Retractable step

The invention relates to a so-called sliding step for a vehicle, in particular a rail vehicle, which is arranged on the vehicle to bridge a gap between the vehicle and a platform or the like, is designed to be substantially horizontally displaceable in a linear direction, and a walkable area in the extended position and has at least one sensor connected to a collision preventing device. In the extended position, a sliding step forms an accessible area between the vehicle and the platform and serves as a boarding aid for passengers when entering or exiting the vehicle. Depending on the positioning between the vehicle body and the platform, the sliding step reaches the area of ​​the platform, usually towards the end of its extension movement, and there is a risk that it will drive sideways into the essentially vertical platform wall. This problem can be overcome by sensors which are connected to a collision preventing device.

Such a sliding step is known, for example, from EP 0 641 701 A1. The aim of this invention is to create an entrance for rail vehicles that can be adapted to different heights of platforms and different distances between the platform and the outer wall of the vehicle. For this purpose, the entrance consists of several steps, the lowest step being extendable. In addition to this, the top step can also be designed to be extendable and retractable. In order to avoid collision with foreign bodies when extending these sliding steps, the movement can be interrupted by mechanical elements such as a slip clutch or by electrical or electronic components such as limit switches, contact strips, pressure wave switches or overload control. With regard to the design and mode of operation of these sensors, which among others However, no further explanations are given.

GB 2 223 211 A discloses an entrance to a railway wagon which comprises a sliding step, a sensor which detects the width of the gap between the platform and the entrance, a drive and an adjustment mechanism which in individual cases determines how far the sliding step is extended. Optical sensors are preferably used to determine the distance between the platform and the entrance. No sensors are provided for other obstacles. Rather, impacts with unexpected obstacles, such as passengers, items of luggage, etc., cannot be prevented, but can only be cushioned using buffer devices, which is extremely problematic in view of increasingly strict safety regulations.

DE 37 08 498 A1 discloses a control for a sliding step. A pneumatic dynamic pressure sensor, which is fixedly arranged on the front edge of an extendable sliding step and can be moved with it, detects when the sliding step is moving towards an obstacle, as a result of which the extension movement of the sliding step is stopped. In refinements, instead of a dynamic pressure sensor, ultrasonic sensors can be used to control the extension movement, with which the gap between the platform and the entrance is measured. The ultrasonic sensors can be attached to the railroad car or, if necessary, also to the sliding step itself. However, due to its limited detection area, a sensor can only cover small segment areas. Particularly in the case of double doors, where the width of the entry and thus the length of the step can be more than a meter, dangerous situations cannot be ruled out with individual sensors. However, the use of several sensors with a single sliding step, as stated as an embodiment, significantly increases the costs of such an entry.

In order to be able to measure the height and distance of the platform from the entrance, individual sensors are sufficient, since the height and distance of the platform do not essentially change over the entire width of the sliding step and so from the measured values ​​to the entire area below or in front of the Sliding step can be extrapolated. In contrast, other obstacles that generally do not extend the full width of the sliding step, such as a passenger's legs, pets, suitcases, backpacks, abandoned tools and the like., With the sensors as they are in the stand Technique described cannot be reliably detected. This does not rule out dangerous situations for passengers and can also lead to the sliding step being damaged if it drives into an obstacle in an uncontrolled manner.

Another problem is that while the vehicle is stopped in the station with the sliding step extended, the height of the sliding step can change. this

AT 41 2 394 Β can be done in a short time by giving in the suspension, by changing the vehicle load when passengers get on and off, by changing wind loads and the like. The greatest possible change in height is determined by various parameters of the vehicle (type of suspension, position of the stops, length of the lever arms of the sliding step with respect to the pivot axis, etc.) and is referred to below as the maximum change in height. As a result of the actual change in altitude within the scope of this maximum change in altitude, luggage or passengers can now be trapped, or the sliding step can be damaged if the sliding step is lowered accordingly. Since the endangered objects generally do not extend over the entire width of the sliding step and it cannot be predicted in which area of ​​the sliding step they are, detection was previously impossible and there was a risk of body parts or objects being trapped or damage accept the sliding step.

