VANE LOCAL CONTROL SYSTEM FOR ELEVATORS

• US 3,815,711 A
• Filed: 02/08/1973
• Issued: 06/11/1974
• Est. Priority Date: 02/08/1973
• Status: Expired due to Term

• Current Assignee: William R. Hoelscher
• Original Assignee: William R. Hoelscher
• Inventors: Hoelscher, William R.
• Primary Examiner(s): Dobeck, B.
• Assistant Examiner(s): Duncanson, Jr., W. E.
• Application Number:
  US05/330,494
• Time in Patent Office: 488 Days
• Field of Search: 187/29 318/480,640
• US Class Current: 187/291
• CPC Class Codes: B66B 1/40 and for correct levelling at landings

Abstract

A system for controlling the approach or departure of an elevator cab to a floor level. The system utilizes a sensor array of solid state photocells and light emitting diodes to detect the presence of a vane. The vane is positioned to indicate the landing floor level. The sensors are arranged to function in conjunction with a logic system whereby the distance to the floor will be indicated with either direction of approach. The logic system enables multiple use of one or more of the sensors. The signals from the logic system are utilized in conjunction with an electronic motion control system for elevators to command the appropriate velocity at each incremental distance. Upon reaching the immediate vicinity of the floor level, a floor hold system is activated which accomplishes the micro-leveling of the elevator despite changes in load or other disturbances which would tend to move the elevator away from the precise floor level.

Claims

1. In a system for controlling the approach of an elevator cab to a selected floor level, said system including means for commanding a pre-determined cab speed for discreet intervals of distance away from a floor level of intended landing, motor drive control means for causing a drive motor to operate at said commanded speed, and car velocity sensor means for determining actual car velocity, wherein the improvement comprises:

a plurality of position sensing means carried on said elevator cab, said position sensing means for providing a plurality of discreet signals in response to the elevator reaching a predetermined distance above or below said floor level, said position sensing means comprising spaced radiation emitting and radiation sensing elements, vane means mounted in said elevator shaft for interrupting said radiation from reaching successive radiation sensors during the approach of said cab to said floor level, logic means for combining the outputs of said sensors close to a position corresponding to the floor level to produce a pOsition output signal only when both sensors are covered by said vane.

2. The system of claim 1 wherein:

said position sensing means comprising light emitting diodes and light sensitive solid state devices.

3. The system of claim 1 wherein:

at least one pair of said position sensing means being utilized by said logic means both to indicate a first distance from floor level when the radiation to only one of said pair of sensors is cut off by said vane means and a second distance from floor level when the radiation to both of said pair of sensors is cut off by said vane means.

4. The system of claim 1 further including:

floor hold sensor means for providing a signal indicative of the direction said cab is displaced from said floor level.

5. The system of claim 5 wherein:

said floor hold sensor means comprises a pair of lights having a centerline spacing slightly greater than the vertical height of said vane, said lights being positioned so that both lights will be partially exposed and transmit light to sensor elements when said cab is positioned at floor level.

6. The system of claim 1 including:

check sensor means for detecting failure and interruption of the radiation emitting elements.