Patent Application
20090249697
This invention generally relates to automatically moving doors. More particularly, this invention relates to controlling movement of an automatically moveable door.
There are various automated door arrangements used in various contexts. In some instances, the automated door slides in a direction parallel to the door panel between open and closed positions. This type of arrangement is commonly used for providing access to an elevator car.
Whenever an automated door moves toward a position where an edge of the door approaches another structural member in a closed position, it is possible for an object to get caught between the door and the other structural member. Various arrangements have been proposed to avoid such a situation.
In the case of elevator doors, it has been known to use a safety shoe that mechanically detects an obstacle near a closed position of a door by including a bar at the leading edge of the door. If an obstacle contacts the bar, that provides an indication that the door should not be fully closed automatically to allow for the obstacle to be removed so that it will not be caught between the door and another surface. Another example approach has been to use light-based detectors that generate a sensing light beam across an opening. If an obstacle is within the opening while a door is automatically closing and interrupts the light beam, the door will not be fully closed automatically to avoid the object being caught by the door.
There are limitations to such devices. For example, the safety shoe bar typically is not sensitive enough to detect relatively small objects such as a strap on a handbag or an individual finger. Additionally, such small objects may get caught if they are not located at the same position as the bar of the safety shoe. The light-based detectors are also limited in that an object may not be within the field of vision (e.g., the light beam) even though the object is in a position where it can be caught by the door. Another drawback to known light-based arrangements is that they are typically exposed to dust or debris that can interfere with proper operation. Another potential issue is presented if other light sources interfere with the detectors.
Another shortcoming of such devices is that they only address the possibility of an object being caught at the leading edge of the door as it moves toward a closed position.
It would be desirable to provide an improved arrangement for detecting when an object may be in a position to be caught by a door that is automatically moving. It would be beneficial to provide an arrangement that can detect the potential for an object being caught when a door is automatically moving toward a closed position, toward an open position or both. This invention addresses those needs.
An exemplary door assembly includes a door panel that is automatically moveable between open and closed positions. At least one switch is activated responsive to an increase in a gap at an interface between the door panel and another surface that the door panel moves past while the door panel moves between the open and closed positions. A controller controls automatic movement of the door responsive to activation of the switch.
In one example, the switch is supported on the door and is activated responsive to movement of the door panel away from the surface the door moves past. The switch is activated when the door panel moves in a direction generally perpendicular to a direction of movement of the door panel as it moves between the open and closed positions.
One example includes two switches. One switch is activated when a first amount of pressure is applied to the door panel. This switch provides an indication that an object may be in a position where it could become caught at the interface between the door panel and the other surface. Another switch is activated responsive to more pressure on the door panel. This other switch provides an indication that an object has become caught at the interface.
Another example includes a switch supported on a return panel associated with a door frame. In one example, the return panel has at least one portion that flexes or moves responsive to pressure applied by an object approaching or caught in the interface between the door and the return panel.
An exemplary method of automatically controlling movement of the door panel includes determining whether a gap increases at an interface between the door panel and another surface that the door panel moves past as the door panel moves between open and closed positions. If the gap increases, an indication that an object should be moved away from the interface can be provided, automatic movement of the door panel can be at least temporarily prevented, the door panel may be automatically moved in a first direction and then in a second, opposite direction, or a combination of more than one of these may be done responsive to determining that the gap has increased.
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.
Disclosed examples include a sensor on at least one of a door panel or a door frame that allow for detecting when a gap between the door panel and the door frame is caused by an object being in a position relative to the door panel or door frame where the object may be caught during automatic movement of the door panel relative to the frame. With the example approach, a wider variety of objects may be reliably detected and a larger number of scenarios within which an object may be caught during automatic door movement can be addressed.
Whenever pressure is applied on the first surface 34, there will be some flexing or movement of the first surface 34 relative to the second surface 36. In one example, this occurs because of the material used for the first surface 34. A sheet of metal, for example, has some resiliency or flexibility such that it can be deflected toward the second surface 36 when pressure is applied onto the first surface 34 (e.g., from the bottom according to the drawing). The first switch 30 is positioned to detect such pressure on the first surface 34 and the switch arm 32 moves responsive to such pressure-induced movement of the first panel 34.
