Abstract:
A weight based load limiting system for a refuse vehicle. The system includes a weight determination module that generates a signal that varies in accordance with a vehicle weight. If the vehicle weight approaches or exceeds a predetermined maximum weight, the signal inhibits a portion of the loading or packing operation to prevent overloading the vehicle. In various configurations, the inhibiting can be to prevent a lifting of a refuse container to prevent emptying the container into the vehicle hopper. In other various configurations, the inhibiting occurs by maintaining engine power to less than the engine power typically output during a packing operation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/368,984, filed on Jul. 29, 2010. The entire disclosure of the above application is incorporated herein by reference. 
     FIELD 
     The present disclosure relates to refuse vehicles and a load limiting mechanism for the same. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Refuse vehicles play a key role in dispensing of refuse by traversing an area, stopping at a location where the user, resident, commercial business, or the like has deposited refuse for collection, depositing the refuse in the refuse vehicle, and transporting the refuse to a processing center, such as a recycling center, landfill, or incineration center. With a continuing need to reduce energy and emissions, there has been a trend towards designing and building lighter refuse vehicles. Lighter refuse vehicles are typically more limited in the payload that they can carry, but are more fuel efficient. This trend towards designing and building more economically operated vehicles has resulted in refuse vehicles having lighter components, and, consequently, lighter payload capacities. It is thus easier to overload contemporary refuse vehicles than their traditional counterparts. 
     In typical refuse collection operations, it is often difficult to estimate the weight of the refuse collected because of the many variables that determine the weight of the refuse. For example, the nature of the refuse itself can vary from collection to collection. Some refuse may be more dense resulting in more weight for a given volume when such refuse is added to the vehicle. Other refuse might be less dense resulting in less weight for a given volume when such refuse is added to the vehicle. Environmental conditions can cause the weight of a particular load to vary significantly. For example, if a load of refuse includes material which may absorb liquid, the weight of that load will vary depending on whether it is collected on a rainy or a dry day. Thus, vehicle operators cannot determine with certainty that a predetermined number of collections will result in maximizing the payload of the vehicle, without overloading the vehicle, prior to returning to the processing center to dump the collected refuse. It is generally desirable to not return to the processing center before the vehicle payload has been maximized. Because of this variability in load-to-load and to overall payload weights, vehicle operators presently have limited knowledge of the payload of the vehicle. 
     Further, operators are sometimes prone to push the limits of payload capacity. While pushing the payload capacity may have had less impact when utilizing traditional refuse vehicles, newer, more efficiently designed refuse vehicles are less tolerant of overload conditions and could damage the vehicle. Present refuse vehicles have no way of limiting further intake of refuse based upon weight. While in certain instances, the volume of the container portion of the refuse vehicle imposes limits, when moving particularly dense materials, it may be necessary to return to the processing center prior to the container becoming full. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     A refuse vehicle including a hopper supported by the refuse vehicle. A lift mechanism for attaching to a container containing refuse to be added to the hopper via a lift operation. A sensor senses a weight that varies in accordance with the refuse contained in the hopper. A controller receives a weight signal from the sensor. A lift lockout inhibits operation of the lift mechanism if the weight sensed by the sensor exceeds a predetermined value. 
     A refuse vehicle includes a hopper supported by the refuse vehicle. A gripper mechanism takes hold of a container containing refuse to be added to the hopper. A sensor for senses a weight that in accordance with the refuse contained in the hopper. A controller receives a weight signal from the sensor. A lockout inhibits operation of the gripper mechanism if the weight sensed by the sensor exceeds a predetermined value. 
     A refuse vehicle includes a hopper supported by the refuse vehicle. A load door enables adding refuse to the hopper. A sensor senses a weight, the weight varies in accordance with the refuse contained in the hopper. A packer compacting refuse in the hopper, wherein the engine of the vehicle operates at a predetermined power level during a packing operation. A control circuit, the control circuit receiving a signal that varies in accordance with the weight sensed by the sensor. The control circuit limits the power output of the engine to an amount less than the predetermined power level when the weight sensed by the sensor exceeds a predetermined weight. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a side view of a front loading refuse vehicle having a load limiting system; 
         FIG. 2  is a block diagram of a load limiting system for a front loading refuse vehicle according to various embodiments; 
         FIG. 3  is a side view of a side loading refuse vehicle having a load limiting system; 
         FIG. 4  is a block diagram of a load limiting system for a side loading refuse vehicle according to various embodiments; 
         FIG. 5  is a block diagram of a load limiting system for a side loading refuse vehicle according to various embodiments; 
         FIG. 6  is a side view of a rear loading refuse vehicle having a load limiting system; and 
         FIG. 7  is a block diagram of a load limiting system for a rear loading refuse vehicle according to various embodiments. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
       FIG. 1  depicts a side view of a front loading refuse vehicle  10  arranged in accordance with various embodiments. Vehicle  10  is arranged as a front loading refuse vehicle and includes a front loading lift arm assembly  12  which connects to a front portion of a container or bin  14  and extends from behind the operator cab  16  to in front of the operator cab  16 . Front loading lift arm assembly  12  includes a fork mechanism  18  which can be deployed to a generally horizontal position for engaging corresponding passages in an on-site refuse container (not shown). Once fork mechanism  18  has engaged the container, lift arm assembly  12  is pivoted upwardly and rearwardly to invert the container and dispose the contents into vehicle container  14  via a hopper. Refuse vehicle  10  may also include a compaction mechanism  20  which compacts refuse within container  14  to allow more refuse to be disposed therein. As will be described in greater detail and shown schematically in  FIG. 1 , refuse vehicle  10  includes a load limiting system  22  which limits operation of lift arm assembly  12  upon detection that vehicle  10  is near or exceeds its maximum payload, or other predetermined, condition. 
