Patent Publication Number: US-2005126052-A1

Title: Blade device

Description:
TECHNICAL FIELD  
      This invention concerns a blade device that can be changed in width.  
     BACKGROUND ART  
      As examples of conventional working machines equipped with a blade device for use in excavation work, etc., the arrangements disclosed in Japanese Laid-open Patent Publication No. 2000-96602 and U.S. Pat. No. 2,855,579 maybe cited. With such a working machine, a blade device, mounted to a main machine body, is made variable in width in correspondence to the width variation of travelling devices at the respective sides of the main machine body.  
      Among such blade devices that are made variable in width, there is an arrangement wherein a main blade body, which is long in the width direction, has a fixed width dimension, and for width expansion, width expansion blade body are mounted to the ends of the main blade body in the width direction. On the other hand, in the contracted state in which the width expansion blade body are not used, that is, in the state in which the width expansion blade body are housed, the width expansion blade body are housed by being mounted to the back face side of the main blade body.  
      With the blade device described in Japanese Laid-open Patent Publication No. 2000-96602, a pair of upper and lower main blade brackets are disposed at the back face of a main blade body and a pair of upper and lower width expansion blade brackets, which overlap with the upper and lower faces of the main blade brackets, are disposed at the back face of a width expansion blade body. For width expansion, the width expansion blade body is positioned at an end part of the main blade body, the width expansion blade brackets overlap with the upper and lower faces of the main blade brackets, and two pins are inserted from above into these width expansion blade brackets and main blade brackets to fix the brackets. For housing, the two pins are pulled out to remove the width expansion blade body from the main blade body, the width expansion blade is positioned at the back face blade of the main blade body upon turning around the front and back faces, the width expansion blade brackets are overlapped with the upper and lower faces of the main blade brackets, and the two pins are inserted from above into these width expansion blade brackets and main blade brackets to fix the brackets. During work in the width-expanded state, loads in the front/back direction of the width expansion blade body are received by the two pins that have been inserted into the width bade brackets and the main blade brackets.  
      With the blade device disclosed in U.S. Pat. No. 2,855,579, a cylindrical mounting cylinder, which is opened in the width direction of a main blade body, is provided at the back face of the main blade body, and a columnar mounting shaft, which is inserted into the mounting cylinder, is provided at the back face of a width expansion blade body. For width expansion, the mounting shaft is inserted from the outer end side of the mounting cylinder, the width expansion blade body is positioned at an end part of the main blade body, and a single pin is inserted into mounting holes, which are provided in the mounting cylinder and the mounting shaft and respectively intersect the axial direction, to fix the cylinder and the shaft. For housing, the pin is drawn out and after removing the width expansion blade body from the main blade body, the width expansion blade body is positioned at the back face side of the main blade body upon turning around the front and back faces, the mounting shaft is inserted from the inner end side of the mounting cylinder, and the single pin is inserted into the mounting hole of the mounting cylinder and the mounting hole of the mounting shaft to fix the cylinder and the shaft. Though the mounting shaft that has been inserted into the mounting cylinder is rotatable, by inserting the pin into the mounting hole of the mounting cylinder and the mounting hole of the mounting shaft, the width expansion blade body is prevented from rotating with respect to and falling out from the main blade body.  
      With the blade device disclosed in Japanese Laid-open Patent Publication No. 2000-96602, two pins are required to receive loads in the front/back direction that are applied to the width expansion blade body, the insertion/extraction operations of these two pins are not easy, and since loads in the front/back direction that are applied to the width expansion blade body must be received by the pins, a large burden is placed on the pin parts.  
      Also with the blade device disclosed in U.S. Pat. No. 2,855,579, since by the insertion of the mounting shaft into the mounting cylinder, loads in the front/back direction that are applied to the width expansion blade body are received by the mounting cylinder, a single pin suffices for preventing rotation and fall-out. However, since loads in the direction of rotation of the width expansion blade about the mounting shaft must be received by the pin, a large burden is placed on the pin part. Also, with the width expansion blade body, the mounting shaft is rotatable with respect to the mounting cylinder and the center-of-gravity balance is such that the width expansion blade body is directed downwards about the mounting shaft. Thus in inserting the pin, the pin must be inserted upon matching the positions of the mounting hole of the mounting cylinder and the mounting hole of the mounting shaft while supporting the width expansion blade body against the center-of-gravity balance. The pin therefore cannot be inserted readily. Also in extracting the pin, the edge part of the mounting hole of the mounting shaft, which tends to rotate in accordance with the center-of-gravity balance of the width expansion blade body, presses against the pin. The pin therefore cannot be extracted readily.  
