Locking and latching system for a telescoping boom
AssigneesLink-Belt Construction Equipment Co., L.P., LLLP, Sumitomo Construction Machinery Co., Ltd.
InventorDaniel L. Harrington
Life of this patent
Estimating the term…
Abstract
A locking and latching system for use with a telescoping boom assembly in a crane or other lifting device is provided. The system may include complementary devices for latching and unlocking a selected boom section for telescoping movement relative to a next-adjacent boom section using an extension cylinder. Preferably, the devices are activated in a predetermined sequence using a single motive device. The motive device may include a single cylinder for performing both the locking and latching function. The locking and latching cylinder may be axially aligned with the extension cylinder to create a relatively compact locking and latching system that easily fits within the confines of the innermost boom section in a conventional boom assembly.
Claims24
In a crane or lifting device having a telescoping boom assembly including at least two boom sections and an extension device for telescopically moving a selected boom section relative to at least one next-adjacent boom section, a system for selectively latching and unlocking the selected boom section for relative telescoping movement, comprising:
- a latching device for latching the selected boom section to the extension device in a latched position;
- a locking device for locking the selected boom section in place relative to the next-adjacent boom section;
- and
- a motive device including at least one locking and latching cylinder for moving said latching device into the latched position and moving said locking device to an unlocked position to permit the extension device to telescopingly move the selected boom section, and then moving the locking device to a locked position and moving the latching structure to an unlatched position when the telescoping movement is completed,
- wherein said latching device includes at least two pivoting latching plates, each having a portion capable of projecting into a corresponding aperture in the selected boom section in the latched position and a camming surface;
- wherein the locking and latching cylinder is supported by and axially aligned with the extension device and is coupled to an engagement structure forming part of the motive device for moving the latching device between the latched and unlatched positions, said engagement structure including a projection for engaging each camming surface to move the latching plates into the latched position during extension of the latching cylinder and to an unlatched position during retraction of the latching cylinder;
- whereby efficient and effective locking and latching action is reliably achieved.
A telescoping boom assembly including at least two boom sections and an extension cylinder having a first longitudinal axis for telescopically moving a selected boom section relative to at least one next-adjacent boom section, said boom assembly comprising:
- a latching device associated with the extension cylinder, said latching device including at least two pivoting latching plates for latching the selected boom section to the extension cylinder in a latched position, each said latching plate having a portion for projecting at least partially into a corresponding aperture in the selected boom section in the latched position and a camming surface;
- a locking device associated with the selected boom section, said locking device including a retractable locking pin for locking the selected boom section in place relative to the next-adjacent boom section;
- and
- a locking and latching cylinder having a second longitudinal axis axially aligned with the first longitudinal axis of the extension cylinder, said locking and latching cylinder being associated with an engagement structure including a projection for engaging each camming surface for moving said latching plates into the latched position and moving said locking pin to an unlocked position to permit the extension cylinder to telescopingly move the selected boom section and moving the latching structure to an unlatched position and moving the locking pin to a locked position when the telescoping movement of the. selected boom section is completed.
In a crane or lifting device having a telescoping boom assembly including at least two boom sections and an extension cylinder for telescopically moving a selected boom section relative to at least one next-adjacent boom section, a system for selectively latching and unlocking the selected boom section for relative telescoping movement, comprising:
- at least one pair of latching plates associated with the extension cylinder for engaging the selected boom section in a latched position;
- at least one retractable locking pin for locking the selected boom section in place relative to the next-adjacent boom section;
- and
- a motive device including a locking and latching cylinder attached to a movable support frame having an engagement structure for moving the latching plates to the latched position and a retraction structure for engaging and retracting the locking pin to permit the extension cylinder to telescopingly move the selected boom section;
- wherein the engagement structure includes an engagement head having opposed projections, each capable of engaging and moving one of said pair of latching plates between the latched and unlatched positions;
- and
- the pivoting retraction structure includes a bellcrank capable of pivoting to retract the locking pin once the latching plates are in a latched position.
A method of telescopingly latching, unlocking, and moving a selected boom section relative to a next-adjacent boom section in a telescoping boom assembly, comprising:
- actuating a latching device to latch the extension cylinder to the selected boom section using a motive device including a locking and latching cylinder for moving an engagement structure associated therewith into engagement with a camming surface on each of at least one pair of rotatably mounted latching structures forming part of the latching device such that a portion of each said structure engages the selected boom section;
- actuating a locking device to unlock the selected boom section for movement relative to the next-adjacent boom section using the locking and latching cylinder;
- and
- telescopingly moving the selected boom section.
In a crane or lifting device having a telescoping boom assembly including at least two boom sections, an extension cylinder for telescopically moving a selected boom section relative to at least one next-adjacent boom section, and a locking device for locking the selected boom section against telescoping movement in a locked position, a latching system for coupling the extension cylinder to the selected boom section for movement therewith when the locking device is in an unlocked position, comprising:
- at least one pair of pivotably mounted latching plates associated with the extension cylinder for engaging the selected boom section in a latched position;
- and
- a motive device including a latching cylinder attached to a movable support frame having an engagement structure for pivoting the latching plates to the latched position and back to an unlatched position as the latching cylinder is selectively actuated.
In a crane or lifting device having a telescoping boom assembly including at least two boom sections, an extension cylinder for telescopically moving a selected boom section relative to at least one next-adjacent boom section, and a latching device for latching the selected boom section to the extension cylinder for telescoping movement, a locking system for locking the selected boom section in place or unlocking the selected boom section for telescoping movement, comprising:
- a locking pin capable of movement between a locked position for preventing the selected boom section from telescopingly moving and an unlocked position for permitting telescoping movement;
- a pin puller coupled to the locking pin;
- a bellcrank assembly including a pivoting bellcrank supported by and moving with the extension cylinder, said bellcrank including at least one cam for engaging the pin puller in a first position and moving the pin puller to a second position to move the locking pin to the unlocked position;
- and
- a motive device including a locking cylinder for assisting in pivoting the bellcrank between the first position and the second position.
In a crane or lifting device having a telescoping boom assembly including at least two boom sections and an extension device for telescopically moving a selected boom section relative to at least one next-adjacent boom section, a system for selectively latching and unlocking the selected boom section for relative telescoping movement, comprising:
- a latching device for latching the selected boom section to the extension device in a latched position, said latching device including at least two rotatably mounted latching structures, each having a first engagement surface capable of frictionally engaging the selected boom section in the latched position and a second engagement surface;
- a locking device for locking the selected boom section in place relative to the next-adjacent boom section, including when the selected boom section is in an unlatched position;
- and
- a motive device including an engagement structure capable of frictionally engaging the second engagement surface and moving each latching structure to the latched position, said motive device also moving the locking device to an unlocked position to permit the extension device to telescopingly move the selected boom section, and then moving the locking device to a locked position and moving each latching structure to an unlatched position when the telescoping movement is completed,
- wherein the frictional force between the engagement structure and the second engagement surface of each latching structure once the locking device is moved from the locked position and the weight of the selected boom section is assumed by the latching structures securely holds the latching structures in the latched position.
Dependencies are inferred from the claim text.