Moving walkway

Abstract: A walkway includes a succession of substantially flat belts (50,52,54) and a handrail (56). The walkway includes an accelerating section comprising at least one relatively short belt (50,52) leading to a faster moving longer belt (54). The hand rail (56) moves at the speed of the longer belt (54) and the speed of the shorter belt (50,52) is such that substantially no passenger will reach a state of imbalance requiring correction by foot movement on the belt. The walkway may have more than one such accelerating section.

Description: This invention relates to moving walkways and more particularly walkways of the type which consist of belts. More specifically, the present invention seeks to minimise the upsetting effects of acceleration on a walkway of the type which uses a sequence of successive belts which travel at different speeds to accelerate a passenger in stages to a higher speed. Successful operation of a system using accelerating sections requires proper coordination between the belts and moving handrails. Codes of practice require a restricted differential movement between the feet and hands of a passenger during the use of any one handrail. In the relevant US code, this differential movement must not exceed 400 mm. It is also desirable from the stand-point of passenger comfort to provide a minimum number of handrail changes. Acceleration is more difficult for a passenger to counteract than deceleration basically because the human foot projects forward from the centreline of the leg to the toes by more than four times the distance from the centreline to the back of the heel. Acceleration can rock a person onto the heels whereby balance can easily be lost, whereas deceleration will cause rocking onto the toes and arching of the foot can readily result in restoration of balance. If an accelerating section of a walkway is associated with a change of handrail from one handrail to a faster handrail, substantial passenger instability may result in this section. US-A-3799060 discloses a belt-type walkway system with an accelerating section consisting of a series of shorter belts of progressively increasing speed leading to a longer main belt. Hand support for a passenger moving on the walkway system is provided by a series of handles which move at a progressively increasing speed along the accelerating section, a relatively complex mechanism being required to achieve this effect. In accordance with the invention, there is provided a walkway comprising a succession of substantially flat belts, said walkway including at least one accelerating section having at least one relatively short belt leading to a faster moving longer belt, and a handrail associated with the accelerating section and extending the length of the accelerating section, characterised in that the handrail moves at the speed of the longer belt over the entire length of the accelerating section and the speed and length of the short belt is such that the transit time of a passenger on that belt is no more than about 1 second. Accordingly, in the invention, the use of a single handrail extending over the length of the accelerating section and moving at the speed of the faster moving belt in conjunction with the short transit time on the shorter belt minimises passenger instability during acceleration while using a simple handrail system. Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:- Figure 1 is a schematic plan view of an arrangement of belts and handrails in an accelerating section of a walkway. The walkway with which the invention can be most readily used has thin flat slider belts (generally less than 5 mm) passing about rollers having a small diameter. A typical diameter of roller, although this is not restrictive, is approximately from 30 mm to 70 mm, with a diameter of the order of 30 mm being preferred. It is however to be understood that the principles disclosed are also applicable when larger diameter rollers are used, say, rollers of up to about 150 mm. The embodiment of the invention to be described results in a system of accelerating belts and associated handrails which minimises handrail changes and minimises passenger instability during acceleration. With reference to Figure 1, an accelerating section comprises two relatively short initial belts 50,52, with the second belt 52 travelling at a speed higher than the first belt 50, and a third, longer, belt 54 travelling at a higher speed than the second belt 52. The three belts are associated with a handrail 56 which moves at the speed of the third belt 54. In contrast, conventional theory of accelerating sections in walkways suggested that the handrail should move at the average speed of the belts in any particular section. This leads to the disadvantage that in the fastest section, the handrail lags behind the belt thereby creating a tendency for the passenger to rock back onto a destabilising position on the heels. By using relatively short belts at the start of an accelerating section, the forward momentum of a passenger walking onto the first belt 50 will itself engender stability and this can be used to offset the destabilising effects of acceleration. By making the first and second belts 50, 52 sufficiently short, for an average passenger only the first foot will land on the first belt 50 and the second foot will not touch the belts until the first foot has been transferred to the second belt 52. At that time the two feet of the passenger may be more or less side-by-side and it is in this state that the passenger is most prone to imbalance. However the passenger is then immediately transferred to the third, longer, belt 54. When on the longer belt 54 the passenger is able to retain his balance by moving one foot behind the other with the certainty that both feet will be moving at the same speed. In summary, the length of the first and second belts 50, 52 is sufficiently shorter than the time required to induce, in all but a very small minority of passengers a state of instability requiring foot movement for correction, at least until the passenger has reached the third belt 54. In practice, this can be achieved if the transit time on the first and second belts is no more than about 1 second on each belt. As described earlier, the handrail 56 associated with the three belts is travelling at the speed of the fastest belt 54. Accordingly, when the passenger is transferred onto the second belt 52 while holding the handrail 56, although the passenger's feet might assume on the second belt 52 a position at which instability can occur, the handrail 56 is moving faster than the second belt 52 and will therefore tend to pull the passenger forwards into a stable position. However, due to the relatively short lengths of the first and second belts 50, 52, despite the difference in speed between the handrail 56 and the first two belts, the differential movement between the hands and the feet can be easily maintained within limits required by codes of practice without having to change handrails. When the passenger is on the third belt 54 the handrail 56 and belt 54 will be travelling at the same speed and hence no differential movement will result. Accordingly, the third belt 54 and handrail 56 can extend over any required distance sufficient to enable a passenger to fully recover stability on the third belt 54 while still maintaining hold of the handrail 56. The third belt 54 may then lead onto a further accelerating section comprising two further short belts 58, 60 and then onto a main belt 62 travelling at the required higher speed. The length considerations of the belts 58, 60 correspond to those of the belts 50, 52 as discussed above in order to prevent instability on thse belts. A second handrail 64 travelling at the speed of the main belt 62 extends over part of the length of the third belt 54 and also over the two shorter accelerating belts 58, 60 after the third belt 54. The changeover from the first handrail 56 to the second handrail 64 occurs while the passenger is on the third belt 54 after a time of transit on the third belt 54 sufficient to have enabled a passenger to have regained stability after movement from the second to the third belt. We have determined that the change in handrails on the third belt 54 should not take place until there has occurred at least about one second of travelling time of a passenger on the third belt 54. Correction of balance is an instinctive reaction and a travelling time of at least about one second on the third belt 54 is necessary for passengers to regain their balance on the third belt before change of handrails occurs. The table below indicates, by way of example, the speed, belt length and transit time in the sequence of two accelerating sections as described above. In this configuration, the first handrail 56 will be travelling at the speed of the third belt 54 which in the example shown is 1.2 m/s and the second handrail 64 will be travelling at the speed of the main belt 62 which in the example shown in 1.6 m/s. SPEED m/s LENGTH m TIME s 1st Belt 0.7 0.5 0.71 2nd Belt 1.0 0.5 0.5 3rd Belt 1.2 2.5 2.08 4th Belt 1.35 0.5 0.37 5th Belt 1.5 0.5 0.33 6th Belt (main belt) 1.6 as required - If higher speeds are required, further accelerating sections will be added, each comprising two short belts followed by a longer belt with the associated handrail moving at the speed of the longer belt. The main belt carries passengers to the far end of the system at which a succession of progressively slower belts decelerates the passengers to a speed at which they may comfortably and safely step off the system. The belts are preferably thin flexible belts which pass over small diameter rollers, and the moving handrails are of continuous form. Although as described, each of the accelerating sections has two shorter belts followed by a longer belt, it is possible for the accelerating section to comprise just one short belt followed by a longer belt, or more than two belts followed by a longer belt. The principles disclosed above are, however, still applicable; in particular, the transit time on the or each of the shorter belts should be no more than about 1 second per belt, the handrail moves at the speed of the longer belt, and no change of handrail on the longer belt will occur until at least about 1 second of travelling time on the longer belt. The configuration described provides good passenger comfort and safety during the acceleration phases while providing a minimum of handrail changes and permitting operation within codes of practice which determine maximum differential movement between the hands and feet. The embodiments have been described by way of example only and modifications are possible within the scope of the invention.

