Patent Publication Number: US-2018029851-A1

Title: Linkage assembly for machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to a linkage assembly for a machine. 
     BACKGROUND 
     Machine, such as material handler is used in industries, such as scrap recycling, handling of bulk material, and forestry. The machine includes an elongated linkage assembly for accommodating different work tools. The linkage assembly includes a boom and a stick. Generally, the boom of the linkage assembly includes a top plate, a bottom plate and a pair of side plates, and multiple baffle plates. In conventional design, each of the top plate, the bottom plate, and the side plates of the boom is constructed using multiple plates attached to each other using butt weld. Typically, butt welding process is complex and time consuming compared to other types of weld joints and a butt welded location is often considered as a failure initiation location in the boom. Further, providing multiple baffle plates within a box structure of the boom increases weight of the boom. Also, installing the multiple baffle plates at multiple locations make the manufacturing of the boom complex. 
     U.S. Pat. No. 8,991,029, hereinafter referred to as the &#39;029 patent, discloses a beam structure. The beam structure includes a baffle plate. A plurality of lap strips is attached around outer edges of the baffle plate. An adhesive layer is applied to outer surfaces of the lap strips. A plurality of sidewalls is assembled together around the adhesive layer, the lap strips and the baffle plate, thereby forming the beam structure. The beam structure of the &#39;029 patent discloses the linkage assembly having multiple baffle plates and mounting arrangement of the multiple baffle plates within the beam structure. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a linkage assembly for a machine is provided. The linkage assembly includes a boom having a front end and a rear end. The boom includes a base plate having a first portion and a second portion. The second portion is inclined at an angle with respect to the first portion. The boom further includes a pair of side plates attached to the base plate. The boom further includes a top plate attached to the pair of side plates. The base plate, the pair of side plates, and the top plate together define a box structure for the boom. Further, the boom includes a baffle plate which is disposed within the box structure at a predefined distance from the front end of the boom. The baffle plate is further attached to the base plate, the pair of side plates, and the top plate. The linkage assembly further includes a stick pivotally coupled to the front end of the boom. The linkage assembly further includes a mounting member attached to the base plate. The mounting member is configured to couple with a first hydraulic actuator and a second hydraulic actuator. Each of the first hydraulic actuator and the second hydraulic actuator is coupled to a frame of the machine and the stick, respectively. 
     In another aspect of the present disclosure, a linkage assembly for a machine is provided. The linkage assembly includes a boom having a front end and a rear end. The boom includes a base plate having a first portion and a second portion. The second portion is inclined at an angle with respect to the first portion. The boom further includes a first side plate attached to a first side edge of the base plate, and a second side plate spaced apart from the first side plate and attached to a second side edge of the base plate. The boom further includes a top plate attached to the first side plate and the second side plate. The base plate, the first side plate, the second side plate, and the top plate define a first T-joint and together define a box structure for the boom. The boom further includes a baffle plate disposed within the box structure of the boom at a predefined distance from the front end of the boom. The baffle plate is further attached to the base plate, the first side plate, the second side plate, and the top plate using a fillet weld. The first side plate, the second side plate, the base plate, the top plate and the baffle plate together define a chamber within the box structure for the boom. The linkage assembly further includes a stick pivotally coupled to the front end of the boom. The linkage assembly further includes a mounting member attached to the base plate to define a second T-joint. The mounting member is further configured to couple with a first hydraulic actuator and a second hydraulic actuator. Each of the first hydraulic actuator and the second hydraulic actuator is coupled to a frame of the machine and the stick, respectively. 
