LINEAR HANDRAIL DRIVE

Description

Technical Field

[0001] The invention concerns a linear handrail drive for an escalator or a moving sidewalk.

Background of the Invention

[0002] Conventional handrail drives for passenger conveyors such as escalators or moving sidewalks are also driven by the motor for the conveyor's tread area. Frequently one of the reversing wheels in the end areas of the balustrades is used as the handrail's drive wheel. Another common type of drive uses a circulating endless drive belt which for example contacts the inside of the handrail along a predetermined path, and presses against it in order to drive it. The drive belt itself is driven by the conveyor's motor via a drive pulley. Also known are drive types which receive their power from the tread area belt.

[0003] The lengthy power transmission paths often lead to an irregular or a jerky movement of the handrail. It is furthermore difficult to adjust the handrail speed to the exact speed of the tread area. Add to that the increased wear of the handrail or the drive belt, especially due to the frictional interaction with the driven power wheel. This requires relatively frequent replacements of the typical wearing parts and additionally leads to undesirable downtime for the passenger conveyor, and to associated costs.

Disclosure of the Invention

[0004] It is the task of the present invention to make available a handrail drive which provides uniformity to the handrail drive and causes less wear.

[0005] GB-A-2096966 discloses a hand-rail drive for an escalator or a moving sidewalk wherein the handrail drive is designed as an electrical linear drive with a stationary primary part and a moveable secondary part.

[0006] The present invention is characterised over this document in that the secondary part is located on a circulating drive belt, which acts in combination with the handrail in order to drive it.

[0007] Thus the handrail of a conveyor is provided with its own drive, which eliminates the long power transmission paths and their associated disadvantages. In addition the linear movement of the drive can easily be translated into the circulating movement of the handrail without requiring an abrasion-intensive power transmission path between a drive wheel and the handrail for example. The "primary part" and "secondary part" concepts of the invention are used in the sense of a first and a second part and have no significance with respect to the special construction of the linear drive, for example in the sense of an excitation system and a conductor system.

[0008] A distributed arrangement of several such handrail drives in different areas of the handrail's moving path can ensure a uniform movement of the handrail, particularly with long handrail lengths.

[0009] The secondary part of the linear drive is located in a circulating drive belt which acts in combination with the handrail to drive the latter. Although this type of handrail drive may require a frictional power transmission from the drive belt to the handrail, and therefore leads to a certain amount of wear in the area where this frictional contact with the handrail or the drive belt takes place, this construction avoids the primary source of wear in the transition between the drive wheel and the drive belt, or the handrail.

[0010] In the preferred embodiment, the drive belt acts in combination with the handrail in a partial area where it is guided over separate deflection pulleys to close off the moving path of the drive belt; it is also possible however to let the drive belt run parallel to the handrail along its entire length and also to guide it around the reversing wheels of the handrail. It is generally advantageous to choose a material with a high coefficient of friction for the drive belt in the area where it acts in combination with the handrail. In cases where the drive belt runs parallel to the handrail along its entire length, a material with particularly good adhesion characteristics can be an advantage. In extreme cases an adhesive is used to attach the drive belt to the handrail.

[0011] The linear drive preferably has an excitation system that is composed of permanent magnets. In that case a multipolar permanent magnet linear drive is especially preferred. This could also be an excitation system with coils supplied with direct current, or an excitation system with coils supplied with alternating or three-phase current, where the excitation system produces a time-variable magnetic field for example.

[0012] Preferably the excitation system and the permanent magnets in particular are provided in the secondary part. The use of permanent magnets as an excitation system in the secondary part has the decisive advantage of offering a particularly simple and space-saving solution. The moveable secondary part particularly requires no power supply for any type of coils.

[0013] The linear drive preferably has a conductor system, where the speed of the linear drive is governed by a controller which controls a time-variable magnetic field of the conductor system. The conductor system is preferably located in the stationary primary part. The conductor system may have coils with wound coil cores. These may consist of a laminated material and are preferably interconnected at the end of their base. The current flowing through the conductor system and the excitation system's magnetic field produces a directed force which generates a relative movement between the primary and the secondary parts.

