US 2015/0101891 A1 · LIFT SAFETY MECHANISM

Abstract

A safety mechanism for a lift system, the safety mechanism including a first motion retarder which operates frictionally between a load-carrying platform and a hoistway and a second motion retarder which operates by breaking a frangible element. The two motion retarders may act together so that when the frictionally engaging element is depleted, the frangible elements are then broken. In an embodiment, the frictional element is disengaged to engage the breaking of the frangible elements when the car is a predetermined distance above a floor of the hoistway, thereby ensuring that the load-carrying platform can be stopped prior to a collision with the floor or ceiling of the hoistway.

Claims26

Dependent claims

A safety mechanism for a lift, the lift comprising a passenger car arranged for movement relative to a hoistway, the safety mechanism comprising first and second motion retarders acting between the load-carrying platform and the hoistway for reducing a speed of the load-carrying platform relative to the hoistway wherein the first motion retarder includes a friction brake and the second motion retarder includes a frangible element, wherein

the first safety mechanism includes a pad which engages frictionally with the hoistway to retard a speed of the load-carrying platform, the frictional engagement of the pad with the hoistway causes depletion of the pad, and the second motion retarder is mounted relative to the first motion retarder so that depletion of the pad causes engagement of the second motion retarder.

Dependencies are inferred from the claim text.

Lift safety mechanism

Life of this patent

Lift safety mechanism

Life of this patent

Abstract

Claims26