Abstract:
A parking stand for a detachable front loader assembly including a support leg pivoted to a boom, which is able to pivot between an extended and a retracted position. A set of parallel struts engage a locking plate, which is attached to the support leg. Being engaged within locking mechanism divots, the support leg is secured within an optimally extended position. Extending the parking stand support leg into a parking configuration is achieved by way of a series of semi-automated actions that are triggered and propelled by way of hydraulic movement of a loader&#39;s boom and bucket. Such semi-automated actions include unlocking, extending, and securing the support leg. Retraction of the support leg is similarly executed.

Description:
TECHNICAL FIELD 
       [0001]    A parking stand for supporting a boom-type loader assembly, which is commonly mounted onto tractors such as front loaders. More particularly, the parking stand includes a locking mechanism to facilitate semi-automated parking stand positioning. 
       BACKGROUND 
       [0002]    Used in the context of heavy equipment, a “loader” is a type of tractor having a front-mounted rectangular wide bucket connected to the end of two hydraulic booms. A loader, may also be referred to as a bucket loader, front loader, front-end loader, payloader, scoop, shovel, skip loader, or wheel loader. It is most often a wheeled vehicle, although loaders moving about tracks are often used where the geography is not suitable for wheels. Loaders are commonly used to scoop material from ground level and dump it into a dump truck, hole, trench, bin, or the like. Depending on the intended application, a loader&#39;s design, components and specific functionality can vary significantly. However, many components are common to all types of loaders such as, for example, hydraulic booms that are attached to a tilting bucket. 
         [0003]    Because front loader assemblies (e.g. booms and bucket) are often required for short operations and at infrequent intervals, such implements are normally detachably attached to a vehicle (i.e., “tractor”) so that the boom and bucket (i.e., “loader assembly”) can be removed from the tractor and parked. When detached from the tractor, the bucket portion of the loader assembly typically rests on the ground in an upright position. To keep the loader assembly in the upright position, the boom portions of the loader assembly can be configured to include a parking stand. 
         [0004]    A parking stand is most often extended and retracted manually. When in the retracted position, the parking stand folds such that it is parallel to the boom and is secured by a lock or lever device. To “park” the loader assembly, the operator typically lowers the booms and tilts the bucket so that the flat portion of the bucket is level with and resting on the ground. The operator exist the cab and walks to the front of the tractor to disengage the parking stands and allow them to swivel and drop down into a rest position on the ground. When retracting the parking stands, the reverse is performed. 
         [0005]    To ensure that the loader assembly can later be reattached without significant difficulty, the parking stands should be extended and locked into a precise position where the connectors on the loader assembly will align with the connectors on the tractor. At a minimum, the above steps represent a tedious and time consuming task. However, as can be true with any task requiring manual interaction with heavy equipment in an operational state, the manual process of setting and retracting parking stands exposes the operator to a number of hazards. 
       SUMMARY 
       [0006]    Disclosed herein is a unique parking stand assembly, which provides temporary support for a front loader boom and bucket. The parking stand includes a latch and lock mechanism that is activated when the boom and/or bucket is in a specific position, indicative of a parking procedure. Activation of the latch and lock mechanism unlocks a parking stand when it is in a stowed position, such that it can drop and lock into a position where the parking stand is able to support the weight of the boom. 
         [0007]    The present invention comprises a loader assembly having a suspension and support mechanism, which include a boom with a movable implement attached at one end and a parking stand attached to the boom comprising a first strut pivotally attached to a second strut and a locking plate, wherein the locking plate comprises plurality of locking divots for receiving the first strut and second strut. 
     
    
     
       BRIEF DESCRIPTION OF EXEMPLARY DRAWINGS 
         [0008]    A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the Figures, wherein like reference numbers refer to similar elements throughout the Figures, and: 
           [0009]      FIG. 1  is a perspective view of a boom with the parking stand in a stowed and locked position in accordance with one embodiment; 
           [0010]      FIG. 2  is a perspective view of an engaged parking stand and strut pivotally connected to a loader assembly boom in accordance with one embodiment; 
           [0011]      FIG. 3  is a perspective view of a loader assembly boom with a pivotally attached support leg and strut in a stowed position in accordance with one embodiment; and 
           [0012]      FIG. 4  is a perspective view of a support leg component of the parking stand including a ratchet-type mechanism for locking the support leg in an extended position in accordance with one embodiment 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0013]    In general, this disclosure presents a unique front-end loader parking stand arrangement, which is of a simple, compact design, which may be easily moved between stowed and parking positions. More specifically, the front-end loader parking stand arrangement includes a pair of support legs, which are each pivotally mounted to a respective boom of the loader assembly. A support leg include a pair of independently pivoting support struts, which function in a ratchet-like manner relative to a locking mechanism. The locking mechanism comprises a plate having a pair of rows that each include a number of sequential divots. The divots receive the free-end of the respective support strut and secure it unidirectionaly, thereby preventing the support legs from collapsing. 