      This invention has been made in view of such points and an object there of is to provide a blade device, which is lightened and the burden placed on a latching member and with which the attachment and detachment of the latching member can be carried out readily.  
     DISCLOSURE OF THE INVENTION  
      The invention&#39;s blade device including a main blade body, in turn having a main blade, which is long in the width direction, and mounting parts, each disposed at an end part in the width direction of the back face of the main blade and having formed therein a mounting hole, which is opened in the width direction and with which the cross section in the direction intersecting the width direction is non-circular. Width expansion blade bodies, each in turn including a width expansion blade, which can be positioned at an end, in the width direction of the main blade, and a fitting part, which is disposed at the back face of the width expansion blade and inserts removably into a mounting hole of the main blade body. The width expansion blade is positioned at the end part of the main blade by the fitting of the fitting part from the outer end side of the mounting hole. Also, latching members, each detachably latching the fitting part of a width expansion blade body that has been fitted into a mounting hole of the main blade body. With this blade device, in the width-expanded state, in which a width expansion blade body is positioned at an end part of the main blade body upon fitting of a fitting part into a mounting hole from the outer end side, loads placed on the width expansion blade body can be received by the mounting part with a box structure, and the latching member that latches the fitting part, fitted in the mounting hole of the mounting part, functions only to prevent the falling out of the fitting part. The burden placed on the latching member is thus lightened and the latching member can also be attached or detached readily.  
      Also, each width expansion blade body is arranged so that the width expansion blade is positioned at the back face side of the main blade by the fitting of the fitting part from the inner end side of a mounting hole of the main blade body. A width expansion blade can thus be housed at the back face side of the main blade body when it is not used.  
      Also, the main blade body is equipped with supporting arms, each of which supports an intermediate part in the width direction of the back face of the main blade body, the length in the width direction, including the fitting part, of each width expansion blade body is longer than the interval between a supporting arm and the inner end side of a mounting hole, and each fitting part is enabled to be inserted and removed from the inner end side of a mounting hole by a change of orientation of the width expansion blade body. Thus even when there is a restriction in regard to the width direction, the fitting part of a width expansion blade body can be inserted and removed from the inner end side of a mounting hole.  
      Each mounting part of the main blade body comprises a back face plate of the main blade, a pair of main blade brackets, extending from the back face plate to the supporting arm and spaced apart from each other, and a supporting part, disposed opposite the back face plate and between the pair of main blade brackets, and by shared use of the back face plate equipped by the main blade body and the main blade brackets, each mounting part can be arranged in a simple manner.  
      The fitting part of each width expansion blade body has a notched part, which allows changing, with respect to the supporting part of a mounting part of the main blade body, of the orientation of the width expansion blade body that is inserted and removed from the inner end side of the corresponding mounting hole. The orientation of the width expansion blade body that is inserted and removed from the inner end side of the mounting hole can thus be changed readily.  
      Also, each latching member has a single pin, which is inserted into a mounting part of the main blade body and into the fitting part of the width expansion blade body that has been fitted into the mounting hole of the mounting part. The fitting part of the width expansion blade body that has been fitted into the mounting hole of the main blade body can thus be latched with a single pin and the latching member can be attached and detached readily.  
      In an embodiment, each latching member has a single pin, which is inserted into a mounting part of the main blade body and into the fitting part of the width expansion blade body that has been fitted into the mounting hole of the mounting part, and a rotation stopping part, which is inserted into the mounting part of the main blade body and into the fitting part of the width expansion blade body that has been fitted from the inner end side of the mounting hole of the mounting part. The fitting part of the width expansion blade body that is fitted into a mounting hole of the main blade body can thus be latched with a single pin and the latching member can be attached and detached readily. Furthermore, the rotation of the fitting part of the width expansion blade body that has been fitted from the inner end side of the mounting hole is prevented by the rotation stopping part, enabling prevention of the jittering of the width expansion blade body in the housed state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view showing an embodiment of a blade device by this invention in the width-expanded state in which a width expansion blade body is used;  
       FIG. 2  is a plan view of the blade device in the width-expanded state;  
       FIG. 3  is a plan view of the housed state in which the width expansion blade body of the blade device is housed;  
       FIG. 4  is a rear view of the blade device in the width-expanded state;  
       FIG. 5  is a side view of a main blade body of the blade device;  
       FIG. 6  is a side view of a working machine to which the blade device is applied; and  
       FIG. 7  is a plan view of the working machine of  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The invention shall be described in detail with reference to an embodiment illustrated in  FIG. 1  through  FIG. 7 .  FIG. 6  and  FIG. 7  show a hydraulic shovel  11  as an example of a working machine. This hydraulic shovel  11  comprises a main machine body  12  and travelling devices  13  (e.g. tracks or wheels), disposed at the respective sides in the width direction of main machine body  12 .  
