JPS592060Y2 - Toothed step link for transportation equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a transportation device, particularly a passenger transportation device such as an escalator-1 moving passage, which has a plurality of steps, platforms or pallets attached to a flexible conveyor consisting of a step link and a step shaft. It is related to the device.

BACKGROUND OF THE INVENTION Passenger transport devices, such as escalators, in which steps are raised along a predetermined slope by means of toothed step links are known.

A modular drive installed in a truss between the load-bearing run and the return run, directly below the change of direction between the inclined part and the upper horizontal part of the escalator, is used to control the upper load-bearing run. It has a drive chain that engages toothed step links in both the upper and lower return runs.

An escalator structure of the above type has an endless belt with two sides each formed by toothed step links which are pivotally connected to each other.

These step links are constructed from a plurality of superimposed flat steel laminates.

The two sides of the endless belt are connected to each other by a step shaft, and the step is fastened to the step shaft.

Endless belts and steps have only a load-bearing run and a return run, with an axial roller or guide wheel at the end of the step shaft, a trailer wheel on the step, and a separate guide track that supports the guide wheel and the trailer wheel. rather, it is also guided through a turning section that connects these two running sections to each other.

This type of escalator structure has many advantages over escalators that utilize a step chain and upper sprocket drive to pull the steps up a slope.

One of the biggest advantages is that the loads acting on moving parts can be reduced.

As the lifting length increases, the loads on the moving parts remain small and the modular drive force for the slope can be increased as required.

The use of rigid step links allows for constant spacing between step axes, thereby eliminating the need for tensioning devices required in step chain structures.

Compared to conventional drive types, the loads on the conveyor components of modular drive escalators are small.

However, it is desirable to reduce the weight of the conveyor if possible, but this cannot be done without sacrificing mechanical strength.

Generally, reducing weight reduces component costs and
There is less dead load on the modular drive and track system, thus extending chain life and smoother running.

The main purpose of the present invention is to provide a toothed step link for transportation equipment that enables a significant reduction in the weight and cost of the step link and the articulated endless belt constructed therefrom without adversely affecting the mechanical strength of the step link or belt. Our goal is to provide the following.

That is, the present invention provides a toothed step link for interconnecting similar step links by a step shaft to form an articulated endless belt for a transportation device, the toothed step link having first and second ends spaced apart from each other. an elongate member and a second elongate member having the same ends disposed adjacent to each other; the second elongate member having a first end and a second end and having a plurality of teeth; and a third elongated member disposed in a gap between the first end of the second elongated member, and the first elongated member, the second elongated member, and the third elongated member are combined. , the third above
The first end of the elongate member and the second ends of the first and second elongate members constitute an assembly forming a male portion and a female portion, respectively, of a similar structure. a coupling device adapted to cooperate with said third elongate member, said third elongate member including at least one hollow metal assembly formed of assembled right and left hand shell members, each of said right and left hand shell members The left hand shell member includes a flat earthen wall portion formed of a metal plate having a predetermined through opening and a plurality of teeth along an outer edge thereof, and extending outwardly from the same side of the flat main wall portion and having a plurality of teeth along the outer edge thereof. an integral flange portion having a portion surrounding the outer periphery of the main wall portion including the teeth thereof, and a portion surrounding the predetermined through opening, and at least one end of the flange portion is in a common plane. The ends of the flange portions of the right-hand shell member and the left-hand shell member located in a common plane contact each other, and the flange portions surrounding the outer peripheries cooperate to connect the side wall and the plurality of teeth. A toothed gear for a transportation device, characterized in that the flange portion surrounding the predetermined through opening is assembled to form a wall of the opening passing through the hollow composite structure. It provides a step link.

Simply put, the present invention consists of a 19th, a 2nd, and a 3rd basic long member, with a 3rd member sandwiched between the 1st and 2nd members, and a stand-up member. The present invention provides an improved toothed step link that is assembled and held together by a pressure-fit tubular member.

The third member has a plurality of teeth, and one of these ends is connected to the third member.
The male part of the step link is formed by protruding outward from the member.

The male and female parts of the step link constructed in this way cooperate with the female and male parts of other similarly constructed step links, so that when the step shaft is assembled with the connected step link, an endless belt is formed. form.

The improved toothed step link of this invention has a modular structure, so
Only three basic sections are required to form the first, second and third base members.