         [0014]    When stowed, each parking stand is secured within a respective locking receptacle, which is affixed to each respective loader boom. The locking feature of the receptacle may comprise, for example, a cross pin or cover. Each of a pair of parallel but independently pivoting struts are brought into contact with one of a plurality of divots in the locking mechanism when the support leg is lowered to establish the parking stand park position. 
         [0015]    Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Further embodiments of the invention may include any combination of features from one or more dependent claims, and such features may be incorporated, collectively or separately, into any independent claim. 
         [0016]    In describing embodiments herein, directional and positional descriptors (e.g., left, right, front, and back) are based on a perspective of one who is facing the bucket from the position of the boom/tractor connections. As such, for example, the bucket is at the front and the tractor is at the back of the boom assembly. 
         [0017]      FIG. 1  is a perspective view of a boom with the parking stand in a stowed and locked position in accordance with one embodiment. For simplicity, a loader assembly is illustrated as being detached from the front-end of a tractor. However, those of ordinary skill in the art will appreciate that the described processes for parking and un-parking the loader assembly  100  will most often be performed while the loader assembly  100  is pivotally attached to the tractor. For example, a front-end of a tractor may include a first coupling pin positioned and affixed to a first side of the tractor frame and a second coupling pin positioned and affixed to a second opposing side of the tractor frame, the first and second coupling pins pivotally securing first boom  105  and second boom  110  of a loader assembly  100  to the tractor frame. 
         [0018]    In one embodiment, the loader booms  105 ,  110  are pivoted about a tractor frame coupling pins by a first pair of hydraulic motors  120  that are respectively coupled between each tractor frame coupling pin and the associated boom  105 ,  110 . A second pair of hydraulic motors may be implemented to control the disposition of a bucket about its pivotal connections with the forward end  115  of the each boom  105 ,  110 . In one embodiment, the bucket is removable, such that it may be detached from the loader assembly  100  and interchanged with other implements. 
         [0019]    In one embodiment, the parking stand  125  and the strut  130  are pivotally connected to the primary boom  135 . Front-loader assemblies typically fall into one of two common boom configurations. In a first configuration, a single boom  135  pivots at an end where it connects to the tractor and pivots at the opposing end to control the tilt of an attached bucket. In a second configuration, the boom  135  includes an additional pivot point that is positioned at a point between the tractor end  105 ,  110  and the bucket end  115  of the boom. For simplicity, a single boom will be described with reference to the disclosed parking stand  125 . However, those of ordinary skill in the art will appreciate that the parking stand  125  may be applied to any or all of various boom configurations. Moreover, the parking stand  125  may be positioned at any point along the length of a boom  135  and/or boom segment. 
         [0020]      FIG. 2  is a perspective view of an engaged parking stand and strut pivotally connected to a loader assembly boom in accordance with one embodiment. As shown, a parking stand assembly  200  includes a support leg  225  and strut  220 , which are each connected to a boom  205 . In one embodiment, the support leg  225  includes on a first end, a through-hole  210 , which engages a boom  205  attached coupling pin. The through-hole and coupling pin attachment  210  allows the support leg  225  to move on a single axis (e.g., front to back). 
         [0021]    In a typical configuration, a loader assembly  200  will include a parking stand that is positioned on each of two parallel booms. Elements of the parking stands and their associated booms may be referenced in the singular throughout this disclosure. However, the description of the parking stand and interconnected loader assembly components will at least equally apply to a second parking stand assembly that is positioned on and attached to a second boom. For simplicity, only one parking stand assembly is described. 
         [0022]    In one embodiment, a strut  220  is pivotally attached to the boom  205  in order to follow the front-to-back movement of the support leg  225 , which the strut  220  supports. Similar to the support leg  225  attachment to the boom  205 , the strut  220  includes a through hole  215  at a boom engaging end. A coupling pin that is affixed to the boom  205  passes through the through-hole  215  of the strut  220  such that a hinge-like attachment is provided. 