     In yet another aspect of the present disclosure, a machine is provided. The machine includes a frame and a linkage assembly coupled to the frame. The linkage assembly includes a boom having a front end and a rear end. The boom includes a base plate having a first portion and a second portion. The second portion is inclined at an angle with respect to the first portion. The boom further includes a pair of side plates attached to the base plate. A top plate of the boom is further attached to the pair of side plates. The base plate, the pair of side plates, and the top plate together define a box structure for the boom. The boom further includes a baffle plate disposed within the box structure at a predefined distance from the front end of the boom. The baffle plate is further attached to the base plate, the pair of side plates, and the top plate. The linkage assembly further includes a stick pivotally coupled to the front end of the boom. The linkage assembly further includes a mounting member attached to the base plate, and configured to couple with a first hydraulic actuator and a second hydraulic actuator. Each of the first hydraulic actuator and the second hydraulic actuator is coupled to the frame of the machine and the stick, respectively. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a machine having a linkage assembly, according to one embodiment of the present disclosure; 
         FIG. 2  is a perspective view of a boom of the linkage assembly, according to one embodiment of the present disclosure; and 
         FIG. 3  is a sectional view of the boom taken along line A-A′ of  FIG. 2 , according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. 
       FIG. 1  illustrates a side view of a machine  100 , according to one embodiment of the present disclosure. In the illustrated embodiment, the machine  100  is a material handler. In other embodiments, the machine  100  may be an excavator or a hydraulic shovel. It should be understood that the machine  100  may be associated with various industries, such as mining, construction, agriculture, and forestry. The machine  100  includes a frame  102 , and an operator cabin  104  coupled to the frame  102 . More specifically, the operator cabin  104  is coupled to the frame  102  of the machine  100  using a hydraulic cab riser  106 . The hydraulic cab riser  106  is configured to move the operator cabin  104  with respect to the frame  102  of the machine  100 . The machine  100  includes ground engaging members  108  for providing mobility to the machine  100  over a ground surface  109 . In the illustrated embodiment, the ground engaging members  108  includes tracks. In an alternate embodiment, the ground engaging members  108  may include wheels. The machine  100  may further include a power source (not shown) and a drivetrain (not shown) operatively coupled to the power source and the set of ground engaging members  108 . The drivetrain may be configured to transmit motive power from the power source to the set of ground engaging members  108 . The machine  100  further includes a chassis  110  for supporting the frame  102 , the operator cabin  104 , and the set of ground engaging members  108  of the machine  100 . 
     The machine  100  further includes a linkage assembly  112  coupled to the frame  102 . The linkage assembly  112  includes a boom  116  and a stick  118 . The boom  116  has a front end  120  and a rear end  122 . The rear end  122  of the boom  116  is pivotally coupled to the frame  102 . The front end  120  of the boom  116  is pivotally coupled to the stick  118 . The linkage assembly  112  further includes a mounting member  124  that is attached to the boom  116 . The mounting member  124  is coupled to a first hydraulic actuator  126  and a second hydraulic actuator  128 . The first hydraulic actuator  126  is further operatively coupled to the frame  102  of the machine  100 , and is configured to move the boom  116  with respect to the frame  102  of the machine  100 . The second hydraulic actuator  128  is further operatively coupled to the stick  118 , and is configured to move the stick  118  with respect to the boom  116 . The linkage assembly  112  further includes a work tool  130  pivotally coupled to an end  132  of the stick  118  as illustrated in  FIG. 1 . Further, the work tool  130  may be removably coupled to the end  132  of the stick  118 . As such, the work tool  130  may be selected based on application of the machine  100 . In the illustrated embodiment, the machine  100  includes an orange peel grapple. In other embodiments, the work tool  130  may include, but is not limited to, a hydraulic hammer, a bucket, a grapple or a clamshell. The work tool  130  may be associated with hydraulic cylinders (not shown) and fluid line (not shown) for enabling an operation of the work tool  130 . 
