Patent Application
20180105399
The invention relates to a people conveyor with a moving handrail and a sensor which is configured for preventing parts of the human body from being jammed or squeezed between the moving handrail and a stationary handrail exit/entry portion. The invention also relates to a method of operating such a people conveyor.
A people conveyor such as an escalator or a moving walkway is usually provided with balustrades extending on both sides along a longitudinal (conveying) direction of the people conveyor. A moving handrail in the form of a belt usually circulates in a closed loop around each balustrade.
There is some risk that parts of a human body, in particular fingers, are trapped and jammed between the moving handrail and a stationary handrail exit/entry portion provided at an end of the balustrade. In order to reduce said risk, the handrail exit/entry portion is provided with a mechanical safety switch which stops the movement of the handrail (and usually the movement of the whole people conveyor) when activated.
There, however, is still some risk that a human body part, in particular a child's finger, is jammed and injured before the movement of the handrail is completely stopped. In addition, with this solution there is some risk of unnecessary shut-off times of the people conveyor after the safety switch has been activated.
It therefore would be beneficial to provide an improved people conveyor which reliably prevents parts of a human body from being trapped and jammed at the handrail exit/entry portion. Further, it would be helpful to minimize the shut-off times of the people conveyor.
According to an exemplary embodiment of the invention, a people conveyor comprises two landing areas located at two opposing ends of the conveyor; a movable conveying element extending between the two landing areas and configured for conveying passengers between the two landing areas; a handrail, which extends parallel to the conveying element between the two landing areas and which is configured for moving with the conveying element; and handrail exit/entry portions. The handrail in particular may extend along a balustrade extending parallel to the conveying element between the two landing areas. At least one handrail exit/entry portion is provided at each of the landing areas, in particular at the bottom of the balustrade, and configured for emitting/receiving a return portion of the handrail. Depending on the conveyance direction of the people conveyor, each handrail exit/entry portion may act as handrail exit portion or as handrail entry portion, respectively.
A safety switch assembly is provided at a handrail exit/entry portion and configured for stopping the handrail when activated. When the people conveyor is configured for being operated in only one conveyance direction, it might be sufficient to provide a safety switch assembly on only one end of the people conveyor, i.e. the end comprising the handrail entry portion receiving a return portion of the handrail. In case the people conveyor is switchable between two conveying directions, safety switch assemblies preferably should be provided at both ends of the people conveyor, as, depending on the actual conveying direction, both ends may act as handrail exit portion or as handrail entry portion, respectively.
The safety switch assembly comprises at least one sensor surface providing a touch sensor for detecting any part of a human body, in particular a finger, approaching and/or touching at least one of the at least one sensor surfaces.
According to an exemplary embodiment of the invention, a method of operating a people conveyor comprises issuing an optical and/or an acoustical alarm signal and/or reducing the speed of the handrail element in case the touch sensor detects any part of a human body, in particular a finger, approaching and/or touching at least one of the at least one sensor surfaces.
By detecting any part of a human body, in particular a finger, approaching and/or touching the sensor surface even before the safety switch assembly is (mechanically) activated, the operational security of the people conveyor is enhanced. By issuing an alarm signal and/or reducing the speed of the handrail element, the dangerous situation detected by the touch sensor may be resolved before the part of the human body is trapped. In consequence, stopping the handrail element or even the conveying element of the people conveyor, which is inconvenient for potential passengers and requires human interaction for restarting the operation of the people conveyor, may be avoided.
Exemplary embodiments of the invention will be described with respect to the enclosed figures:
The people conveyor 2 comprises a truss 3 extending between the lower landing area 4 and the upper landing area 6. The truss 3 supports a movable conveying element 8, which in the case of an escalator is a step chain, and two balustrades 12 (only one of which is visible in
A moving handrail 10, which is provided in the form of a belt forming a closed loop, extends and circulates around each of the balustrades 12.
Handrail exit/entry boxes 18 providing handrail exit/entry portions 19 are arranged at the ends of the lower base portions 14. Each of the handrail exit/entry boxes 18 comprises an opening (not visible in
The handrail exit/entry box 18 comprises an opening 20 for receiving a lower return portion of the handrail 10, which is not shown in
A safety switch 30 (see
As a result, in case a part of a human body, e.g. a finger, is pressed against the cap 24 and/or the switching element 22 and moves the switching element 22 towards the handrail exit/entry box 18, the safety switch 30 is activated. When the safety switch 30 is activated, any movement of the handrail 12 is stopped in order to avoid that the part of the human body touching the cap 24 and/or the switching element 22 is pulled into the opening 25 and squeezed between the rim of the opening 25 and the handrail 12, which may result in severe injuries.
Furthermore, at least one of the outer surfaces 26, 28 of the cap 24 and/or of the switching element 22 is configured as a sensor surface 27, 29 for providing, in combination with a corresponding detection circuit 32, a touch sensor, which allows to detect a part of a human body touching or approaching the at least one of the outer surfaces 26, 28 of the cap 24 and/or of the switching element 22.