Furthermore, it is also possible to form the first and second step links with different strengths using the same three basic sections.

The first and second step links of different strengths have widths of 81 crn (32 in) and 122 cm (48 i), respectively.
n) Used for standard escalators.

Each of the three basic sections is a pultruded steel shell member, which is made as follows.

First, a sheet metal 1.22 mm (0.048 in) thick is stamped, and the resulting profile is then drawn to curve the edges in a common direction, creating a uniform flange around the perimeter of the sheet body. form.

The ends of the flanges lie in a common plane.

Two of the three basic sections are a right-hand member and a left-hand member, which when assembled with their flanged ends abutted form a hollow assembly with a plurality of cooperating teeth.

This hollow assembly may be used alone or in conjunction with other similarly configured hollow assemblies to form the third member of the step link.

The ends of the teeth are circular in cross section. Since the cross section is circular,
The blanking out of the profile during the drawing operation is simplified and the pitch can be brought as close as possible to the tips or ends of the teeth.

Moving the pitch to the outside of the teeth minimizes the amount of overlap between the teeth and the drive chain of the modular drive, thus reducing vibrations and noise in the area of the modular drive, resulting in smoother running. can.

The remaining basic profile is a long shell member symmetrical about its longitudinal axis.

When this section is assembled alone or with similar sections and the flanged ends are butted together, a hollow metal structure forms the first and second members of the step link. can.

The manufacturing cost of the new improved step link according to the invention is lower than that of known step links.

The new improved step link according to the invention also has a width of 122
The weight of the step link used for cm (48 inches) is 5.
67 kg (12,51b) to 2.49 g (5
, 5 lb), and the weight of the step link used on an 81 cm (32 in) wide escalator is 1.25
kg (2,75 lb).

For example, when used on an escalator with a lifting length of 4.58 m (15 ft), the weight of a known step link is 7.
03 kg (1,550 lb), but the step link of the present invention weighs only 308 kg (680 lb) on a 122 cm (48 in) wide escalator, and only 308 kg (680 lb) on an 81 cm (32 in) wide escalator. weighs only 154 kg (340 lb).

Referring now to the accompanying drawings, FIG. 1 is a front view showing a transportation device 10 to which the step link of the present invention is applied.

Although the present invention is equally applicable to moving passages in which rigid parts or platforms commonly called pallets are connected in an endless manner, escalators will mainly be described here.

The transportation device 10 uses a conveyor 12 to transport users between a first landing 14 and a second landing 16.

The conveyor 12 is of the endless type and has an articulated belt 15 driven along a closed path or loop.

The invention can be applied to any type of moving staircase in which the spacing of the belt supporting guide wheels is kept constant by means of toothed step links, but in particular in British Patents Nos. 1,371,519 and 1,362,016.
Since it is advantageously applied to the modular passenger conveyor described in No. 1 and No. 1,336,360, the invention will be described below with respect to a conveyor of such construction.

The conveyor 12 has an upper load supporting running section 18 where users stand while being conveyed between the first landing 14 and the second landing 16, a lower return running section 19, and a load supporting running section. It has reversing parts or direction changing parts 21 and 23 interconnecting the return traveling part.

The conveyor 12 has a plurality of steps 26 (only some of which are shown in FIG. 1).

The steps 26 are driven by a modular drive 44 and run in a closed path.

The flexible endless belt 15 has first and second sides each consisting of toothed step links 30 that are pivotally connected to each other.

Both sides of the belt are interconnected, as shown in FIG. 8, by step shafts to which steps 26 are connected.

Belt 15 is supported by guide/support wheels or rollers 38 that cooperate with guide tracks 40 .

The steps 26 are not only supported by the belt 15;
In cooperation with the trailer track 60, the steps are guided into the endless loop, where they are also guided and supported by supporting trailer wheels or rollers 58.

A modular drive system 44 meshingly engages the drive motor, sprockets, and toothed step links 30 of the conveyor 12 to drive the endless belt 15 upwardly along the slope between the first landing 14 and the second landing 16. It has a chain that pulls it.

The first and second sides of the endless belt 15, each consisting of toothed step links 30 pivotally connected to each other, form first and second closed loops, respectively (one of these closed loops being partially (This is shown in the perspective view of Figure 8).

