This invention generally relates to elevator systems. More particularly, this invention relates to position detection within elevator systems.
Elevator systems typically include a car that moves vertically along a hoistway to carry passengers, cargo or both between various levels of a building. Typical arrangements allow an elevator car to service a plurality of floor levels within a building. The car doors preferably are controlled so that they open only when the car is within an acceptable distance from a final resting point at a landing according to local codes.
Various arrangements are known for controlling elevator door operation to ensure that the car is within the appropriate distance of a landing. One example arrangement includes a sequence of optical or inductive sensors and vanes that cooperate to provide information regarding the elevator car being within the zone where the car doors can be opened. A significant shortcoming of such arrangements is that the vane system is typically installed on the elevator guide rails at or near each landing. Installation of such a vane system requires precise adjustment relative to landing doors to ensure that the detected elevator car position is accurate. Accurate information is typically required because the same vane system is often used for leveling, position system corrections and initialization, advanced door opening control and elevator car slowdowns near a landing. Additionally, building settling over time or changes in elevator system components caused by rope stretching, for example, alters the accuracy of such a vane system. Periodic inspection and maintenance, therefore, is required.
There is a need for an improved arrangement for detecting the position of an elevator car within a hoistway and, in particular, for determining when a car is appropriately positioned relative to a landing for operating the car doors. It would be beneficial to have such a system that does not suffer from the drawbacks associated with rail-mounted vane and sensor systems.
This invention addresses those needs.
An exemplary disclosed device for determining a position of a door in an elevator system includes a reflector that is mountable on one of a hoistway door or an elevator car door. A sensor is mountable on the other of the elevator car door or the hoistway door. The sensor has an emitter portion that emits radiation in a direction toward the reflector. A receiver portion of the sensor receives reflected radiation from the reflector when the sensor is aligned with the reflector.
In one example, the sensor provides a signal indicative of the received, reflected radiation for providing an indication of a position of the corresponding door.
One example includes using radiation from within the range of electromagnetic radiation including light, infrared radiation and microwave radiation. One disclosed example includes optical sensors that utilize light as the emitted and reflected radiation.
The disclosed example avoids the difficulties associated with mounting position sensor components on guide rails. This provides a more consistently reliable system that is more economical to install.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
As best appreciated from
In the illustrated example, the device 40 includes a reflector 42 that is supported in a fixed position on the hoistway door 30 in this example. As can be appreciated from
The device 40 also includes a sensor 44 that interacts with a reflector 42 when the car door 34 is appropriately positioned relative to the corresponding hoistway door 30. For example, when the elevator car 22 approaches the landing 26, the sensor 44 interacts with the reflector 42 on the hoistway door 30 at the landing 26.
In the illustrated example, the sensor 44 is fixed to the car door 34 and includes a plurality of sensor elements 46, 48 and 50. Each sensor element includes an emitter portion that emits radiation toward the reflector 42. Each sensor element also includes a receiver portion that receives reflected radiation from the reflector 42.
In one example, the radiation is selected from the range of electromagnetic radiation that includes light, infrared radiation and microwave radiation. One particular example includes optical sensor elements and the emitted and reflected radiation comprises light.
In the example of
In one example, the sensor 50 provides position information within a range corresponding to a leveling zone within which powered operation of the car door 34 may be initiated. In this example the leveling zone extends from a final car leveling position in two directions a distance corresponding to one-half the length of the reflector 42. The sensor element 50 can emit radiation toward the reflector 42 and receive radiation reflected off the reflector 42 at any position within a range that corresponds to the entire length L of the reflector 42. In one example, the sensor element 50 provides position feedback information within a leveling zone that is 300 millimeters in height.
The sets of sensor elements 46A, 46B, 48A and 48B cooperate to provide a range of position information corresponding to an inner landing zone. In one example, the sensor elements 48A and 48B combined with the sensors 46A and 46B provide position information that is accurate to within 75 millimeters. Spacing the sensor elements 48A and 46A by 75 mm and spacing the sensor elements 48B and 46B by the same amount provides the +/−75 mm range. An inner landing zone range is useful to control car movement outside of this range based on whether the doors are closed. In one example, the car will not be moved beyond the inner landing zone if the doors are open.
One feature of the example device 40 is that the reflector 42 has a length L that is long enough to allow all of the sensor elements 46-50 to simultaneously receive radiation reflected from the reflector 42.
Providing various ranges for position information allows a controller 52 to communicate with an elevator system controller, for example, regarding elevator car position along the hoistway 24 or relative to a particular hoistway door 30 to allow for the desired level of door control and car position control. In one example, the controller 52 is capable of utilizing a variety of position information based on signals from the different example sensor elements to achieve the desired level of control of door movement or car position, for example.
Referring to
The example embodiment of
Another example includes positioning at least a portion of the sensor 44 on a sill member 80 near a bottom of the elevator car door 34. In the same example, at least a portion of the reflector 42 is positioned on a sill member 82 near a bottom of the hoistway door 30.
Accordingly, supporting the reflector 42 and the sensor 44 on the doors does not necessarily require the entire sensor or reflector to be mounted on a door panel of the doors. Other frame members adjacent the door panels are considered part of the door for some example embodiments. One advantage to using an arrangement as shown in the example of
A significant advantage to the disclosed arrangement is that the fixed position of the sensor 44 and the fixed position of the reflector 42 relative to the corresponding doors eliminates dependencies on building settlement, rail positions or rope stretching when determining a position of the car door 34 relative to the hoistway door 30. The disclosed example, therefore, eliminates the maintenance and adjustment procedures that were involved with conventional arrangements, which has been undesirable from a cost standpoint, for example.
Another advantage to the disclosed example is that it allows for relatively easy installation from a landing adjacent the hoistway. Any maintenance or adjustment can also be made from a landing and does not require an individual to enter the hoistway, which has been required with conventional arrangements that relied upon vanes secured to the guide rails.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US05/19205 | 6/1/2005 | WO | 00 | 10/22/2007 |