Claims: A walkway comprising a succession of substantially flat belts, said walkway including at least one accelerating section having at least one relatively short belt (52) leading to a faster moving longer belt (54), and a handrail (56) associated with the accelerating section and extending the length of the accelerating section, characterised in that the handrail (56) moves at the speed of the longer belt (54) over the entire length of the accelerating section and the speed and length of the short belt (52) is such that the transit time of a passenger on that belt is no more than about 1 second. A walkway according to claim 1, including a second accelerating section comprising at least one relatively short belt (58) following the longer belt (54) of the first accelerating section and leading to a faster moving longer belt (62) of the second accelerating section, the speed and length of the short belt (58) of the second accelerating section being such that the transit time of a passenger on that belt is no more than about 1 second, and a second handrail (64) associated with the belts of the second accelerating section, the second handrail (64) moving at the speed of the longer belt (62) of the second accelerating section, and change from the first (56) to the second handrail (64) occurring on the longer belt (54) of the first accelerating section at a position a sufficient distance from the commencement of that belt to enable a passenger to have corrected any imbalance engendered by the preceding acceleration. A walkway according to claim 2, wherein the change from the first to the second handrails (56, 64) occurs at a position corresponding to at least about 1 second of travelling time of a passenger on the longer belt (54) of the first accelerating section. A walkway according to any one of claims 1 to 3, wherein the or each accelerating section comprises a plurality of said relatively short belts (50, 52, 58, 60) travelling at successively higher speeds and leading to the longer belt of the section, the speed and length of each of the short belts of the section being such that the transit time of a passenger on each of the short belts is no more than about 1 second.

Inventors: LODER JOHN LOUIS, LODER, JOHN LOUIS
Applicants: LODERWAY PTY LTD, LODERWAY PTY. LIMITED
Application year: 1992
Main classification: B66B21
IPC codes: B66B29, B66B23, B66B21