Patent Application
20170130419
The present disclosure relates to the field of lift arm for machines. In particular, the present disclosure relates to a latch assembly for holding a service pin with a lift arm of a machine.
Machines such as earth moving machines, construction machines, mining machines or underground mining machines for example underground mining loaders or a load haul dump machine generally include a bucket to carry or load the material. The bucket is attached to one end of a lift arm of the loader and raised by moving the lift arm using fluid cylinders. The other end of the lift arm is attached to the frame of the machine.
For desired operational performance, regular servicing or maintenance of the machine is performed. For inspection or maintenance of the lift arm, fluid cylinders associated with lift arm, bucket or other components, the lift arms are generally maintained in a raised position. One way of holding the lift arm in the raised position is to extend the lift arm cylinder by operating a lever in an operator cabin and hold the lever in that position. However, the lift arm may come down due to fluid leakage in the cylinders or inadvertent movement of the lever by a person.
The other way of maintaining the lift arm in the raised position is to provide a pin on the lift arm. The pin is movable to an operational position for engaging a stationary frame. When not in use, the pin is moved to a storage position and locked onto the lift arm using a locking device. The locking and unlocking of the pin may be performed by a tool. Also, the removed locking device may get lost which is not desirable. U.S. Pat. No. 7,712,235 discloses a lock device that prevents a boom of a backhoe work machine from being rotated downward by its weight.
According to an aspect, a latch assembly for a service pin of a machine is disclosed. The latch assembly includes a housing for rotatably receiving the service pin. Further, the housing defines a sliding structure for axial movement of the service pin at a rotational position of the service pin. The latch assembly further includes a first member pivotably attached to the housing and is adapted to selectively prevent rotation of the service pin. A second member of latch assembly is configured to be slidably attached to the housing and movable to a bottom position to retain the first member.
According to another aspect, a service pin assembly for a machine is disclosed. The service pin assembly includes a service pin, a housing, a first member, and a second member. The housing is configured for rotatably receiving the service pin. The housing includes a sliding structure for axial movement of the service pin at a rotational position of the service pin. The first member is pivotably attached to the housing and is adapted to selectively prevent rotation of the service pin. The second member is slidably attached to the housing and movable to a bottom position to retain the first member.
In yet another aspect, a machine is disclosed. The machine includes a lift arm, a service pin, a housing, a first member, and a second member. The service pin is configured for insertion in the lift arm. The housing is configured for rotatably receiving the service pin. The housing includes a sliding structure for axial movement of the service pin at a rotational position of the service pin. The first member is pivotably attached to the housing and is adapted to selectively prevent rotation of the service pin. The second member is slidably attached to the housing and movable to a bottom position to retain the first member.
As shown in
The machine 100 may also be provided with one or more lift arm actuators 116 that operatively couples the lift arms 110 to the frame 102. The lift arm actuators 116 are extended or retracted to raise or lower the lift arms 110. Further, the cab 106 may generally house an operator interface 120 through which an operator may be able to operate any one or more of the traction devices 104, the power source 108, the lift arms 110, the implement 112, and the like.
As shown in
Referring to
The latch assembly 124 includes a housing 136, a first member 138, and a second member 140. The housing 136 is configured to receive the rotatable service pin 126 by permitting axial movement of service pin 126 at a specified angle of rotation. The housing 136 is configured to restrict the axial movement of the service pin 126 unless the service pin 126 is rotated to the specified angle of rotation. The first member 138 and the second member 140 are mounted on the housing 136 and when engaged with the service pin 126 prevent a rotational movement of the service pin 126 in the housing 136. In an embodiment, the housing 136 may include a cylindrical portion 142 defining a sliding structure 144, a first end 146, a second end 148, and a plate portion 150. The cylindrical portion 142 is a hollow portion and may enclose the cylindrical structure 128 of the service pin 126 such that the arm 130 remains outside the cylindrical portion 142 and may abut the first end 146. The housing 136 may be attached to the lift arm 110 by coupling the second end 148 to the inner plate 114 of the lift arm 110.
The sliding structure 144 is configured to allow axial movement of the service pin 126 when the service pin 126 is rotated to a predefined rotational position to align the arm 130 with the sliding structure 144. The sliding structure 144 extends along entire length of the cylindrical portion 142 in direction parallel to the longitudinal axis 132. In the present embodiment, the sliding structure 144 is an opening extending in a direction parallel to the longitudinal axis 132. In another embodiment, the sliding structure 144 may be a groove, a slot, a dome or any structure generally known in the art which may allow the axial movement of the service pin 126.
