Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B23/00—Component parts of escalators or moving walkways
  • B66B23/02—Driving gear

Definitions

• Escalators and many other conveyors employ what is commonly known as a "twin chain” drive mechanism.
• the twin chain drive comprises two chain loops of the same length and arranged in synchrony. Steps or pallets are fixed between the two loops to corresponding points on each loop.
• the loops are driven in synchronism by synchronised sprockets.
• the loops are usually supported in space by wheels running on tracks to reduce frictional losses. These wheels are usually mounted externally to the chains for ease of servicing, at either end of an axle that is fixed either to or through corresponding points on each of the two chains.
• the through axle is present to resist large cyclic bending forces imposed on the axle by couples determined by the distance between chain centre and its corresponding wheel centre, without subjecting the steps or pallets to fatigue -inducing loading. These couples occur when a particular section of chains, axles and wheels is running over any area of the machine that causes the chains to be pulled either away from or toward the wheel running tracks.
• Escalators are subject to a phenomenon known as "lateral float” by which the steps exhibit a strong tendency to drive themselves into the side panels of the escalator adjacent to the steps, known as “skirt” panels. This damages the skirt panels, the edges of steps and often the wheels associated with steps.
• the available solution is to replace the main chains, at huge expense and disruption. It is one object of this invention to provide an escalator assembly or the like which is less prone to lateral float.
• a twin drive mechanism for an escalator or conveyor or the like comprising at least two chain loops disposed in parallel relation, means for moving the loops in synchronism, at least one axle bridging the loops, a wheel at each end of the axle, a step or pallet mounted on the axle, the wheels being connected to the axle by a joint which permits relative pivotal movement of the axle.
• each wheel is fixed to the respective chain running parallel to the chains gearing rollers, mounted on an extended chain pin and not directly on to the axle as is the normal practice.
• the invention is based on the first realisation that one should arrange the supporting wheels to point only in exactly the desired direction of conveyor motion, irrespective of relative chain positioning. To achieve this, it is necessary to fix wheels to individual chains.
• the axle between the chains must be permitted to "articulate” about a known fulcrum at its chain attachment points in a free and unrestrained manner in the plane of motion of the system while preventing similar axle articulation in a direction pe ⁇ endicular to that of the direction of motion.
• the invention includes a method of running an escalator or the like in lateral float-free mode by running an escalator of this invention.
• Figure 1 is a plan view of a chainstep escalator
• Figure 2 is a large scale view of one end of an axle
• Figure 3 is an enlarged sectioned end view of an axle shaft and extended chain hollow pin.
• the escalator shown in Figure 1 includes two chain loops, C1, 02, each made up of loops of identical length having aligned links.
• the loops are driven by sprockets not shown.
• the links are bridged at intervals by axles 1 which carry steps 2.
• a wheel 3 is present at each of the axle 1 and travels in a track 4 outboard of the respective chain.
• the escalator is mounted between walls 5, having side panels 6.
• Each axle 1 is connected to the chains 01 and 02 by a joint 10 which permits a limited amount of pivotal movement.
• each axle 1 terminates in a shaft portion 11 which is received in the bore 12, of an extended hollow chain pin 13, the extended portion passing through the wheel 3.
• the shaft 11 has two flats 14 machined at 180° on its outer diameter.
• the bore 12 of the chain hollow pin 13 has two keyways 18 cut at 180° and is stepped to define shoulders 15 which locate the outer diameter of the shaft portion 11, concentric to the chain hollow pins bore, both ends of which are enlarged into a lobed form 19 at 90° to the keyways.
• Keys 20 are inserted locating the flats on the shaft, preventing rotation, but allowing the axle to slew in the desired direction, the shaped form of the shoulders 15, providing the pivot point, and the enlarged lobed form of the bore ends enabling this slewing to take place.
• Figure 3 shows the lobed end form in relation to the shaft end drawn to an enlarged scale).
• the hollow chain pin has an outer shoulder 16 to receive ball bea ⁇ ngs 17, on which the wheel 3, runs. These are held in place by a circlip and which also retains the keys 20.
• the axle shaft has a reduced diameter end which locates the retaining cap 21 , which is held in place by the circlip 22.
• the invention is not limited to the embodiment shown.

Landscapes

• Escalators And Moving Walkways (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10788640

Family Applications (1)

Country Status (4)

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Family Cites Families (4)

• 1996
  • 1996-02-13 GB GB9602940A patent/GB2310185B/en not_active Expired - Fee Related
• 1997
  • 1997-02-11 EP EP97904524A patent/EP0880464A1/de not_active Withdrawn
  • 1997-02-11 AU AU17300/97A patent/AU1730097A/en not_active Abandoned
  • 1997-02-11 WO PCT/GB1997/000378 patent/WO1997029987A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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