The two closed loops are spaced apart and arranged side by side, and the closed loop surfaces are oriented vertically.

A plurality of spaced apart step wheels 36 are extended between the closed loops to intersect the vertical planes of the loops, and step shafts 36 are inserted through openings provided in alignment with each pair of adjacent toothed step links 30 in both loops. protrude the end of the

In the conventional technology, the ends of the toothed step links 30 are dovetailed, and the toothed step links 30 are made of metal so that the openings at the ends are aligned and the toothed step links 30 of each loop are also aligned. It is formed by a stack of layers.

For example, typical known step links each have a wall thickness of 2.7 mm.
The weight of the completed laminated step link is 5.67 kg (1
2°51b).

For example, the endless belt 15 that constitutes an escalator with a height of 4.6 m (15 ft) has a total of 124 step links, so the weight of only the step links is 703.1
kg (1,5501b).

2, 3 and 4 illustrate a new and improved step link 30 constructed in accordance with a first embodiment of the present invention.

This new improved step link 30 uses the same members,
The width is 81 cm (32in) and 122cm (48i).
It is characterized by its modular construction, which allows easy production of different step links that can be applied to the escalator (n).

The step link 30 in FIGS. 2, 3, and 4 has a width of 81 mm.
Suitable for escalators of cm (32 inches).

That is, FIG. 2 is a front view of the step link constructed according to the first embodiment of the present invention, FIG. 3 is a plan view showing the step link 30 of FIG. 2, and FIG. 4 is a plan view of the step link 30 of FIG. FIG. 3 is a cross-sectional view of the step link 30 in the direction of arrows IV-IV of FIG.

Step link 30 has first, second and third elongate members 62, 64 and 66, each preferably constructed of steel.

The first member 62 and the second member 64 have the same elongated configuration;
Each has a first end 68 and a second end 70.

The first member 62 and the second member 64 are spaced apart and have the same ends adjacent to each other.

An elongated third member 66 having a first end 72 and a second end 74 is sandwiched between the spaced apart first and second members 62 and 64 such that the second end 74 is connected to the first member 62. and second member 6
4 into the gap adjacent to each first end.

The third member 76 has an opening arrow adjacent to its first end 72;
And adjacent to the second end 74, the first and second open lowers 8
, and the centers of these openings are all located on the longitudinal axis 82 of the step link 30.

The third member also has a plurality of teeth 84, for example eight, which will be explained in more detail below.

Teeth 84 form a flat rack along one side of elongated third member 66.

Each first member 62 and second member 64 has a first aperture 86 and a second aperture 88 adjacent its first end 68 and a third aperture 90 adjacent its second end 70.

The center of all these openings is the longitudinal axis 8 of the step link 30.
It's on top of 2.

The first, second and third base members 62, 64 and 66 are assembled and held together by first and second tubular members 92 and 94, which are preferably formed of steel.

The openings 86 of the first member 62 and the second member 64 are connected to the third member 66.
and the tubular member 92 is force fit into these aligned openings.

For example, if the opening diameter is 25.3 mm (0,998 in)
In the case of (+Omm, -0,1mm (0021n)),
To achieve the desired interference fit or force fit, the outer diameter of the tubular member 92 should be 25.4 mm (1 in) (+0 mm, -0,1
mm (0,021n)) Te is sufficient.

In order to prevent the tubular member 92 from loosening during use,
The length may be selected so that it is slightly longer than the width of the step link to be assembled, and the end thereof can be fixed with a stand-up member as shown at 96.

Similarly, the apertures 88 in the first and second members are aligned with the apertures 80 in the third member, and the tubular member 94 is force fit into these aligned apertures and the ends of the member are press-fitted as shown at 98. be determined using stand-up members.

Hardened sleeve bushing 100 in the opening of the third member
The step link 30 is completed by press-fitting the flanged hardened bushings 102 into the respective openings 90 of the first member 62 and the second member 64.

The flange of the flanged bushing 102 is connected to the first member 62
and the second end 70 of the second member 64 .

The first end 72 of the third member 66 of the step link 30 becomes the male portion of the step link 30, and the spaced apart second ends 70 of the first member 62 and second member 64 become the female portion, and these male portions The female portions cooperate with the respective female and male portions of similar adjacent step links.

