HOLDER FOR AN ELEVATOR DOOR PROTECTION

ELEMENT

1. Field of the Invention

This invention generally relates to elevator systems. More particularly, this invention relates to elevator door protection systems.

2. Description of the Related Art

Elevator systems typically include an elevator car that travels between different levels within a building. The car has car doors that open and close to allow access to the car. It is known to provide various types of door protection arrangements for detecting the presence of an object or individual in the pathway of the doors. Such door protection arrangements allow for controlling door positions to avoid undesirable contact between the doors and an individual standing in the pathway of the doors, for example. The usual arrangement includes an array of emitting elements on one car door, and an array of receiver detecting elements on the oppositely facing door.

Many door protection systems provide a two-dimensional field of view that is generally parallel to the plane of the doors. Other systems include a three- dimensional field of view that extends beyond the plane of the doors. In order to provide accurate detection for either a two-dimensional or three-dimensional arrangement, it is important to carefully align the emitter elements so that they point in a specific direction. For example, in a three-dimensional arrangement, the emitters must be aligned so that they point out toward a lobby or hallway at a given angle. That provides for energy reflecting off an object to be detected by the system to prevent closing a door, for example. At the same time, the energy emitted by the emitters must not be allowed to travel straight across the opening to another receiver or that may be interpreted by the system as an object in the field of vision. It is known to use baffles across emitters for blocking the energy in such a direction.

One example approach is to carefully align a lens in front of each emitter and receiver to direct the energy in the appropriate direction. For a three-dimensional arrangement, the lens typically is displaced laterally from the emitter so that only

energy proceeding at the desired angle is collected by the lens and collimated. One drawback to such arrangements is that they limit the useful solid angle of the energy (i.e., vignetting) used for detecting and they limit the potential intensity of the collimated energy. Additionally, the radiation characteristic of the energy becomes altered by the lens and some stray energy may be directed across to the receivers, which causes a false detect.

An approach to limit this stray radiation has been to use a long baffle extending across the entire detector assembly on a door. One difficulty with such baffles is that they are subject to warping, manufacturing tolerances and improper alignment. Any one of these conditions can render the baffle essentially ineffective for its intended purpose. Another drawback with such baffles is that using them to direct the energy for establishing a three-dimensional field of view at least partially blocks energy useful for a two-dimensional field of view and, therefore, reduces the performance of the two-dimensional curtain. In other words, known plastic baffles tend to cause a trade off between the performance of the two dimensional and three dimensional fields of view.

It is necessary to be able to reliably position the door protection elements of an elevator door protection system to achieve the necessary alignments of the emitters and receivers. A further complication is presented by the door protection elements, themselves. Tolerances on the manufacturing of elements such as light emitting diodes (LEDs) and photodetectors are such that there can be wide variation in the physical configuration of such devices. These variations present problems when trying to design the overall door protection arrangement because positioning the individual elements becomes problematic. For example, a LED has an optical axis along which the light should travel. The physical structure of the LED tends to be a tapered cylinder that is not consistently parallel with the optical axis. Accordingly, positioning the LED to direct the emitted energy as desired cannot simply be done against a flat surface. Accurate alignment can be time-consuming and labor- intensive.

There is a need for an improved arrangement in an elevator door protection system. This invention addresses that need by providing a unique holder device for

door protection elements that facilitates proper alignment and does not rely upon lenses or other devices for directing energy to establish a desired field of view.

SUMMARY OF THE INVENTION

An example device for supporting a door protection element useful in an elevator door protection assembly includes a housing having a recess with an at least partially deformable surface for engaging an elevator door protection element that is received at least partially within the recess.

In one example, the deformable surface in the recess comprises a generally pliable, plastic material.

In one example, the deformable surface has a plurality of extensions that extend toward a center of the recess. As the door protection element is placed within the recess, the extensions deflect as necessary to accommodate physical variations in the exterior of the door protection element.

One example supports a plurality of detectors or emitters at different angles to establish a two-dimensional field of view with some of the elements and a three- dimensional field of view with other elements.

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagrammatic illustration of selected portions of an elevator system.

Figure IA schematically shows a top view of door protection assemblies installed on doors, showing the radiation characteristic of the example beams of 2D and 3D fields of vision beams.

Figure 2 is a cross-sectional illustration of one example holder device.

Figure 3 shows the embodiment of Figure 2 including a detector element.

Figure 4 is a diagrammatic, perspective illustration of a portion of an example holder device.

Figure 5 is a partially exploded view showing the portion illustrated in Figure 4, detector elements and another portion of the example holder device.

Figure 6 diagrammatically illustrates selected portions of an elevator door detector assembly.

Figure 7 is a cross-sectional illustration as would be viewed from the perspective of the lines 7-7 in Figure 6 within a completed, example detector assembly.

Figure 8 is a cross-sectional illustration as would be viewed from the perspective of the lines 8-8 in Figure 6 within a completed, example detector assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 diagrammatically shows selected portions of an elevator car assembly 20. A cab portion 22 includes car doors 24 that move in a known manner between open and closed positions to allow access to the interior of the cab portion 22. Door protection assemblies 26 detect the presence of an object in the pathway of at least one of the doors 24 to provide control over the position of the doors to avoid contact with such an object, for example. A field of vision 28 of the door protection assemblies 26 is schematically shown. In one example, the field of vision 28 is two- dimensional. In another example, the field of vision 28 is three-dimensional. In another example as shown in Figure IA, the field of vision 28 is two-dimensional for some detector elements and three-dimensional for others.

