WO2005082768A1

WO2005082768A1 - Travelator, moving ramp or escalator

Info

Publication number: WO2005082768A1
Application number: PCT/FI2005/000006
Authority: WO
Inventors: Esko Aulanko; Jorma Mustalahti; Marc Ossendorf
Original assignee: Kone Corporation
Priority date: 2004-02-26
Filing date: 2005-01-05
Publication date: 2005-09-09
Also published as: FI20040304A0

Abstract

A travelator, moving ramp or escalator, which comprises a conveyor (1) having a first end (2) and second end (3), and which conveyor comprises a number of conveyor platforms (4); an endless drive element (5, 6), to which the conveyor platforms (4) are secured one after the other; and a first power means (7), which is disposed at or near the first end (2) of the conveyor to move the drive element (5, 6). The conveyor (1) also comprises a second power means (8), which is disposed at or near the second end (3) of the conveyor (1) to move the drive element (5, 6).

Description

TRAVELATOR, MOVING RAMP OR ESCALATOR

FIELD OF THE INVENTION

The present invention relates to a travelator, moving ramp or escalator as defined in the preamble of claim 1.

BACKGROUND OF THE INVENTION

In prior art, a travelator, moving ramp or escalator comprising a conveyor is known. The conveyor is of an elongated design and it has a first end and a second end. In addition, the conveyor comprises a number of conveyor platforms connected one after the other to an endless drive element. A power means, which drives the drive element and thus moves the conveyor platforms, is provided at one end of the conveyor, in the case of a travelator usually at the exit end relative to the transport direction, or in the case of a moving ramp and escalator usually at the upper end.

The drive element driving the pallets or escalator is subject to two main design criteria:

1) safety against fracture loading of the drive element , and

2) pulley/tooth pressure and shearing resistance of the tooth.

Often criterion 2) is dominating, especially if the driving pulley has a small diameter, which is necessary in the case of flat travelators, moving ramps and escalators. Especially if the conveyor is driven by means of a synchronized toothed belt, tooth strength is the stronger criterion.

The problem in prior art is that when tooth strength is used as a design criterion, the drive element, such as a toothed belt or link chain, has to be oversized, which increases the costs and dimensions of the system. Especially when the drive element is a toothed belt, it is typical of it that the belt has to be pre- tensioned with a relatively high pre-tensioning force to prevent the belt from rising off the teeth of the wheel. The pre-tensioning force is roughly of the same order as the effective force available from the belt, which is why the tooth strength of a belt driven from one end constitutes a factor limiting the maximum length of the conveyor.

OBJECT OF THE INVENTION

The object of the present invention is to overcome the above-mentioned drawbacks.

BRIEF DESCRIPTION OF THE INVENTION

The invention is characterized by what is disclosed in the characterization part of claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims. Inventive embodiments are also presented in the description part and drawings of the present application. The inventive content disclosed in the application can also be defined in other ways than is done in the claims below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of explicit or implicit sub-tasks or in respect of advantages or sets of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Within the framework of the basic concept of the invention, features of different embodiments of the invention can be applied in conjunction with other embodiments. According to the invention, the conveyor comprises a second power means, which is placed at or near the second end of the conveyor to move the drive element .

By driving the conveyor according to the invention from both ends, a more advantageous force situation on the drive element is achieved than in prior art. Using the same drive element, a longer conveyor can be constructed. The conveyor structures can be made smaller due to the smaller dimensions of the drive element and the pulleys needed for it. In addition, the conveyor can be operated in either direction with a full load.

In an embodiment of the invention, the conveyor comprises a first drive element and second drive element, which are disposed at a distance from each other and parallel to each other, each drive element being implemented as an endless loop, the conveyor platforms being connected to both drive elements. Further, the conveyor comprises a first diverting pulley, which is disposed at the first end and over which the first drive element is passed, which first diverting pulley can be driven by a first power means. Further, the conveyor comprises a second diverting pulley, which is disposed at the second end and over which the first drive element is passed, and which second diverting pulley is driven by a second power means. Further, the conveyor comprises a third diverting pulley, which is disposed at the first end and over which the second drive element is passed, which third diverting pulley can be driven by the first power means. Further, the conveyor comprises a fourth diverting pulley, which is disposed at the second end and over which the second drive element is passed, and which fourth diverting pulley is driven by the second power means. In an embodiment of the invention, the conveyor comprises a first drive shaft, to which the first power means is connected to rotate it. Further, the conveyor comprises first transmission elements, and the first drive shaft has been arranged to rotate the first diverting pulley and the third diverting pulley by means of said first transmission elements.