      Main machine body  12  has an upper rotating body  16  mounted, in a manner enabling rotation via a rotating part  15 , to a lower travelling body  14 , which can be made to travel by travelling devices  13  at both sides. A driving seat  18  is mounted to an upper part of upper rotating body  16 , and a working device  19  for excavation is mounted to the front face of upper rotating body  16 .  
      Lower travelling body  14  has an unillustrated travelling base, travelling devices  13  are positioned at both sides of this travelling base, and rotating part  15  is positioned at the upper face of the travelling base. Travelling devices  13  at both sides may be of a type that can be expanded or contracted in the width direction by means of a width varying device or of a type that does not have a width varying device and is not expanded or contracted in the width direction. With this embodiment, expansion and contraction in the width direction are enabled.  
      A blade device  17  is mounted by being pivotally supported in a manner enabling swinging in the vertical direction with respect to the front side of the travelling base of lower travelling body  14  and is swung in the vertical direction by a hydraulic cylinder  20 , disposed between the blade device and the travelling base.  
      Blade device  17  is arranged to expand or contract to vary its width as needed. That is, as shown in  FIG. 7 , blade device  17  is equipped with a main blade body  21 , which is mounted to main machine body  12 , width expansion blade bodies  22 , mounted in a detachable manner to the respective end parts in the width direction of main blade body  21 , and latching members  23 , latching these width expansion blade bodies  22  to main blade body  21 . For width expansion, blade device  17  is expanded in width by width expansion blade bodies  22  being mounted to the respective end parts in the width direction of main blade body  21  as indicated by the alternate long and two short dashes lines in  FIG. 7 , and for width contraction, that is, for the housing of width expansion blade bodies  22  when they are not used, blade device  17  is contracted in width by width expansion blade bodies  22  being removed from the respective end parts in the width direction of main blade body  21  and housed at the back face side of main blade body  21  as indicated by the solid lines in  FIG. 7 .  
      Blade device  17  is shown in  FIG. 1  through  FIG. 5 . Main blade body  21  of this blade device  17  has a main blade  31 , which is an excavation plate that is formed to have a concavely curved cross sectional shape at the front face side and to be long in the width direction, and at both ends of this main blade  31  are mounted end plates  33 , each being provided with a suspending hole  32 .  
      A back face plate  34  is mounted to the back face of main blade  31  and at intermediate parts in the width direction of this back face plate  34  are mounted a pair of supporting arms  35  that are pivotally supported in a swingable manner by main machine body  12 , that is, by the travelling base of lower travelling body  14 . A connection part  36  is connected between the inner faces of these pair of supporting arms  35  and a hydraulic cylinder  20  is connected to connection part  36 . At the outer face side of each supporting arm  35  are mounted a pair of main blade brackets  37 , which extend from back face plate  34  to supporting arm  35  and are separated from each other in the vertical direction.  
      At the respective end parts of the back face of main blade  31  are formed mounting parts  38  for detachably mounting width expansion plates  22 . Each mounting part  38  is formed as a box structure having back face plate  34 , the pair of upper and lower main blade brackets  37 , and a plate-shaped supporting part  39 , which opposes back face plate  34  in parallel between main blade brackets  37 . At the inner side of mounting part  38 , which is surrounded by back face plate  34 , the pair of upper and lower main blade brackets  37 , and supporting part  39  is formed a mounting hole  40 , which opens through in the width direction and with which the cross section in the direction intersecting the width direction is non-circular, that is, rectangular. Mounting part  38  has formed therein latching holes  41 , which pass coaxially through the pair of upper and lower main blade brackets  37  in the vertical direction, and an engaging hole  42 , which passes through the upper main blade bracket  37  in the vertical direction alongside latching holes  41 . Engaging hole  42  is formed to have a slot-like shape that is long in the direction of latching holes  41 .  
