Patent Publication Number: US-2016230371-A1

Title: Guard system for a sensing device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a guard system for a sensing device, and more particularly to a guard system for a sensing device associated with a work tool. 
     BACKGROUND 
     Typically, machines may include implements such as, a bucket, a grapple and the like to perform various operations. The implements may be moved to different positions to perform the operations. Such a movement may be accomplished by one or more linkage components and actuators associated therewith. In some cases, the machine may include a sensor apparatus associated with the linkage components to determine the position of the implement in the operating space of the machine. 
     During operation of the machine, there may be a risk of debris falling into the sensor apparatus and damaging the sensor apparatus. Further, the falling debris may clog the sensor apparatus and hinder the operation of the sensor apparatus. Typically, a guard is provided for the sensor apparatus in the machine. Conventional guards such as, guards shaped like a fender or an enclosure, covers the sensor apparatus within a region defined by the range of motion of the sensor apparatus. Additionally, in case of underground mining applications, rocks and/or debris may fall onto the linkage components from ceilings of a mining tunnel. Further, an impact loading in such applications may also be high. As such, the conventional guards may not be suitable. 
     U.S. Patent application Number 2013/0283648 describes a guard for a sensor apparatus in a tilting arrangement. The guard includes a first tubular portion supported on the tilting arrangement, a longitudinal portion extending from the first tubular portion, and a second tubular portion extending from the longitudinal portion. The first tubular portion provides a first cavity adapted to partially enclose a first mounting stud of the sensor apparatus. Similarly, the second tubular portion provides a second cavity adapted to partially enclose a second mounting stud of the sensor apparatus. Further, the longitudinal portion provides a recess adapted to partially enclose a lever member of the sensor apparatus. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a guard system for a sensing device in a linkage assembly having a first linkage component and a second linkage component is provided. The guard system includes a tube member and a cover member. The tube member includes a base portion coupled to the first linkage component. The tube member also includes a projecting portion extending from the base portion and coupled to the second linkage component. The projecting portion has a first surface facing the second linkage component and a second surface opposite to the first surface. The cover member is coupled to the projecting portion. The cover member includes a body having an internal surface configured to at least partly abut the second surface of the projecting portion. An external surface of the body is opposite to the internal surface. The body defines a cavity configured to receive the sensing device therein. The cover member also includes a plate disposed adjacent to the external surface. The plate is configured to enclose the sensing device within the cavity. Further, the sensing device is coupled to the plate. 
     In another aspect of the present disclosure, a machine is provided. The machine includes a frame and an implement configured to perform an earth moving operation. The machine also includes a linkage assembly configured to move the implement with respect to the frame. The linkage assembly includes a tilt lever pivotally coupled to the implement and a lift arm coupled to the frame. The machine also includes a sensing device associated with the linkage assembly and a guard system for the sensing device. The guard system includes a tube member and a cover member. The tube member includes a base portion coupled to the first linkage component. The tube member also includes a projecting portion extending from the base portion and coupled to the second linkage component. The projecting portion has a first surface facing the second linkage component and a second surface opposite to the first surface. The cover member is coupled to the projecting portion. The cover member includes a body having an internal surface configured to at least partly abut the second surface of the projecting portion. An external surface of the body is opposite to the internal surface. The body defines a cavity configured to receive the sensing device therein. The cover member also includes a plate disposed adjacent to the external surface. The plate is configured to enclose the sensing device within the cavity. Further, the sensing device is coupled to the plate. 
     In yet another aspect of the present disclosure, sensor system for a linkage assembly having a first linkage component and a second linkage component is provided. The sensor system includes a sensing device. The sensing device includes a sensor body and a cable connected to the sensor body. The sensing device also includes a lever pivotally coupled to the sensor body and a mounting stud operatively connected to the lever and the second linkage component. The sensor system also includes a tube member. The tube member includes a base portion coupled to the first linkage component. The tube member also includes a projecting portion extending from the base portion and coupled to the second linkage component. The projecting portion has a first surface facing the second linkage component and a second surface opposite to the first surface. The sensor system further includes a cover member that is coupled to the projecting portion. The cover member includes a body having an internal surface configured to at least partly abut the second surface of the projecting portion. An external surface of the body is opposite to the internal surface. The body defines a cavity configured to receive the sensing device therein. The cover member also includes a plate disposed adjacent to the external surface. The plate is configured to enclose the sensing device within the cavity. Further, the sensing device is coupled to the plate. 