         [0023]    At a strut end  235  opposite the boom engaging end, the strut  220  includes a portion that is sized and comprises a shape that may be suitably received by or retrained by one of a series of locking mechanism divots or grooves on a locking mechanism  240 . As will be described in greater detail herein, the divots or grooves are machined or molded along the strut facing side of the support leg. In one embodiment, the locking mechanism  240  comprises a plate that is fixed to the support leg  225  by way of, for example, welds, bolts, pins, or rivets. 
         [0024]    In one embodiment, the support leg  225  includes a ground-engaging foot  230 , which is pivotally attached to an end opposing the boom  205  engaging end of the support leg  225 . To provide greater support on a ground surfaces of variable grades, the foot  230  is attached to the support leg  225  to allow limited movement along a single axis. 
         [0025]      FIG. 3  is a perspective view of a loader assembly boom with a pivotally attached support leg and strut in a stowed position in accordance with one embodiment. In the stowed position of the parking stand, the support leg  310  is pivoted and latched against the boom  305  so as not to interfere with the operation of the front-loader assembly. A latching mechanism  330  secures the support leg  310  while stowed and may comprise a pivoting hook that is held into a default latched position by a spring or similar. In one embodiment, the latching mechanism  330  may be operated by linkages or cable controls. Alternatively, the latching mechanism  330  may be actuated electrically, hydraulically, or pneumatically using power sources made available by the tractor. Further, a means for activating the latching mechanism  330  may include an electromagnet. For example, through the use of an electromagnet, a latch pin or lock may be controlled, with the pin being spring biased to a position such that when the electromagnet is de-energized, even by a power failure, the support leg  310  would remain latched in the stowed position. 
         [0026]    When the latching mechanism  330  is released, the support leg  310  pivots down due to the force of gravity. In one embodiment, the support leg  310  may be driven down toward a parking position by a motor, spring, or actuator. While not wholly visible when the support leg  310  is stowed, a strut is pivotally connected to the boom  305 . In one embodiment, movement of the strut is provided by any means disclosed herein, thereby causing movement of the support leg  310  to correspond to the guided movement of the strut. In order to return the support leg  310  to a position in which is pivoted upward in the stowed position, the strut may be manually or automatically pivoted upward toward the boom, where it is secured by the latching mechanism  330 . 
         [0027]    In one embodiment, powered movement to either of the support leg  310  or the strut is provided by hydraulic driven movements of boom  305  components. For example, in order to park the loader assembly, an operator uses tractor controllers to invoke movement of the boom  305  and the bucket  325 . By raising or lowering the boom  305  and tilting the bucket  325  into a specific position, attached cabling may translate the hydraulic driven movements into mechanical movements of parking stand components. These movements may be applied to open or close a latching mechanism  330 , lower or retract the support leg  310 , or pivot a strut. 
         [0028]      FIG. 4  is a perspective view of a support leg component of the parking stand including a ratchet-type mechanism for locking the support leg in an extended position in accordance with one embodiment. A support leg is presented in  FIG. 4  with respect to the interconnections with the boom and struts while in a parking position. When the parking stand is released and lowered from its stowed position, downward motion is stopped when a foot  435  contacts the ground surface. At the ground-engaging end of the support leg, the foot  435  is pivotally attached to the support leg  405  by means of a coupling pin  445 , in accordance with one embodiment. 
         [0029]    To provide vertical reinforcement to the support leg  405  and to lock the support leg  405  into a precise ground-engaging position, the parking stand assembly includes two struts  415 ,  420 . In accordance with this embodiment, the struts  415 ,  420  are pivotally attached to a loader boom by way of a through hole and coupling pin  425 , such that each strut is able to pivot independently. 
         [0030]    Each of the struts  415 ,  420  include a locking element (e.g., divot or groove)  440  engaging portion  455  at the end opposite of the pivotally connected end  425 . The size and shape of the engaging portion  455  may vary based on the size and shape of the divots  440 . In one embodiment, the parking stand assembly includes a single strut, which is pivotally attached to the boom and engages a single row of sequentially positioned divots  440 . 
         [0031]    In one embodiment, each of the two struts  414 ,  420  are pivotally attached by way of a coupling pin  425 , which secures the struts to a mounting bracket that is attached to the boom. In accordance with this embodiment, the two struts  414 ,  420  are configured to pivot in unison when moving in a single direction. Accordingly, a first strut  420  includes a stopper  450  attached thereto to prevent the second strut  415  from pivoting ahead of the first strut  420  while moving in single direction. 