The aim of the invention is to change this and to specify a device with which it is possible to carry out such a detection correctly and at low cost.

According to the invention, this is achieved in that the device has a movably mounted on the underside of the sliding step, extending essentially over the entire length of the sliding step, the bar in the activated state being located essentially under the front edge and that the at least one sensor either the position of the bar with respect to the front edge or the force of the bar on its storage is detected.

As a result, every impermissible approach of the sliding step to the platform can be recorded as well as the impending danger of an object or part of the body being trapped or colliding. By positioning the bar, the space (detection space) in which the sliding step could move during lowering, for example for one of the reasons mentioned above, is also recorded during the extension of the sliding step, and is thus secured. The bar assumes the activated state at least while the sliding step is being extended.

The movable connection between the bar and the sliding step makes it possible to bring the bar into the desired position, if necessary automatically, while the sliding step is being extended. The monitoring of this position remains activated during the extension of the sliding step into its end position.

Of course, the sensor that detects the force of the bar on its mounting does not necessarily have to be arranged in the mounting of the bar itself. Force sensors arranged on the front edge of the sliding step can also be used to determine this force.

One embodiment of the invention is characterized in that the bar is a rotatable flap. This represents the simplest and most cost-effective embodiment of the invention. A flap is reliable, easy to assemble, and complicated readjustments are unnecessary.

In a further embodiment, the invention is characterized in that the bar is a rotatable bracket. When the sliding step is retracted, the storage of the bracket disappears in or under the vehicle and is protected there from contamination, moisture, cold, etc., factors that can all impair the mobility of the bracket.

Another embodiment is characterized in that the bar is a bracket that can be displaced in a guide. This reduces the number of moving parts and, at the same time, the device's susceptibility to failure.

One embodiment of the invention is characterized in that the sensor measures an angle between the bar and the sliding step. Such a sensor measures the change in position preferably in the area of ​​the bearing and not directly at the front edge, and is thus protected from damage that can occur in the event of collisions with obstacles.

In a further embodiment according to the invention it is provided that the sensor is mounted on the front edge of the bar. A sensor on the front edge of the bar detects any obstacles that are in the way. This measure ensures that other vibrations or Movements transmitted to the sliding step, which should in no way lead to retraction of the sliding step, for example vibrations of a train passing on an adjacent track, are not detected.

If a change in the position of the bar is detected, the extension movement is stopped and the sliding step is retracted by a predetermined length, through which a safe distance from

AT 41 2 394 Β

Obstacle is guaranteed. In addition, an acoustic and / or visual alarm signal can be emitted, for example. Of course, another reaction is possible if this is requested by the operator.

The bar itself can either perform an extension movement that is inclined to the direction of extension of the sliding step, but is essentially linear, it can also perform a rotary movement and, so to speak, can be folded out.

Depending on the design and movement of the bar, a wide variety of sensors, which can be designed as switches or strain gauges or are based on an electrodynamic or piezoelectric effect, are suitable as the actual sensor. The sensors can either be arranged directly in the bar and measure the force between the ground and the bar or they are housed in the area of ​​the bar's bearings and measure the forces between the bar and the sliding step, which result from the forces mentioned first.

The transition of the bar from the passive position to the active position can be done by the weight of the bar, a link guide and possibly a spring. It is of course also possible to provide a motor drive.

It is beneficial to achieve the aim of the invention, and especially if the sliding step is to be withdrawn when a risk of entrapment is detected, that the bar releases any objects that have already been jammed as quickly as possible without further stress and does not become trapped and fixed.