       FIG. 2  illustrates a perspective view of the boom  116  of the linkage assembly  112 . The rear end  122  of the boom  116  is coupled to the frame  102 . The boom  116  includes a base plate  202  that is made of a metal or metal alloy, such as steel. The base plate  202  has a thickness that remains constant throughout a length of the boom  116 . The base plate  202  has a first portion  204  and a second portion  206 . The first portion  204  of the base plate  202  is located proximal to the front end  120  of the boom  116  and the second portion  206  is located proximal to the rear end  122  of the boom  116 . The second portion  206  of the base plate  202  is inclined at an angle ‘A’ with respect to the first portion  204 . The angle ‘A’ of the boom  116  may be defined based on various factors including, but not limited to, an application of the machine  100 , and a load that has to be carried by the linkage assembly  112 , without limiting the scope of the present disclosure. The base plate  202  has a first side edge  208  and a second side edge  210  opposite to the first side edge  208 . A distance between the first side edge  208  and the second side edge  210  defines a width for the base plate  202 . The base plate  202  has a bottom surface  212  and a top surface  214  opposite to the bottom surface  212 . A distance between the bottom surface  212  and the top surface  214  defines the thickness for the base plate  202 . 
     The boom  116  further includes a pair of side plates. The pair of side plates includes a first side plate  216  and a second side plate  218  spaced apart from the first side plate  216 . The first side plate  216  is attached to the top surface  214  of the base plate  202  at an offset distance from the first side edge  208 . Similarly, the second side plate  218  is attached to the top surface  214  of the base plate  202  at an offset distance from the second side edge  210 . In an example, the first side plate  216  and the second side plate  218  may be made from a metal or metal alloy, such as steel. Each of the first and second side plates  216 ,  218  has an inner surface  220  and an outer surface  222  opposite to the inner surface  220 . A distance between the inner surface  220  and the outer surface  222  defines a thickness for each of the first and second side plates  216 ,  218 . In one embodiment, the thickness of each of the first and second side plates  216 ,  218  may be equal to the thickness of the base plate  202 . In another embodiment, the thickness of each of the first and second side plates  216 ,  218  may be different from the thickness of the base plate  202 . 
     A pair of first connecting members  224  is connected to each of the first and second side plates  216 ,  218  at the front end  120  of the boom  116  to enable coupling of the boom  116  with the stick  118 . The first connecting member  224  includes a through hole  228  for receiving a pivot pin (not shown) that enables coupling of the stick  118  with the boom  116 . The pair of the first connecting members  224  is attached to the first and second side plates  216 ,  218  by providing a lap weld joint between each of the pair of first connecting members  224  and each of the respective first and second side plates  216 ,  218 . In the illustrated embodiment, the first connecting member  224  has a thickness greater than the thickness of the first and second side plates  216 ,  218 . The pair of first connecting members  224  is configured to withstand a load of the stick  118  and the work tool  130 . 
     The boom  116  further includes a first reinforcement member  230  and a second reinforcement member (not shown) attached to the first side plate  216  and the second side plate  218 , respectively, proximal to the rear end  122  of the boom  116 . In an embodiment, the first reinforcement member  230  and the second reinforcement member may be made of a material similar to the material of the first and second side plates  216 ,  218 . In one embodiment, a thickness of each of the first reinforcement member  230  and the second reinforcement member may be equal to the thickness of each of the first and second side plates  216 ,  218 , respectively. In another embodiment, the thickness of each of the first reinforcement member  230  and the second reinforcement member may be different from the thickness of each of the first and second side plates  216 ,  218 , respectively. 
     The rear end  122  of the boom  116  further includes a second connecting member  234  welded to the first and second side plates  216 ,  218  and the first and second reinforcement members  230 . The boom  116  is pivotally coupled to the frame  102  of the machine  100  using the second connecting member  234 . The first and second reinforcement members  230  may increase strength of a weld provided between the second connecting member  234  and the first and second side plates  216 ,  218 . Further, the first and second reinforcement members  230  may improve a load bearing capacity of the boom  116  owing to the additional thickness of each of the first and second side plate  216 ,  218  at the rear end  122  of the boom  116 . In one embodiment, the second connecting member  234  may be configured to receive a connecting pin (not shown) provided in the frame  102  to enable coupling of the boom  116  with the frame  102 . 