The plate portion 150 may extend from an outer surface 152 of the cylindrical portion 142 in a direction perpendicular to the longitudinal axis 132. In the present embodiment, the first member 138 and the second member 140 are engaged with the plate portion 150.
The first member 138 is configured to engage with the second member 140 and the service pin 126 to selectively restrict the rotational movement of the service pin 126. The first member 138 may include a first end 154, a stopper 156, an engagement structure 158, and a pin 160. The first member 138 is pivotally attached to the housing 136. The first member 138 may be pivotally attached by attaching the first end 154 of the first member 138 to the plate portion 150. The first member 138 may include the stopper 156 at its other end. The stopper 156 may engage to the arm 130 of the service pin 126. In the present embodiment, the stopper 156 engages the groove 134. When engaged with the service pin 126, the stopper 156 prevents the rotational movement of the service pin 126. The stopper 156 may include but not limited to a hook structure, a protrusion, a pin or the like. In the present embodiment, the stopper 156 is a pin type structure.
The first member 138 may further include the engagement structure 158 configured to engage the second member 140. The engagement structure 158 engages the first member 138 with the second member 140 when the second member 138 is at the bottom position. The engagement structure 158 may be a protrusion, a hook, a pin or a similar structure known in the art. Furthermore, the pin 160 is configured to couple the first member 138 to the second member 140.
The second member 140 is slidably attached to the housing 136. In an embodiment, the second member 140 may be attached to the plate portion 150. The second member 140 is configured to slide between a bottom position and a top position with respect to the plate portion 150. In the bottom position, the second member 140 may retain the first member 138 engaged with the service pin 126. The second member 140 may include a straight portion 162 having a slot 164 and a lock structure 166. The slot 164 may extend along the length of the straight portion 162. The second member 140 may be engaged to the plate portion 150 by engaging the slot 164 with the plate portion 150 by using a bolt 168 such that the second member 140 is able to slide with respect to the plate portion 150. Further, the second member 140 may be engaged to the first member 138 by inserting the pin 160 in the slot 164. The slot 164 and the pin 160 may be configured to guide travel of the second member 140 between a bottom position (shown in
Referring to
The present disclosure provides for the service pin assembly 118 for attachment to the lift arm 110 of the machine 100. The service pin assembly 118 includes the service pin 126 and the latch assembly 124. The latch assembly 124 when engaged with the service pin 126, retains the service pin 126 with the lift arm 110 in a disengaged position and restricts the axial and rotational movement of the service pin 126. The latch assembly 124 is configured to operate under gravity to lock or unlock the service pin 126 without using any tools.
During servicing of the machine 100, the lift arms 110 of the machine 100 are maintained in a raised position. An operator or a service personal raises the lift arms 110 to the desired height by operating a lever to extend the lift arm actuators 116. Once, the lift arms 110 are raised to the desired height and aligned with the stationary frame, the extension of the lift arm actuators 116 is stopped.
Now, the operator or service personal operates the latch assembly 124 to disengage the latch assembly 124 from the service pin 126. For disengaging the latch assembly 124, the second member 140 is moved to the top position by sliding it. As the second member 140 moves from the bottom position, the first member 138 is free to pivot about the first end 154. After moving the second member 140 from the bottom position, the service personal moves the first member 138. The movement of the first member 138 disengages the stopper 156 from the arm 130 and allows the rotation of the service pin 126 inside the cylindrical portion 142 of the housing 136.
The service pin 126 is rotated inside the cylindrical portion 142 to a rotation position such that the arm 130 of the service pin 126 is aligned with the sliding structure 144. Once, arm 130 is aligned with sliding structure 144, the second member 140 returns to the bottom position due to gravity. After aligning the arm 130 with sliding structure 144, the service pin 126 is pushed axially to couple the lift arm 110 to the stationary frame and thereby maintaining the lift arms 110 at the raised position during servicing. Therefore, the service pin 126 may be coupled with stationary frame without using any additional tools. Also, as all the components of the latch assembly 124 always remains coupled to the lift arm 110, the loss of the components is prevented.