In an embodiment of the invention, the first transmission elements comprise a fifth diverting pulley, which is mounted on the first drive shaft. Further, the first transmission elements comprise a sixth diverting pulley, which is mounted on the same shaft with the first diverting pulley. Further, the first transmission elements comprise a third drive element, which is passed as an endless loop over the fifth diverting pulley and the sixth diverting pulley. Further, the first transmission elements comprise a seventh diverting pulley, which is mounted on the first drive shaft at a distance from the fifth diverting pulley. Further, the first transmission elements comprise an eight diverting pulley, which is mounted on the same shaft with the third diverting pulley. In addition, the first transmission elements comprise a fourth drive element, which is passed as an endless loop over the seventh diverting pulley and the eighth diverting pulley.

In an embodiment of the invention, the conveyor comprises a second drive shaft, to which the second power means is connected to rotate it. Further, the conveyor comprises second transmission elements, and the first drive shaft has been arranged to rotate the second diverting pulley and the fourth diverting pulley by means of said second transmission elements. In an embodiment of the invention, the second transmission elements comprise a ninth diverting pulley, which is mounted on the second drive shaft. Further, the second transmission elements comprise a tenth diverting pulley, which is mounted on the same shaft with the second diverting pulley. Further, the second transmission elements comprise a fifth drive element, which is passed as an endless loop over the ninth diverting pulley and the tenth diverting pulley. Further, the second transmission elements comprise an eleventh diverting pulley, which is mounted on the second drive shaft at a distance from the ninth diverting pulley. Further, the second transmission elements comprise a twelfth diverting pulley, which is mounted on the same shaft with the fourth diverting pulley. In addition, the second transmission elements comprise a sixth drive element, which is passed as an endless loop over the eleventh diverting pulley and the twelfth diverting pulley.

In an embodiment of the invention, the drive element is a link chain.

In an embodiment of the invention, the drive element is a toothed belt .

In an embodiment of the invention, the conveyor platforms are pallets.

In an embodiment of the invention, the conveyor platforms are stair elements.

In an embodiment of the invention, the travelator, moving ramp or escalator is a low-construction travelator, moving ramp or escalator designed to be mounted on a fixed base, such as a floor or other support. LIST OF FIGURES

In the following, the invention will be described in detail with reference to embodiment examples and the attached drawings, wherein

Fig. 1 presents a diagrammatic side view of an embodiment of the travelator of the invention,

Fig. 2 presents the travelator of Fig. 1 as seen from above,

Fig. 3 illustrates the situation of forces acting on the drive element of the conveyor in a prior-art travelator, and

Fig. 4 illustrates the situation of forces acting on the drive element of the conveyor in a travelator according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Figures 1 and 2 present diagrammatic views of a low-construction horizontal travelator installed on a fixed base, such as a floor or other support, which means that no pit needs to be made in the fixed base for the travelator machinery. In the following description of an example, the invention is described with reference to a travelator, but it is obvious that corresponding principles of the invention can also be applied to moving ramps and escalators.

The travelator comprises a conveyor 1 , which in this case is a pallet conveyor. The construction 1 is supported on a conveyor frame 29. The entire length of the conveyor frame 29 rests on a floor base. Secured to the conveyor frame 29 are usually two side handrails 30 extending alongside the conveyor 1 throughout its length on either side of it.

The conveyor 1 has a first end 2 and a second end 3. The conveyor comprises a number of conveyor platforms 4, which are secured one after the other to two drive elements 5 and 6 consisting of endless loops, which are a first drive element 5, which is placed on one of those sides of the conveyor platforms 4 that are parallel to the transport direction, and a second drive element 6, which is placed on the other side of the conveyor platforms 4 parallel to the transport direction at a distance from the first drive element and parallel to it. The drive elements 5 and 6 are link chains or toothed belts. The conveyor platforms 4 in this example are pallets.

