Mast lift and mast lift system
AssigneeJLG Industries, Inc.
InventorsGeoffrey George Campbell, Hugh Lithgow Stark, Alexander (Sandy) McKechran Hardie McNeil, Frank Fornasari
Life of this patent
Estimating the term…
Abstract
A lift system is coupled between a work platform and a mast on a mast lift. The lift system includes an overload clutch that slips upon an overload on the lift system, an overrun brake that prevents the lift system from running beyond a fully lowered position and that prevents the lift system from running if the platform is hung up, and an emergency brake. The lift system is safe and lightweight and is effective for controlling a position of the work platform on the mast.
Claims12
A mast lift comprising:
- a mast supported on a mast base;
- a work platform movably secured to the mast;
- and
- a lift system coupled between the work platform and the mast, the lift system effecting raising and lowering of the work platform on the mast and including:
- an overload clutch that slips upon at least one of an overload on the lift system or at end of travel,
- an overrun brake that prevents the lift system from running beyond a fully lowered position,
- an emergency brake biased toward an engaged position,
- at least one lifting rope windable on a hoist drum from one end and secured to the mast at an opposite end, and
- an idler roller coupled with the emergency brake and disposed between the opposite end of the mast and the hoist drum, the idler roller being cooperatively engageable with the at least one lifting rope such that the tension in the lifting rope displaces the idler roller to maintain the emergency brake in a disengaged position.
A lift system coupleable between a work platform and a mast, the lift system effecting raising and lowering of the work platform on the mast, wherein the lift system comprises:
- an overload clutch that slips upon at least one of an overload on the lift system or upon reaching end of travel;
- an overrun brake that prevents the lift system from running beyond a fully lowered position;
- an emergency brake biased toward an engaged position;
- at least one lifting rope windable on the hoist drum from one end and securable to the mast at an opposite end;
- and
- an idler roller coupled with the emergency brake, the idler roller being cooperatively engageable with the at least one lifting rope such that the tension in the lifting rope displaces the idler roller to maintain the emergency brake in a disengaged position.
Dependencies are inferred from the claim text.