[0014] A continuous drive is produced in that the current flowing through the conductor system is controlled as a function of its relative position with respect to the excitation system's magnetic field. This control allows to manage the speed of the linear drive. The controller preferably controls the synchronism of the handrail with the tread area of the escalator or the moving sidewalk, in response to speed signals from the tread area of the escalator or the moving sidewalk. These signals are received by a sensor for example, and are relayed to the controller. A very precise synchronous control can be established in this way between the tread area and the handrail. Since the handrail is driven by the drive belt an additional speed sensor, which detects the speed of the handrail, can compensate for a possible slippage of the drive belt with respect to the handrail. The controller evaluates the corresponding sensor data and converts them into control data for the linear drive.

[0015] It is preferred if the surface of the primary part facing the secondary part, or the surface of the secondary part facing the primary part, is provided with a friction-reducing coating.

[0016] It is preferable to provide two primary parts where one of them is located on one side of the secondary part and the other on the other side of the secondary part. This kind of sandwich arrangement which places the secondary part between two primary parts makes it possible to create a large driving force on a short length of the secondary part. The two primary parts can either be parts that are separated from each other, or they can be connected to a yoke bridge, or they may be constructed in one piece.

[0017] It is preferred if the secondary part is equipped with a device that essentially causes the distance between the primary part and the secondary part to remain constant. This distance or the air gap between the primary part and the secondary part affects the driving force which the linear drive is capable of producing. Such a device is preferred in this case in order to essentially eliminate any fluctuations which in turn could lead to a jerky operation of the handrail. This defines the driving force of the linear drive to a higher degree and allows to design the linear drive in smaller size which contributes to a cost reduction.

[0018] The special feature of the electrical linear drive is its elongated construction which is particularly suited for use as a handrail drive. Typical space problems, such as often occur with conventional handrail drives, do not take place with an electrical linear drive. The electrical linear drive can even be installed in the visible area of glass balustrades without attracting any undue attention. The electrical linear drive can generally be installed in the most diverse areas along the handrail path, for example in the area where the handrail is grasped by the passengers, or in the handrail's return area, or even in the reversing areas.

[0019] The invention also concerns an escalator or a moving sidewalk which has a handrail drive according to the present invention.

Brief Description of the Drawings

[0020] The invention will now be explained in greater detail by means of a configuration example illustrated by drawings wherein:

Fig. 1 is a schematic illustration of a handrail drive according to the present invention; and

Fig. 2 is an enlarged illustration of a cross section of part of a drive belt with the configuration according to Fig. 1.

Best Mode for Carrying Out the Invention

[0021] Reference is made to Fig. 1. It shows a handrail 2 and a handrail drive 4. The handrail 2 is shown with its hand support area 6 facing upward.

[0022] The handrail drive 4 is a linear drive with a stationary primary part 12 and a moveable secondary part 14 A circulating drive belt 30 acts on the inside 20 of the handrail 2 and forms the secondary part 14 of the linear handrail drive 4. Fig. 4 shows that permanent magnets 16, 18 are embedded in this belt.. The permanent magnets 16, 18 are made of a high-grade magnetic material, whose north N and south S poles are respectively arranged upward in the lengthwise direction of the drivebelt 30 As large a number of permanent magnets 16, 18 as possible is provided and they closely follow each other in the lengthwise direction of the drivebelt 30. The more and the smaller the permanent magnets 16, 18 are and the closer they follow each other, the smoother and more uniform is the driving characteristic of the linear drive 4.

[0023] In an escalator or a moving sidewalk, the primary part 12 is stationary and is attached to its frame for example. The primary part 12 is a long comb-like element in which individual teeth 22, 24 are provided which form electromagnets with wound coils. The primary part's body which supports the coil windings consists preferably of an easily remagnetized soft metal and particularly has a laminated construction of individual sheet metals. The base 6 of the primary part's body is solid throughout.

[0024] The stationary primary part 12 can either be straight as shown and can be attached to the escalator or to the moving sidewalk in the straight areas of the handrail 2. However it can also be provided in bent form for areas where the handrail 2 is not straight but runs along an arc, as is the case in the reversing areas for example.

[0025] The primary part 12 is provided with a friction-reducing coating on the surface that faces the inside of the drivebelt 30.

