The present invention relates to passenger conveyors like escalators and moving walks and particularly relates to a method for compensating a movable handrail in a passenger conveyor having a passenger transportation belt defining at least one passenger transportation surface, wherein the handrail is traveling along a closed handrail path which extends through an exposed path along the passenger transportation belt, around a turnaround means, through a return path and around a further turnaround means, and which handrail path defines a handrail plane which is substantially perpendicular to the passenger transportation surface.
Such passenger conveyors are widely in use. The handrails thereof are typically made from a rubber or plastics material and are internally reinforced by reinforcing elements like reinforcing longitudinal cables which are typically made from metal material. The handrail is typically a closed loop and has a length depending of the particular application, but typically at least 30 to 35 meter. In order to compensate for manufacturing tolerances as well as shortening which occurs due to aging of the handrail, a length compensation of the handrail is typically made. To this end at least one compensation device is placed in the return path of the handrail. The manufacturing tolerances, which are substantially independent from the handrail length, are ±12.5 mm so that a length compensation of typically at least 60 mm but preferably between 60 and 75 mm or even more is desired. With existing passenger conveyors, these compensation devices consume space within the plane as defined by the handrail path. This space is, however, required for placing other components of the passenger conveyor like the passenger transportation belt guiding elements, e.g. step roller tracks, or drive elements like step chains or step chain drives. Particularly with “slim” modern passenger conveyors and particularly with class-balustrade conveyors, this space problem is acerbated. Thus, with such construction frequently the problem emerges that conventional compensation devices cannot be used due to the fact that they require too much space or a plurality of such compensation devices is required for a single handrail in order to provide sufficient compensation length.
It is the object of the present invention to provide a method and a device which obviates the space problem with the prior art passenger conveyors and which provides the designer with more flexibility for designing the arrangement of the components of the passenger conveyor in an area where space is of premium concern.
In accordance with an embodiment of the present invention this object is solved by a method as defined above including the following steps:
(a) turning the handrail out of the handrail plane;
(b) directing the handrail through a compensation means; and
(c) turning the handrail back into the handrail plane.
The object is further solved with a handrail compensation device having a compensation means and a means for turning the handrail around its longitudinal axis.
By turning or twisting the handrail around its longitudinal axis, it is possible to tilt the compensating device out of the plane of the handrail path and away from that portion of the passenger conveyor where space is particularly restricted. Particularly, it is to tilt the compensation device by an angle which is sufficient for allowing the handrail in the compensation device to travel laterally past other components which are positioned within or extending into the plane as defined by the handrail path.
It is preferred to turn the handrail around its neutral longitudinal axis in order to reduce or avoid unnecessary flexing work.
Preferably the step of turning the handrail out of the handrail plane comprises turning the handrail out of the handrail plane by between approximately 2° and 30°. Other values particularly within this range are possible, for example between approximately 5° and 25°, between approximately 10° and 20° and between 12° and 18°.
Preferably, the handrail compensation device comprises first turning means in the moving direction of the handrail, followed by the compensation means and a second turning means. The first turning means can turn the handrail by a predetermined amount in a first direction and the second turning means can turn the handrail by the same predetermined amount in the opposite direction. Such a construction shows that the handrail moves in exactly the same direction before and after the compensation device. It is also possible to not turn the handrail in one single step by the desired amount but to provide a plurality of turning means for even a continuous turning means over a prolonged distance in order to achieve a predetermined turning angle.
Preferably, the turning means comprises a first and second guide roller sets each for contacting the handrail on its upper side, i.e. the side which is to be contacted by the user, and its inner side, i.e. the side which faces away from the upper side wherein the second guide roller set is angularly offset with respect to the first guide roller set so that in use the handrail is turned while traveling from the first to the second guide roller set. Each guide roller set preferably forms a slit or nip through which the handrail passes. The angular difference between the first slit and the second slit defines the angular offset and consequently the handrail turning angle. Instead of the guide roller sets any other guiding elements like sliding contact plates or moving contact belts can be used. It is preferred that such alternative guide means also form a slit or nip for guiding the handrail.