     The boom  116  further includes a top plate  236 . The top plate  236  is attached to the first and second side plates  216 ,  218 . In one embodiment, the top plate  236  may be a made of a metal or a metal alloy, such as steel and may have a thickness equal to the thickness of the base plate  202 . The base plate  202 , the first and second side plates  216 ,  218  and the top plate  236  together define a box structure for the boom  116 . A cover plate  238  is disposed at the front end  120  of the boom  116 . The cover plate  238  may be provided in the boom  116  for preventing entry of dust or other particles into the boom  116  during operation of the machine  100 . In one embodiment, the cover plate  238  may be welded to the base plate  202 , the first side plate  216 , the second side plate  218 , and the top plate  236 . 
     The boom  116  further includes a baffle plate  240  disposed within the box structure of the boom  116  at a predefined distance ‘D’ from the front end  120  of the boom  116 . In one embodiment, the predefined distance ‘D’ may be measured from a location of the cover plate  238  at the front end  120  of the boom  116 . In another embodiment, the predefined distance ‘D’ may be measured from the front end  120  of the boom  116  based on various factors including, but not limited to, side load acting on the boom  116  during operation of the machine  100 , and easy accessibility of the baffle plate  240  from the front end  120  of the boom  116  for a welder. In various embodiments, the predefined distance ‘D’ may be determined based on application of the machine  100 . In an example, the predefined distance ‘D’ ranges from 400 mm to 500 mm. The baffle plate  240  may be made of a metal or a metal alloy, such as steel, and may have a predefined thickness. In the illustrated embodiment, the predefined thickness of the baffle plate  240  is defined based on the thickness of at least one of the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236 . In an example, the predefined thickness of the baffle plate  240  may be at least 60% of the thickness of at least one of the base plate  202 , the first and the second side plate  216 ,  218 , and the top plate  236 . In other embodiments, the predefined thickness of the baffle plate  240  may be defined based on various factors including, but not limited to, the side load acting on the boom  116 . The baffle plate  240  is disposed perpendicular to the base plate  202 . In another embodiment, the baffle plate  240  may be disposed at a predefined angle ‘0’ with respect to the base plate  202 . In an example, the predefined angle ‘0’ may range from 80° to 110°. 
     The baffle plate  240  has a plurality of side edges  241 . In the illustrated embodiment, the baffle plate  240  includes four side edges. Each of the plurality of side edges  241  of the baffle plate  240  is attached to the base plate  202 , the first side plate  216 , the second side plate  218 , and the top plate  236  using a fillet weld  217 . In the illustrated embodiment, each of the plurality of side edges  241  of the baffle plate  240  is provided with a chamfering portion (not shown) to define a single bevel grove, and hence to provide the fillet weld  217  along the plurality of side edges  241  of the baffle plate  240 . The base plate  202 , the first side plate  216 , the second side plate  218 , the top plate  236 , and the baffle plate  240  together define a chamber within the box structure of the boom  116 . The baffle plate  240  includes a through hole  242  to allow air to flow in and out of the chamber of the boom  116 , which may otherwise cause air block in the chamber during manufacturing of the boom  116 . Thus, the boom  116  of the present disclosure is provided with the single baffle plate  238  at the front end  120  of the boom  116  to achieve a desired strength of the boom  116 . 
     Referring to  FIG. 1  and  FIG. 2 , the linkage assembly  112  further includes the mounting member  124 . The mounting member  124  is attached to the bottom surface  212  of the base plate  202 . The mounting member  124  includes a first mounting plate  244  and a second mounting plate  246 . In the illustrated embodiment, the first mounting plate  244  is attached to the base plate  202  at an offset distance from the first side edge  208  of the base plate  202 . Similarly, the second mounting plate  246  is attached to the base plate  202  at an offset distance from the second side edge  210  of the base plate  202 . The mounting member  124  has a first end  248  proximal to the rear end  122  of the boom  116  and a second end  250  proximal to the front end  120  of the boom  116 . 
