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US 12,269,713 B2Granted
Lifting clamp
OwnerKenneth Brandon Homewoodinventor
Life of this patent
Estimating the term…
Abstract
A scissor-type lifting clamp has two locking clutches, one on each side of a central plane separating hoisting arms of the clamp, for automatically locking the clamp in an opened configuration. The use of two locking clutches reduces the overall vertical distance through which the scissor arms need to travel in order to lock the scissor arms in the opened configuration once an object gripped by the clamp is delivered by the clamp, thereby permitting the use of the clamp with a smaller vehicle, such as a skid steer. A height adjustable outrigger oriented to engage a top of the object to be clamped cooperates with the two locking clutches to further reduce required overall vertical travel distance of the clamp to lock the clamp in the opened configuration.
Claims13
A lifting clamp comprising:
- a lifting lug connectable to a lifting machine;
- a first hoisting arm pivotally connected to and extending away from the lifting lug on a first side of a central plane through the lifting lug, and a second hoisting arm pivotally connected to and extending away from the lifting lug on a second side of the central plane such that the central plane is between the first and second hoisting arms;
- a first scissor arm pivotally connected to the first hoisting arm, the first scissor arm extending away from the first hoisting arm to cross through the central plane to the second side of the central plane, and a second scissor arm pivotally connected to the second hoisting arm, the second scissor arm extending away from the second hoisting arm to cross through the central plane to the first side of the central plane;
- a cross-brace pivotally connected to the first scissor arm on the second side of the central plane and pivotally connected to the second scissor arm on the first side of the central plane;
- a first gripper connected to the first scissor arm, and a second gripper connected to the second scissor arm;
- at least two locking clutches and at least two corresponding clutch receivers, the clutch receivers configured to receive the locking clutches and the locking clutches configured to be lockable in the clutch receivers for preventing pivoting of the first and second hoisting arms and the first and second scissor arms when the first and second grippers are in an opened configuration;
- and,
- at least one outrigger mounted on the cross-brace, the at least one outrigger oriented to engage a top of an object to be clamped between the first and second grippers, the at least one outrigger comprising
- a shoe for engagement with the top of the object,
- an elongated element extending from the shoe,
- a mounting plate mounted on the cross-brace, the mounting element comprising an aperture for receiving the elongated element and
- a releasable and securable securement element for securing the elongated element in the aperture of the mounting plate and for permitting the elongated element with the shoe to be adjustable vertically in relation to the cross-brace,
- wherein lifting the lifting lug causes the first and second hoisting arms to pivot toward each other and toward the central plane, the first and second scissor arms to pivot toward each other and toward the central plane and the first and second grippers to pivot toward each other and toward the central plane to clamp the object disposed between the first and second grippers.
10 more elements
A lifting clamp comprising:
- a lifting lug connectable to a lifting machine;
- a first hoisting arm pivotally connected to and extending away from the lifting lug on a first side of a central plane through the lifting lug, and a second hoisting arm pivotally connected to and extending away from the lifting lug on a second side of the central plane such that the central plane is between the first and second hoisting arms;
- a first scissor arm pivotally connected to the first hoisting arm, the first scissor arm extending away from the first hoisting arm to cross through the central plane to the second side of the central plane, and a second scissor arm pivotally connected to the second hoisting arm, the second scissor arm extending away from the second hoisting arm to cross through the central plane to the first side of the central plane;
- a cross-brace pivotally connected to the first scissor arm on the second side of the central plane and pivotally connected to the second scissor arm on the first side of the central plane;
- a first gripper connected to the first scissor arm, and a second gripper connected to the second scissor arm;
- at least two locking clutches and at least two corresponding clutch receivers, the clutch receivers configured to receive the locking clutches and the locking clutches configured to be lockable in the clutch receivers for preventing pivoting of the first and second hoisting arms and the first and second scissor arms when the first and second grippers are in an opened configuration;
- and,
- at least one outrigger mounted on the cross-brace, the at least one outrigger oriented to engage a top of an object to be clamped between the first and second grippers.
5 more elements
A locking clutch comprising:
- a housing having an internal bore;
- a cam body comprising a plurality of cams, the cam body situated in the bore proximate a distal end of the bore;
- a mechanical helical compression spring seated in the bore in the housing between a proximal end of the bore and the cam body;
- and,
- an elongated clutch stem seated on the spring in the bore such that the spring biases the clutch stem distally in the bore,
- wherein
- the clutch stem extends from the spring through the cam body and out of the housing,
- the clutch stem is rotatable within the bore,
- the clutch stem comprises a locking disc situated at a distal end thereof whereby the locking disc rotates with rotation of the clutch stem, and
- the locking disc is configured to be insertable into a corresponding clutch receiver when the locking disc is rotated to an unlocking position and
- the locking disc is configured to engage with an inner surface of the clutch receiver when the locking disc is rotated to a locking position to prevent the locking disc from exiting the clutch receiver when the locking disc is rotated to the locking position, and
- the clutch stem comprises a plurality of cam stops that engage the cam body to automatically rotate the clutch stem when the clutch stem is biased distally by the spring and when the clutch stem is biased proximally against the spring by an external force on the clutch stem,
- wherein the plurality of cam stops engages the plurality of cams during rotation of the clutch stem when the clutch stem is biased distally to stop rotation of the clutch stem at a first rotational position and the plurality of cam stops engages the plurality of cams during rotation of the clutch stem when the clutch stem is biased proximally to stop rotation of the clutch stem at a second rotational position different from the first rotational position thereby automatically switching the locking clutch between the locking and unlocking positions.
10 more elements
Dependencies are inferred from the claim text.