     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 work tool connected to a linkage assembly, according to an embodiment of the present disclosure; 
         FIG. 2  is a perspective view of a first linkage component of the linkage assembly showing a tube member, according to one embodiment of the present disclosure; 
         FIG. 3  is partial perspective view of a sensor system showing a cover member coupled the tube member, according to one embodiment of the present disclosure; 
         FIG. 4  is a perspective view of the tube member, according to an embodiment of the present disclosure; 
         FIG. 5  is a side perspective view of the cover member showing an external surface, according to one embodiment of the present disclosure; and 
         FIG. 6  is a side perspective view of the cover member showing an internal surface, 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 an embodiment of the present disclosure. More specifically, the machine  100  may embody an underground wheel loader as shown in the illustrated embodiment. However, it may be contemplated that the machine  100  may be any other machine known in the art, such as a skid loader, a track loader, an excavator and the like, used for various industries including construction, mining, agriculture and transportation. 
     Referring to  FIG. 1 , the machine  100  may include a frame  102  to support various components of the machine  100 . A powertrain or a drivetrain (not shown) may be provided on the machine  100  for the production and transmission of motive power. The powertrain may include a power source that may be located within an enclosure of the machine  100 . The power source may include one or more engines, power plants or other power delivery systems like batteries, hybrid engines, and the like. It should be noted that the power source may also be external to the machine  100 . A set of ground engaging members  106 , such as wheels, may also be provided on the machine  100  for the purpose of mobility. The powertrain may further include a torque converter, transmission inclusive of gearing, drive shaft and other known drive links provided between the power source and the set of ground engaging members  106  for the transmission of motive power. Further, the machine  100  may include an operator cabin  108  which houses controls for operating the machine  100 . 
     The machine  100  further includes an implement  110  connected to the frame  102 . The implement  110  may be configured to move and/or tilt to different positions in order to perform earth moving operations such as, excavation, dumping and the like. In the present embodiment, the implement  110  is illustrated as a bucket, which may be used to scoop and/or lift the material. In various alternate embodiments, the implement  110  may be a blade, an auger, a fork, a snow plow, and the like. 
     Referring to  FIGS. 1 and 2 , an exemplary linkage assembly  200  configured to move the implement  110  with respect to the frame  102  is illustrated. The linkage assembly  200  may include a lift arrangement  202  for controlling a raising or a lowering movement of the implement  110 . 
     The lift arrangement  202  may include one or more first linkage components  206 . In the illustrated embodiment, the lift arrangement  202  includes two first linkage components  206 A,  206 B (also collectively referred to as “the first linkage components  206 ”) in a spaced apart relationship. The first linkage components  206  may be pivotally coupled to the frame  102  adjacent to first ends  208  thereof. In an example, the first linkage components  206  may be coupled to the frame  102  via pivot pins. Further, second ends  210  of each of the first linkage components  206  may be pivotally coupled to the implement  110 . In an example, the second ends  210  may be coupled proximate to a bottom of the implement  110  via a coupler (not shown). In the illustrated embodiment, the first linkage component  206  is a lift arm. 
     The lift arrangement  202  may also include one or more lift actuators  212  (shown in  FIG. 1 ). In the illustrated embodiment, the lift arrangement  202  may include two lift actuators  212  associated with the corresponding first linkage components  206 . However, it may also be contemplated to implement the lift arrangement  202  using a single first linkage component  206  and a corresponding lift actuator  212 , or two first linkage components  206  driven by the single lift actuator  212 . 
     The lift actuators  212  may be coupled to each of the first linkage components  206  at an intermediate location  213  (shown in  FIG. 2 ) between the first end  208  and the second end  210 . The lift actuators  212  may be configured to provide an actuating force for a movement of the corresponding first linkage components  206 . 
     The linkage assembly  200  further includes a tilt arrangement  300  (shown in  FIG. 1 ) that is configured to control a rotatory and/or tilting movement of the implement  110 . The tilt arrangement  300  includes a second linkage component  302  having a first end  304  and a second end  306 . In the illustrated embodiment, the second linkage component  302  is a tilt lever. 
