Hydraulic latch pin assembly for coupling a tool to a construction equipment

A tool coupler for coupling an excavation to an apparatus for operating the excavation tool, the apparatus including a base, a hydraulic system in the base with controls for distributing hydraulic pressure from the hydraulic system, a movable dipper stick having a free end, and a hydraulic tool cylinder hydraulically coupled to the hydraulic system, the tool coupler comprising:

• a frame, including side walls and cross members that define a central space, a dipper pivot at a forward end of the frame for pivotally connecting to the free end of the dipper stick, and a link pivot located rearward from the dipper pivot for pivotally coupling to an end of the tool cylinder, wherein extension of the tool cylinder rotates the frame forward around the dipper pivot;
• forward extending hook structure depending from the frame, structured and arranged to engage a cross member located at an upper and forward portion of the tool;
• an actuator assembly attached to the frame, the actuator assembly including:
• a latch pin located substantially within the central space and movable between an extended position wherein a first end of the latch pin projects out from a rear end of the frame for engaging a receptacle formed in the excavation tool, and a retracted position for disengaging from the receptacle of the excavation tool;
• a bias member structured and arranged to apply a bias force to the latch pin urging the latch pin towards the extended position;
• a hydraulic latch cylinder having a fixed part and a movable part that can be extended from the fixed part;
• and a latch pin coupling assembly coupling between the latch pin and the movable part such that extension of the movable part urges the latch pin to the retracted position;
• and
• a hydraulic switch assembly operably coupling hydraulic pressure from the hydraulic system to the latch cylinder.

A method for coupling an excavation tool to a coupler body pivotally attached at an end of an arm, the coupler body including a latch pin capable of sliding between an engaged position with an end of the latch pin projecting out from the coupler body and a retracted position with the end not projecting out from the coupler body, the method comprising:

• applying hydraulic pressure to a latch cylinder that has a part fixed relative to the coupler body and a movable part coupled to the latch pin;
• extending the movable part relative to the fixed part, thereby urging the latch pin to the retracted position;
• engaging a cross member of the excavation tool with a hook structure depending and extending forward from the coupler body;
• rotating the coupler body toward the tool, aligning the latch pin with a mating receptacle formed in the excavation tool;
• reducing the hydraulic pressure to the latch cylinder;
• and
• applying a bias force to the latch pin, urging the latch pin to the engaged position, thereby engaging the latch pin in the receptacle and securing the excavation tool to the coupler body.

A coupling assembly for coupling a bucket to a dipperstick of an hydraulic equipment, the coupling assembly comprising:

• a frame structured for attachment to the dipperstick and including an aperture formed by an underside;
• an actuator assembly in the frame, including a latch pin, the actuator assembly structured to move a latch pin between an engaged position engaged with a mating structure of the bucket and a retracted position disengaged from the mating structure;
• and
• an indicator member coupled to the latch pin and movable therewith, wherein the indicator member is visible through an opening of the bucket and through the aperture from outside the frame by an operator of the equipment such that the position of the indicator member indicates the position of the latch pin to the operator.

A method of operating a bucket from a free end of a dipperstick of an excavation equipment, comprising:

• providing a coupler at the free end of the dipperstick, the coupler including a body and latch pin capable of sliding between an engaged position with an end of the latch pin projecting out from the coupler body and a retracted position with the end of the latch pin retracted within the coupler body;
• attaching a bucket to the coupler by moving the coupler pin to the engaged position engaged with a mating structure of the bucket;
• and
• viewing an indicator member, coupled with the latch pin, through an opening of the bucket when the latch pin is moved to a retracted position disengaged from the mating structure.

A coupling assembly for coupling a tool to an arm of an apparatus, wherein tilting of the coupling assembly from the arm is powered by a hydraulic system, the coupling assembly comprising:

• a coupler body, including a frame defining a central cavity, and link structure for pivotally coupling the arm to the tool;
• and
• an actuator assembly attached to the frame, the actuator assembly comprising:
• a latch pin movable between an extended position for securing the tool to the arm, and a retracted position for releasing the tool;
• a hydraulic latch cylinder having a fixed part and a movable part that can be extended relative to the fixed part;
• and
• a latch pin coupling assembly coupling between the latch pin and the movable part such that extension of the movable part urges the latch pin to the retracted position.

A tool coupler for coupling an excavation tool to an apparatus for operating the excavation tool, the apparatus including a base, a hydraulic system in the base with controls for distributing hydraulic pressure from the hydraulic system, a movable dipper stick coupled to the base and having a free end, and a hydraulic tool cylinder hydraulically coupled to the hydraulic system and having one end pivotally linked to the dipper stick at a location spaced apart from the free end of the dipper stick, the tool coupler comprising:

• a frame, comprising side walls and cross members that define a central space, a dipper pivot at a forward end of the frame for pivotally connecting to the free end of the dipper stick, and a link pivot located rearward from the dipper pivot for pivotally coupling to a second end of the tool cylinder, wherein extension of the tool cylinder rotates the frame forward around the dipper pivot;
• a hook structure depending from the frame, structured and arranged to engage a cross member located at a first end of the tool;
• an actuator assembly attached to the frame, the actuator assembly comprising:
• a latch pin located substantially within the central space and movable between an extended position wherein a first end of the latch pin secures a mating structure of the excavation tool to the tool coupler, and a retracted position for releasing the mating structure of the excavation tool from the tool coupler;
• a bias member structured and arranged to apply a bias force to the latch pin urging the latch pin towards the extended position;
• a hydraulic latch cylinder having a fixed part and a movable part that can be extended from the fixed part;
• and a latch pin coupling assembly coupling between the latch pin and the movable part such that extension of the movable part urges the latch pin to the retracted position;
• and
• a hydraulic switch assembly operably coupling hydraulic pressure from the hydraulic system to the latch cylinder.

A method for coupling an excavation tool to a coupler body pivotally attached at the end of an arm, the coupler body comprising a latch pin capable of sliding between an extended position and a retracted position, the method comprising:

• applying hydraulic pressure to a latch cylinder that has a part fixed relative to the coupler body and a movable part rigidly coupled to the latch pin;
• extending the movable part relative to the fixed part, thereby urging the latch pin to the retracted position;
• engaging a cross member of the excavation tool with a hook structure depending and extending from the coupler body;
• rotating the coupler body toward the tool to position a mating structure of the tool to be secured by the latch pin;
• reducing hydraulic pressure to the latch cylinder;
• and
• applying a bias force to the latch pin, urging the latch pin to the extended position to secure the mating structure, and thereby the excavation tool, to the coupler body.