Patent Publication Number: US-8979468-B2

Title: Loading work apparatus with attachment tools

Description:
BACKGROUND OF THE INVENTION 
     1. Filed of Invention 
     The present invention relates to a loading work apparatus removably attaching an implement tool thereto. 
     2. Description of Related Art 
     The loading work apparatus mounted on a tractor, a wheel loader, a skid-steer loader and the like includes an implement tool removably attached to distal ends of booms for easy exchange for another implement tool. As disclosed in JP 2011-099239 A and U.S. Pat. No. 5,562,397, the loading work apparatus of this type includes a pair of right and left booms, attachment tools each pivotally supported at a distal end of the boom associated therewith by a transverse shaft, an implement tool removably attached to the attachment tools, and a pair of right and left implement tool cylinders each connected to the attachment tools associated therewith by support shaft for pivoting the implement tool about the transverse shaft. 
     The implement tool has an engaged member provided in a back surface thereof. The attachment tools include an attachment unit provided along and close to the back surface of the implement tool and having an engaging member engaged with the engaged member, a pair of right and left of coupling members each provided in a back surface of the attachment unit to support the transverse shaft, and a pair of right and left of lock members supported by the attachment unit for locking and unlocking engagement between the engaging member and engaged member. 
     The attachment tool has a quick-hitching structure for removably mounting various types of implement tools (attachments), with the transverse shaft and support shaft being arranged in positions laterally displaced from each lock member in the back surface of each attachment tool. 
     In the above-noted conventional apparatus, the right and left lock members of the attachment tools are provided at fixed positions for common attachment of a variety of implement tools, and further the transverse shaft and support shaft of each coupling member are arranged laterally outward of each of the lock members. As a result, the conventional apparatus is not easily applicable when the interval defined between the right and left booms is the same as or smaller than the interval defined between the right and left lock members. 
     An object of the present invention is to provide a loading work apparatus for solving the above-noted problem. 
     SUMMARY OF THE INVENTION 
     The above object is fulfilled by one aspect of the present invention as under: 
     A loading work apparatus comprising: 
     a pair of right and left booms; 
     attachment tools, each of the attachment tools being pivotally supported at a distal end of the boom associated therewith by a transverse shaft; 
     an implement tool removably attached to the attachment tools; and 
     a pair of right and left implement tool cylinders, each of the implement tool cylinders being connected to the attachment tool associated therewith by a support shaft for rotatting the implement tool about the transverse shaft; 
     wherein the implement tool includes an engaged member on a back surface thereof; 
     wherein the attachment tools include:
         an attachment unit provided along and close to the back surface of the implement tool, the attachment unit having an engaging member engageable with the engaged member;   a pair of right and left coupling members, each of the coupling members being provided on a back surface of the attachment unit for supporting the transverse shaft; and   a pair of right and left of lock members supported by the attachment unit for locking and unlocking engagement between the engaging member and engaged member; and       

     wherein each of the coupling members includes a pair of right and left brackets standing upright from the back surface of the attachment unit on lateral opposite sides of the lock member associated therewith; 
     the transverse shaft is supported at opposite ends thereof on respective lower portions of the right and left brackets; 
     the support shaft is supported at opposite ends thereof on respective intermediate portions of the right and left brackets; and 
     wherein the transverse shaft and the support shaft are arranged to bridge across each of the lock members. 
     With the above-noted arrangement, since the transverse shaft at the distal end of each boom and the support shaft at a distal end of each implement tool cylinder are arranged to bridge across each of the lock members in the back surface of the attachment tools, the apparatus is easily applicable when the interval defined between the right and left booms is the same as or smaller than the interval defined between the right and left lock members. 
     More particularly, each of the coupling members includes right and left upright brackets on lateral opposite sides of each of the lock members on the back surface of the attachment unit, the transverse shaft is supported at opposite ends thereof by lower portions of the right and left brackets, the support shaft is supported at opposite ends thereof by intermediate portions of the right and left brackets, and the transverse shaft and the support shaft are arranged to bridge across each of the lock members. Thus, even if the interval defined between the right and left booms is the same as or smaller than the interval defined between the right and left lock members, the attachment tools can be attached to removably connect the implement tool thereto. 
