Otis Elevator Company

George A David

Richard E Peruggi

David W Barrett

Ernest P Gagnon

John F Cassidy, Jr

David H Sorenson

Andrew F Peruggi

An elevator system has a plurality of elevator cars traveling upwardly in one hoistway and downwardly in an adjacent hoistway, the cars being propelled in a series of overlapping segments, each segment including a pair of couplers roped to counterweights and driven by elevator traction machines. A variant uses a closed loop rope with a pair of couplers to transfer elevator cars from a counterweighted coupler of one segment to a counterweighted coupler of an adjacent segment. An upper passenger landing moves cars on overhead trolleys and a lower passenger landing moves cars on dollies to take them from a hoistway through unloading and loading stations and back to another hoistway. The elevator car roller guides are releasable to permit lateral movement of cars to and from landings. A latched spring buffer and/or a LEM decelerate and accelerate unbalanced counterweights.

Elevator system with overlapped roped-coupler segments

Each of a pair of vertically and horizontally adjacent hoistways has an elevator car coupler roped through a traction machine to a counterweight so as to be able to raise and lower the elevator car within the related hoistway. A transition section joins the upper end of the lower hoistway with the lower end of the upper hoistway. A pair of guide rails are disposed on each side of the elevator system, including the upper hoistway, the transition section and the lower hoistway. Elevator cars are guided from the top of the upper hoistway to the bottom of the lower hoistway and/or vice versa by one of the pairs of rails. Power in the transition section is provided by a pair of LEMs, one on each side of the hoistways.

Elevator cars switch hoistways while traveling vertically

Elevator load is computed from sensors. These sensors provide load signals. The load, defined by a stored load equation, is the product of those signals and a gain signal summed with an offset signal. Load computation using those signals is augmented by a recalibration routine. The routine to adjust the offset is initiated when the car transits floors in an empty car condition. Current equation offset and the latest empty car signal levels are compared. If the difference is less than a value the last levels become the offset; if not the equation offset is incremented changed. Load computation is further augmented by sensing car rollback, to augment the gain signal. Rollback may occur after the brake holding the car in position is lifted but before a speed dictation signal is given to the motor, causing the car to move if motor torque is not matched to the load as computed from the load equation. Depending on the magnitude of the rollback, the gain is increased or decreased in increments through successive elevator stops at floors provided there is sufficient passenger (cab) load. Rollback not caused by incorrect motor pretorquing when the brake is lifted is discarded by comparing the actual change in position of the car with the change in motor shaft or sheave position.

Growing community of inventors

West Hartford, CT, United States of America

George A David