         [0032]    In a further embodiment, the two pivotally attached  425  struts are bound together in a manner that causes them to pivot in unison. A bracket  450  that functions to bind a first strut  415  and second strut  420  is configured in a manner that creates a slight offset, wherein the second strut  420  is held in a position that is slightly ahead of the first strut  415 . Two rows of divots  440  for securing the engaging end  455  of each strut  415 ,  420  are similarly offset to allow for a greater density of divots allowing for greater precision in strut positioning. Having a greater number of divots  440  in close proximity contributes to the increased positioning precision without significantly impacting the tensile strength of the locking plate  410 . 
         [0033]    When the first strut  415  engages one of the divots  440  in the first row, the second offset strut  420  engages a divot  440  in the slightly offset second row. Because the two struts  415 ,  420  engage two slightly offset divots  440 , the locking plate  410  is not overly weakened by having two horizontally aligned divots  440  or holes in very close proximity, which forms a straight line of significantly removed material. Those of ordinary skill in the art will appreciate that having a series of cutouts  440  positioned along a shared axis of a metal plate  410  will result in a logical breaking point  410  when subjected to excessive weight. 
         [0034]    In one embodiment, the support leg  405  comprises a length of C-shaped metal (i.e., c-beam), where the open side of the “C” faces the boom and struts  415 ,  420 . The locking plate  410  is attached to the support leg  405  and likewise faces the boom and struts  415 ,  420 , such that the divot engaging ends  455  of the struts  415 ,  420  are able to engage the locking plate divots  440 . Positioning the locking plate  410  within the channel of the c-beam shaped support leg  405  further secures locking plate  410  by preventing side-to-side movement. 
         [0035]    The locking plate  410  comprises a high-strength material and includes, in one embodiment, two parallel lines of sequential insets, divots, or grooves  440 . A locking divot  440  may comprise a hole that is bored through the locking plate  410 , where the depth of the divot  440  equals the thickness of the locking plate  410 . In the illustrated embodiment, the divot  410  is pill shaped, wherein the long side of the divot  440  is perpendicular to the support leg  405  length. However, the divots  440  may comprise any shape and may take the form of a through-hole or an inset, which does not pass through the locking plate  410 . In one embodiment, narrow strips of a hardened material (e.g., steel) may be formed into a grid-like structure, which is attached to the top of the locking plate  410 . In accordance with this embodiment, the strut end portions  455  are secured between a series of grid lines. 
         [0036]    In one embodiment, the locking plate  410  is permanently or semi-permanently secured to the support leg  405  by way of bolts, rivets, or welds. The locking plate  410  is of a sufficient width to fit within the support leg  405  channel and is of a sufficient length to engage the struts  415 ,  420  when the support leg  410  is pivoting into or out of a locked position. 
         [0037]    In another embodiment, the locking plate  410  slides along a track within the support leg  405  channel. In addition to an ability to move along a track, either the locking plate  410 , the support leg  405 , or a combination thereof, include a mechanical means for securing the locking plate  410  into a position along the track. The struts  415 ,  420  remain engaged with the locking plate  410  as the support leg  405  pivots between a fully extended position and a stowed position, such that the locking plate  410  moves along the length of the support leg  405  in response to movement of the support leg  405 . In the previously disclosed embodiment, having the secured locking plate rather than having the struts  415 ,  420  ratchet over a secured locking plate  410 . 
         [0038]    Those of ordinary skill in the art will appreciate that there are a variety of methods and mechanisms that would effectively secure the locking plate  410  into a desired position and release the locking plate  410  to allow full or limited movement. In various embodiments, the disclosed parking stand utilizes automatic means, manual means, or a combination of means to secure and release the locking plate  410 . Those of ordinary skill in the art will appreciate that whether the securing means comprises a cable and lever arrangement or a sensor and solenoid actuator, the elected method for securing does not alter, nor does it limit the scope of the invention. 
         [0039]    Moreover, relative to the mechanical components for carrying out the features of the disclosed parking stand, various known methods, mechanisms, and systems exist, for example, to determine and measure movement, facilitate movement and secure components to prevent movement. The disclosed parking stand may incorporate any known method for carrying out the various mechanical features disclosed herein, without departing from the scope of the invention. 
         [0040]    In the foregoing specification, the system has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes may be made without departing from the scope of the invention. The specification and figures are to be regarded in an illustrative manner, rather than a restrictive one, and all such modifications are intended to be included within the scope of invention. Accordingly, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given above. For example, the steps recited in any of the method or process claims may be executed in any order and are not limited to the order presented. 
         [0041]    Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, no element described herein is required for the practice of the invention unless expressly described as “essential” or “critical.”