereafter developed is included within the common meaning of the term. That is, the term includes, for example only, a winch assembly powered by a hand crank or electric motor, a gear rack powered by a hand crank or electric motor and/or a linear actuator powered by hand or motor. 
     Still further, the term “flexible connection” is used herein with its common meaning and as known in the art of flexible mechanical connections such as chain and wire. Obviously any other connection that is flexible is included herein as well as for example only and not limitation, multiple pivotable links and slippery mechanical joints including pins sliding in slots. 
     In another aspect of the invention a limiter is connected with the lift apparatus such that movement of the lift arm beyond a predetermined amount is limited. In another aspect of the invention, a lid connector is connected with the lid and the lift arm and the lid connector includes a number of separate connections with the lid. In a further aspect, the lid includes a first side and a second side and the lid connector is connected to the first side and at least one lid reinforcement is connected to the second side and through the lid to the lid connector. In another aspect, the lid connector is connected with the lift arm at approximately a right angle. In another aspect, the lift arm and the lid reinforcements can be built into the lid itself. 
     According to another aspect, the flexible connection is selected from a group including: chain, wire, multiple pivotable links and slippery mechanical joints including pins in slots. In another aspect, the actuator is powered by a hydraulic pump. In another aspect, the hydraulic pump is selected from a group including: manual pumps and electrical pumps. 
     In a further aspect, the limiter includes a limiter return. In another aspect, the limiter return is automatic. In another aspect, the limiter return is selected from a group including: gas and spring operated limiter returns. 
     According to another embodiment of the invention, in a structure with a lid, a lift apparatus includes a lift arm connected with the lid and with a lift pivot. A lid connector is connected with the lid and the lift arm and the lid connector includes more than one connection with the lid. A movement arm, with a flexible connection with a first end and a second end, is provided and the first end of the flexible connection is connected with the lift arm and the second end of the flexible connection is connected with the movement arm. An actuator is connected with the movement arm and a limiter is connected with the lift pivot such that movement of the lift arm beyond a predetermined amount is limited. 
     According to a further aspect, the lid includes a first side and a second side and the lid connector is connected to the first side and at least one lid reinforcement is connected to the second side and through the lid to the lid connector. In another aspect, the lid connector is connected with the lift arm at approximately a right angle. 
     In a further aspect, the flexible connection is selected from a group including: chain, wire, multiple pivotable links and slippery mechanical joints including pins in slots. In another aspect, the actuator is powered by a hydraulic pump. In another aspect, the hydraulic pump is selected from a group including: manual pumps and electrical pumps. 
     In another aspect, the limiter includes a limiter return. In a further aspect, the limiter return is automatic. 
     According to another embodiment of the invention, in a structure with a lid, a lid lift method includes the steps of providing a lift arm connected with the lid and with a lift pivot, a movement arm with a flexible connection, with a first end and a second end, where the first end of the flexible connection is connected with the lift arm and where the second end of the flexible connection is connected with the movement arm, and an actuator is connected with the movement arm and operating the actuator so as to move the lift arm and move the lid. 
     In another aspect of the method, the actuator is powered by a manual hydraulic pump and operation of the hydraulic pump moves the lift arm and moves the lid. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiment, the appended claims and the accompanying drawings in which: 
         FIG. 1  is an exploded view of the lift apparatus according to one embodiment of the invention; 
         FIG. 2  is a perspective view of the lift apparatus of  FIG. 1  connected with a dumpster with the lid down; 
         FIG. 3  is a perspective view of the lift apparatus of  FIG. 1  connected with a dumpster with the lid in the raised position; and 
         FIG. 4  is a perspective view of the lift arm connected with the lid connector and lid reinforcers according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiment of the present invention is illustrated by way of example in  FIGS. 1-4 . With specific reference to  FIG. 1 , lift apparatus  10 , according to one embodiment of the invention, includes a lift arm  12 . As illustrated in the exploded view of  FIG. 1 , lift arm  12  includes a first end  14  and a second end  16 . First end  14  of lift arm  12  includes hinge bearing  18  and attachment point  20 . Hinge bearing  18  is conformed to connect with and rotate about lift pivot  22 . Lift pivot  22  is connected with mounting plate  24 . Mounting plate  24  also includes rear mount  26 . 
     Actuator  28  includes movement arm  30  and flexible connection  32  connected at the front  34  of actuator  28 . Rear connector  36  on actuator  28  is conformed to connect with rear mount  26  on mounting plate  24 .  FIG. 1  also illustrates an aspect of the invention in which actuator  28  includes hydraulic fluid ports  38  as will be described more fully hereafter. 
     Flexible connection  32  includes a first end  40  and a second end  42  in which the first end  40  is connected with the movement arm  30  at movement arm connection  44 . Second end  42  of flexible connection  32  is conformed to connect with attachment point  20  of lift arm  12 . 
     Still referring to  FIG. 1 , limiter  46  includes return connection  48  and limiter bearing  50  conformed to connect with lift pivot  22 . Further, according to one aspect of the invention, limiter return  52  includes extendable shaft  54  and receiver  56  within which extendable shaft  54  is moveably retained. Extendable shaft  54  is connected with limiter  46  at return connection  48 . Receiver  56  is connected with actuator  28  by receiver connector  58 . 
       FIG. 1  also illustrates lid connector  60  connected at approximately a right angle to lift arm  12  at second end  16  as will be more fully described with reference to  FIG. 4 . 