     According to a preferred embodiment: 
     the engaged member includes right and left upper engaged portions and right and left lower engaged portions provided on lateral opposite sides of the back surface of the implement tool; and 
     the attachment unit includes:
         right and left upper engaging portions and right and left lower engaging portions engageable with the right and left upper engaged portions and right and left lower engaged portions of the implement tool, respectively;   a pair of right and left backing plates, each of the backing plates having the right and left brackets and the lock member; and   a connecting rod for connecting the right and left backing plates to each other.       

     With the above-noted arrangement, the attachment unit has right and left backing plates including the upper and lower engaging portions, the right and left brackets and the lock members, and a connecting rod for connecting the right and left backing plates to each other. Thus, such an arrangement makes an inexpensive construction with the right and left backing plates being connected to each other by the connecting rod. 
     According to another preferred embodiment: 
     each the lock members includes:
         a lock pin vertically movably supported by the attachment tool associated therewith and projecting downward therefrom to be engaged with the engaged member associated therewith of the implement tool; and   a manual lever pivotally supported by the attachment tool associated therewith for pushing and pulling the lock pin through a link; and       

     wherein the lock pin is positioned laterally outward of each of the pair of right and left booms. 
     With the above-noted arrangement, since the lock pin is positioned laterally outward of each of the pair of right and left booms, the present invention is applicable even if the interval defined between the right and left booms and the interval defined between the right and left implement tool cylinders are smaller than the interval defined between the right and left lock members. 
     Other features, advantages and effects of the present invention will be apparent from the following descriptions with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a loading work apparatus according to one embodiment of the present invention with an implement tool being removed; 
         FIG. 2  is a side view of the loading work apparatus with the implement tool being attached; 
         FIG. 3  is a top plan view of the loading work apparatus shown in  FIG. 2 ; 
         FIG. 4  is an enlarged rear view of an attachment tool; 
         FIG. 5  is a side view in vertical section of the attachment tool with the implement tool being attached; and 
         FIG. 6  is a rear view of the attachment tool. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. 
       FIG. 1  shows a front loader attached to a traveling vehicle body  20 , as an example of a loading work apparatus F. A tractor acting as the traveling vehicle body  20  includes: a transmission case  22  connected to a rear portion of an engine  21 ; front frames  23  projecting forward from the engine  21 ; a front wheel  24  suspended from the front frame  23  associated therewith; a hood  25  covering the engine  21 ; and front loader attachment frames  27  mounted on lateral opposite sides of the engine  21  and transmission case  22 . 
     Each of the front loader attachment frames  27  includes: an attachment plate  27 A extending from the engine  21  to the transmission case  22  and bolted thereto; a cylindrical attachment tube  27 B secured to the attachment plate  27 A and extending laterally outward therefrom; and a supporting plate  27 C extending upright from an outer end portion of the attachment tube  27 B. The supporting plate  27 C has a receiving recess  28   a  formed in a vertical intermediate portion thereof and an attachment-pin hole  28   b  formed in an upper portion thereof. 
     The front loader F includes: right and left masts  29 ; right and left booms B, each having a proximal portion thereof pivotally supported at an upper portion of the mast  29  associated therewith through a pivotal shaft  30 ; boom cylinders  31  each connected between a longitudinal intermediate portion of the boom B and a lower portion of the mast  29  associated therewith; attachment tools  5  each pivotally supported at a distal end of the boom B associated therewith through a transverse shaft  4 ; an implement tool (bucket) G removably attached to the attachment tools  5 ; and implement tool cylinders (bucket cylinders) S each provided between a longitudinal intermediate portion of the boom B and the attachment tool  5  associated therewith. 
     Each of the right and left masts  29  is removably attached to the attachment frame  27  associated therewith by engagement between the receiving recess  28   a  of the supporting plate  27 C and a pin-shaped engaging portion  32  formed in a lower end of the mast  29 , and by insertion of an attachment pin  33  into a connecting-pin hole formed in a vertical intermediate portion of the mast and the attachment-pin hole  28   b  of the supporting plate  27 C. 
