Patent Publication Number: US-10316557-B2

Title: Latch system for hood of a machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to a latch system for a hood of a machine. 
     BACKGROUND 
     The engine compartment of machines, such as mining trucks, wheel loaders, excavators, and the like, is typically enclosed by a hood. The hood is coupled to the frame of the machine and may be operated by an actuator, which may be driven by electric power, hydraulic power or pneumatic power. The hood is moved to an opened position by the actuator for servicing and maintenance of an engine, a radiator or other components disposed in the engine compartment. An operator may activate the actuator to move the hood to the opened position and a closed position. During loading of the machines, especially in the event of vertical loading, the hood may vibrate in the closed position and thereby generate noise. The hood may be constrained in the closed position, but activating the actuator while the hood is restricted to the closed position may cause damage to the actuator. 
     U.S. Pat. No. 8,584,787 (the &#39;787 patent) discloses an active hood apparatus. The active hood apparatus includes a main frame fixed to a vehicle body. A latch assembly is disposed at a back side of the main frame for locking and releasing a hood. A hood rise and fall device is disposed between the back side of the main frame and the hood latch assembly. The hood rise and fall device moves the hood latch assembly in a vertical direction based on a control signal from a controller. The controller receives a sensing signal from a pedestrian collision sensor. The active hood apparatus is actuated by the control signal from the controller to move the hood from the locked position. However, not all machines include a hood such as in the &#39;787 patent, including latch assemblies that are electronically controlled and receive control signals from a controller. Therefore, a need remains for improvements in this technology area. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, an interlock lever for actuating a latch member of a machine is provided. The latch member is configured to selectively lock a hood of the machine in a closed position of the hood. The machine has an input member configured to move the hood between the closed position and an opened position. The input member is movable in a first direction to move the hood towards the opened position and a second direction to move the hood towards the closed position. The interlock lever includes a body movable between a first position and a second position. In the second position, the body is configured to actuate the latch member to allow the hood to move from the closed position thereof. The interlock lever further includes a slot defined in the body. In the first position of the body, the slot is configured to prevent movement of the input member in the first direction. In the second position of the body, the slot is configured to allow movement of the input member in the first direction. 
     In another aspect of the present disclosure, a latch system for a hood of a machine is provided. The machine includes an input member configured to move the hood between a closed position and an opened position. The input member is movable in a first direction to move the hood towards the opened position and a second direction to move the hood towards the closed position. The latch system includes a latch member switchable between a locked configuration and an unlocked configuration. In the locked configuration, the latch member is configured to retain the hood in the closed position thereof. In the unlocked configuration, the latch member is configured to allow movement of the hood from the closed position thereof. The latch system further includes an interlock lever movable between a first position and a second position. In the first position, the interlock lever is configured to prevent the movement of the input member in the first direction. In the second position, the interlock lever is configured to actuate the latch member to the unlocked configuration thereof and allow movement of the input member in the first direction. 
     In yet another aspect of the present disclosure, a machine is provided. The machine includes a frame, a hood coupled to the frame and movable between an opened position and a closed position, and an actuator for selectively moving the hood between the opened position and the closed position. The machine further includes an input member coupled to the actuator. The input member is configured to actuate the actuator based on a user input. Further, the input member is movable in a first direction to move the hood towards the opened position and a second direction to move the hood towards the closed position. The machine further includes a latch member switchable between a locked configuration and an unlocked configuration. In the locked configuration, the latch member is configured to retain the hood in the closed position thereof. In the unlocked configuration, the latch member is configured to allow movement of the hood from the closed position thereof. The machine further includes an interlock lever movable between a first position and a second position. In the first position, the interlock lever is configured to prevent movement of the input member in the first direction. In the second position, the interlock lever is configured to actuate the latch member to the unlocked configuration thereof and allow movement of the input member in the first direction. 
     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 an exemplary machine having a hood shown in an opened position. 
         FIG. 2  is a perspective view of a latch member disposed on a frame of the machine. 
         FIG. 3  is a perspective view showing an interlock lever associated with a latch system of the machine. 
         FIG. 4  is a view of the interlock lever of  FIG. 3  shown in a first position thereof. 
         FIG. 5  is a view of the interlock lever of  FIG. 3  shown in a second position thereof. 
     
    
    
     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  shows a side view of an exemplary machine  100 . In the illustrated embodiment, the machine  100  is a wheel loader. Although a wheel loader is disclosed, it should be noted that the machine  100  may alternatively be embodied in the form of a backhoe loader, an excavator, a dozer, an off-highway truck or other machines typically employed in applications such as mining, forestry, waste management, construction, agriculture, transportation, and the like. The present disclosure is generally relevant to any machine having a hood, as will become evident from the following description. 
