Abstract:
Disclosed is a lower track for mounting rubber pads on a track shoe to be attachable and detachable after assembling a steel plate which is adhered with divisionally formed rubber pads as a single unit without additionally perforating coupling through-holes in the track shoe when the rubber pad which forms the lower track and the track shoe which is formed of a metal material are coupled. The lower track of a crawler excavator according to the present invention comprises: first and second rubber pads which are divisionally formed; a first steel plate which supports the bottom surface of the first rubber pad by surrounding the same, and has first hooks formed on the bottom surface thereof and coupling holes formed in a connection stepped-portion, which is formed at the opposite side of the first hooks; a second steel plate which supports the bottom surface of the second rubber pad by surrounding the same, and has second hooks formed on the bottom surface thereof, connection protrusions formed at the opposite side of the second hooks so as to be secured on the connection stepped-portion, and connection through-holes formed in the protrusions so as to correspond to the coupling holes; and coupling members sequentially passing through the through-holes formed in the second rubber pad and the through-holes formed in the second steel plate so as to be fixed in the coupling holes of the first steel plate.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a track shoe of a crawler type excavator. More particularly, the present invention relates to a lower track of a crawler type excavator, in which in the case where a pair of rubber pads and a track shoe made of a metal material, which constitute a lower track of the crawler type excavator, are coupled to each other, a pair of steel plates to which the rubber pads dividedly formed are joined can be assembled into a single unit, and then the rubber pads can be detachably mounted on the track shoe without having a separate fastening through-hole drilled on the track shoe. 
       BACKGROUND OF THE INVENTION 
       [0002]    A lower track of a general crawler type excavator shown in  FIG. 1  includes: 
         [0003]    a plurality of track shoes  1  each configured to form a ground plane of a crawler to allow an orbital motion of the track shoes to be performed by a drive wheel (i.e., referring to a sprocket) connected to a travel motor (not shown); 
         [0004]    a pair of opposed track links  3  and  4  each mounted on the track shoe  1  by means of a bolt or the like and including a plurality of link segments consecutively connected to each other by a plurality of track pins to allow the orbital motion of the track shoes to be performed by the drive wheel; 
         [0005]    a plurality of bushings  5  engaged into associated ones of engagement holes  3   a  and  4   a  formed to confront each other in the track links  3  and  4  in such a manner that the bushings are spaced apart from each other at equal distances, and configured to surroundingly support the track pins  2 . 
         [0006]    Since such a crawler type excavator causes damage to an asphalt or concrete surface when it travels on the asphalt or concrete surface, a rubber pad is mounted on a track shoe by a bolt or the like to prevent damage of a road surface due to its travel. 
         [0007]    A means for mounting a rubber pad to a track shoe of a crawler type excavator in accordance with the prior art as shown in  FIG. 2(   a ) includes a plurality of fastening members  7  (for example, four bolts are used) protrudingly formed on the underside of the rubber pad  6 , a plurality of fastening holes  1   a  penetratingly formed on the track shoe  1  to correspond to the fastening members  7 , and a plurality of fastening nut  8  fastened to the fastening members  7  engaged into the fastening holes  1   a.    
         [0008]    As described above, the lower track of the conventional crawler type excavator in accordance with one embodiment of the prior art entails a problem in that the fastening holes  1   a  are required to be separately drilled on the track shoe  1  in order to mount the rubber pad  6  to the track shoe  1 , leading to an increase in the manufacturing cost and a degradation of the strength of the track shoe  1  due to the drilled fastening holes  1   a.    
         [0009]    A means for mounting a rubber pad to a track shoe of a crawler type excavator in accordance with the prior art as shown in  FIG. 2(   b ) includes a pair of hooks  9  formed on one side of the underside of a rubber pad  6  so as to allow a track shoe  1  to be fixedly seated thereon, and a pair of fastening members  10  (for example, two bolts are used) engaged into screw holes (not shown) formed on the other side of the underside of the rubber pad  6  via through-holes  1   a  formed on one side of the track shoe  1  seated on the hooks  9 . 
