GB2087331A

GB2087331A - Passenger conveyor steps

Info

Publication number: GB2087331A
Application number: GB8024243A
Authority: GB
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1979-08-01
Filing date: 1980-07-24
Publication date: 1982-05-26
Also published as: GB2087331B; HK63185A; JPS5623183A; SG42185G; JPS5846434B2

Abstract

Passenger conveyor steps each include a cleat 6a constituting a surface layer and shaped by bending a steel sheet into a corrugation having a plurality of elevated portions and a plurality of depressed portions alternately arranged and each having a top and a bottom respectively, and a reinforcing member 7 connected to the under- surface of the cleat. A guide member 11 of an entity separate from the reinforcing member is attached to either side of each step, the guide member having a width substantially equal to the thickness of guide rollers for restricting the sideways movement of the step and a length substantially equal to the length of the step as measured in the direction of its movement. The guide member together with a side portion 10 are preferably secured to the reinforcing member 7. The guide member 10a in Fig. 11 is an integral portion of the side portion 10. <IMAGE>

Description

SPECIFICATION Passenger conveyor steps BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to steps of a passenger conveyor, such as a moving stairway, moving walk etc.

DESCRIPTION OF THE PRIOR ART Now a days passenger conveyors are indispensable to living in urban communities as an installation adding to the comfort of the citizens by facilitating their movements. Functioning as escalators, passenger conveyors are now building not only inside buildings, such as department stores, but also in subway stations and elevated railroad stations as a link for means of public transportation. Since subway stations and elevated railroad stations are usually located in densely populated areas, the passanger conveyors built in these areas are forced to operate under conditions which are heavier than those under which the counterparts in department stores have hitherto been operated.

For example, passenger conveyors have hitherto been built mostly in department stores and large office buildings. The conditions under which passengers conveyors are built and operated therein are somewhat distinct from the conditions under which they are built and operated as facilities in stations. One problem which is raised with regard to passenger conveyors in subway stations involves corrosion of conveyor components due to exposure to underground water. Another problem is how to increase surface hardness of the conveyor components to avoid damage thereto which might be caused by frequent contact with passengers. Increased popularization achieved in recent years has made it necessary to increase durability of passenger conveyors and there is a demand for such passenger conveyors in the market.

A passenger conveyor of the prior art comprises movable parts and stationary parts. The movable parts include a plurality of treads or steps linked in an endless belt, a pair of handrails disposed on both sides of the steps and movable in synchronism therewith, etc., and the stationary parts include a pair of balustrade sections disposed on both sides of the steps and supporting handrails, outer decks, inner decks, panels, etc. All the component parts, both movable and stationary, are supported by a strongly built support structure.

The steps which are important for transporting passengers are each composed of a tread on which a passenger stands, a riser connected to the trailing edge of the cleat for closing the gap, and a frams supporting the tread and riser. Each step has a pair of rollers connected to either end and rotated to move the step forwardly.

The tread cleat of each step of the prior art has hitherto been made of an aluminum alloy by using extrusion techniques, and a problem has hitherto been raised with regard to its duarability and susceptibility to surface damage as subsequently to be described in detail.

A proposal has recently been made by us to make step tread of stainless steel. Such steps are faced with the following problem. Each step made of stainless steel include a cleat formed by shaping thin stainless steel sheet (or steel sheet) of 1-3 mm thich into a corrugation, and a reinforcing member attached to the undersurface of the cleat tread.

As subsequently to be described, when provision is made for rilling surfaces of guide rollers restricting the sideways movement of the step by increasing the thickness of the reinforcing member, the thickness of the reinforcing member would inevitably become substantially equal to the thickness of the guide rollers. This would considerably increase the weight of the reinforcing member, and the increased weight of the step would not only form an obstacle to increased transportation efficiency but also cause an increase in energy consumption, thereby running counter to the policy of energy conservation.

SUMMARY OF THE INVENTION This invention has as its object the provision of steps of a passenger conveyor which enable guidance of the guide rollers to be effected without increasing the thickness of the reinforcing member for each cleat.