[0026] The drive belt 30 runs around two idle deflection rollers 32, 34 and its lower inside area shown in Fig. 3 acts in combination with the stationary primary part 12. The inside 20 of the drive belt 30 is preferably provided with a friction-reducing coating which together with the friction-reducing coating on the opposite surface of the primary part 12 ensures low friction losses. The drive belt 30 is preferably guided by a not illustrated lateral guidance device so that it cannot swerve sideways, particularly in relation to the stationary primary part 12. A device can also be provided to hold the drive belt 30 against the stationary primary part 12, or to maintain a constant air gap between them.

[0027] The outside of the drive belt 30, i.e. the side of the drive belt 30 which acts on the inside 20 of the handrail 2 to drive it, preferably has a relatively high coefficient of friction to prevent any slippage of the drive belt on the inside 20 of the handrail 2, thereby causing any increase in its wear. In addition the shown configuration has pressure rollers 36, 38, 40 in the inside of the drive belt 30, which press the drive belt 30 against the inside 20 of the handrail 2. This also reinforces the frictional effect between the drive belt 30 and the handrail 2.

[0028] The drive belt 30 is made of a flexible material, for example a plastic material which like a handrail can be provided with reinforcing strands or a reinforcing fabric in the lengthwise direction to increase its strength.

[0029] To increase the driving force of the linear handrail drive 4, the stationary primary part 12 can be provided with a second stationary primary part on the drive belt 14 or the handrail 2, in an essentially symmetrical mirror-fashion. In this way the driving force can be doubled for the same length of the linear handrail drive 4. In addition to the pressure rollers 36, 38, 40 shown in Fig. 3, or as an alternative thereto, pressure rollers can be provided to act on the hand support area 6 of handrail 2 and press it against the drive belt 30.

[0030] The lengthwise section in Fig. 2 shows the permanent magnets 16, 18 in the drive belt 30, which form the secondary part 14 of the linear handrail drive 4. The letters N and S on the permanent magnets 16, 18 designate their north or their south poles. The alternating arrangement of the permanent magnets 16, 18 in the lengthwise direction of the secondary part 14 can be seen.

Claims

1. A handrail drive (4) for an escalator or a moving sidewalk, wherein the handrail drive (4) is designed as an electrical linear drive (4) with a stationary primary part (12) and a moveable secondary part (14), characterised in that the secondary part (14) is located on a circulating drive belt (30) which acts in combination with the handrail (2) in order to drive it.

2. A handrail drive (4) as claimed in claim 1, characterized in that the linear drive (4) contains an excitation system which is formed of permanent magnets (16;18).

3. A handrail drive (4) as claimed in claim 2, characterized in that the permanent magnets (16;18) are located on the secondary part (14).

4. A handrail drive (4) as claimed in any of the preceding claims, characterized in that the linear drive (4) has a conductor system where the speed of the linear drive can be controlled by a controller which governs a time-variable current flow in the conductor system.

5. A handrail drive (4) as claimed in any of the preceding claims, characterized in that the controller controls the synchronism between the handrail (2) and the tread area of the escalator or the moving sidewalk as a function of their speed signals.

6. A handrail drive (4) as claimed in any of the preceding claims, characterized in that a friction-reducing coating is provided on the surface of the primary part (12) which faces the secondary part (14).

7. A handrail drive (4) as claimed in any of the preceding claims, characterized in that a friction-reducing coating is provided on the surface of the secondary part (14) which faces the primary part (12).

8. A handrail drive (4) as claimed in any of the preceding claims, characterized in that two primary parts (12) are provided, one of which is located on one side of the secondary part (14) and the other is located on the other side of the secondary part (14).

9. A handrail drive (4) as claimed in any of the preceding claims, characterized in that the secondary part (14) is provided with a device which essentially causes the gap between the primary part (12) and the secondary part (14) to remain constant.

10. An escalator or a moving sidewalk equipped with a handrail drive (4) as claimed in any of the preceding claims.

Ansprüche

1. Handlaufantrieb (4) für eine Rolltreppe oder einen Fahrsteig, wobei der Handlaufantrieb (4) als ein elektrischer Linearantrieb (4) mit einem stationären Primärteil (12) und einem bewegbaren Sekundärteil (14) ausgelegt ist,
dadurch gekennzeichnet, dass der Sekundärteil (14) sich an einem umlaufenden Antriebsriemen (30) befindet, der mit dem Handlauf (2) zusammenwirkt, um diesen anzutreiben.