     The machine  100  includes a frame  102  having a drive system (not shown) supported thereon for driving ground engaging members  104  of the machine  100 . In the embodiment of  FIG. 1 , the ground engaging members  104  includes front wheels and rear wheels. It may also be contemplated that the ground engaging members  104  may be tracks. 
     The drive system includes a power source, such as an engine  106  configured to supply power to various components including, but not limited to, the ground engaging members  104  and an implement system  108 . The engine  106  is located within an engine compartment  110  adjacent to a rear end  112  of the machine  100 . The engine compartment  110  may include various components associated with the engine  106  such as, a radiator and a fuel injection pump, and others. In an embodiment, the engine  106  may be coupled to a generator (not shown) for generating electric power. The generator may be further coupled with one or more batteries  114  disposed adjacent to the engine compartment  110  of the machine  100 . The batteries  114  may be configured to supply electric power to the various electric components and the lighting system of the machine  100  when the engine  106  is inoperative. 
     The machine  100  further includes a hood  120  configured to enclose the engine compartment  110  of the machine  100 . The hood  120  may include an upper panel  119  and one or more side panels  121  extending from the upper panel  119 . The upper panel  119  and the side panels  121  may be together configured to enclose the engine compartment  110 . The hood  120  may further include one or more reinforcing members  122  to reinforce the structure of the upper panel  119  and the side panels  121  and to support the hood  120  on the frame  102  of the machine  100 . The reinforcing members  122  may be welded or bolted on an inner surface of the upper panel  119  and the side panels  121  of the hood  120 . 
     The hood  120  is moveable between an opened position (shown in  FIG. 1 ) and a closed position. In the embodiment shown, a bottom end of the reinforcing members  122  attached to the side panels  121  may include a pivot pin member  123 . The pivot pin member  123  is coupled on the frame  102  adjacent to the rear end  112  of the machine  100  such that the hood  120  may move between the closed position and the opened position about the pivot pin member  123 . The hood  120  may be used for protecting the engine  106 , the radiator, the fuel injection pump, the batteries  114  and other components associated with the engine  106  from water and dust within the engine compartment  110 . Further, the hood  120  may also avoid physical contact of any external body with the components disposed within the engine compartment  110 . 
     The machine  100  further includes an actuator, such as a linear actuator  124 , configured to selectively move the hood  120  between the closed position and the opened position. The linear actuator  124  may be communicably coupled to the batteries  114  to receive an electric power therefrom. The linear actuator  124  includes a cylinder  126  for receiving a motor (not shown) therein. The motor may be configured to be in electric communication with the batteries  114  to receive required electric power to move the hood  120 . The linear actuator  124  further includes a rod  128  movable between an extended position and a retracted position. The rod  128  may be engaged with the motor. Further, the rod  128  may move between the extended position and the retracted position upon actuation of the motor. A free end of the rod  128  is pivotally coupled to the reinforcing member  122  attached to the side panel  121  of the hood  120 . A mounting end of the cylinder  126  is pivotally coupled to the frame  102  such that when the rod  128  moves towards the extended position, the hood  120  moves to the opened position. The retracted position of the rod  128  may generally correspond to the closed position of the hood  120 . In other embodiments, the machine  100  may include two or more linear actuators  124  coupled between the hood  120  and the frame  102  to move the hood  120  between the opened position and the closed position. 
     The machine  100  further includes a latch member  130 . The latch member  130  is switchable between a locked configuration and an unlocked configuration. In the locked configuration, the latch member  130  is configured to retain the hood  120  in the closed position thereof. In the unlocked configuration, the latch member  130  is configured to allow movement of the hood  120  from the closed position thereof. In the embodiment shown, the latch member  130  is disposed on the frame  102  within the engine compartment  110 . An exemplary construction of the latch member  130  is described in detail later with reference to  FIG. 2 . 
     A striking pin  132  associated with the latch member  130  is mounted on the inner surface of the upper panel  119  to engage with the latch member  130  in the closed position of the hood  120 . The striking pin  132  may be mounted on a reinforcing member (not shown) attached to the upper panel  119  of the hood  120 . The striking pin  132  may be a rod adapted to be received within the latch member  130  in the closed position of the hood  120 . 
     The machine  100  further includes a latch system  150  that is configured to be in communication with the hood  120  to move the hood  120  between the closed position and the opened position. Further, the latch system  150  is configured to selectively actuate the latch member  130  and the linear actuator  124  based on an input received from an operator. In the illustrated embodiment, the latch system  150  may be disposed on the frame  102  outside an operator cab  105  of the machine  100 , as shown in  FIG. 1 . However, it may be contemplated that the latch system  150  may be disposed at any location of the frame  102  based on convenience of the operator to operate the latch system  150 . In other embodiments, the latch system  150  may be disposed within the operator cab  105 . 