The aforesaid object is accomplished according to the invention by providing a guide member of a width substantially equal to the thickness of the guide rollers for preventing sideways movement of each step and of a length substantially equal to the length of the step as measured in the direction of its movement, to either side of each step. Such guide member is of an entity separate from the reinforcing member.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of an upper portion of a passenger conveyor; Figure 2 is a perspective view of a step of the prior art; Figure 3 is a sectional view taken along the line Ill-Ill in Fig. 2; Figure 4 is a bottom view of the step shown in Fig. 3, as viewed obliquely upwardly from below; Figures 5-9 show steps of a stainless steel material in which the invention is to be incorporated, Fig. 5 being a sectional view corresponding to Fig. 3, Fig. 6 being a bottom view corresponding to Fig. 4, Fig. 7 being a perspective view corresponding to Fig. 2, Fig.

8 being a sectional view taken along the line VIII-VIII in Fig. 7 and Fig. 9 being a perspective view, on an enlarged scale, of the essential portions of the step shown Fig. 7; Figure 10 is a sectional view of a side portion of the tread cleat of the step in which one embodiment of the invention is incorporated; and Figure 11 is a sectional view corresponding to Fig. 10 showing another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODI MENTS Referring to Fig. 1, a passenger conveyor comprises a plurality of steps 1 linked in an endless belt for supporting passengers thereon, a pair of handrails 2 located on opposite sides of the steps 1 and moved in synchronism with the steps, a pair of balustrade sections 3 located on opposite sides of the steps 1 for supporting the handrails 2 thereon, and panels 4 disposed on opposite sides of the steps. These parts of the passenger conveyor, both movable and stationary, are supported by a strongly built main frame 5. The steps 1 which are the main component for conveying passengers each comprise a tread cleat 1 a on which passengers stand, a riser 1 b closing the gap between the steps 1 and a frame 1c supporting the tread cleat 1a and riser 1 b, as shown in Fig. 2.A pair of rollers 1 d are connected to each step 1 at either end thereof for moving same.

The tread cleat 1 a has a width W of about 1 m and extend through the entire length of the passenger conveyor. The tread cleat 1 a which usually has a transverse cross section as shown in Fig. 3 is ridged at its surface and includes a plurality of elevated portions each having a top 1 e and a plurality of depressed portions each having a bottom If. The undersurface of the tread cleat 1 a has a reinforcing member 1 g in the form of a grill attached thereto as shown in Fig. 4. Recently, in order to draw passengers' attention to possible danger, it has become customary to arrange a colored portion 1 h on either side of the tread cleat 1 a made of resin and colored yellow or other suitable color.

Each step 1 is ridged on its surface and has a reinforcing member on it underside as aforesaid. Thus the steps 1 are sufficiently sturdy to enable passengers to be conveyed without anxiety.

Meanwhile the riser 1 b has the same width as the tread cleat 1 a and serves to close the gap between the adjacent steps 1. The riser 1 b is somewhat curved so that the vertical movement of the steps 1 and their movement in an endless belt may not be interfered with.

Usualiy the riser 1 b is also ridged at its surface so that the edge of the tread cleat 1 a may interfit.

The tread cleat 1 a and riser 1 b described hereinabove have usually been made of an aluminum alloy by using die casting, and it has been usual practice to give considerably high precision finishes thereto for the sake of passengers safety.

Arranged on the path of movement of the steps 1 are guide rollers R which are each disposed horizontally on either side of the steps 1 to meash with a com C at the passenger boarding end of the conveyor as shown in Fig. 2. The provision of the guide rollers R avoid wobbling of the steps 1 in the directions of arrows X in Fig. 2.

The guide rollers R each have a built-in ball bearing to enable smooth horizontal rotation and their thickness is about t, = 20-50 mm.

The colored portion 1 h of the tread cleat 1 a at its side is formed of nylon or other synthetiresin and susceptible to wear and breakage, so that the guide rollers R are prevented from coming into contact with the colored tread cleat portions 1 h. Thus the side portions of each tread cleat 1 a have a thickness T (T > t or T =. t,) of 20-50 mm. As a result, the weight of the step 1 is increased, causing trouble in operation and an increase in operation expenses.

In the steps of the aforesaid construction of the prior art, there has been a demand for improvements for increasing the wear resistance of the steps and making them economi caliy acceptable.