Disposed at the first end 2 of the conveyor 2 is a first power means 7, such as an electric motor, and at the second end 3 of the conveyor 1 is a second power means 8, such as an electric motor, to move the drive elements 5, 6. The power means 7 and 8 naturally drive the drive elements 5, 6 at the same speed of rotation and in the same direction.

The first drive element 5 is passed over a first diverting pulley 9, which is located at the first end 2 of the conveyor 1 and rotated by the first power means, and over a second diverting pulley 10, which is located at the second end 3 and rotated by the second power means 8. The second drive element 6 is passed over a third diverting pulley 11 , which is located at the first end 2 of the conveyor 1 and rotated by the first power means, and over a fourth diverting pulley 12, which is located at the second end 3 and rotated by the second power means 8.

At the first end 2, the first power means 7 is connected to a first drive shaft 13 to rotate it, from which the power is transmitted over first transmission elements 14 to provide a force driving the first diverting pulley 9 and the third diverting pulley 11.

The first transmission elements 14 comprise a fifth diverting pulley 15, which is mounted on the first drive shaft 13. A sixth diverting pulley 16 is mounted on the same shaft with the first diverting pulley 9. A third drive element 17 is passed as an endless loop over the fifth diverting pulley 15 and the sixth diverting pulley 16. A seventh diverting pulley 18 is mounted on the first drive shaft 13 at a distance from the fifth diverting pulley 15. An eighth diverting pulley 19 is mounted on the same shaft with the third diverting pulley 17. A fourth drive element 20 is passed as an endless loop over the seventh diverting pulley 18 and the eighth diverting pulley 19. At the second end 3, the second power means 8 is connected to the second drive shaft 21 to rotate it, from which the power is transmitted over second transmission elements 22 to provide a force driving the second diverting pulley 10 and the fourth diverting pulley 12. The second transmission elements 22 comprise a ninth diverting pulley 23, which is mounted on the second drive shaft 21. A tenth diverting pulley is mounted on the same shaft with the second diverting pulley 10. A fifth transmission element 25 is passed as an endless loop over the ninth diverting pulley and the tenth diverting pulley 24. An eleventh diverting pulley 26 is mounted on the second drive shaft 21 at a distance from the ninth diverting pulley 23. A twelfth diverting pulley 27 is mounted on the same shaft with the fourth diverting pulley 12. A sixth drive element 28 is passed as an endless loop over the eleventh diverting pulley 26 and the twelfth diverting pulley 27.

As can be seen from Fig. 1 and 2, the conveyor 1 is a pallet conveyor of flat construction. The pallets 4 move from the beginning 3 of the conveyor 1 to its end 2 and vice versa along a conveying track formed by upper supporting guide tracks provided in the conveyor frame 29. At the exit end 2 of the conveyor, the pallets, maintaining their position and direction, move onto a lower return track formed by lower supporting guide tracks provided in the conveyor frame, along which the pallets 4 return in a direction opposite to the transport direction of the conveyor to the beginning 3 of the conveyor.

As can be seen from Fig. 2, the rotation axis of the first diverting pulley 9 is on the same first axis line Li with the rotation axis of the sixth diverting pulley 16, and the first drive shaft 13 is at a distance from the said axis line Li outside the path of the conveyor platforms 4. Similarly, at the other end of the conveyor, the rotation axis of the second diverting pulley is on the same axis line L₂ with the rotation axis of the tenth diverting pulley 24 and the second drive shaft 21 is at a distance from the said second axis line L₂ outside the path of the conveyor platforms 4. This arrangement permits the pallet 7 to move past the drive shafts 13 and 21 from the lower return track to the upper transport track and vice versa at the entry and exit ends of the conveyor 1. Correspondingly, in another embodiment one or both of the drive shafts 13, 21 can be disposed inside the track of the conveyor platforms so that the drive shafts 13 and/or 21 are located between the upper transport track and the lower return track, which allows a shorter construction to be achieved.

Referring to Fig. 3 and 4, a prior-art solution as represented by Fig. 3 and a solution according to the invention as represented by Fig. 4 are compared by means of a calculation example.