Figure 2 is a schematic, cross-sectional illustration of an example holder device 30 that is useful for holding a door protection element such as an emitter or photodetector that is used as part of the door protection assemblies 26. In this example, a housing 32 includes a recess 34 within which at least a portion of a door protection element can be received. The recess 34 has a deformable interior surface 36. In this example, the deformable interior surface 36 includes at least one first portion 38 that extends generally, radially inward toward a center of the recess 34 further than a second portion 40. The first portion 38 in this example establishes a first, nominal interior dimension of the recess 34. The second portion 40 establishes a second, larger interior dimension.

The first portions 38 in this example are flexible or pliable so that they can deflect from the position shown in Figure 2 to accommodate the exterior surface of a door protection element received at least partially within the recess 34. Such a condition is shown schematically in Figure 3. Some of the first portions 38 are deflected while others are not based upon an irregular contour of an exterior of an example element 42. In Figure 3, a first portion 36A of the interior surface 36 is deformed compared to the configuration shown in Figure 2. A second portion 36B is deformed compared to the configuration shown in Figure 2. A third portion 36C of the interior surface 36 is not deformed. Figure 3 schematically shows how the example holder device 30 has a selectively deformable interior surface 36 to accommodate a wide variety of physical configurations of a door protection element 42 received at least partially within the recess 34.

Although the illustrated example includes a deformable surface 36 along most of the interior of the recess, it is possible to have a deformable surface along only selected portions of the interior. For example, extensions 38 may be provided near the opposite ends of the recess but may not be required along a central portion for some applications. Those skilled in the art who have the benefit of this description will be able to select an appropriate configuration of a deformable surface to meet the needs of their particular situation.

In one example, the housing 32 is made of a generally pliable plastic material. One example includes a material sold under the trademark ZYTEL that is 13% glass filled for sufficient structural strength.

One such example is shown in Figures 4 and 5. A first housing portion 32A is injection molded and provides a plurality of recesses 34 to receive a corresponding plurality of door protection elements, such as emitters. One half of each recess 34 is established by the first housing portion 32A. A second housing portion 32B is received against the first housing portion 32A to establish the desired configuration of the recesses 34. Figure 5 also shows door protection elements 42 received by the recesses of the first housing portion 32A prior to the two housing portions being secured together. The deformable surfaces 36 on each housing portion accommodate variations in the physical structures of the door protection elements 42 so that a desired alignment of those elements within the housing 32 is readily achieved.

In the illustrated example, the door protection elements 42 comprise light emitting diodes (LEDs). The housing 32 includes baffle sections 44 near one end of the recesses 34. In this example, some of the deformable surfaces 36 operate as baffles, also. The baffle sections 44 and 36 direct energy emitted by the LEDs 42 to establish the desired field of vision of the door protection assembly and reduce stray light (i.e., infrared). In the illustrated example, the center LED 42 (according to the drawing) is useful for establishing a three-dimensional field of view while the other two LEDs 42 are useful for a two-dimensional field of view.

In one example, the door protection elements 42 include a base surface 43 that is aligned with a known orientation relative to an optical axis of the devices, the recesses 34 include a cooperating notch 45 that, together with the deformable surfaces 36, automatically positions the door protection elements in a manner that provides the desired forward position of protection elements 42 and alignment of the optical axes. The base surface 43 of the LED is used to set the "height" of the LED (i.e., most forward position). This places the baffles at the optimum location relative to the LED' s. This makes up for irregularities in the thickness of the base. In this example, each recess has a directional axis that is designed to point in the desired direction of an operational axis of the received door protection element. For emitter elements, the directional axis can be considered a protection axis.

Figure 6 schematically shows several holder devices 30 containing door protection elements 42 mounted upon a printed circuit board 50 in a known manner. The printed circuit board 50 is supported within a bracket that is then secured in a known manner for movement with the elevator car doors 24. In one example, the printed circuit board 50 is vertically positioned near an edge of the door structure.

Figure 7 is a cross-sectional illustration showing one example bracket 52. One side 54 of the bracket 52 is aligned generally parallel with the plane of the doors 24, which is parallel to the direction of movement of the doors. Figure 7 shows one example alignment of a door protection element 42 used for a three-dimensional field of vision. In this example, the optical axis 56 of the door protection element 42 is aligned relative to the plane of the door at 37.68°. In one example, this angle provides the preferred solution to the trade off between the distance that can be reached into the hall or lobby area for a three-dimensional field of view on the one hand, and

unwanted reflections off an edge of the hall or landing doors (not illustrated), on the other hand. Such an arrangement reduces the requirement for tight tolerances on adjusting the amount of door lead between the hall doors and the car doors. For example, when there is a 6" spacing between the hall doors and the car doors 24, the illustrated angle provides for accommodating approximately 2.6" of door lead before the hall doors begin encroaching upon the three-dimensional field of vision. One example includes aligning the optical axis 56 at an angle between 32° and 43° relative to the plane of the doors 24.

Figure 8 is an illustration similar to that in Figure 7 but showing a door protection element 42 useful for a two-dimensional field of vision. In this example, the optical axis 58 is aligned generally parallel with the plane of the doors 24.

One advantage of the disclosed example is that the baffle portions 36 and 44 restrict unwanted energy emitted by LEDs (i.e., the emitting door protection elements 42) without the use of an off-axis lens and baffle (vignetting) for directing the emitted energy. By avoiding the use of vignetting, better performance can be achieved because more emitted energy is useful for the field of vision and an increased horizontal or look-out angle becomes possible. Additionally, there are fewer false positive detections and an increased ability to detect smaller objects when a door protection assembly does not rely upon vignetting for directing the energy used for the three-dimensional field of vision.

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.