     The tilt arrangement  300  may also include a connecting member  308 . The first end  304  of the second linkage component  302  is pivotally coupled to the implement  110  via the connecting member  308 . Alternatively, the first end  304  may be directly coupled to the implement  110 . The tilt arrangement  300  may also include a tilt actuator  310  that is pivotally connected to the second end  306  of the second linkage component  302 . The tilt actuator  310  may be configured to provide an actuation force for a rotary/tilting movement of the implement  110  with respect to the second linkage component  302 . 
     During operation of the machine  100 , the first and second linkage components  206 ,  302  and the implement  110  may be moved to different positions in order to perform different operations such as loading, dumping, excavating, and the like. The movement of the first and second linkage components  206 ,  302  and/or the implement  110  may be controlled by the corresponding lift and tilt actuators  212 ,  310  which are coupled to these parts as described above. Accordingly, based on the movement of the implement  110 , the machine  100  may perform the required operation. 
     In an example, the lift actuators  212  and the tilt actuators  310  may be hydraulic cylinders driven by pressurized hydraulic fluid. In such a case, an extending movement of the lift actuator  212  may raise the first linkage component  206  while a retracting movement of the lift actuator  212  may lower the first linkage component  206 . Similarly, a linear movement of the tilt actuator  310  translates to a tilt movement of the implement  110 , via the second linkage component  302 . 
     Alternatively, other types of lift and tilt actuators  212 ,  310  such as, pneumatic linear actuators, piezoelectric actuators, electro-mechanical actuators, and the like may be used to provide actuation force for corresponding movement of the implement  110 . 
     It may also be noted that the linkage assembly  200  and the implement  110  of the machine  100  may vary based on the type of machine or the type of operation or task required to be carried out by the machine  100 . For example, the first linkage component  206  may be a lift arm. Further, the second linkage component  302  may be a tilt lever. Each of the first linkage component  206  and the second linkage component  302  may be coupled to suitable parts such as, the implement  110 , the frame  102  and the like by various linkage mechanisms known in the art. 
     Referring to  FIGS. 3 to 6 , the machine  100  further includes a sensor system  418  associated with the linkage assembly  200 . The sensor system  418  includes a sensing device  420  (best shown in  FIG. 6 ) configured to detect a movement of the second linkage component  302 . The sensing device  420  may include a sensor body  422  and a lever member  424  pivotally coupled to the sensor body  422 . The lever member  424  may be configured to move in conjunction with the second linkage component  302 , the details of which will be explained with reference to  FIGS. 3 to 6 . 
     The sensing device  420  may further include a sensor probe (not shown) and a rotational angle detecting device (not illustrated). The sensor probe, in conjunction with the rotational angle detecting device, may determine the movement of the lever member  424 . The sensor probe may be disposed in the sensor body  422 . 
     The sensor probe may include, for example, a magneto-resistive sensor, an interferometer, an optical encoder, a photo-reflective sensor, or the like. As may be understood by a person having ordinary skill in the art that, the sensor probe may read one or more markings or patterns on the lever member  424 , based on the type of sensor probe, and generates an electric signal proportional to the movement of the lever member  424 . The electric signal may be transmitted to the rotational angle detecting device via a cable  430 . The electric signal may be processed by the rotational angle detecting device to determine a tilting movement of the implement  110 . 
     The sensor system  418  further includes a guard system  500  for the sensing device  420  in the linkage assembly  200  having the first linkage component  206  and the second linkage component  302 . The sensing device  420  may be configured to be integrated with the guard system  500 . 
     The guard system  500  includes a tube member  400 . Referring to  FIGS. 3 and 4 , the tube member  400  includes a base portion  402  coupled to each of the first linkage components  206 . The tube member  400  may be coupled to each of the first linkage components  206  at an intermediate location between the first ends  208  and the second ends  210 . In an embodiment, the base portion  402  may be detachably fastened to the first linkage components  206 . In another embodiment, the base portion  402  may be attached to the first linkage components  206  by welding. Alternatively, at least one of the first linkage components  206  and the tube member  400  may form a unitary construction. In the illustrated embodiment, the tube member  400  is a torque tube configured to minimize a bending of the first linkage components  206 . 