     The mounting member  124  further includes a first pivot pin  252  and a second pivot pin  254  spaced apart from the first pivot pin  252 . The first pivot pin  252  and the second pivot pin  254  are connected to the first end  248  and the second end  250 , respectively, of the mounting member  124 . The first pivot pin  252  is configured to couple the first hydraulic actuator  126  for moving the boom  116  with respect to the frame  102  of the machine  100 . The second pivot pin  254  is configured to couple the second hydraulic actuator  128  for moving the stick  118  with respect to the boom  116  of the linkage assembly  112 . 
       FIG. 3  illustrates a sectional view of the boom  116  taken along a line A-A′ of  FIG. 2 . As mentioned earlier, the boom  116  includes the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236 , which together define the box structure for the boom  116 . Each of the first side plate  216  and the second side plate  218  includes the inner surface  220  and the outer surface  222 . 
     In order to attach the first side plate  216  with the base plate  202 , a chamfering portion  303  is provided along a length of a bottom end  302  of the first side plate  216 . More specifically, the chamfering portion  303  extends from the outer surface  222  of the first side plate  216 , as shown in  FIG. 3 . In the illustrated embodiment, the first side plate  216  is positioned at an offset distance from the first side edge  208  of the base plate  202 , and is disposed perpendicular to the top surface  214  (as shown in  FIG. 2 ) of the base plate  202  so as to define a first T-joint  306  between the first side plate  216  and the base plate  202 . In another embodiment, the first side plate  216  may be positioned at an angle with respect to the top surface  214  of the base plate  202 . Thus, a single bevel groove  308  is formed between the bottom end  302  of the first side plate  216  and the base plate  202 . The first side plate  216  is further attached to the base plate  202  by providing a fillet weld along the single bevel groove  308  formed between the first side plate  216  and the base plate  202 . 
     In order to attach the second side plate  218  with the base plate  202 , a chamfering portion  309  is provided along a length of a bottom end  314  of the second side plate  218 . The second side plate  218  is positioned at an offset distance from the second side edge  210 , and is disposed perpendicular to the top surface  214  of the base plate  202  so as to define a first T-joint  310  between the second side plate  218  and the base plate  202 . Thus, a single bevel groove  312  is formed between the bottom end  314  of the second side plate  218  and the base plate  202 . The second side plate  218  is further attached to the base plate  202  of the boom  116  by providing a fillet weld along the single bevel groove  312  formed between the second side plate  218  and the base plate  202 . 
     In order to form the box structure of the boom  116 , the top plate  236  is attached to the first side plate  216  and the second side plate  218 . More specifically, the top plate  236  is disposed perpendicular to each of the first side plate  216  and the second side plate  218 . Owing to the perpendicular positioning of the first side plate  216  with the top plate  236 , a first T-joint  316  is defined between the first side plate  216  and the top plate  236 . Further, a chamfering portion  322  is provided along a length of a top end  304  of the first side plate  216 . A single bevel groove  320  is formed between the top end  304  of the first side plate  216  and the top plate  236 . The first side plate  216  is further attached to the top plate  236  by providing a fillet weld along the single bevel groove  320  defined between the first side plate  216  and the top plate  236 . Similarly, the top plate  236  is disposed perpendicular to the second side plate  218 . Owing to the perpendicular positioning of the second side plate  218  with the top plate  236 , a first T-joint  318  is defined between the second side plate  218  and the top plate  236 . Further, a chamfering portion  323  is provided along a length of a top end  313  of the second side plate  218 . Thus, a single bevel groove  324  is formed between the top end  313  of the second side plate  218  and the top plate  236 . The second side plate  218  is further attached to the top plate  236  by providing a fillet weld along the single bevel groove  324  formed between the second side plate  218  and the top plate  236 . 
