HK1089145B - An assembly and a method for driving a passenger conveyor system - Google Patents

Description

Apparatus and method for driving passenger conveyor system

Technical Field

The present invention relates generally to passenger conveyor drive systems. More particularly, the present invention relates to a drive belt assembly for a passenger conveyor.

Background

Passenger conveyors such as escalators or moving walkways typically include a plurality of steps or pallets that move in a circular pattern. The drive means for moving the steps are typically supported within the building structure below the respective floor or enclosed and therefore appear hidden. In recent years, it has been desired to leave excessively complicated and bulky machinery. Those skilled in the art have endeavored to improve passenger conveyor drive systems to make them easier to install into building structures and more economical, for example.

A difficulty associated with many escalator drive systems is the need for frequent maintenance or repair. Not only increases the cost of maintaining the escalator system, but also brings difficulty to the maintenance technicians. The need to hide escalator drive components under the floor or within other structures of a building certainly limits the ability to easily access the components for repair or replacement.

There is a need for an improved escalator drive system. There are various difficulties and obstacles to overcome in successfully designing such drive systems. The present invention provides a unique belt drive having a support arrangement for ensuring satisfactory performance of the drive system under all conditions.

Disclosure of Invention

In general, the present invention is an apparatus for driving a passenger conveyor. A drive arrangement designed according to this invention includes a drive belt having a toothed surface adapted to engage correspondingly shaped links of a stepchain, the links being connected to a plurality of steps. The drive belt forms a loop. A drive pulley is disposed at one end of the loop and engages the inner surface of the drive belt to move the belt around the loop. An idler pulley is disposed at the opposite end of the ring and engages the inner surface of the belt. The idler pulley moves with the belt in response to movement of the drive pulley. A belt support is disposed between the drive pulley and the idler pulley. The belt support has at least one movable element spaced from but in close proximity to the inner surface of the belt to engage the inner surface of the belt in response to movement of the belt toward the belt support under certain conditions to ensure a desired engagement between the toothed drive belt surface and the step chain links in the vicinity of the belt support.

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.

Drawings

Figure 1 schematically illustrates an escalator system.

Figure 2 schematically illustrates selected portions of an exemplary embodiment of a drive device designed according to this invention.

Detailed Description

Fig. 1 shows a passenger conveyor system 20, the conveyor system 20 including a plurality of steps 22 adapted to carry passengers between landings 24 and 26 in a conventional manner. An escalator is shown in fig. 1 as an example of a passenger conveyor. The invention is equally applicable to moving or walkway or other passenger conveyors.

More specifically, referring to the broken away portion of fig. 1 and 2, a stepchain 30 is connected to the steps 22. The stepchain 30 includes a plurality of stepchain links 32, each stepchain link 32 having teeth 34 that cooperate with a drive assembly 40 to provide the desired movement of the steps 22. The step chain 30 is connected to the steps 22 and in one of many known ways.

The drive assembly 40 includes a belt 42 having a toothed outer engagement surface 44, the engagement surface 44 carrying a plurality of teeth 46, the teeth 46 cooperating with the plurality of teeth 34 on the stepchain links 32. The belt 42 preferably includes strength members such as steel cords or polymer strands embedded in a polymer material. As the belt 42 moves around a loop, the teeth 46 on the outer surface 44 engage the teeth 34 on the step chain links 32 to provide the desired movement of the step chain 30 and steps 22.

The loop about which the belt 42 travels has a drive pulley 50 at one end and an idler pulley 52 at the other end. A drive unit 54 having a conventional motor and brake arrangement propels the drive pulley 50 such that a toothed surface 56 on the drive pulley 50 engages teeth 57 on an inner surface 58 of the belt 42 to propel the belt around the loop.

Under normal operating conditions, the teeth 46 on the belt 42 cooperate with the teeth 34 on the step chain links 30. In accordance with the present invention, under normal operating conditions, the belt 42 is in proper, desired engagement with the step chain links 32. However, there are instances where very high loads are applied to the step chain 30 and thus to the belt 42, where the separating force tends to separate the teeth 46 from the teeth 34. An example of this is when there is a passenger on the escalator to brake completely to stop the escalator.

For these situations, the inventive arrangement includes a belt support 60 that operates even under such abnormal operating conditions to maintain proper engagement between the belt 42 and the step chain links. The belt support 60 includes at least one movable member that is spaced from the inner side 58 of the belt 42 in the belt region between the drive pulley 50 and the idler pulley 52.