         [0010]    As described above, the lower track of the conventional crawler type excavator in accordance with one embodiment of the prior art entails a problem in that the fastening holes  1   a  are required to be separately drilled on the track shoe  1  in order to mount the rubber pad  6  to the track shoe  1 , leading to an increase in the manufacturing cost and a degradation of the strength of the track shoe  1  due to the drilled fastening holes  1   a.    
         [0011]    A means for mounting a rubber pad to a track shoe of a crawler type excavator in accordance with the prior art as shown in  FIG. 2(   c ) includes a pair of hooks  9  formed on one side of the underside of a rubber pad  6  so as to allow a track shoe  1  to be fixedly seated thereon, a bottom plate hook  11  mounted on one side of the rubber pad  6  so as to support the other side of the track shoe supported at one side thereof by the hooks  9 , and a pair of fastening members  10  engaged into screw holes  6   a  formed on a side of the rubber pad  6  via through-holes  1   a  formed on the bottom plate hook  11 . 
         [0012]    As described above, the lower track of the conventional crawler type excavator in accordance with one embodiment of the prior art entails a problem in that the heads of the fastening members  10  are protrudingly exposed to the outside in order to mount the rubber pad  6  to the track shoe  1 , the fastening members  10  may be damaged due to a shock applied thereto from the outside, leading to an escape of the rubber pad  6  from the track shoe  1 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problems 
       [0013]    Accordingly, the present invention has been made to solve the aforementioned problem occurring in the prior art, and it is an object of the present invention to provide a lower track of a crawler type excavator, in which in the case where a rubber pad is coupled to a track shoe made of a metal material, which constitutes the lower track, a separate fastening through-hole is not required to be drilled on the track shoe, thereby reducing the manufacturing cost and preventing a degradation of the strength of the track shoe  1 . 
         [0014]    Another object of the present invention is to provide a lower track of a crawler type excavator, in which a pair of steel plates to which a pair of rubber pads dividedly formed are joined are assembled into a single unit, and then the rubber pads are be detachably mounted on the track shoe, thereby improving workability of assembly, and the fastening members by which the rubber pad coupled to the track shoe are prevented from being exposed to the outside, thereby avoiding damage of the fastening members due to an external impact. 
       Technical Solution 
       [0015]    To accomplish the above object, in accordance with an embodiment of the present invention, there is provided a lower track of a crawler type excavator, including: 
         [0016]    a pair of first and second rubber pads which are dividedly formed; 
         [0017]    a first steel plate configured to surroundingly support the underside of the first rubber pad, the first steel plate having one or more first hooks formed on the underside thereof so as to allow one end of a track shoe to be supportingly seated thereon, and a joint stepped portion having one or more fastening holes formed thereon, the joint stepped portion being formed on an opposite side of the first hook; 
         [0018]    a second steel plate configured to surroundingly support the underside of the second rubber pad, the second steel plate having one or more second hooks formed on the underside thereof so as to allow the other end of the track shoe to be supportingly seated thereon, and a joint projection portion having one or more through-holes formed thereon to correspond to the fastening holes, the joint projection portion being formed on an opposite side of the second hook so as to be seated on the joint stepped portion; and 
         [0019]    one or more fastening members fixedly engaged into the fastening holes of the first steel plate after passing through one or more through-holes formed in the second rubber pad and the through-holes of the second steel plate in this order, 
         [0020]    wherein the track shoe is supported by hooking the first and second hooks on both ends of the track shoe, the first and second steel plates are assembled into a single unit by superimposing the joint projection portion of the second steel plate on the corresponding joint stepped portion of the first steel plate, and the first and second rubber pads having the undersides on which the first and second steel plates are supported are detachably mounted on the track shoe by the fastening members fixedly engaged into the fastening holes of the first steel plate after passing through the through-holes of the second rubber pad and the through-holes of the second steel plate. 