     Further, the second linkage component  302  may also be pivotally connected to the first linkage component  206  via the tube member  400 . The tube member  400  includes a pair of projecting portions  404 A,  404 B (also collectively referred to as “the projecting portions  404 ”) extending from the base portion  402  and coupled to the second linkage component  302 . The projecting portions  404 A and  404 B may be spaced apart from each other. Further, each of the projecting portions  404  includes a first surface  406  facing the second linkage component  302  and a second surface  408  that is opposite to the first surface  406 . The first surfaces  406  of the projecting portions  404  may receive a portion of the second linkage component  302  therebetween. 
     Moreover, the projecting portions  404  may be pivotally coupled to the second linkage component  302  at an intermediate location between the first end  304  and the second end  306  of the second linkage component  302 . In the illustrated embodiment, each of the projecting portions  404  defines a mounting aperture  409  configured to be pivotally coupled to the second linkage component  302 . In an example, the coupling between the projecting portions  404  and the second linkage component  302  may be accomplished by pivot pins received in each of the mounting apertures  409 . However, a person of ordinary skill in the art will recognize that the second linkage component  302  may be coupled to the tube member  400  using various other mechanisms known in the art. 
     Referring still to  FIGS. 3 and 4 , one of the projecting portions  404 , for example, the projecting portion  404 A defines a slot  412  adjacent to an end  416  of the projecting portion  404 A that is distal to the base portion  402 . Further, a perimeter surface of the end  416  surrounding the slot  412  may extend adjacent to the second surface  408 . The slot  412  may be configured to receive a mounting stud  414  therethrough. The mounting stud  414  may be coupled to the second linkage component  302  at one end while the other end may extend through the slot  412  adjacent to the second surface  408  of the projecting portion  404 A. As such, the mounting stud  414  moves in conjunction with the second linkage component  302 . 
     The lever member  424  is disposed adjacent to the slot  412  defined in the projecting portion  404 A. Further, the lever member  424  is operatively coupled to the mounting stud  414  received in the slot  412 . In the illustrated embodiment, the lever member  424  includes a fork section  426  that is disposed adjacent to the slot  412  and configured to receive the mounting stud  414 . Moreover, the lever member  424  is supported on the mounting stud  414  at the fork section  426  so as to move along with the mounting stud  414 . With such an arrangement, the lever member  424  may move in conjunction with the mounting stud  414  which in turn moves along with the second linkage component  302 . As such, a movement of lever member  424  defines a movement of the second linkage component  302  which in turn defines a tilt movement of the implement  110 . 
     Referring to  FIGS. 5 and 6 , the guard system  500  also includes a cover member  502 . The cover member  502  includes a body  504  having an external surface  506  and an internal surface  508 . Further, the cover member  502  is configured to be coupled to the tube member  400  as illustrated in  FIG. 3 . Specifically, the cover member  502  may be coupled to the projecting portion  404 A that defines the slot  412 . Accordingly, the body  504  of the cover member  502  defines multiple holes  509  therethrough. Each of the holes  509  (shown in  FIG. 5 ) may be configured to receive a fastening member  510  (shown in  FIG. 3 ) therein. The fastening members  510  are configured to couple the cover member  502  to the projecting portion  404 A of the tube member  400 . In an example, the fastening members  510  may be bolts. 
     The body  504  may include one or more engaging members  514  projecting from the internal surface  508 . The engaging members  514  may be configured to detachably engage with a recess  513  adjacent to the second surface  408  of the projecting portion  404 A. Further, the recess  513  may be defined around the projecting portion  404 A so as to receive the engaging members  514  therein. In the illustrated embodiment, the engaging members  514  may be annular segments and the projecting portion  404 A may be substantially circular so as to correspondingly define the annular recess  513  thereabout. In another embodiment, there may be separate recesses  513  for each of the engaging members  514 . Alternatively, the engaging members  514  may be defined adjacent to the second surface  408  of the projecting portion  404 A. In such a case, the body  504  of the cover member  502  may define the recess  513  to detachably engage with the engaging members  514 . 