The forces braking the system are FL and FR:

FL = the frictional force caused by the upper portion of the conveyor, which is due to the frictional force caused by the weight of the pallets/stairs and the load on the pallets/stairs

FR = the frictional force caused by the returning pallets/stairs in the lower return portion of the conveyor

The force FD driving the system:

FD = driving force produced by the motor and transmitted via the driving pulley to the belt/chain.

When there are two driving pulleys as in Fig. 4, the forces are indicated as FD1 and FD2.

In the case of a downwards inclined conveyor, force FL may become negative due to the gravitation of the load, in which case force FD is a force braking the system.

The internal forces in the system are:

FP = pretensioning force of the drive element (belt/chain). Especially in the case of a synchronized belt drive, pretensioning is needed to prevent disengagement of teeth of the belt from the teeth of the belt pulley. In the case of synchronized belts, the magnitude of force FP is about 50 ... 100% of the driving force FD. Other symbols used in Fig. 3 and 4:

BF1 = force at point 1 on the drive element BF2 = force at point 2 on the drive element BF3 = force at point 3 on the drive element BF4 = force at point 4 on the drive element

CALCULATION EXAMPLE

Assuming a horizontal travelator having a width of 1 m and a load of 200 kg/m².

Pallet weight 10 kg, pallet length 400 mm = 25 kg/m.

Friction coefficient = 0.05

Driven by means of two toothed belts.

Failure load of the toothed belt = 30 kN

Maximum driving force FD = 3 kN

Required pretensioning FP = 70% of the driving force FD

Minimum safety coefficient against breakage = 5, so the maximum belt force = 6 kN.

The maximum length L of the travelator is calculated

FL = 225 g ^* 9,81 m/s2 ^* 0.05 ^* L/2 = 55 N/m (2 belts) FR = 25 kg * 9.81 m/s2 * 0.05 * L/2 = 6 N/m

1 ) For a conveyor driven from one end (Fig. 3):

FD = FL + FR = 61 N/m

Maximum length L = 3000 N / 61 N/m = 49.2 m

FP = 0.7 ^* 3 kN = 2.1 kN

Maximum force on the belt BF1 = FD + FP = 5.1 kN

Safety coefficient Sf = 30 kN/ 5.1 kN = 5.9

The dominating factor is the tooth load, max L = 49.2 m 2) For a conveyor driven from two ends (Fig. 4):

Assumption FD1 = FD2

2 FD = FL + FR = 61 N/m => FD = 30.5 N/m

FP = 0.7 * FD = 21.4 N/m

Maximum belt force

BF1 = 2FD - FR + FB = L ^* (61 - 6 + 21.4) N

=> 6000 N = L ^* 76.4 N => Maximum length L = 78.5 m (safety coefficient

5)

FD = 30,5 + 78,5 = 2394 N < 3000 N

The dominating factor is the safety coefficient, max L = 78.5 m

As can be clearly seen from the example, with the same belt or the length of the travelator may be about 60 % longer when it is driven from both ends (Fig. 4) and the tooth load is only about 80% as compared to a situation where the conveyor is driven in the prior-art manner from only one end (Fig. 3). If the failure load of the belt is large enough, then the belt length can be doubled by driving the belt from both ends.

The invention is not limited to the embodiment examples described above; instead, many variations are possible within the scope of the inventive concept defined in the claims.

List of reference numbers:

conveyor (1 ) - first end (2) - second end (3) conveyor platform (4) first drive element (5) second drive element (6) first power means (7) second power means (8) first diverting pulley (9) second diverting pulley (10) third diverting pulley (11 ) fourth diverting pulley (12) first drive shaft (13) f irst transmission elements (14) fifth diverting pulley (15) sixth diverting pulley (16) third drive element (17) seventh diverting pulley (18) eighth diverting pulley (19) fourth drive element (20) second drive shaft (21 ) second transmission elements (22) ninth diverting pulley (23) tenth diverting pulley (24) fifth drive element (25) eleventh diverting pulley [26) twelfth diverting pulley (27) sixth drive element [28) conveyor frame [29) side handrail [30)

Claims

1. A travelator, moving ramp or escalator, which comprises a conveyor (1 ) having a first end (2) and second end (3), and which conveyor comprises a number of conveyor platforms (4); an endless drive element (5, 6), to which the conveyor platforms (4) are secured one after the other; and a first power means (7), which is disposed at or near the first end (2) of the conveyor to move the drive element (5, 6), c h a r a c t e r i z e d in that the conveyor (1 ) comprises a second power means (8), which is disposed at or near the second end (3) of the conveyor (1 ) to move the drive element (5, 6).