       FIG. 2  is a block diagram of the load limiting system  22  of  FIG. 1 . Load limiting system  22  includes a weight determination system  24 , a lift control system  26 , and a lift mechanism  28 . Weight determination system  24  includes a weight measuring module  30 , such as a weight sensor, scale, or other weight measuring device. Weight measuring module  30  sends a signal to controller  32  of weight determination system  24 . Controller  32  determines whether a maximum payload weight is being approached or exceeded, as defined in accordance with various design specifications, and generates a signal  38  output by weight determination system  24  to interlock switch module  36  of lift control system  26 . The signal  38  output by controller  32  to interlock switch module  36  may be a signal indicating an actual or near-overload condition, which can occur before or during a lift operation. Interlock switch module  36  inhibits operation of lift mechanism  28  via interlock module  40 . In various embodiments signal  38  is an activation signal for interlock switch module  36 . In other embodiments, signal  38  may be a signal indicating a predetermined condition which may be further processed by interlock switch module  36  prior to determining whether to activate interlock module  40 . In various embodiments, interlock switch module  36  may include a relay or other switch which generates an inhibit signal to interlock module  40 . Interlock module  40  may include an interlock solenoid or other device, such as an electrical, mechanical, pneumatic device or combination thereof, which inhibits operation of lift mechanism  28 . 
     In various embodiments, interlock module  40  includes an interlock solenoid. The interlock solenoid may operate with lift arm assembly  12  of refuse vehicle  10  of  FIG. 1  to prevent lift arm assembly  12  from being raised a predetermined height. In various embodiments, interlock module  40  may include an interlock relay. In various embodiments, the interlock relay can inhibit upward motion of lift arm assembly  12  beyond a predetermined travel position if the door to container  14  is not open to receive refuse. The interlock module  40  can also be used to limit the upward motion of the arm if the present vehicle weight of the vehicle and weight of the container being lifted causes a predetermined vehicle weight parameter, such as the gross vehicle weight to be exceeded. This allows the operator to set the container back on the ground while preventing the operator from loading the refuse vehicle  10  beyond the predetermined gross vehicle weight limit. 
     In various embodiments, controller  32  generates a second signal  42  to an alarm  44 , such as an audible and/or visual alarm. Signal  42  can operate an alarm  44  in response to a near overload or actual overload condition, so that the operator can be advised to avoid attempting to add further payload to refuse vehicle  10 . In various other embodiments, alarm signal  42  may indicate that a predetermined percentage of gross vehicle weight has been exceeded so that the operator can plan additional stops prior to nearing the gross vehicle weight capacity. 
     In various embodiments, lift control system  26  includes an alarm  46  which receives signal  38  from controller  32 . Alarm  46  may be an audible or visual alarm and may indicate an overload condition. Alarm  46  may work independently of or in conjunction with alarm  44  to provide the same or additional information to the vehicle operator about the present state of the loading of the vehicle  10 . 
     Weight determination system  24 , according to various embodiments, can determine a running tare weight for an empty container, a gross vehicle weight (which is typically the tare weight and the payload weight), or individual axle weights. Of particular relevance is that the weight or weights monitored are monitored to prevent the payload carried by the refuse vehicle  10  from exceeding a predetermined payload. 
       FIG. 3  depicts a side view of a side-loading refuse vehicle  50 . Side-loading refuse vehicle  50  includes container  52  including a hopper for receiving refuse. Side-loading refuse vehicle  50  typically includes a lift assembly  54  configured to engage a refuse container, lift the refuse container, and deposit refuse from the container into hopper  52 . Lift assembly  54  raises the container and inverts the container to empty the refuse from the container into hopper  52 . Lift assembly  54  includes a gripper  58  which typically encircles the refuse container and then lifts the container upward for emptying its contents in the hopper of container  52 . Load limiting system  56  is shown in schematic form in  FIG. 3 . Various embodiments of load limiting system  56  can be described in connection with  FIGS. 4 and 5 . 
       FIG. 4  depicts a load limiting system  56 A arranged according to various embodiments.  FIG. 4  operates similarly to  FIG. 2  but affects the limiting operation by preventing activation of the gripper portion of lift mechanism  54 , thereby preventing the gripping, lifting, and emptying of a container process. Load limiting system  56 A of  FIG. 4  includes a weight determination system  60 , a lift control system  62 , and a gripping mechanism  64 . 