Since the passenger conveyors installed in subway stations are exposed to underground water and liable to develop corrosion and the passenger conveyors at the site of building construction are liable to develop corrosion due to adhesion of concrete, the problem with regard to corrosion caused in passenger conveyors has been discussed and various proposals have been made to obviate such problem. However, an aluminium alloy which is the principal material for forming the steps 1 is considered to be low in resistance to corrosion, particularly so when it is brought into contact with concrete (alkaline). It has been recognized that when concrete adheres to an aluminum alloy it is pitted with ugly dark spots in about 10 days.

A report made in the Japan Metal Society ("Corrosion Resting Alloys" published in 1962) shows that aluminum alloys are 2,000 times higher in susceptibility to corrosion than stainless steel and iron with respect to alkalinity. The table shown below contains data supporting this report.

Metal Degree of Corrosion Aluminum Alloys 25,000 Stainless steel I Iron 1 Unit: mg/dm2/day Remarks: Tests were conducted by immersion in a 5% cautic soda solution.

This report should be given serious consideration in view of the fact that a passenger conveyor is generally surrounded by concrete of high alkalinity and the influences of concrete are not negligible. It would appear that the incidence of corrosion is considerably high in passenger conveyors now in service.

Meanwhile, in view of the fact that the tread cleat 1 a of each step 1 supports passengers thereon at all times and is affected by contact therewith, wear resistance is one of the imprtant factors which should be taken into consideration in selecting the material for the tread cleat 1 a. Generally, aluminum alloys are believed to have wear resistance which is about 1 /1 0 that of stainless steel or iron by those who have ordinary skill in the art.

In addition to the aforesaid disadvantages of aluminum alloys, it is impossible to overlook the economic side of the problem concerning aluminum alloys. In recent years cost of aluminum alloys has been increasing under circumstances of increased cost of generating electric power because melting of aluminum requires lots of electricity, thereby making aluminum alloys an economically undesirable material.

In light of these circumstances, the use of aluminum alloys for making steps 1 must be reconsidered from the points of view of corrosion resistance, wear resistance and economical feasibility.

A proposal has recently been made by us to form steps of a passenger conveyor of stainless steel. The steps made of stainless steel as proposed are of the constructional form shown in Figs. 5-9.

Reference will be made to a cleat 6a shown in these figures as an example of the constructional form of the cleat made of stainless steel. As shown, the cleat 6a is made of stainless steel sheet (or iron sheet) of 1-3 mm thick which is shaped into a corrugation as shown in Fig. 5. In the example shown, the sheet is worked by means of a press to alternately from elevated portions and depressed portions each having a top 6e and a bottom 6f respectively, and has a reinforcing member 7 joined so its undersurface as by spot welding by using an upper electrode Y and a lower electrode Z. Alternatively, the reinforcing member 7 may be connected to the undersurface of the corrufation as by screwing or other suitable connecting means, in place of welding.

The cleat 6a made in this fashion has openings K as shown in Fig. 6. The prescence of the openings K would create the danger that a passenger might stick the tip of an aumbrella thereinto or the finger tips of a passenger might be jammed therein. To eliminate this danger, it has come to our mind to attach front and rear closing members 8 and 9 to the front and rear ends respectively as shown in Fig. 7. The rear closing member 9 is constructed as shown in Figs. 8 and 9. More specifically, the front end closing member 9 which is similar in appearence to the cleat 6a is intimately connected to the cleat 6a at one end Q and has the riser 6b intimately connected to the other end thereof. In recent years, a side portion 10 formed of a plastic material and colored such as yellow has customarily been attached to either side of the cleat 6a to draw passengers' attention to the danger.

However, in the step 1 having the cleat 6a provided with the front and rear closing members 8 and 9 and side portions 10, difficulties are encountered in attaching the reinforcing member 7 as shown in Fig. 6. More specifically, as described by referring to Fig. 4, the rolling surfaces of the guide rollers R must be provided for by the thickness t2 of the reinforcing member 7 because of the lack of strength in the side portions 10 formed of a plastic material. This inevitably leads to the thickness t2 of the reinforcing member 7 becoming substantially equal to the thickness t, of the guide rollers R.

Thus, since the guide rollers R have a thickness t, = 20-50 mm as aforesaid, the reinforcing member 7 will have a thickness t2 = 20-50 mm. This would considerably increase the weight of the reinforcing member 7 and raise the problems that operation of the passenger conveyor requires added energy consumption and maintenance thereof is time consuming because attaching and detaching of the steps would have to be performed under difficult conditions.