     With reference to  FIGS. 1 to 4 , each boom B has an inverted V-shape. The pair of right and left booms B are connected to each other through an intermediate coupling member Ba. The attachment tool  5  has a lower portion thereof pivotally supported at the distal end of the boom B through the transverse shaft  4 , and an intermediate portion thereof connected to a distal end of a cylinder rod of the implement tool cylinder S through a support shaft  6 . 
     The implement tool G is removably attached to the attachment tools  5 , the implement tool G and attachment tools  5  forming an implement tool attachment device  2  together. The right/left implement tool cylinder S is opposed to a forward and upward portion of the right/left boom B, and extended and contracted to pivotally rotate the right/left attachment tool  5  about the transverse shaft  4  associated therewith. The cylinders S are contracted from a position where the implement tool G contacts the ground to allow the implement tool G to perform a scooping operation and extended to allow the implement tool G to perform a dumping operation to a position shown in  FIG. 2 . 
     It should be noted that the terms “vertical direction” and “longitudinal direction” are used in the embodiment with reference to  FIGS. 1 and 5 , in which a bottom wall G 1  of the bucket G comes into contact with the ground. 
     With reference to  FIGS. 1 to 5 , the bucket G is shown as an example of the implement tool G. The bucket G includes: the bottom wall G 1 , a rear wall G 2 , and lateral walls G 3  provided at lateral opposite ends of the bottom wall and rear wall. A top plate  35  is mounted on the top of the bucket G to extend substantially over an entire width thereof; stiffening plates  36  and guide plates  37  are provided on lateral opposite sides of a back surface of the rear wall G 2 ; and a bottom plate  38  extends from the bottom wall G 1  to lower portions of the stiffening plates  36 . 
     The implement tool G includes an engaged member  7  on the back surface of the rear wall G 2 . The engaged member  7  has right and left upper engaged portions  7 U each formed by the top plate  35  projecting rearward and downward from a top portion of the stiffening plate  36 , and right and left lower engaged portions  7 D each formed by a lower portion of the stiffening plate  36  bending and projecting rearward and downward. 
     The right and left guide plates  37  are provided laterally outward of the right and left stiffening plates  36  and have rear portions thereof inclined to flare rearward, thereby to guide right and left positions of the attachment tools  5  approaching the guide plates  37  from behind. 
     The attachment tools  5  include: an attachment unit  9  provided along with and close to the back surface of the implement tool G and having an engaging member  8  engageable with the engaged member  7 ; a pair of right and left coupling members  10  provided on the back surface of the attachment unit  9  to support the respective transverse shafts  4 ; and right and left pair of lock members  11  supported by the attachment unit  9  to lock and unlock the engagement between the engaging member  8  and engaged member  7 . 
     The attachment unit  9  may be a single plate with a lateral width thereof extending between the right and left stiffening plates  36 . In the illustrated embodiment, however, the attachment unit  9  is formed of a pair of right and left backing plates  9 A each having a lateral width thereof corresponding to that of the right/left stiffening plate  36 ; and a connecting rod  9 B interconnecting the right and left backing plates  9 A, so that the attachment unit makes lighter than the single plate extending over the entire lateral width. 
     Each of the backing plates  9 A has an upper portion thereof bent into V-shape to form an upper engaging portion  8 U coming into and engageable with a bottom surface of the engaged portion  7 U, and a lower portion thereof bent in V-shape to form a lower engaging portion  8 D placed on and engageable with a top surface of the lower engaged portion  7 D. Lock pin holes  39   a ,  39   b  are formed in the lower engaged portion  7 D and lower engaging portion  8 D, respectively to come into alignment with each other when the lower engaged portion  7 D and lower engaging portion  8 D are overlapped with each other. 
     Each of the right and left backing plates  9 A has right and left brackets  10 A standing upright therefrom for extending the connecting rod  9 B therethrough. The right and left brackets  10 A form the coupling member  10 . 