      With each pair of upper and lower main blade brackets  37 , the rear edge parts between supporting arm  35  and mounting part  38  are inwardly formed towards main blade  31  at the front, thereby forming relief parts  43 , which allow the housing of a width expansion blade body  22 .  
      Each end plate  33  has a notched part  44  formed in correspondence to the shape of the opening of mounting hole  40 .  
      Each width expansion blade body  22  has a width expansion blade  51 , which is formed to have the same cross sectional shape as main blade body  31 , that is, a cross sectional shape, which is concavely curved at the front face side, and end plates  52  and  53  are respectively mounted to one end and the other end in the width direction of this width expansion blade  51 . A fitting part  54 , which is removably inserted into mounting hole  40  of mounting part  38  of main blade body  21 , is positioned at the back face of each width expansion blade  51 . This fitting part  54  has a pair of upper and lower width expansion blade brackets  55  that are mounted to the back face of width expansion blade  51 , and the ends at one side of these width expansion blade brackets  55  protrude from one end side of width expansion blade  51  and fitting part  54  is formed at the protruding parts at the ends at one side of these width expansion blade brackets  55 . The cross sectional shape of fitting part  54  is formed to a non-circular shape, that is, a substantially rectangular shape by the upper and lower faces and front and rear faces of the upper and lower width expansion blade brackets  55  and is formed to a shape enabling fitting into mounting hole  40  of mounting part  38 .  
      As shown in  FIG. 2 , for width expansion by each width expansion blade body  22 , fitting part  54  is fitted from the outer end side of mounting hole  40  of mounting part  38  and width expansion blade  51  is thereby positioned at an end part of main blade  31 . Also as shown in  FIG. 3 , for width contraction, that is, for housing, fitting part  54  is fitted from the inner end side of mounting hole  40  of mounting part  38  and width expansion blade  51  is thereby positioned in a housed manner at the back face side of main blade  31 .  
      In the state in which fitting part  54  is fitted in mounting hole  40  of mounting part  38 , the upper and lower faces of the upper and lower width expansion blade brackets  55  of fitting part  54  are fitted in contact with the mutually opposing faces of the upper and lower main blade brackets  37  of mounting part  38 , and the front and rear faces of the upper and lower width expansion blade brackets  55  of fitting part  54  are fitted in contact with mutually opposing faces of back face plate  34  and supporting part  39  of mounting part  38 . Thus in the state in which the width is expanded and fitting part  54  is fitted in mounting part  38  and width expansion blade  51  is positioned at the end part of main blade  31 , the position of width expansion blade body  22  is set in a restricted manner with respect to main blade body  21  in regard to its position in the front/rear direction, vertical direction, and direction of rotation about the fitted portion, and loads in the front/rear direction, vertical direction, and direction of rotation about the fitted portion that are applied during work can be received by mounting part  38 , which has a box structure.  
      As shown in  FIG. 2 , the length L 1  of width expansion blade body  22 , including fitting part  54 , is longer than the interval L 2  between supporting arm  35  and the inner end side of mounting hole  40  of main blade body  21 , by a change of orientation by rotational movement of width expansion blade body  22  as shown in  FIG. 3 , fitting part  54  can be inserted and removed from the inner end side of mounting hole  40 .  
      At one rim of fitting part  54  at the side opposite the width expansion blade  51  side at the front end is formed a guide part  56 , which has been chamfered obliquely to serve as a guide for insertion of fitting part  54  into mounting hole  40  during width expansion and to prevent interference of fitting part  54  with back face plate  34  of main blade body  21  during the housing process. Also, at the other rim of fitting part  54  at the width expansion blade  51  side at the front end is formed a notched part  57 , which, in the housing process, allows a change of orientation by rotational movement of width expansion blade body  22  with respect to supporting part  39  of mounting part  38  for insertion or removal of fitting part  54  from the inner end side of mounting hole  40  as shown in  FIG. 3 .  