2. A travelator, moving ramp or escalator according to claim ^ c h a r a c t e r i z e d in that the conveyor comprises - a first drive element (5) and a second drive element (6), which are disposed at a distance from each other and parallel to each other, each being implemented as an endless loop, the conveyor platforms (4) being secured to both drive elements (5, 6), - a first diverting pulley (9), which is located at the first end (2) and over which the first drive element (5) is passed, and which first diverting pulley is driven by the first power means (7), - a second diverting pulley (10), which is disposed at the second end (3) and over which the first drive element (5) is passed, and which second diverting pulley is driven by the second power means (8), - a third diverting pulley (11 ), which is disposed at the first (2) end and over which the second drive element (6) is passed, which third diverting pulley is driven by the first power means (7), and - a fourth diverting pulley (12), which is disposed at the second end (3) and over which the second drive element (6) is passed, and which fourth diverting pulley is driven by the second power means (8).

3. A travelator, moving ramp or escalator according to claim 2, c h a r a c t e r i z e d in that the conveyor (1 ) comprises - a first drive shaft (13), to which the first power means (7) is connected to rotate it, and - first transmission elements (14), by means of which the first drive shaft (13) has been arranged to rotate the first diverting pulley (9) and the third diverting pulley (11 ).

4. A travelator, moving ramp or escalator according to claim 3, c h a r - a c t e r i z e d in that the first transmission elements (14) comprise - a fifth diverting pulley, which is mounted on the first drive shaft (13), - a sixth diverting pulley (16), which is mounted on the same shaft with the first diverting pulley (9), - a third drive element (17), which is passed as an endless loop over the fifth diverting pulley (15) and the sixth diverting pulley (16), - a seventh diverting pulley (18), which is mounted on the first drive shaft (13) at a distance from the fifth diverting pulley (15), - an eight diverting pulley (19), which is mounted on the same shaft with the third diverting pulley (17), and - a fourth drive element (20), which is passed as an endless loop over the seventh diverting pulley (18) and the eighth diverting pulley (19).

5. A travelator, moving ramp or escalator according to any one of claims 2 - 4, c h a r a c t e r i z e d in that the conveyor (1 ) comprises - a second drive shaft (21 ), to which the second power means (8) is connected to rotate it, and - second transmission elements (22), by means of which the first drive shaft (13) has been arranged to rotate the first diverting pulley (10) and the third diverting pulley (12).

6. A travelator, moving ramp or escalator according to claim 5, c h a r - a c t e r i z e d in that the second transmission elements (22) comprise - a ninth diverting pulley (23), which is mounted on the second drive shaft (21 ), - a tenth diverting pulley (24), which is mounted on the same shaft with the second diverting pulley (10), - a fifth drive element (25), which is passed as an endless loop over the ninth diverting pulley (23) and the tenth diverting pulley (24), - an eleventh diverting pulley (26), which is mounted on the second drive shaft (21) at a distance from the ninth diverting pulley (23), - a twelfth diverting pulley (27), which is mounted on the same shaft with the fourth diverting pulley (12), and - a sixth drive element (28), which is passed as an endless loop over the eleventh diverting pulley (26) and the twelfth diverting pulley (27).

7. A travelator, moving ramp or escalator according to any one of claims 1 - 6, ch a ra cte rized in that the drive element (5, 6) is a link chain.

8. A travelator, moving ramp or escalator according to any one of claims 1 -7, ch a racte rized in that the drive element (5, 6) is a toothed belt.

9. A travelator or moving ramp according to any one of claims 1 - 8, c h a ra cte rized in that the conveyor platforms (4) are pallets.

10. An escalator according to any one of claims 1 -9, ch a racte rize d in that the conveyor platforms (4) are stair elements.

11. A travelator, moving ramp or escalator according to any one of claims 1 - 10, c h a ra cte rized in that the travelator, moving ramp or escalator is a low-construction travelator, moving ramp or escalator designed to be installed on a fixed base, such as a floor or other support.