Preferably, the second roller set comprises two inner rollers on that side which in use is adjacent to the inner side of a generally C-shaped handrail, said two inner rollers are arranged with its rotational axis substantially perpendicular to each other so that in use one of the inner rollers will contact the lateral legs of the C-shaped handrail while the other inner roller will contact the web between the legs. In order to provide for a secure guidance of the inner side of the handrail, a single roller needs a relatively large diameter which might collide with space requirements. In order to obviate this problem, an embodiment of the invention suggests using one roller or disc which has a diameter slightly smaller than the distance between the two legs of the C-shaped handrail and using a further roller whose circumferential surface contacts the web portion between the two legs and which may have a relatively small diameter. This double roller arrangement can be constructed in a way that it is only slightly extending above the thickness of the handrail.
Preferably, the first and second roller sets are spaced from each other by a distance that is at least two times the width of the handrail. The distance between the first and second roller sets corresponds to the length through which the handrail is turned around its longitudinal axis. It is preferred to turn the handrail in a way that the lateral legs of the C-shaped handrail do not flex or flex only at a minimum amount. This will avoid aging of the handrail due to flexing work. In order to avoid this aging, a predetermined distance is provided between the first and second roller sets.
Preferably, the compensation means comprises a compensation roller, in use acting against the inner side of the handrail and bulging the handrail in the direction of the upper side thereof, and wherein the second roller set is offset by a predetermined distance from the first roller set in a direction opposite to the bulging direction of the compensation roller. With such a construction the handrail is—as viewed from the side—first directed upward between the first and second roller sets and subsequently directed downward by the compensation roller before it is directed back to the second roller set of the return turning device and again downward towards its original direction. With such a construction a particularly compact compensation device can be realized.
An embodiment of the invention further relates to a passenger conveyor having a passenger transportation belt defining at least one passenger transportation surface and a movable handrail which is traveling along a closed handrail path extending through an exposed path along the passenger transportation belt, around a turnaround means, through a return path, and around a further turnaround means, and defining a handrail plane which is substantially perpendicular to the passenger transportation surface, further comprising a compensation means and a means for turning the handrail around its longitudinal axis. The turning means does not necessarily have to be a part of the compensation device, but can be located at other positions, preferably along the return path of the handrail. One might contemplate to guide the handrail over an extended distance in a tilted manner and possibly out of the plane of the handrail path and to position the compensation means in such portion.
Preferably, the passenger conveyor comprises a compensation device according to an embodiment of the invention.
Preferably, some or all components of the compensation device are mounted to a support element, for example a support plate. Such support element can be mounted with the predetermined turning angle in the passenger transportation device. By providing virtually all the components on the single support element, these components can be aligned with ease in the factory and can easily be assembled in the conveyor, for example attached to the conveyor trust, etc. without the need for mounting and aligning the components individually.
Preferably, the components of the compensation device or alternatively the support element are/is attached to precisely aligned components of the passenger transportation device. Such precisely aligned components can for example be the step roller tracks, the chain roller tracks, the balustrade holder, etc. By providing a suitable mounting arrangement, for example mating surfaces, specific fasteners, etc. it is possible to design the passenger conveyor in a way that the components of the passenger transportation device are precisely aligned by merely securing it to the respective aligned components. Such a design can substantially reduce the efforts for assembling the passenger conveyor.
The invention and embodiments of the invention are described in greater detail below with reference to the Figures, wherein:
In
One can further see that the handrail 10 generally is of C-shaped cross section having two lateral legs 52 protruding away from a central web 54 (see
The first and second turning means 40, 42 are each shown as comprising a first 56 and a second 58 guide roller sets. The first and second guide roller sets 56, 58 each define a slit or nib through which the web 54 of the handrail 10 is guided. The extension of the slit with the guide roller set 56 is perpendicular to the plane as defined by the handrail path. The slit of the second roller set 58 is angled with respect thereto by a predetermined amount which finally defines the twist or turning amount of the handrail. The second guide roller set 58 may comprise one or more rollers of the back bending roller bow 50.
As may be seen by comparing
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP04/07331 | 7/5/2004 | WO | 12/22/2006 |