         [0021]    In accordance with a preferred embodiment of the present invention, the through-holes and the fastening holes are formed on the second rubber pad, and the joint stepped portion and the joint projection portion of the first and second steel plates, so that the first and the second rubber pads are mounted on the track shoe by bolts passing through the through-holes of the second rubber pad and the fastening holes and the through-holes of the first and second steel plates and nuts fastened to the bolts and positioned in mud holes of the track shoe. 
         [0022]    In addition, the through-holes are formed on the second rubber pad, and the joint stepped portion and the joint projection portion of the first and second steel plates, and one or more fixing plates are provided which are fixed by welding to the underside of one or more through-holes of the joint stepped portion, have one or more fastening holes formed thereon to coincide with the through-holes, and are positioned in mod holes of the track shoe, so that the first and second rubber pads are mounted on the track shoe by bolts which are fixedly engaged into the fastening holes of the fixing plates after passing through the through-holes of the second rubber pad and the through-holes of the first and second steel plates. 
       Advantageous Effect 
       [0023]    The lower track of a crawler type excavator in accordance with an embodiment of the present invention as constructed above has the following advantages. 
         [0024]    In the case where a rubber pad is coupled to a track shoe made of a metal material, which constitutes the lower track, a separate fastening through-hole is not required to be drilled on the track shoe, thereby reducing the manufacturing cost and preventing a degradation of the strength of the track shoe and thus ensuring reliability. 
         [0025]    In addition, the steel plates to which the rubber pads dividedly formed are joined are assembled into a single unit, and then the rubber pads are be detachably mounted on the track shoe, thereby improving workability of assembly. Further, when the rubber pads are damaged during the work, only a relevant rubber pad can be replaced with new one, thereby enhancing the economic efficiency, and the fastening members by which the rubber pad is coupled to the track shoe are prevented from being exposed to the outside, thereby avoiding damage of the fastening members due to an external impact. 
       BRIEF DESCRIPTION OF THE DRAWINGS 
       [0026]    The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which: 
         [0027]      FIG. 1  is an enlarged perspective view showing the main elements of a crawler of a general crawler type excavator; 
         [0028]      FIGS. 2(   a ) to  2 ( c ) are schematic exploded perspective views showing a lower track of a crawler type excavator in accordance with the prior art; 
         [0029]      FIG. 3  is an assembled perspective view showing a lower track of a crawler type excavator in accordance with an embodiment of the present invention; 
         [0030]      FIG. 4  is an exploded perspective view showing a lower track of a crawler type excavator in accordance with an embodiment of the present invention; and 
         [0031]      FIG. 5  is an exploded perspective view showing a lower track of a crawler type excavator in accordance with another embodiment of the present invention. 
         [0032]    *Explanation on reference numerals of main elements in the drawings * 
         [0033]      50 : first rubber pad 
         [0034]      51 : second rubber pad 
         [0035]      50   a : first steel plate 
         [0036]      51   a : second steel plate 
         [0037]      50   b : first hook 
         [0038]      51   b : second hook 
         [0039]      52 : fastening member 
         [0040]      53 : through-hole 
         [0041]      54 : fastening hole 
         [0042]      55 : track shoe 
         [0043]      56 : mud hole 
         [0044]      57 : through-hole 
       PREFERRED EMBODIMENTS OF THE INVENTION 
       [0045]    Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The matters defined in the description, such as the detailed construction and elements, are nothing but specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the invention, and the present invention is not limited to the embodiments disclosed hereinafter. 