      Latching holes  58 , which are positioned so as to be coaxial to latching holes  41  of mounting part  38  in the state in which the pair of upper and lower width expansion blade brackets  55  of fitting part  54  are fitted in mounting hole  40  of mounting part  38 , are formed through the brackets in the vertical direction, and in the upper width expansion blade bracket  55  are formed engaging holes  59  and  60 , which are positioned coaxial to engaging hole  42  of mounting part  38 . These engaging holes  59  and  60  are disposed at two locations at the front end side and the base end side of fitting part  54  for the width expansion process, in which fitting part  54  is fitted from the outer end side of mounting hole  40 , and for the housing process, in which insertion is performed from the inner end side.  
      Latching member  23  has a single, columnar pin  71 , which is removably inserted into latching holes  41  of mounting part  38  and latching holes  58  of fitting part  54 , and a handle  72  for the insertion and removal operation of pin  71  is fixed to one end of pin  71 . Handle  72  is formed by bending a columnar wire rod into a substantially U-like shape, is fixed at one end side to pin  71 , and has formed, at the front end of this one end side, a rotation stopping part  73 , which is bent so as to be parallel to pin  71  and is inserted into engaging hole  42  of mounting part  38  and engaging hole  59  or engaging hole  60  of fitting part  54 .  
      Of the upper and lower latching holes  41  of mounting part  38  into which pin  71  is inserted, the inner diameter of the upper latching hole  41  is formed at a dimensional precision that is comparatively high with respect to the outer diameter of pin  71 . The dimensional precision of the lower latching hole  41  may be made lower in comparison to that of the upper latching hole  41  to facilitate manufacture.  
      The operations and effects of the present embodiment shall now be described.  
      As shown by the alternate long and two short dashes lines in  FIG. 7 , blade device  17  is expanded in width in accompaniment with the width expansion of travelling devices  13  at the respective sides of hydraulic shovel  11 .  
      To expand the width of blade device  17 , fitting part  54  of a width expansion blade body  22  is inserted and fitted from the outer end side of mounting hole  40  of a mounting part  38  of main blade body  21  and width expansion blade body  22  is thereby positioned at an end part of main blade body  21  as shown in  FIG. 1 ,  FIG. 2 , and  FIG. 4 . In the state in which fitting part  54  is fitted in mounting hole  40  of mounting part  38 , width expansion blade body  22  is set and restricted in position in the front/rear direction, vertical direction, and direction of rotation about the fitted portion with respect to main blade body  21 , and thus latching holes  58  and engaging hole  59  of fitting part  54  are respectively positioned coaxial to latching holes  41  and engaging hole  42  of mounting part  38 .  
      Pin  71  of latching tool  23  is matched to latching holes  41  of mounting part  38  and inserted into these latching holes  41  and latching holes  58  of fitting part  54 , and furthermore, rotation stopping part  73  is matched to engaging hole  42  and inserted into this engaging hole  42  and engaging hole  59  of fitting part  54 . In this width-expanded state, the position of width expansion blade body  22  in the direction of rotation about pin  71  is set by mounting part  38  with a box structure. Rotation stopping part  73  functions to prevent the rotation of latching member  23 , including pin  71 .  
      In this width-expanded state in which width expansion blade body  22  is positioned at the end part of main blade body  21  with fitting part  54  being fitted from the outer end side of mounting hole  40 , loads of the vertical direction, front/rear direction, and direction of rotation about the fitted portion that are applied to width expansion blade body  22  can be received by mounting part  38  with a box structure.  
      Latching member  23 , which latches fitting part  54  that has been fitted into mounting hole  40  of mounting part  38 , thus functions only as a part for preventing the fall-out of fitting part  54  and the burden placed on latching member  23  can thus be lightened. Latching by just the single pin  71  of latching member  23  is thus enabled.  
      By providing supporting part  39  between the pair of main blade brackets  37  so as to oppose back face plate  34  in addition to back face plate  34  of main blade  31  and the pair of main blade brackets  37 , extending in mutually separated manner from back face plate  34  to supporting arm  35 , mounting part  38  with a box structure can be arranged simply by shared use of back face plate  34  and main blade brackets  37 , which are generally equipped by main blade body  21 .  
      Also, blade device  17  is contracted in width in accompaniment with the contraction of width of travelling devices  13  at the respective sides of hydraulic shovel  11  as shown in  FIG. 7 .  
      To contract the width of blade device  17 , fitting part  54  of a width expansion blade body  22  is fitted by insertion from the inner end side of a mounting hole  40  of main blade body  21  to position width expansion blade body  22  at the back face side of main blade body  21  as shown in  FIG. 3 .  