       FIG. 2  shows the latch member  130  that is mounted on the frame  102  of the machine  100 . The latch member  130  is detachably mounted on a support member  134  via fastening members  136  such as bolts. The support member  134  is further mounted on the frame  102  of the machine  100  via fasteners (not shown). The latch member  130  further includes a pair of engaging members  138  configured to engage with the striking pin  132  in the closed position of the hood  120 . The latch member  130  further includes a cable member  142  configured to actuate the pair of engaging members  138  and thereby to move the latch member  130  in the unlocked configuration. The cable member  142  includes a first end  144  configured to couple to the engaging members  138 . Further, the cable member  142  is configured to be coupled between the latch member  130  and the latch system  150 . 
     In the illustrated embodiment, the cable member  142  further includes a guiding member  146  for allowing the cable member  142  to move fore and aft therethrough. The support member  134  further includes a first bracket member  147  for supporting one end of the guiding member  146  adjacent to the first end  144  of the cable member  142 . In an alternative embodiment, a linkage mechanism may be coupled between the latch system  150  and the latch member  130  for switching the latch member  130  to the unlocked configuration. The linkage mechanism may include one or more links coupled to each other. Further, the one or more links may move relative to each other to switch the latch member  130  in the unlocked configuration. 
       FIG. 3  illustrates a perspective view showing an interlock lever  152  associated with the latch system  150 . The interlock lever  152  is configured to actuate the latch member  130  of the machine  100 . The interlock lever  152  includes a body  153 , which in the embodiment shown is movably coupled to the frame  102  of the machine  100 . The body  153  is movable between a first position ( FIG. 4 ) and a second position ( FIG. 5 ). In the second position, the body  153  of the interlock lever  152  is configured to actuate the latch member  130  to allow the hood  120  to move from the closed position thereof. 
     In the illustrated embodiment, a box  154  is formed below a floor panel  156  of the machine  100 . The box  154  includes a bottom plate  158  and a plurality of side plates  159  to define a hollow space along with an opening. The body  153  of the interlock lever  152  is movably coupled on the bottom plate  158  of the box  154 . The hollow space may also include various machine operating switches, such as disposed on the bottom plate  158 . The opening may give access to the operator to operate the interlock lever  152  and the various machine operating switches. The opening may be further closed by a door member (not shown) to enclose the interlock lever  152  when not in use. Moreover, the interlock lever  152  and the machine operating switches may be restricted from unauthorized use with the help of the door member. 
       FIG. 4  illustrates a view of the interlock lever  152  shown in the first position thereof. In the first position, the interlock lever  152  is configured to engage with an input member  162  associated with the linear actuator  124  of the machine  100 . The input member  162  is coupled to a switching device  160  to move the hood  120  between the closed position and the opened position based on a user input. The input member  162  is further configured to be movable in a first direction D 1  to move the hood  120  towards the opened position and a second direction D 2  opposite to the first direction D 1  to move the hood  120  towards the closed position. The switching device  160  may be in electric communication with the batteries  114  and the linear actuator  124  via one or more cables  161 . 
     In an embodiment, the input member  162  may also be configured to be in a neutral position N when not operated by the operator. Further, the input member  162  may also be configured to move to the neutral position N if the operator releases the input member  162  after moving to the first direction D 1  or the second direction D 2 . In an example, the input member  162  may be a toggle switch. 
     The bottom plate  158  may include a through hole (not shown) to receive the input member  162  therethrough such that the switching device  160  may be mounted on the bottom plate  158 . The switching device  160  is mounted on an inner surface of the bottom plate  158  via fastening members (not shown), such that the input member  162  may project from an outer surface  164  of the bottom plate  158 . 
     The body  153  of the interlock lever  152  extends between a first end  168  and a second end  170 . The body  153  may be formed from a metallic plate. In the illustrated embodiment, a cross section of the body  153  may be in a C shape defined by a base portion  172  and a pair of side portions  174 . The interlock lever  152  includes a pivot member  176  configured to couple the body  153  of the interlock lever  152  to the frame  102 . The body  153  of the interlock lever  152  is movably coupled to the bottom plate  158  via the pivot member  176 . The body  153  is further movable between the first position and the second position about the pivot member  176  based on a user input. In the illustrated embodiment, the pivot member  176  is disposed between the side portions  174  adjacent to the second end  170  of the body  153 . 