The switch 30 provides an output indicative of the detected movement of the first surface 34 responsive to an object applying pressure against the first surface 34. The output signal from the switch 30 is provided to a controller 40 that responsively controls automatic movement of the door assembly by controlling a door mover 42. Example control strategies are described below.
In one example, the first switch 30 is configured to provide an indication of an amount of movement of the door panel 22, such as movement of the first surface 34 relative to the return panel 26, that corresponds to an increase in the gap at the interface 28 between the door panel 22 and the return panel 26. An increase in the gap may correspond to deflection of the first surface 34 or movement of the entire door panel 22 in a direction that corresponds to an increase in the gap at the interface 28. The increase will occur in some cases at only a localized portion of the interface 28. Depending on the object, the gap along the entire interface 28 may change.
Microswitches are used in one example because they have the ability to provide a significant electrical output responsive to a very minor change in position of a switch component. In other words, microswitches are used in one example because of the ability to detect very small changes in a gap between the door panel 22 and the return panel 26 at the interface 28.
The example door panels 22 also include a second switch 50. An activating switch arm 52 in this example, moves responsive to a deflection or movement of the first surface 34 corresponding to increased pressure on the first surface 34 compared to the amount of pressure applied to cause the movement for activating the switch 30. The switch 50 in this example provides a second level of object detection. Further movement of the first surface 34 in many circumstances will correspond to an object becoming caught at the interface 28 resulting in the increased pressure on and corresponding increased movement of the surface 34. The second switch 50 provides an output to the controller 40 indicative of this condition.
A first amount of movement or deflection of the portion 60 activates the switch 30 to provide an indication that an object is approaching the interface 28. The second switch 50 is configured to provide an indication when a further deflection occurs corresponding to an object becoming caught at the interface 28. As can be appreciated from the illustration, when the portion 60 moves from the position shown in solid lines to the position shown in phantom lines, the corresponding gap between the return panel 26 and the door panel 22 increases. The first switch 30 and the second switch 50 are supported and configured to provide respective indications of an initial amount of an increase in the gap and a further increase. The two switches provide corresponding outputs indicating conditions that are interpreted by the controller 40 as corresponding to an object being at the interface 28 or caught I the interface 28.
In the event that the door is about to move, a decision is made at 76 whether the first switch 30 has been activated. If so, the example of
In the example of
In some circumstances, enough pressure is applied on the door panel 22 to increase the gap between the door panel 22 and the return panel 26, for example, to activate the second switch 50. As mentioned above, the second switch 50 preferably is configured to be activated responsive to an amount of movement of the door panel 22 corresponding to an object being caught in the interface 28. The example of
If the second switch 50 has been activated at 126, the door stops moving at 128. A timer begins at 130 to allow for a predetermined amount of time to pass before the door will continue moving in an opening direction. In this example, the determination regarding that amount of time is made at 132. If that amount of time has not passed, a command is issued at 136 to move the door in a closing direction for a short period of time to assist in removing any object that was caught at the interface 28. In this example, the determination at 132 includes determining whether the amount of time for moving the door in the closed direction has passed, also. Once that has passed, the door continues opening at 134.
In one example, continued movement of the door in the opening direction is carried out at a lower speed and with less torque than would have been done if no indication was provided from either the first switch 30 or the second switch 50. In other words, one aspect of the example technique for controlling automatic door movement includes reducing the speed and torque used for opening a door responsive to activation of at least one of the switches to provide additional protection to the object involved. Using lower speed and lower torque also facilitates allowing for an object to be removed from the interface 28 in the event that it became caught but could not be freed during the reversed movement of the door in the closing direction for the short period of time.
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 |
|---|---|---|---|---|
| PCT/US2006/035137 | 9/12/2006 | WO | 00 | 2/27/2009 |
