Drive mechanism for elevator door

In an elevator car, the car including a housing, a sliding door, and a drive mechanism for moving the door, the improvement wherein the drive mechanism comprises a rotatable shaft, means for rotating the shaft, a block defining recesses which contain at least one rollable bearing, the bearing being fixedly mounted in the block and the block being mounted on the shaft such that rotation of the shaft causes the block to slide along the shaft, the block having a bracket attached thereto, wherein the bearing contacts the shaft with a pressure which is substantially uniform for any position of the block along the shaft, and the door being attached to the bracket, wherein rotation of the shaft causes the door to open and close.

In an elevator car, the car including a housing, a sliding door, and a drive mechanism for moving the door, the improvement wherein:

• the drive mechanism is contained within a module which is removably attached to the housing,
• the module includes a rotatable shaft, means for rotating the shaft, a block defining recesses which contain at least one rollable bearing, the bearing being fixedly mounted in the block, the block being mounted on the shaft such that rotation of the shaft causes the block to slide along the shaft, the block having a bracket attached thereto, the bracket extending from the module, wherein the bearing contacts the shaft with a pressure which is substantially uniform for any position of the block along the shaft,
• and wherein the door is attached to the bracket.

A method of retrofitting an elevator car with a drive mechanism, the elevator car having a housing and a slidable door, the method comprising the steps of:

• a) providing a module which includes a rotatable shaft, means for rotating the shaft, a block defining recesses which contain at least one rollable bearing, the bearing being fixedly mounted in the block and the block being mounted on the shaft such that rotation of the shaft causes the block to slide along the shaft, the block having a bracket attached thereto and extending from the module, wherein the bearing contacts the shaft with a pressure which is substantially uniform for any position of the block along the shaft,
• b) mounting the module to the housing, and
• c) connecting the bracket to the door.