The invention is explained in more detail below with reference to the drawing. 1 shows a front view of an entry aid designed according to the invention, FIG. 2 shows a purely schematic section in the direction of arrow II in FIG. 1, FIG. 3 shows a variant of a sliding step similar to that of FIG. 2 on an enlarged scale, FIG. 4 shows a view similar to FIG. 3 of another variant of the invention and FIG. 5 shows the variant of the invention according to FIG. 4th in a different position between the vehicle and the platform.

Fig. 1 shows a vehicle 1 with a two-leaf door 2 and a sliding step 3. Below the sliding step 3, the so-called detection space 4 is shown with dashed lines, that is, the space that the device according to the invention enters during the sliding out of the sliding step for collision. or risk of entrapment is to be monitored.

The positioning and significance of this detection space 4 can be seen from the cohesion of FIGS. 1 and 2: In FIG. 2, a platform 5 is drawn as it should run according to the standard with respect to the vehicle 1 with its surface and its side wall. Between the platform 5 and the vehicle 1 there is an unavoidable gap 6, precisely this gap

Gap which in many cases, think of platforms in curved track sections in rail vehicles, can also be significantly wider than in the exemplary embodiment shown and the sliding step 3 is provided to safely overcome or climb over it.

3 shows the situation in the area of ​​the platform 5 on an enlarged scale, but also completely schematically. In the embodiment shown, the bar 7 provided according to the invention consists of a rotatable flap which extends over the entire length L (Fig. 1) of the sliding step 3 and is essentially exactly below the front edge 8 of the sliding step 3 when it is in its activated position , as shown in Fig. 3, is extended.

The dashed line below the sliding step 3 in turn indicates the detection space 4, ie the space which the lower edge 9 of the bar 7 sweeps over during the extension in the direction A of the double arrow EA. If the bar 7 hits an obstacle at any point of length L during extension, this is detected by a sensor, which in the exemplary embodiment is arranged in the bearing 10 between the bar 7 and the sliding step 3, for example a position sensor that detects an angle between the Measure the bar (7, 7 ') and the sliding step, and the measures provided by the operator are taken. After reaching the end position of the sliding step, the bar must fold away and clear the detection area.

4 shows, likewise purely schematically, another embodiment of a strip 7 '. In this example, the bar 7 'is designed in the form of a rotatable bracket and is lowered around a hinge 10'; a sliding movement would be possible in a similar manner, for example, as already mentioned above, in a link guide. The movement of the bar 7 or 7 'between the illustrated active position and the one placed on the sliding step or in

AT 412 394 B

Recesses of the outline of the sliding step 3 pushed in position is brought about by its own weight and / or by support by means of spring force, of course, as mentioned above, an active movement by a servomotor or the like is also possible. possible.

5 shows the situation that arises with a device according to the invention according to FIG. 4 when the height of the vehicle 1 with respect to the platform top edge 11 is too low when the sliding step 3 is extended, so that the front edge of the bar 7 ' 9 ′ abuts against the vertical front 12 of the platform 5 below the upper edge 11 of the platform. This is also determined by the position sensor in the joint 10 'and leads to the predetermined reaction, as stated above. The same thing happens when the bar 7 'hits another obstacle io. Instead of the position sensor in the joint 10 ', a force sensor can be installed directly on the front edge 9' of the

Bar 7 'be arranged.

The invention is not restricted to the illustrated and described exemplary embodiments. It is thus possible to design the front edges 9, 9 'themselves as sensors, be it by having these edges carry profiles that are designed as electrical switching strips or that are filled with gas, the increase in gas pressure being measured and ascertained when encountering an obstacle is or it is that the strips 7, 7 'in turn consist of two mutually movable parts and the movement of these parts to each other is used as a measure of the impact on an obstacle.

It is essential that a bar 7, 7 'is arranged in the area below the front edge 8 of the sliding step 3 and over the entire length 11 of the sliding step and that the load acting on this bar in its entirety and / or the position of the bar by means of a sensor is determined and that when a predetermined value is exceeded, the movement is stopped and, if necessary, an alarm is triggered.