One embodiment of the invention will now be described by referring to Fig. 1 0. In this embodiment, the configuration of the cleat 6a and the arrangement of the reinforcing member 7 as well as the manner in which the latter is connected to the former are similar to those described by referring to Fig. 5. However, the embodiment shown in Fig. 10 offers the advantage that the rolling surfaces of the guide rollers R are provided without requiring to increase the thickness t2 of the reinforcing member.

The cleat 6a shown in Fig. 10 has a metallic guide member 11 disposed below the side portion 10 and attached to one side of the reinforcing member 7. The metallic guide member 11 is connected to the reinforcing member 7 by screws 12. The guide member 11 provides a flat rolling surface for each roller R having a length substantially equal to the length of the step 1 as measured in the direciton of its movement and width H greater than the thickness of the roller R (H > t1 or H t1). It will be apparent that the provision of the metallic guide members 11 eliminates the need to use the sides of the reinforcing member as the rolling surfaces of the guide rollers R. Thus the reinforcing member 7 has only to perform the functions of supporting the cleat 6a on its surface and the guide members 11 at the sides.The numeral 14 designates screws connecting the side portions 10 to the reinforcing member 7.

By this arrangement, it is possible to provide a suitable rolling surface for each guide roller R without increasing the weight of the reinforcing member 7.

Fig. 11 shows another embodiments in which the side portion 10 is made of metal instead of a plastic material and formed such that its outer side extends downwardly along the side of the reinforcing member 7 and beyond the underside of the member 7, to provide a rolling surface for the guide roller R.

It will be appreciated that this embodiment can acheive the same effects as the embodiment shown in Fig. 10.

The reinforcing member 7 is shown in Figs.

10 and 11 as being in the form of a plate extending along the entire length of each step 1 in the direction of its movement. However, the invention is not limited to this specific form of reinforcing member and the reinforcing member 7 may be composed of a plurality of bars arranged in the direction of movement of each step 1 in spaced apart relation and extending crosswise of the step 1.

From the foregoing, it will be appreciated that the invention enables a suitable rolling surface to be provided to each guide roller without increasing the weight of the reinforcing member of the tread cleat. Thus the invention provides passenger conveyor steps which are light in weight and conveniently carried at the time maintenance is carried out.

Claims

1. Passenger conveyor steps each comprising a tread cleat constituting a surface layer and shaped by bending a steel sheet into a corrugation having a plurality of elevated portions and a plurality of repressed portions alternately arranged and each having a top and a bottom respectively, and a reinforcing member connected to the undersurface of the cleat, wherein the'improvement comprises: a plurality of guide members each attached to one of oppsite sides of each said step, each said guide member being of an entity separate from said reinforcing member and having a width substantially equal to the thickness of guide rollers restricting the sideways movement of each said step and a length substantially equal to the length of each said step as measured in the direction of its movement.

2. Passenger conveyor steps as claimed in claim 1, wherein the improvement further resides in that each said guide member is securely connected to one side of said reinforcing member.

3. Passenger conveyor steps each comprising a tread cleat constituting a surface layer and shaped by bending a steel sheet into a corrugation having a plurality of elevated portions and a plurality of depressed portions each having a top and a bottom respectively, a reinforcing member connected to the undersurface of the treat cleat, and a plurality of side cleat portions each attached to one of opposite sides of each said treat cleat; wherein the improvement comprises: a plurality of guide members each attached to one of opposite sides of each said step, each said guide member being of an entity separate from said reinforcing member and having a width substantially equal to the thickness of guide rollers restricting the sideways movement of each said step and a length substantially equal to the length of each said step as measured in the direction of its movement.

4. Passenger conveyor steps as measured in claim 3, wherein the improvement further resides in that said side cleat portions are formed of metal such as steel, and one side of each said side cleat portion extends downwardly to constitute one of said guide members.

5. Passenger conveyor steps substantially as hereinbefore described with reference to Figs. 5 to 9, or Fig. 10 or Fig. 11 of the accompanying drawings.

6. A passenger conveyor substantially as hereinbefore described with reference to Figs.

5 to 9, or Fig. 10 or Fig. 11 or the accompanying drawings.