Elevator system

Claim 2

A traction elevator system in which the time required to start a motor driven elevator car stopped at a floor with its door open and brake set is reduced, and the start away from the floor when the elevator car makes a run is smooth notwithstanding an unbalanced load, comprising: means closing the door of the elevator car preparatory to a run, means monitoring the position of the elevator car relative to the floor while the door is closing, means releasing the brake before the door reaches the closed position, means correcting for unbalanced load when the brake is released to hold the elevator car at floor level, and means starting the elevator car away from the floor when the door reaches the closed position.

Claim 3

The elevator system of claim 1 wherein the means releasing the brake does so in at least two steps, with the first step being a partial release of the brake, and with a subsequent step initiating full release of the brake.

Claim 4

The elevator system of claim 1 wherein the means monitoring the position of the elevator car includes leveling means, and the means correcting for unbalanced load includes an elevator drive motor which builds up the armature current necessary to hold the elevator car at floor level in response to said leveling means.

Claim 5

The elevator system of claim 1 including means responsive to door position providing a first door signal when the door is closing and it reaches a predetermined position, with the predetermined position being selected such that the time from this position to the closed position is adequate for full release of the brake, and the position prevents passenger transfer, and wherein the means releasing the brake is responsive to the first door signal.

Claim 6

The elevator system of claim 1 including means responsive to door position providing a second door signal when the door reaches the closed position, with the means starting the elevator car away from the floor being responsive to the second door signal.

Claim 7

The elevator system of claim 1 in which the means releasing the brake before the door reaches the closed position initiates the release with a transition which results in substantially full brake release by the time the door reaches the closed position.

Claim 8

An elevator system, comprising: an elevator car having a door, motive means for moving the car to provide service for selected landings of a structure, a brake for restraining movement of the elevator car when it is operated from a released to a set condition, control means for operating the motive means to start the elevator car away from a landing, to stop the elevator car at a selected landing, and to maintain the elevator car within a predetermined landing zone at a landing at which the elevator car is stopped, means for opening the door of the elevator car as the elevator car stops at a selected landing to permit passenger transfer, means for setting the brake to restrain movement of the elevator car after the elevator car stops at a landing, means for closing the door of the elevator car preparatory to starting the elevator car away from the landing, and means for releasing the brake in at least two steps, with a step after the initial step initiating full release of the brake at a predetermined point when the door is closing, with the predetermined point being selected to permit the brake to be substantially completely released by the time the door is closed while preventing passenger transfer during this time, said control means starting the elevator car away from the landing after the door reaches the closed position.

Claim 9

An elevator system, comprising: an elevator car having a door, motive means for moving the car to provide service for selected landings of a structure, a brake for restraining movement of the elevator car when it is operated from a released to a set condition, control means for operating the motive means to start the elevator car away from a landing, to stop the elevator car at a selected landing, and to maintain the elevator car within a predetermined landing zone at a landing at which the elevator car is stopped, means for opening the door of the elevator car as the elevator car stops at a selected landing to permit passenger transfer, means for setting the brake to restrain movement of the elevator car after the elevator car stops at a landing, means for closing the door of the elevator car preparatory to starting the elevator car away from the landing, and means for releasing the brake in at least two steps, with a step after the initial step initiating full release of the brake at a predetermined point when the door is closing, with the predetermined point being selected to permit the brake to be substantially completely released by the time the door is closed while preventing passenger transfer during this time, said control means starting the elevator car away from the landing after the door reaches the closed position.

Claim 10

An elevator system, comprising: a structure having a plurality of landings, an elevator car having a door operable between open and closed positions, motive means for moving said elevator car relative to said structure to serve the landings, brake means operable between a set condition wherein the brake means restrains the elevator car against movement by said motive means and a released condition wherein the motive means is free of such restraint, leveling means operating in response to the position of said elevator car within a predetermined zone adjacent each landing at which the elevator car is stopping, and at which it is stopped, door position responsive means providing a first signal when said door reaches a predetermined position when it is closing, and a second signal when said door reaches the closed position, motive control means providing signals for starting the elevator car away from a landing, and for stopping the elevator car at a selected landing, door control means opening the door of said elevator car as the elevator car stops at a landing, and brake control means operating said brake means to its set condition after the elevator car stops at a landing, said door control means initiating closure of said door when the elevator car is about to leave a landing, said brake control means partially releasing the brake when the elevator car is about to leave the landing, and being responsive to said first signal for initiating substantially full release of said brake means before said door reaches its closed position, with said leveling means operating to maintain the elevator car at the landing as the brake means is released, said motive control means providing said signal for starting the elevator car away from the landing after said door reaches its closed position.

Claim 11

An elevator system, comprising: a structure having a plurality of landings, an elevator car having a door operable between open and closed positions, motive means for moving said elevator car relative to said structure to serve the landings, brake means operable between a set condition wherein the brake means restrains the elevator car against movement by said motive means and a released condition wherein the motive means is free of such restraint, leveling means operating in response to the position of said elevator car within a predetermined zone adjacent each landing at which the elevator car is stopping, and at which it is stopped, door position responsive means providing a first signal when said door reaches a predetermined position when it is closing, and a second signal when said door reaches the closed position, motive control means providing signals for starting the elevator car away from a landing, and for stopping the elevator car at a selected landing, door control means opening the door of said elevator car as the elevator car stops at a landing, and brake control means operating said brake means to its set condition after the elevator car stops at a landing, said door control means initiating closure of said door when the elevator car is about to leave a landing, said brake control means partially releasing the brake when the elevator car is about to leave the landing, and being responsive to said first signal for initiating substantially full release of said brake means before said door reaches its closed position, with said leveling means operating to maintain the elevator car at the landing as the brake means is released, said motive control means providing said signal for starting the elevator car away from the landing after said door reaches its closed position.