Electrical transmission or interconnection systems – Personnel safety or limit control features
Reexamination Certificate
2000-11-29
2002-12-17
Fleming, Fritz (Department: 2836)
Electrical transmission or interconnection systems
Personnel safety or limit control features
C307S009100, C105S426000
Reexamination Certificate
active
06495933
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to floor door devices which are opened when vestibules with steps of a vehicle are used to allow passengers to get on and off the vehicle by using the steps, that is, powered trap door devices that are capable of safely and automatically opening/closing all trap doors.
2. Description of the Related Art
When a train stops at a platform almost as high as a floor of a vestibule of the train, passengers can get on and off the train without inconvenience. However, in case of a railway in which a station has no platform, since the difference in height between the vestibule of the vehicle and the ground is large, passengers cannot safely and easily get on and off the train in this state. Accordingly, in order to allow the passengers to safely and easily get on and off the train at such stations, collapsible steps are stored under the floor of the vestibule, and the passengers can get on and off the train through a vestibule entrance by using the steps (see Japanese Laid-Open Patent Publication No. 5-229428). This is advantageous since it is not necessary to make any change to the vestibule. However, the collapsible steps are cumbersome as compared. to fixed steps and take much time to be taken in and out. Besides, safety and reliability of operation of the collapsible steps are considered to be relatively low.
On the other hand, there has been proposed trap doors that open/close openings provided on each floor of vestibules to enable the passengers to get on and off the train by using fixed steps provided under each floor of the vestibules. In actuality, since the trap doors are installed on the vestibules, they are manually opened/closed one by one from the view point of safety. It should be noted that Japan has had no examples described above in the past. Hereinafter, such examples are referred to as a “prior art”. The details according to the prior art will be described with reference to
FIGS. 1 through 3
.
Referring now to
FIGS. 1 through 2
, a vehicle A with a sliding door D is provided with trap doors T on right and left sides of floors of front and rear vestibules thereof, respectively, and steps R under each floor opening opened/closed by means of the trap door T. The steps R are approximately as high as 1 m.
The trap door T is configured such that one side thereof is fitted at a floor face by means of a hinge and may be opened upwardly and closed when the vestibule is not used. The trap door T constitutes the floor face of the vestibule in a closed condition. When the train stops at a station with a platform, the sliding door D is opened, and then the passengers can go down from the vestibule to the platform. On the other hand, when the train stops at a station with no platform, the sliding door is first opened and then a person (station staff) manually opens the trap door T and engages the trap door T in an opened position by means of a hook or the like. In this state, the passengers can go down to the ground and go into the train by using the steps R.
According to the prior art described above, a person manually opens/closes the trap door T for the sake of safety. Hence, it requires much time and labor to open/close many trap doors T. Accordingly, it is necessary to speedily and automatically open/close the trap doors by total control with safety.
SUMMARY OF THE INVENTION
In view of such circumstances, the present invention is directed to improving an opening/closing mechanism and an opening/closing control system to open/close all trap doors with safety ensured when opening/closing operation of the trap doors is automated.
In one aspect of the present invention, there is provided a powered trap door device for a vehicle including a trap door hinged at a floor of a vestibule with steps of the vehicle, comprising: a screw driving mechanism that opens/closes the trap door and is driven by an electric motor with an electromagnetic brake; a first limit switch for detecting opening of a sliding door of the vehicle; a second limit switch for detecting closing of the trap door, the trap door being openable only when the sliding door is opened and the. sliding door being closable only when the trap door is closed; and a sensor of a periphery monitoring system provided on the vestibule to check safety of a peripheral area of the trap door, wherein the trap door can be opened/closed by the electric motor with the electromagnetic brake after the periphery monitoring system has checked safety.
With such configuration, all the trap doors are opened and closed by means of the screw driving mechanism provided thereon, and the first and second limit switches serve to detect opening of the sliding door of the vehicle and detect closing of the trap door, respectively. Thereby, the trap door can be opened only when the sliding door of the vehicle is opened and the sliding door can be closed only when the trap door is closed. Also, the electric motor with the electromagnetic brake is driven to open/close the trap door, whereby opening/closing operation of all the trap doors can be carried out safely by a train conductor. Consequently, it is possible to open/close all the doors speedily with safety ensured.
In addition, the screw driving mechanism is driven by the electric motor with the electromagnetic brake, which can be activated to reliably hold the trap door in an opened position. Further, in an emergency, the opening/closing operation of the trap door can be stopped immediately in the middle of the opening/closing operation and the trap door can be reliably held in a stopped position. Accordingly, it is not necessary to provide a mechanical engaging mechanism such as hooks for fixing the trap door in a fully opened or closed position, and it is possible to stop the trap door at any arbitrary open angle.
Besides, there is provided a threshold (guide rail) of the sliding door on an upper face of the trap door, for guiding the sliding door to the opened and closed positions. The (first) limit switch for detecting opening of the sliding door of the vehicle serves to detect opening of the sliding door and the (second)limit switch for detecting closing of the trap door serves to detect closing of the trap door. Thereby, since the trap door can be opened only when the sliding door of the vehicle is opened and the sliding door can be closed only when the trap door is closed, the sliding door is first opened and the trap door is then opened, and the trap door is first closed and the sliding door is then closed. In other words, the trap door is not opened while the sliding door is closed and the sliding door is not closed while the trap door is opened.
Consequently, safety of the opening/closing operation of the trap door associated with the opening/closing of the sliding door is ensured.
Furthermore, a plurality of sensors for a periphery monitoring system are provided around an entrance of the vehicle to check safety of a peripheral area of the trap door, and the trap door can be opened/closed by the electric motor with the electromagnetic brake after the periphery monitoring system has checked safety. Thereby, when any passenger is on the vestibules, the trap door is prevented from being opened/closed. Also, when any passenger enters the vestibule while the trap doors are being opened/closed, the opening/closing operation of the trap door is stopped immediately. Consequently, safety of the opening/closing operation of the trap door associated with the passengers' entry into the vestibules is ensured.
Moreover, since the electromagnetic brake is released and activated in association with the start and stop of the electric motor, the trap door is held in the fully opened or closed position and held in a position in the middle of the opening/closing of the trap door by activating the electromagnetic brake of the electric motor. On the other hand, in an emergency, the electromagnetic brake of the electric motor is forcibly released to allow a person to manually open/close the trap door.
Preferably, the elect
Takagi Kunihiko
Tokuda Kenji
Yagi Masaharu
Fleming Fritz
Kawasaki Jukogyo Kabushiki Kaisha
Marshall Gerstein & Borun
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