     The interlock lever  152  further includes a slot  178  defined in the body  153 . In the illustrated embodiment, the slot  178  may be an elongate opening formed adjacent to the first end  168  along a length of the body  153 . The slot  178  is configured to receive the input member  162  at the first position of the interlock lever  152 . In the first position of the body  153 , the slot  178  is configured to prevent movement of the input member  162  in the first direction D 1  ( FIG. 4 ). Further, in the second position of the body  153 , the slot  178  is not engaged with the input member  162 , which is free to be moved in both the first direction D 1  and the second direction D 2  ( FIG. 5 ). Additionally, in the first position of the body  153 , the slot  178  may be configured to allow movement of the input member  162  in the second direction D 2  ( FIG. 4 ). 
     In various embodiments, the body  153  of the interlock lever  152  may include a clamping member and a locking member instead of the slot  178  to prevent moving of the input member  162  in the first direction D 1  in the first position of the interlock lever  152 . 
     The interlock lever  152  further includes a coupling portion  180  defined in the body  153  between the pivot member  176  and the slot  178 . The coupling portion  180  is configured to couple with a second end  182  of the cable member  142 . Thus the cable member  142  is coupled between the interlock lever  152  and the latch member  130  to switch the latch member  130  in the unlocked configuration in the second position of the interlock lever  152 . Further, the latch member  130  allows the hood  120  to move from the closed position. In the illustrated embodiment, the coupling portion  180  may be defined by the side portions  174  between the pivot member  176  and the slot  178 . The bottom plate  158  further includes an intermediate side plate  184 . A second bracket member  186  is disposed on the intermediate side plate  184  to support the guiding member  146  adjacent to the second end  182  of the cable member  142 . Further, the bottom plate  158  may include an aperture  188  (shown in  FIG. 5 ) to receive the second end  182  of the cable member  142  therethrough and to allow coupling of the cable member  142  with the coupling portion  180 . It may be contemplated that the second bracket member  186  may be disposed at any location of the frame  102 . 
     In an embodiment, an elastic member (not shown), such as a spring may be disposed between the interlock lever  152  and the bottom plate  158 . The elastic member may be configured to retain the interlock lever  152  in the first position. Further, the interlock lever  152  may be moved to the second position against a biasing force of the elastic member. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to the latch system  150  for actuating the latch member  130  and for allowing actuation of the linear actuator  124  for moving the hood  120 . The interlock lever  152  of the latch system  150  is moved to the second position by the operator to allow the hood  120  to move from the closed position before actuating the linear actuator  124 . Actuation of the interlock lever  152  between the first position and the second position is described in detail herein below with reference to  FIG. 5 . 
       FIG. 5  illustrates a view of the interlock lever  152  shown in the second position thereof. When the operator wants to move the hood  120  to the opened position, the operator may move the interlock lever  152  from the first position towards the second position. As the interlock lever  152  moves towards the second position, the interlock lever  152  may pull the cable member  142  to actuate the engaging members  138  of the latch member  130  to the unlocked configuration. In the unlocked configuration, the striking pin  132  disengages from the latch member  130 . Thus, in the second position of the interlock lever  152 , the hood  120  may be moved from the closed position thereof. Further, in the second position of the interlock lever  152 , the input member  162  is also disengaged from the slot  178  of the interlock lever  152 . Thus the interlock lever  152  allows actuation of the input member  162  in both the first direction D 1  and the second direction D 2 . 
     The operator may then move the input member  162  to the first direction D 1 . When the input member  162  moves to the first direction D 1 , an electric communication between the batteries  114  and the linear actuator  124  is established through the cables  161 . The motor actuates the rod  128  to move to the extended position thereof. The operator may hold the input member  162  at a position P 1  for a predetermined time to move the hood  120  to the opened position. The predetermined time may be an amount of time required for moving the hood  120  to the opened position from the closed position. In an example, the operator may hold the input member  162  for 30 seconds in the position P 1  to move the hood  120  to the opened position. After the predetermined time, the operator may release the input member  162  to allow the input member  162  to move back to the neutral position N. 
     For moving the hood  120  from the opened position to the closed position, the operator may move the input member  162  in the second direction D 2 . When the input member  162  moves to a position P 2  in the second direction D 2 , an electric communication between the batteries  114  and the linear actuator  124  may be established through the cables  161 . The motor may further actuate the rod  128  to move to the retracted position thereof. The operator may hold the input member  162  at the position P 2  for the predetermined time. After the predetermined time, the operator may release the input member  162  to allow the input member  162  to move back to the neutral position N. In the closed position of the hood  120 , the striking pin  132  may be engaged with the engaging members  138  of the latch member  130 . The striking pin  132  may engage with the engaging members  138  due to a force caused during movement of the rod  128  from the extended position to the retracted position. Thus the hood  120  is secured in the closed position in the latch member  130 . 
     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.