         [0046]    Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
         [0047]    A lower track of a crawler type excavator in accordance with an embodiment of the present invention as shown in  FIGS. 3 and 4  includes: 
         [0048]    a pair of first and second rubber pads  50  and  51  which are dividedly formed; 
         [0049]    a first steel plate  50   a  which is configured to surroundingly support the underside of the first rubber pad  50 , the first steel plate having a pair of first hook  50   b  formed on the underside thereof so as to allow one end of a track shoe  55  to be supportingly seated thereon, and a joint stepped portion  50   c  having one or more fastening holes  54  formed thereon, the joint stepped portion being formed on an opposite side of the first hook  50   b;    
         [0050]    a second steel plate  51   a  which is configured to surroundingly support the underside of the second rubber pad  53 , the second steel plate having one or more second hooks  51   b  formed on the underside thereof so as to allow the other end of the track shoe  55  to be supportingly seated thereon, and a joint projection portion  51   c  having one or more through-holes  57  formed thereon to correspond to the fastening holes  54 , the joint projection portion being formed on an opposite side of the second hook  51   b  so as to be seated on the joint stepped portion  50   c;  and 
         [0051]    one or more fastening members  52  which are fixedly engaged into the fastening holes  54  of the first steel plate  50   a  after passing through one or more through-holes  53  formed in the second rubber pad  51  and the through-holes  57  of the second steel plate  51   a  in this order, 
         [0052]    wherein the track shoe  55  is supported by hooking the first and second hooks  50   b  and  51   b  on both ends of the track shoe  55 , the first and second steel plates  50   a  and  51   a  are assembled into a single unit by superimposing the joint projection portion  51   c  of the second steel plate  51   a  on the corresponding joint stepped portion  50   c  of the first steel plate  50   a,  and the first and second rubber pads  50  and  51  having the undersides on which the first and second steel plates  50   a  and  51   a  are supported are detachably mounted on the track shoe  55  by the fastening members  52  fixedly engaged into the fastening holes  54  of the first steel plate  50   a  after passing through the through-holes  53  of the second rubber pad  51  and the through-holes  57  of the second steel plate  51   a.    
         [0053]    The through-holes  53  are formed on the second rubber pad  51 , and the fastening holes  54  and the through-holes  57  are formed on the joint stepped portion  50   c  and the joint projection portion  51   c  of the first and second steel plates  50   a  and  51   a , so that the first and the second rubber pads  50  and  51  can be mounted on the track shoe  55  by bolts  52  passing through the through-holes  53  of the second rubber pad  51  and the fastening holes  54  and the through-holes  57  of the first and second steel plates  50   a  and  51   a  and nuts fastened to the bolts  52  and positioned in mud holes  56  of the track shoe  55 . 
         [0054]    Hereinafter, a use example of the lower track of a crawler type excavator in accordance with an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
         [0055]    As shown in  FIGS. 3 and 4 , the first and second hooks  50   b  and  51   b  formed to be opposed to each other on the first and second steel plates  50   a  and  51   a  disposed on the undersides of the first and second rubber pads  50  and  51  are hooked on both ends of the track shoe  55  to support the track shoe  55 . 
         [0056]    The first and second steel plates  50   a  and  51   a  can be assembled into a single unit by superimposing the joint projection portion  51   c  of the second steel plate  51   a  on the corresponding joint stepped portion  50   c  of the first steel plate  50   a.  At this time, the through-holes  53  of the second rubber pad  51 , the through-holes  57  of the joint projection portion  51   c  of the second steel plate  51   a , and the fastening holes  54  of the joint stepped portion  50   c  of the first steel plate  50   a  are positioned on the same line. 
         [0057]    Thus, the track shoe  55  is supported in a state in which the first and second hooks  50   b  and  51   b  are hooked on both ends of the track shoe  55 , and the fastening members  52  are fixedly engaged into the fastening holes  54  of the first steel plate  50   a  after passing through the through-holes  53  of the second rubber pad  51  and the through-holes  57  of the second steel plate  51   a,  so that the first and second rubber pads  50  and  51  having the undersides on which the first and second steel plates  50   a  and  51   a  are supported can be detachably mounted on the track shoe  55 . 
         [0058]    In this case, the heads of the fastening members  52  are accommodated in the through-holes  53  of the second rubber pad  51  in a depressed state, and the distal ends (i.e., referring to screw parts) of the fastening members  52  are accommodated in the mud holes  56  of the track shoe  55  so that they can be prevented from being projected to the outside. 