     The coupling member  10  includes boss portions formed in respective lower portions of the right and left brackets  10 A for supporting opposite ends of the transverse shaft  4 . A distal end of the boom B is inserted between the right and left boss portions and fitted on the transverse shaft  4 . The coupling member  10  includes further boss portions formed in respective vertical intermediate portions of the right and left brackets  10 A for supporting opposite ends of the support shaft  6 . A distal end of the cylinder rod of the implement tool cylinder S is inserted between the right and left boss portions and fitted on the support shaft  6 . 
     The right and left boss portions for the transverse shaft  4  and the right and left boss portions for the support shaft  6  are formed of tubular members, respectively. The lateral width of each tubular member is variable to vary a lateral position of the distal end of the boom B or the implement tool cylinder S. 
     Each of the right and left lock members  11  is disposed between the right and left brackets  10 A associated therewith. A lock pin  12  is vertically movably supported by a tubular guide  40  which is fixed to a back surface of the backing plate  9 A. A lower portion of a link  13  is connected to an upper portion of the lock pin  12  through a pin  12   a . A slidable member  41  is provided at an upper portion of the link  13 . A spring  42  is fitted on an intermediate portion of the link  13 . One end of a manual lever  14  is connected to a pin hole  41   a  of the slidable member  41 . 
     The manual lever  14  is pivotally supported by a support pin  43  which is fixed to the backing plate  9 A. The right and left manual levers  14  are arranged in proper positions that enable one operator to oscillate both the levers  14  simultaneously. 
     With reference to  FIGS. 3 ,  4  and  6 , an unlocking position where a distal end of the manual lever  14  acting as a grip projects from the attachment tool  9  is shown in two-dot chain line, while a locking position where the grip enters the attachment tool  9  is shown in solid line. 
     When the manual lever  14  is oscillated from the unlocking position, a proximal end of the manual lever  14  compresses the spring  42  through the slidable member  41  to push the link  13  and lower the lock pin  12 . An extreme end of the lock pin  12  is projected from the tubular guide  40  and the lock pin hole  39   a  of the lower engaging portion  8 D and inserted into the lock pin hole  39   b  of the lower engaging portion  7 D, thereby to prevent the lower engaged portion  7 D from disengaging from the lower engaging portion  8 D, so that the attachment of the implement tool G is locked. 
     When the manual lever  14  is brought to the locking position, the slidable member  41  passes a center line extending between the pin  12   a  and the support pin  43  to come into contact with one of the brackets  10 A and is maintained in position by an elastic force of the spring  42 . 
     The manual lever  14  is bent so that a portion thereof between the support shaft  43  and the grip extends remote away from the backing plate  9 A. One of the brackets  10 A which is overlapped with the manual lever  14  in the locking position has a smaller height than the other bracket  10 A which is brought into contact with an end of the manual lever  14  connected to the slidable member  41 . 
     An interval defined between the right and left brackets  10 A is determined so that the slidable member  41  comes into contact with one of the brackets  10 A when one end of the manual lever  14  between the right and left brackets  10 A is oscillated to establish the locking position. Then, the lock pin  12  is displaced right or left from a central position of the interval defined between the right and left brackets  10 A, and comes closer to the backing plate  9 A than to the transverse shaft  4  and the support shaft  6 . 
     The transverse shaft  4  is positioned below the lock pin  12  and the support shaft  6  is positioned above the lock pin  12 . The transverse shaft  4  and the support shaft  6  are overlapped with the lock pin  12  in the lateral direction to pass the back surface side of the lock member  11 . The transverse shaft  4  is positioned downward of the lower engaging portion  8 D and remote from the implement tool G. 
     Thus, the transverse shaft  4  and the support shaft  6  are arranged to bridge across the lock member  11 , and the lock pin  12  is positioned laterally outward of the boom B and the implement tool cylinder S disposed in the central region of the interval defined between the right and left brackets  10 A. 