The touch sensor may be a capacitive sensor which is configured for detecting a change of capacity caused by the part of the human body approaching or touching the at least one of the outer surfaces 26, 28. Alternatively, the touch sensor may be an electrical sensor, which is configured for detecting a (small) electrical current flowing through a human body touching the at least one of the outer surfaces 26, 28. In order to provide the desired sensor surface 27, 29, the outer surfaces 26, 28 of the cap 24 and/or the switching element 22 may be covered with an appropriate metallic or non-metallic, but electrically conductive, coating.
In an alternative embodiment the touch sensor may be an optical sensor comprising at least one optical sensor element which reacts on shading at least one of the outer surfaces 26, 28 by means of a part of a human body.
A touch sensor, as it has been described before, allows to detect a severe risk that a part of a human body gets trapped and injured at a very early stage, in particular even before the switching element 22 is moved. Thus, the touch sensor allows to issue an alarm signal even before the switching element 22 is moved and the safety switch 30 is activated. In consequence, an alarm signal may be issued in order to cause the human to remove his/her part of the body from the handrail exit/entry portion 19. Alternatively or additionally the speed of the handrail 12, and optionally the speed of the conveying element 8, may be reduced for reducing the risk of pulling the detected part of the human body into the openings 20, 23, 25.
In consequence, there is some chance that the part of the human body touching or approaching the cap 24 is removed in time and thus there may be no need for stopping the movement of the handrail 12 (and optionally the conveying element 8) completely. As a result, the shut-off times of the people conveyor 2 may be reduced.
In case no part of a human body is detected in the vicinity of the cap 24 for at least a predetermined amount of time, the speed of the handrail 12 (and optionally the speed of the conveying element 8) may be increased back to normal speed without human intervention in order to return to normal operation.
A number of optional features are set out in the following. These features may be realized in particular embodiments, alone or in combination with any of the other features.
In an embodiment the safety switch assembly may comprise a switching element which is configured for activating a safety switch when moved and which extends at least partially around the handrail exit/entry portion. Such a switching element results in a reliable activation of the switch. A switching element extending at least partially around the handrail exit/entry portion is reliably activated by parts of a human body touching the handrail in the vicinity of the handrail exit/entry portion.
In an embodiment the safety switch may be a mechanical switch. A mechanical switch provides a reliable and inexpensive safety switch. Alternatively, the safety switch may be an optical switch, e.g. a switch comprising a light barrier which is blocked when the switch is activated.
In an embodiment the sensor surface may be provided on an outer surface of the switching element in order to cause the touch sensor to be activated when the outer surface of the switching element is touched.
In an embodiment the touch sensor may be provided as a capacitive sensor which is configured for detecting a change of capacity caused by an approaching portion of a human body. Capacitive sensors provide reliable and inexpensive touch sensors, which are able to detect parts of the human body approaching and/or touching the sensor surface.
In an embodiment the touch sensor may be provided as an electrical sensor which is configured for detecting an electrical current flowing through a human body. Such electrical sensors provide reliable and inexpensive touch sensors, which are able to detect parts of the human body touching the sensor surface.
In an embodiment the touch sensor may be provided as an optical sensor which is configured for optically detecting a portion of a human body approaching and/or touching the sensor surface. Optical sensors provide reliable and inexpensive touch sensors, which are able to detect parts of the human body approaching and/or touching the sensor surface.
In an embodiment the people conveyor may be configured for issuing an optical alarm signal and/or an acoustic alarm signal in case the touch sensor detects a part of a human body approaching and/or touching the sensor surface. Thus, a method of operating a people conveyor may include issuing an optical and/or acoustical alarm signal in case the touch sensor detects any part of a human body, in particular a finger, approaching and/or touching the sensor surface.
An optical alarm signal and/or an acoustic alarm signal may cause a human being to remove the detected part of his/her body from the entry portion before it is trapped or jammed within the opening. In case the part of the human body is removed in time, it may not be necessary to stop the movement of the handrail of the people conveyor. Thus, an inconvenient shutoff of the people conveyor may be avoided.
In an embodiment the people conveyor may be configured for reducing the speed of the handrail in case the touch sensor detects a part of a human body approaching and/or touching the sensor surface. Thus, method of operating a people conveyor may include reducing the speed of the handrail element in case the touch sensor detects any part of a human body, in particular a finger, approaching and/or touching the sensor surface.
Reducing the speed of the handrail may allow a human being to remove the detected part of his/her body from the entry portion before it is trapped or jammed within the opening. In case the part of the human body is removed in time, it may not be necessary to stop the movement of the handrail of the people conveyor. Thus, an inconvenient shutoff of the people conveyor may be avoided.
In an embodiment the people conveyor may be configured for reducing the speed of the conveying element together with the handrail in order to avoid a speed difference between the conveying element and the handrail.
In an embodiment the people conveyor may be configured for increasing the speed of the handrail, and of the conveying element if applicable, back to normal operational speed in case the touch sensor does no detect a part of a human body approaching and/or touching the sensor surface for at least a predetermined period of time. This allows the people conveyor to return to normal operation without human intervention.
In an embodiment the people conveyor may be an escalator including a conveying element comprising a plurality of steps. Alternatively, the people conveyor may be a moving walkway including a conveying element comprising a plurality of pallets.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition many modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention include all embodiments falling within the scope of the dependent claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16193910.3 | Oct 2016 | EP | regional |