         [0059]    In the meantime, the fastening holes are required to be separately formed on the track shoe  55  in order to mount the first and second rubber pads  50  and  51  to the track shoe  55 . 
         [0060]    In addition, in the case where any one of the first and second rubber pads  50  and  51  must be replaced due to its damage during the work or the travel of the excavator, the first and second rubber pads  50  and  51  are gripped by operator&#39;s hands and are pulled in opposite directions where the first and second rubber pads are far away from each other in a state in which the fastening members  52  are loosened from the fastening holes  54  of the first steel plate  50   a  so that the first and second rubber pads  50  and  51  can be removed from the track shoe  55 . Therefore, only a relevant damaged rubber pad can be replaced with new one by checking whether or not the first and second rubber pads  50  and  51  are damaged or broken. 
         [0061]    In the lower track of a crawler type excavator in accordance with another embodiment of the present invention as shown in  FIG. 5 , the through-holes  53 ,  60  and  57  are formed on the second rubber pad  51 , and the joint stepped portion  50   c  and the joint projection portion  51   c  of the first and second steel plates  50   a  and  51   a,  and one or more fixing plates  59  are provided which are fixed by welding to the underside of one or more through-holes  60  of the joint stepped portion  50   c,  have one or more fastening holes  58  formed thereon to coincide with the through-holes  60 , and are positioned in mod holes of the track shoe  55 , so that the first and second rubber pads  50  and  51  are mounted on the track shoe  55  by bolts  52  which are fixedly engaged into the fastening holes  58  of the fixing plates  59  after passing through the through-holes  53  of the second rubber pad  51  and the through-holes  60  and  57  of the first and second steel plates  50   a  and  51   a.    
         [0062]    In this case, the configuration of the lower track of a crawler type excavator in accordance with another embodiment of the present invention as shown in  FIG. 5  is the same as that of the lower track of a crawler type excavator in accordance with one embodiment of the present invention as shown in  FIGS. 3 and 4 , except that the through-holes  60  are formed on the joint stepped portion  50   c  of the first steel plate  50   a,  the fastening holes  58  are formed on the fixing plates  59  fixed by welding to the underside of the joint stepped portion  50   c  to coincide with the through-holes  60 , and the through-holes  57  are formed on the joint projection portion  51   c  of the second steel plate  51   a , so that the bolts  52  are fixedly engaged into the fastening holes  58  of the fixing plates  59  after passing through the through-holes  53  of the second rubber pad  51  and the through-holes  60  and  57  of the first and second steel plates  50   a  and  51   a  to allow the first and second rubber pads  50  and  51  to be mounted on the track shoe  55 . Thus, the detailed description of the same configuration and operation thereof will be omitted to avoid redundancy, and the same elements are denoted by the same reference numerals. 
         [0063]    While the present invention has been described in connection with the specific embodiments illustrated in the drawings, they are merely illustrative, and the invention is not limited to these embodiments. It is to be understood that various equivalent modifications and variations of the embodiments can be made by a person having an ordinary skill in the art without departing from the spirit and scope of the present invention. Therefore, the true technical scope of the present invention should not be defined by the above-mentioned embodiments but should be defined by the appended claims and equivalents thereof. 
       INDUSTRIAL APPLICABILITY 
       [0064]    As described above, according to the lower track of a crawler type excavator in accordance with an embodiment of the present invention, in the case where a rubber pad is coupled to a track shoe made of a metal material, which constitutes the lower track, a separate fastening through-hole is not required to be drilled on the track shoe. 
         [0065]    In addition, two rubber pads dividedly formed are be detachably mounted on the track shoe, so that when the rubber pads are damaged during the work, only a relevant rubber pad can be replaced with new one, thereby enhancing the economic efficiency. Besides, the fastening members by which the rubber pad is coupled to the track shoe are prevented from being exposed to the outside, thereby avoiding damage of the fastening members due to an external impact.