     Each backing plate  9 A has a projection  9 Aa in an upper portion thereof projecting to a lateral side. The right and left projections  9 Aa is configured to come into contact with the right and left guide plates  37 , respectively for guiding the right and left positions of the attachment unit  9 , when the attachment unit  9  is engaged with the back surface of the implement tool G. 
     While those projections  9 A project laterally outward from the attachment unit  9 , the projections  9 A may project laterally inward from the projections  9 A instead. Then, the projections  9 A may be applied and attached to the booms B and the implement cylinders S each arranged at enlarged intervals, while the right and left brackets  10 A, transverse shafts  4 , support shafts  6  and locking members  11  remains to be used as they are. 
     With the implement tool G contacting the ground as shown in  FIG. 1 , the attaching operation using the implement tool attachment device  2  is performed by lowering the booms B to move the attachment tools  5  toward the back surface of the implement tool G, engaging the right/left upper engaging portions  8 U with the right/left upper engaged portions  7 U from below, and raising the upper engaging portions  8 U to lift the implement tool G. As a result, the lower engaged portions  7 D of the implement tool G approach and engage with the lower engaging portions  8 D, respectively. 
     With the right and left upper engaged portions  7 U and the right and left lower engaged portions  7 D being engaged with the upper engaging portions  8 U and the lower engaging portions  8 D, respectively, when the right and left manual levers  14  are oscillated from the position shown in two-dot chain line to the position shown in solid line in  FIG. 3 , the extreme ends of the lock pins  12  project from the lock pin holes  39   a  of the lower engaging portions  8 D, and are inserted into and come into engagement with the lock pin holes  39   b  of the lower engaged portions  7 D, thereby coupling and locking the implement tool G to the attachment tools  5 . 
     In forming the implement tool attachment device  2 , the positions of the upper engaged portions  7 U, lower engaged portions  7 D, guide plates  37  and the lock pin holes  39   b  for the implement tool G are predetermined or fixed regardless of the type of the implement tool G to be coupled. Thus, the positions of the upper engaging portions  8 U, lower engaged portions  8 D and lock pin holes  39   a  of the attachment tools  5  are also predetermined or fixed. Inevitably, the positions of the lock members  11  and the position of one of the brackets  10 A with which the slidable member  41  of each manually-operable lock member  11  comes into contact are also predetermined or fixed. 
     The components of the implement tool attachment device  2  other than the one of the brackets  10 A contacting the slidable member  41  of the manually-operable locking member  11  may be designed so as to reverse the lateral positions thereof. For example, the right/left backing plate  9 A may have its projection  9 Aa projecting laterally inward, and the other bracket  10 A not contacting the slidable member  41  may be arranged laterally outward of the bracket  10 A contacting the slidable member  41 , so that the transverse shafts  4  and support shafts  6  may be supported by another brackets provided separately from the right and left brackets  10 A. 
     As described in the above embodiment, however, if the lock member  11  is disposed between the right and left brackets  10 A, and if the transverse shaft  4  and support shaft  6  are disposed to bridge across the lock member  11 , then, such another brackets can be dispensed with for supporting the transverse shaft  4  and support shaft  6 . Further, the boom B and the implement tool cylinder S can be positioned to overlap the lock member  11  or laterally inward of the lock member  11  without being hindered by the lock member  11 . As a result, the implement tool attachment device  2  may be applied to a loading work apparatus F including the right and left booms B with a smaller interval, and the right and left implement tool cylinders S with a smaller interval. 
     It should be noted that the best modes of the shapes of the respective components and the best modes of the positional relationships in the longitudinal direction, transverse direction and vertical direction among the respective components are as shown in  FIGS. 1 to 6 . Alternatively, however, those shapes and relationships should not be limited to the ones as shown and described in the above-described embodiment, but various modifications may be done to the components and arrangements, as well as combinations thereof. 
     For example, the implement tool G may be a fork, thumb implement tool or the like other than the bucket; and the boom B may be for a wheel loader, skid-steer loader, tractor loader backhoe or the like. 
     Further, a hydraulic cylinder may be mounted between the manual levers  14  of the right and left lock members  11  to oscillate the manual levers  14  for locking and unlocking operation.