     As mentioned earlier, the mounting member  124  is attached to the base plate  202  of the boom  116 . The first mounting plate  244  is positioned at an offset distance from the first side edge  208  of the base plate  202 , and the second mounting plate  246  is positioned at an offset distance from the second side edge  210  of the base plate  202 . In order to attach the mounting member  124  to the base plate  202 , a chamfering portion  329  is provided from each of an inner surface  336  and an outer surface  338  of a top end  326  of the first mounting plate  244 . Similarly, a chamfering portion  330  is provided from an inner surface  340  and an outer surface  342  of a top end  328  of the second mounting plate  246 . 
     Each of the first mounting plate  244  and the second mounting plate  246  is positioned perpendicular to the bottom surface  212  of the base plate  202 . Owing to the perpendicular positioning of the first mounting plate  244  with the base plate  202 , a second T-joint is defined between the first mounting plate  244  and the base plate  202 . Thus, a double bevel groove  332  is formed between the top end  326  of the first mounting plate  244  and the bottom surface  212  of the base plate  202 . The first mounting plate  244  is further attached to the base plate  202  of the boom  116  by providing a fillet weld along the double bevel groove  332  formed between the first mounting plate  244  and the base plate  202 . Similarly, the perpendicular positioning of the second mounting plate  246  with the base plate  202 , a second T-joint is defined between the second mounting plate  246  and the base plate  202 . Further, a double bevel groove  334  is formed between the top end  328  of the second mounting plate  246  and the bottom surface  212  of the base plate  202 . The second mounting plate  246  is further attached to the base plate  202  by providing a fillet weld along the double bevel groove  334  formed between the second mounting plate  246  and the base plate  202 . 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to the linkage assembly  112  for the machine  100 . The linkage assembly  112  includes the boom  116 , which is formed by attaching the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  with each other. Each of the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  is made of a single metal piece without any weld joints, such as butt weld joints. Thus, the single metal piece construction of the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  increases load bearing capacity of the boom  116 . Further, the first T-joints  306 ,  310 ,  316 , and  318  provided between the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  improve reliability and durability of the boom  116 . In order to attach the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  with each other, the top ends  304  and  313  of each of the first and second side plates  216 ,  218  are provided with the chamfering portions  322 ,  323 ,  329 , and  330 , respectively. The chamfering portions  322 ,  323 ,  329 , and  330  of the first and second side plates  216 ,  218  provide an increased joint and root penetration along the length of each of the top ends  304 ,  313  and the bottom ends  302 ,  314  of the first side plate  216  and the second side plate  218 , respectively. Each of the base plate  202 , the first and second side plates  216 ,  218 , and the top plate  236  is attached to each other by forming the fillet welds along the single bevel grooves  308 ,  312 ,  320 , and  324  to improve fatigue strength of the boom  116 , and thereby reduce localized stress acting on the boom  116 . 
     The baffle plate  240  is disposed within the box structure of the boom  116  at the predefined distance ‘D’ from the front end  120  of the boom  116 . The predefined distance ‘D’ may be determined in such a way that the baffle plate  240  may be accessed by the welder, and eliminate complexity in construction of the boom  116 . Further, the baffle plate  240  is attached to the boom  116  by providing the fillet weld  217  along each of the plurality of side edges  241  of the baffle plate  240 , the top plate  236 , the first and second side plates  216 ,  218 , and the base plate  202 . The fillet weld reduces localized stress acting on the baffle plate  240 . Owing to the positioning of the single baffle plate  240  at the predefined distance ‘D’, the linkage assembly  112  is able to achieve desired side load bearing capacity. Thus the single piece construction of the boom  116  along with the single baffle plate  240  at an optimized distance from the front end  120  of the boom  116  provides the desired strength of the boom  116  with less cost and reduced complexity in manufacturing and assembly of the boom  116 . Attaching the mounting member  124  to the bottom surface  212  of the base plate  202  of the boom  116  facilitates coupling of the first and second hydraulic actuators  126 ,  128  without making any alteration or modification in the base plate  202 , the first side plate  216 , the second side plate  218 , or the top plate  236 . 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.