     The internal surface  508  of the body  504  may also be configured to at least partly abut the second surface  408  of the projecting portion  404 A. The body  504  may have a shape and a contour that at least partly confirms to a shape and contour of the second surface  408  of the projecting portion  404 A. For example, the body  504  may include a slot cover portion  512  configured to cover the slot  412  defined in the projecting portion  404 A. Specifically, the internal surface  508  of the slot cover portion  512  of the body  504  faces the second surface  408  of the projecting portion  404 A so as to cover the slot  412  from one side. Further, an outer perimeter of the slot cover portion  512  may at least partly abut the perimeter of the projecting portion  404 A surrounding the slot  412 . The slot cover portion  512  of the body  504  and the second surface  408  also defines a recess (not shown) therebetween. 
     The body  504  also includes a cylindrical portion  515  extending from the external surface  506  of the body  504 . The cylindrical portion  515  defines a cavity  516  configured to at least partly receive the sensing device  420  therein. The body  504  may further include an annular lip portion (not shown) extending inside the cavity  516 . The sensing device  420  may be disposed adjacent to the annular lip portion of the body  504 . The sensing device  420  may be disposed inside the cavity  516  such that the lever member  424  of the sensing device  420  is adjacent to the internal surface  508  of the body  504 . Moreover, the lever member  424  is also disposed in the recess defined between the slot cover portion  512  of the body  504  and the second surface  408  of the projecting portion  404 A. 
     As such, the lever member  424  may move in an angular range provided by the recess. Further, the lever member  424  is coupled to the mounting stud  414  so as to move in conjunction with the mounting stud  414  which in turn moves in conjunction with the second linkage component  302 . The body  504  also defines an aperture  520  configured to allow the cable  430  of the sensing device  420  to pass therethrough. 
     The cover member  502  also includes a plate  522  disposed adjacent to the external surface  506  of the body  504 . The plate  522  may be configured to enclose the sensing device  420  within the cavity  516 . Moreover, the plate  522  may be supported on the annular lip portion so as to enclose the sensing device  420 . Additionally or optionally, the plate  522  may also be coupled to the cylindrical portion  515 . Specifically, the plate  522  may be coupled to the annular lip portion. In an example, the plate  522  may be coupled to the annular lip portion via welding. 
     Further, the plate  522  may be coupled to the sensing device  420 . In the illustrated embodiment, the plate  522  may be removably coupled to the sensing device  420 . The plate  522  defines one or more plate holes  524  that are configured to receive a sensor fastening member  526 . The sensor fastening member  526  may be configured to couple the sensing device  420  to the plate  522 . In an example, the sensor fastening member  526  may be a bolt and nut arrangement. In alternative examples, other types of fastening members  526  known in the art may be used to accomplish the coupling between the sensing device  420  and the plate  522 . 
     INDUSTRIAL APPLICABILITY 
     The present disclosure is related to the guard system  500  for the linkage assembly  200 . The guard system  500  includes the tube member  400  and the cover member  502 . The cover member  502  may be coupled to the projecting portion  404 A of the tube member  400 . The cover member  502  includes the body  504  and the plate  522 . The body  504  includes the cylindrical portion  515  that defines the cavity  516  therethrough. The sensing device  420  may be disposed within the cavity  516 . The cover member  502  also includes the plate  522  that encloses the sensing device  420  within the cavity  516 . 
     Further, the lever member  424  of the sensing device  420  may be disposed within the slot  412  defined in the projecting portion  404 A. The body  504  of the cover member  502  may also include the slot cover portion  512  that covers the slot  412 . As such, the lever member  424  may be covered by the slot cover portion  512  of the body  504 . Further, the body  504  also defines the aperture  520  for allowing the cable  430  of the sensing device  420  to pass therethrough. 
     Further, the guard system  500  provides the cover member  502  that is detachably coupled to the tube member  400 . Further, the sensing device  420  may also be removably coupled to the cover member  502 . As such, the guard system  500  facilitates replacement and/or maintenance of the sensing device  420 . 
     The guard system  500  may be specifically advantageous in underground mining applications in which rocks, debris may routinely hit the linkage assembly  200 . The guard system  500  of the present disclosure provides the sensing device  420  disposed with in the cavity  516  of the cover member  502 . Further, the cover member  502  may be integrated with the tube member  400 . As such, the tube member  400  and the cover member  502  together may effectively shield components of the sensing device  420  such as, the lever member  424  and the sensor body  422  from rocks and debris that may hit the linkage assembly  200  of the machine  100 . 
     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.