In the illustrated embodiment, the belt support 60 includes a plurality of rollers 62 supported on a carriage 64 that is supported by a structure that supports the remainder of the drive assembly, in one example in connection with an escalator truss structure (not shown). The rollers 62 generally do not engage the inner surface 58 of the belt 42. Under selected operating conditions, such as full braking when the separating force tends to push the belt 42 away from the step chain links 32, the belt 42 moves toward the belt support 60 until the inner surface of the belt 42 contacts the belt support 60, thus maintaining the teeth 46 on the belt 42 in proper engagement with the teeth 34 on the step chain links 32.

The illustration enlarges the preferred gap between the rollers 62 and the inside of the belt 42. In one embodiment, the outer surfaces of the rollers 62 closest to the inner side 58 of the belt 42 are separated by a distance in the range of about 0.5 to about 1 millimeter. This gap between the rollers 62 and the inside of the belt 42 keeps the rollers from contacting the belt under normal operating conditions. In more difficult operating conditions, such as stopping with a full brake load, the rollers engage the belt and maintain the desired engagement between the belt 42 and the step chain links 32.

In one embodiment, the rollers 62 have an axial length that is equal to the width of the belt 42. The rollers 62 preferably have an outer dimension (i.e., diameter) that is significantly greater than the gap between the teeth 58 on the inside of the belt 42. In one embodiment, the roller 62 has a smooth outer surface. Various materials may be selected for the roller 62 depending on the characteristics of the belt 42.

The arrangement of the present invention has several advantages over arrangements in which, for example, the belt support continuously engages the drive belt. In the present case, there is no noise and vibration generated by the back-up rollers 62 during normal system operation. Furthermore, the rollers and bearings can be inexpensive components because they only operate in limited environments where noise and vibration are not a primary concern. Thus, the apparatus of the present invention provides cost savings and enhanced system operation features, such as smoother and quieter motion.

Given the present disclosure, those skilled in the art will be able to utilize suitable support structures to maintain belt support 60 in a preferred position so that it can function as desired for a particular situation. The embodiment shown comprises a plurality of rollers 62 associated with each side of the belt loop.

These arrangements are particularly useful where the step chain 30 and belt 42 are engaged on both sides of the belt loop.

The preceding description is exemplary rather than limiting in nature. It will be apparent to those skilled in the art that various changes and modifications can be made in the disclosed embodiments without departing from the spirit of the invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims (12)

1. An apparatus for driving a passenger conveyor system, comprising:

a drive belt having an engagement surface adapted to engage correspondingly configured links of a stepchain associated with a plurality of steps, the drive belt forming a loop;

a drive pulley engaging an inner surface of the drive belt to move the belt around the loop;

a second pulley spaced from the drive pulley and engaging an inner surface of the drive belt, the second pulley moving with the belt in response to movement of the drive pulley; and

a belt support disposed between the drive pulley and the second pulley, the belt support being spaced from the inner surface of the belt by a distance such that the support engages the inner surface of the belt to ensure engagement between the engagement surface and the chain links in the vicinity of the belt support.

2. The apparatus of claim 1, wherein the belt support comprises at least one movable support member that moves in response to contact with the belt.

3. The apparatus of claim 2, wherein the belt support comprises a plurality of rollers.

4. The apparatus of claim 3, wherein the inner surface of the belt includes a plurality of spaced apart teeth, and the diameter of the roller is greater than the width of the gap between the teeth.

5. The apparatus of claim 3, wherein the axial length of each roller is equal to the width of the belt.

6. The apparatus of claim 3, wherein the roller comprises a smooth outer surface.

7. The apparatus of claim 1, wherein the belt support does not contact the inner surface of the drive belt during normal conveyor system operation and contacts the inner surface of the drive belt as the belt moves toward the belt support.

8. The apparatus of claim 8, wherein the belt support includes at least one movable member that engages the inner surface of the belt in an abnormal condition.

9. The apparatus of claim 1, wherein the belt support comprises a plurality of rollers, wherein a portion of the rollers are disposed to engage a first portion of the inner surface of the belt and the other rollers are disposed to engage a second, confronting portion of the inner surface of the belt.

10. A method of ensuring engagement between a drive belt and a step chain in a passenger conveyor system, the method comprising:

a belt support is disposed adjacent the inner surface of the drive belt such that the belt support does not engage the drive belt during normal operation and engages the inner surface of the drive belt during abnormal operation to ensure engagement between the drive belt and the step chain.

11. The method of claim 10 including providing a plurality of rollers spaced from the inner surface of the belt.

12. The method of claim 10, comprising maintaining the belt support in a fixed position and engaging the belt in response to the belt moving toward the belt support.