2. Handlaufantrieb (4) nach Anspruch 1, dadurch gekennzeichnet, dass der Linearantrieb (4) ein Erregersystem aufweist, das aus Permanentmagneten (16; 18) ausgebildet ist.

3. Handlaufantrieb (4) nach Anspruch 2, dadurch gekennzeichnet, dass die Permanentmagneten (16; 18) sich an dem Sekundärteil (14) befinden.

4. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass der Linearantrieb (4) ein Leitersystem aufweist, wobei die Geschwindigkeit des Linearantriebs durch eine Steuerung gesteuert werden kann, die einen zeitvariablen Stromfluss in dem Leitersystem vorgibt.

5. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass die Steuerung die Synchronisierung zwischen dem Handlauf (2) und dem Trittbereich der Rolltreppe oder des Fahrsteigs als eine Funktion von deren Geschwindigkeitssignalen steuert.

6. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass eine reibungsreduzierende Beschichtung an der Oberfläche des Primärteils (12), die dem Sekundärteil (14) gegenüber liegt, vorgesehen ist.

7. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass eine reibungsreduzierende Beschichtung an der Oberfläche des Sekundärteils (14), die dem Primärteil (12) gegenüber liegt, vorgesehen ist.

8. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass zwei Primärteile (12) vorgesehen sind, von denen sich einer an einer Seite des Sekundärteils (14) befindet und der andere sich an der anderen Seite des Sekundärteils (14) befindet.

9. Handlaufantrieb (4) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass das Sekundärteil (14) mit einer Vorrichtung vorgesehen ist, die im Wesentlichen bewirkt, dass der Spalt zwischen dem Primärteil (12) und dem Sekundärteil (14) konstant bleibt.

10. Rolltreppe oder Fahrsteig, die/der mit einem Handlaufantrieb (4) gemäß einem der vorangehenden Ansprüche ausgestattet ist.

Revendications

1. Entraînement de main courante (4) pour escalier roulant ou trottoir mobile, dans lequel l'entraînement de main courante (4) est conçu comme un entraînement linéaire électrique (4) avec une partie principale fixe (12) et une partie secondaire mobile (14),
   caractérisé en ce que la partie secondaire (14) est placée sur une courroie d'entraînement circulante (30) qui agit en combinaison avec la main courante (2) pour l'entraîner.

2. Entraînement de main courante (4) selon la revendication 1, caractérisé en ce que l'entraînement linéaire (4) contient un système d'excitation qui est formé d'aimants permanents (16 ; 18).

3. Entraînement de main courante (4) selon la revendication 2, caractérisé en ce que les aimants permanents (16 ; 18) sont placés sur la partie secondaire (14).

4. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérise en ce que l'entraînement linéaire (4) comprend un système conducteur ou la vitesse de l'entraînement linéaire peut être commandée par un contrôleur qui gouverne un débit de courant, variable dans le temps, dans le système conducteur.

5. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérisé en ce que le contrôleur commande le synchronisme entre la main courante (2) et le zone de roulement de l'escalier roulant ou du trottoir mobile en fonction de leurs signaux de vitesse.

6. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérisé en ce qu'un revêtement réduisant la friction est prévu sur la surface de la partie principale (12) qui fait face à la partie secondaire (14).

7. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérisé en ce qu'un revêtement réduisant la friction est prévu sur la surface de la partie secondaire (14) qui fait face à la partie principale (12).

8. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérisé en ce que deux parties principales (12) sont prévues, dont une est placée sur un côté de la partie secondaire (14) et l'autre est placée sur l'autre côté de la partie secondaire (14).

9. Entraînement de main courante (4) selon l'une quelconque des revendications précédentes, caractérisé en ce que la partie secondaire (14) est pourvue d'un dispositif qui maintient l'écart entre la partie principale (12) et la partie secondaire (14) essentiellement constant.

10. Escalier roulant ou trottoir mobile équipé d'un entraînement de main courante (4) selon l'une quelconque des revendications précédentes.

Drawing