      Here, even though there is a restriction in the width direction due to the length L 1  of width expansion blade body  22  in the width direction, including fitting part  54 , being longer than the interval L 2  between supporting arm  35  and the inner end side of mounting hole  40  of main blade body  21 , fitting part  54  can be inserted and fitted at the inner end side of mounting hole  40  by a change of orientation by rotational movement of width expansion blade body  22 . Furthermore, notched part  57 , provided at fitted part  54  of width expansion blade body  22 , allows the change of orientation by rotational movement of width expansion blade body  22 , which is inserted into the inner end side of mounting hole  40 , with respect to supporting part  39  of mounting part  38  of main blade body  21 .  
      In the state in which fitting part  54  is fitted in mounting hole  40  of mounting part  38 , width expansion blade body  22  is set and restricted in position in the front/rear direction, vertical direction, and direction of rotation about the fitted portion with respect to main blade body  21 , and thus latching holes  58  and engaging hole  60  of fitting part  54  are respectively positioned coaxial to latching holes  41  and engaging hole  42  of mounting part  38 .  
      Pin  71  of latching tool  23  is matched to latching holes  41  of mounting part  38  and inserted into these latching holes  41  and latching holes  58  of fitting part  54 , and furthermore, rotation stopping part  73  is matched to engaging hole  42  and inserted into this engaging hole  42  and engaging hole  60  of fitting part  54 .  
      By this fitting of fitting part  54  from the inner end side of mounting hole  40 , width expansion blade body  22  can positioned and housed at the back face side of main blade body  21 .  
      Also, in housing width expansion blade body  22  from the width-expanded state or in contracting the width from the housed state, the work can be performed by removing fitting part  54  from mounting hole  40  of mounting part  38  by drawing out pin  71  and rotation stopping part  73  of latching member  23  from mounting part  38  and fitting part  54 .  
      Since loads of the front/rear direction, vertical direction, and direction of rotation about the fitted portion that are applied to width expansion blade body  22  can be received by mounting part  38  with a box structure, a single pin suffices as pin  71  of latching member  23  that functions only to prevent fall-out and attachment/detachment operations of pin  71  can thus be performed readily. Furthermore, the rotation of fitting part  54  of width expansion blade body  22 , which has been fitted from the inner end side of mounting hole  40 , is prevented by rotation stopping part  73 , provided at one end of handle  72  of latching member  23 , and the jittering of width expansion blade body  22  in the housed state can thus be prevented.  
      By use of such a blade device  17 , a hydraulic shovel  11  or other working machine that exhibits the above-described actions and effects of blade device  17  can be provided.  
      Though latching member  23  is equipped with a single pin  71  and a rotation stopping part  73 , as long as at least pin  71  is equipped, fitting part  54 , which has been fitted into mounting hole  40  of mounting part  38  can be latched and prevented from falling out. Though in this case, jittering of width expansion blade body  22  will occur when width expansion blade body  22  is housed, the jittering of width expansion blade body  22  can be prevented by devising the shape of fitting part  54 , etc. so that the position in the direction of rotation about pin  71  can be set and fixed.  
      Also, in a case where latching member  23  is not provided with rotation stopping part  73 , a fall-out prevention structure may be employed wherein, by rotation of latching member  23  in the state in which pin  71  is inserted in mounting part  38 , one end of handle  72  is engaged or released, for example, with respect to an L-shaped metal member provided on mounting part  38  and the falling out of pin  71  is prevented by the engagement of this end of handle  72  and the metal member.  
      Also, latching member  23  is not limited to pin  71 , and a tightening means that includes a bolt and a nut may be used instead, and in the case where such a tightening means is used, the latched state of mounting part  38  and fitting part  54  can be maintained securely.  
      Also, though with the above-mentioned embodiment, blade device  17  is applied to a hydraulic shovel  11 , with an arrangement wherein travelling devices  13  at the respective sides of lower travelling body  14  are enabled to expand and contract in the width direction by a width varying device, application to a hydraulic shovel  11 , with an arrangement without a width varying device and wherein travelling devices  13  at the respective sides of lower travelling body  14  do not expand or contract in the width direction, is also possible and the same operations and effects are exhibited in such a case as well.  
     INDUSTRIAL APPLICABILITY  
      This invention&#39;s blade device can be applied not only to hydraulic shovels but widely for resolving problems of working machines equipped with a blade device that is enabled to be changed in width.