     Referring now to  FIGS. 2 and 3 , the lift apparatus  10  according to one embodiment is shown connected with a structure, dumpster  62 , with a lid  64 . Lid  64  includes first side  63  and second side  65 . Also shown is pump  66 . Pump  66  may be any type of pump now known or hereafter developed including, for example only and not by limitation, a manual or electric hydraulic pump. As illustrated, pump  66  is a manually operated hydraulic pump including valve lever  68 , and hydraulic lines  72 . Hydraulic lines  72  are connected with hydraulic ports  38  on actuator  28 . Preferably, pump  66  is attached to dumpster  62  on the back  74  and not on the side  76 . Dumpster  62  includes dump truck fork receivers  78  and any item attached to the side(s)  76  of dumpster  62  is going to be damaged, sooner or later, when the dump truck (not shown) picks up the dumpster  62  to empty it. 
       FIG. 2  shows dumpster side door  80  in the closed position and  FIG. 3  shows dumpster side door  80  in the open position. Likewise,  FIG. 2  shows lid  64  in the closed or lowered position and  FIG. 3  shows lid  64  in the open or raised position. In the open position extendable shaft  54  of limiter return  52  is in an extended position. As lift apparatus  10  is operated to lift lid  64 , extendable shaft  54  is compressed within receiver  56  as shown in  FIG. 3 . Receiver  56  may also include a spring or a gas medium that resists extendable shaft  54  and, once the pressure raising lid  64  is released, as will be described more fully hereafter, extendable shaft  54  is forced out of receiver  56 , as shown in  FIG. 2 , thereby causing lid  64  to move toward the closed position. 
     Referring now to  FIG. 4 , an exploded perspective view of the lift arm  12  and lid connector  60  is shown. According to one embodiment of the invention, lid connector  60  is connected with lift arm  12  at approximately right angles. This spreads the lifting force across a greater area of lid  64  (not shown in  FIG. 4 ). Further, in one aspect, lid connector  60  is connected with lid  64  by means of lid reinforcements  82 . Preferably, a number of lid reinforcements  82  are located on the second side  65  of lid  64  and lid connector  60  is located on the first side  63  of lid  64 . Attachments  84  on lid connector  60  are connected with attachers  86  on lid reinforcements  82 . Attachments  84  and attachers  86  may be nut and bolt combinations, for example, or any method and means now known or hereafter developed. In a preferred embodiment, lid  64  is captured between lid connector  60  on one side of lid  64 , first side  63 , and lid reinforcers  82  on another side of lid  64 , second side  65 , for example. Again, this combination spreads the lifting force over a wide area of the lid  64  and enables a user to controllably manipulate the heavy flexible lid  64 . Obviously, the lift arm  12 , lid connector  60 , lid reinforcements  82  may all be built into lid  64  as opposed to being added onto lid  64 . 
     In operation, a user first moves valve lever  68  on pump  66  to the “lift” position. Then the users operates the manual pump handle  70  on pump  66  to supply oil and pressure to actuator  28 . The hydraulic oil forces actuator  28  to retract movement arm  30 . The movement arm  30  is connected with flexible connection  32  which pulls lift arm  12 . As the movement arm  30  is retracted, flexible connection  32  pulls the lift arm  12  around lift pivot  22 . The lift arm  12  with lid connector  60 , and possibly lid reinforcements  82 , raises dumpster lid  64 . 
     Limiter  46  is also mounted to lift pivot  22 , as described and illustrated, and lift arm  12  engages limiter  46  at some point where the lid  64  is above the horizontal or down position. The limiter  46  thereafter rotates with the lift arm  12  around lift pivot  22  until the limiter  46  prevents further rotation by coming in contact with mounting plate  24 . Thus, limiter  46  prevents over rotation of lid  64 . That is, lift arm  12  will continue to rotate around lift pivot  22  and continue to open/lift lid  64  as long as the pump  66  is activated or until movement arm  30  is fully retracted or until the limiter  46  prevents further rotation. 
     Further, limiter  46  includes limiter return  52 . Lid  64  will stay in the raised/open position as shown in  FIG. 3  until valve lever  68  is placed in the lowering position. In the lowering position, hydraulic pressure is released and movement arm  30  is free to return to the extended position shown in  FIG. 2 . If lid  64  was raised enough for lift arm  12  to engage the limiter  46  and pressurize receiver  56  of limiter return  52 , the extendable shaft  54  will be forced out of receiver  56  when pressure is released thereby forcing limiter  46  and lift arm  12  to a position where gravity will take over and return the lid  64  to the closed position shown in  FIG. 2 . 
     An important feature of the invention is that actuator  28  is loosely connected by flexible connection  32  to lift arm  12 . This “loose” connection allows free motion of the lid  64  when lid  64  is in the lowered or down position shown in  FIG. 2 . This feature allows, therefore, a user to simply lift lid  64  by hand whenever extra assistance from the lift apparatus  10  is not needed. Thus, lift apparatus  10  does not interfere with the otherwise normal and expected operation of a dumpster  64 . 
     The Applicant&#39;s lift apparatus and method  10  of the present invention addresses all of the aforementioned needs in the art by providing a device that mechanically assists a user in opening lids of a dumpster so that the user can use both hands to place trash in the dumpster. The lift apparatus and method  10  is of a relatively simple design and construction so that it is relatively inexpensive to manufacture and affordable to a large percentage of users. The lift apparatus and method  10  is also relatively straight forward to install, operate and maintain so that post purchase cost of ownership are reasonable. The lift apparatus and method  10  allows dumpster lids to be opened without the use of the invention and without need to disconnect or disable the invention in any fashion. Thus a user can lift the lid by hand when possible and a garbage truck can empty the dumpster at any time without any prior action of the user or garbage truck operator. 
     The description of the present embodiments of the invention has been presented for purposes of illustration, but is not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. As such, while the present invention has been disclosed in connection with an embodiment thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention as defined by the following claims.