     Weight determination system  60  operates similarly as described above with respect to  FIG. 2 . In particular, weight determination system  60  includes a weight measuring module  66  which generates a signal to controller  68 . Controller  68  generates a signal  70  output to interlock module  72  of lift control system  62 . Interlock module  72  also receives a gripper activation signal  74 . Gripper activation signal  74  may be electrical, mechanical, hydraulic, or a combination thereof. Interlock module  72  receives the signal  70  from controller  68  and gripper activation signal  74  and determines whether activation of the gripper mechanism  64  is appropriate. According to various embodiments, if signal  70  indicates a weight near or above the maximum weight, interlock module  72  can inhibit activation of gripper mechanism  64 . This prevents gripping mechanism  64  from gripping the refuse container in order to pick it up and empty its contents into the hopper of the vehicle container. If the operator cannot cause the gripping mechanism  64  to grip the container to be emptied, additional payload cannot be added to the vehicle. Weight determination system  60  also includes an alarm  76  which may be a visual display or audible alarm. Alarm  76  receives an alarm signal from controller  68  which causes activation of alarm  76 . A second alarm  80  may be activated by signal  70 , which also activates interlock module  72 , to indicate that the interlock function has been activated. Alarms  76  and  80  may operate as described above with respect to  FIG. 2 . 
     With reference to  FIG. 5 ,  FIG. 5  depicts a block diagram for a load limiting system  56 B in accordance with various embodiments. Load limiting system  56 B operate similarly to portions load limiting system  22  of  FIG. 2  and load limiting system  56 A of  FIG. 1 . According to various embodiments of load limiting system  56 B, lift mechanism  54  of  FIG. 3  is operated pneumatically so that inhibiting a lift operation of lift mechanism  54  through pneumatic controls. Load limiting system  56 B includes a weight determination system  84  having a weight measuring module  86 , a controller  88 , an alarm  90  which receives an alarm signal  92 . Weight determination system  84  operates similarly as described above with respect to weight determination system  24  of  FIG. 2  and weight determination  60  of  FIG. 4 . Controller  88  generates a signal  94  to lift control system  98 . Signal  94  is applied to interlock switch module  100 . Interlock switch module  100  generates a signal to interlock module  104 . Interlock module  104  also receives a lift mechanism pneumatic control signal  106 . Lift mechanism pneumatic control signal  106  is generated by the operator to direct lifting of lift mechanism  108 . Lift mechanism  108  is analogous to lift mechanism  54  of  FIG. 3 . Signal  94  is also input to alarm  102  which can indicate that the vehicle weight is approaching maximum payload or has exceeded maximum payload, or to indicate that an inhibit condition exists to prevent operation of lift mechanism due to the vehicle weight. 
     When payload conditions do not indicate inhibiting operation of lift mechanism  108 , lift mechanism pneumatic control signal  106  is passed through interlock module  104  to cause a lift operation of lift mechanism  108 . When the vehicle weight approaches or exceeds a maximum vehicle weight, as determined by various design considerations, interlock module  104  inhibits lift mechanism pneumatic control signal  106  from operating lift mechanism  108 . This inhibits a lifting operation so that the lift mechanism  108  cannot raise the container in order to empty the contents of the container into hopper of container  52  of side-loading vehicle  50 . 
       FIG. 6  depicts a rear loading refuse vehicle  110 . Rear loading refuse vehicle  110  includes a bin or container  112  and a hopper  114 . Hopper  114  enables rear loading of refuse vehicle  110 . In various embodiments, hopper  114  is loaded by hand, and a packing operation then packs the refuse into bin  112  via an electro-pneumatic control system. Shown in schematic is a load limiting system  116  to be described further herein. 
       FIG. 7  is a block diagram of load limiting system  116 . Load limiting system  116  includes a weight determination system  118 , a lift control system  120 , and an engine control module  122 . Weight determination system  118  includes a weight measuring module  124 , a controller  126 , an alarm  128  that receives a signal  130  from controller  126 . Weight determination system  118  operates as described above with respect to the weight determination systems of  FIGS. 2 ,  4 , and  5 . 
     Lift control system  120  includes a switch module  136  that receives the signal  138  from controller  126  and a throttle advance signal  140 . Throttle advance signal  140  is typically generated during a pack cycle. In a typical configuration, throttle advance signal  140  is applied directly to engine control module  122 . During the pack cycle, the engine of the rear loading refuse vehicle  110  operates at a speed approximately twice the idle speed. 
     Throttle advance signal  140  is applied to switch module  136  so that if signal  138  indicates a vehicle weight at or exceeding capacity, switch module  136  inhibits passing throttle advance signal  140  to engine control module  122 . Thus, during a pack cycle if switch module  136  inhibits passing throttle advance signal  140  to engine control module  122 , the pack cycle will be significantly slower, thereby encouraging the operator to empty the vehicle and avoid slow packing cycles. Lift control system  120  also includes alarms  128  and  142  which operates similarly as described above in connection with  FIGS. 2 ,  4 , and  5 . In particular, alarm  142  also receives signal  138  from controller  126 . In various embodiments, alarm  142  can operate to indicate that switch module  136  inhibits throttle advance signal  140  from being applied to engine control module  122 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.