In other words, the first end 72 of another step link 30 is inserted into the gap 30 of the step link 30 and the opening in the bushing 100 is aligned with the opening in the bushing 102.

Either one end of the step shaft 36 is placed in the alignment opening, or the step shaft 36 is fitted with a hardened sleeve 106 on which the bushings 100 and 102 rotate.

The teeth 84 of the third member 66 allow for easy fabrication of the third member in accordance with the preferred embodiment of the invention (described below), and which also allows the endless belt 15 and the connected steps 2
6 is configured so that it can run more smoothly when it runs across the drive device 44.

As shown in FIG. 2, the peak or tip of each tooth 84 has a semicircular shape 107 with a center portion 108. As shown in FIG.

The semicircular portion 107 is configured to smoothly continue with a portion 110 forming a surface perpendicular to the longitudinal axis 82 of the step link 30.

Pitch line 112 bisects portion 110 directly above a line drawn through center portion 108 .

In this case, the tooth root has a radius of 11 with the center indicated by 118.
It continues to the valley 114 via the curved portion of No. 6.

This configuration is highly desirable.

This is because the pitch line can be moved towards the tip of the tooth.

When the pitch line 112 is further moved to the outside of the tooth 84,
The overlapping engagement between the teeth and the drive chain as shown in GB 1371519 can be minimized.

Reducing the amount of overlapping engagement results in less vibration and noise, as well as smoother travel as the steps travel across the drive 44.

For example, in the illustrated tooth configuration where the pitch 120 is 50.8 mm (2 in), the pitch line 112 can be set only 3.05 mm (0.12 in) above the center portion 108.

In this case, the radius of the semicircular part 107 is 8.76 mm (
0,345 in), the length of section 110 is 6.10 m
m (0,24 in) and radius 116 is 14,22 mm
(0.56in).

In order to maintain the engagement amount to a predetermined minimum, the drive device 4
A horizontal slide (not shown) is provided between the drive sprocket and idle sprocket between the teeth 84 and the pitch line 1 of the tooth 84.
It is necessary to support the chain vertically on 12.

The slide also has the advantage of allowing the drive chain of the modular drive 44 to run without pretensioning.

Therefore, the number of chain adjustments can be reduced, and the lubrication condition can be maintained in good condition, resulting in a longer service life.

Due to the modular construction of the step link 30, only three basic sections are required to construct the first, second and third basic members 62, 64 and 66.

Also, using the same three basic shapes, the width is 122 cm
It is also possible to construct a step link for a (48-inch) escalator, which will be described later.

That is, the first and second basic members 62 and 64 are each constructed from one basic section.

These members 62 and 64 are identical in construction and the upper portion about the longitudinal centerline 82 is a mirror image of the lower portion thereof.

Thus, to form the first and second basic members 62 and 64, identical sections are provided in opposite directions.

In this embodiment, one shaped section or shell member 121
serves as each elementary member 62,64.

For example, a 1.22 mm (0,048 in) thick steel plate is stamped to the desired profile, and the resulting cedar board is then drawn to curve the outer edge and create a curved shape on the flat main portion of the cedar board. flanges 122 projecting outwardly from the same or common side 131;
and forming flanges 124 and 126 around openings 86 and 88 and similar flanges around opening 90.

The edges of these seven langes are all in a common plane 128.

The opposite side from the flanged common side part 135 is a flat part without a protrusion, and this flat side faces the gap 104 and abuts on the third basic member 66 .

The third basic member 66 is constructed using the remaining two basic members.

These profiles are the right-hand and right-hand drawn profiles or shell members 132 and 134, respectively, whose construction is the same as the shell member 121 previously described in connection with the first and second basic members. .

When the right and left shell members 132 and 134 are assembled with their flange ends butted together, a hollow but extremely strong metal assembly 135 is formed.

As can be clearly seen from FIG. 4, the right side or right hand profile 132 and the left side or left hand profile 134 cooperate to form not only the wall of the opening lower 8 but also the wall of the remaining opening, and the step link. The outer edge of the wall constitutes the wall.

Although a step link constructed in accordance with the first embodiment of the present invention can be used functionally similar to known step link structures, the new step link of the present invention weighs only 1.25 kg (2,5 kg). 75lb).

Therefore, the 124 step links required for a 4.6 m (15 ft) high escalator would weigh only 154
kg (340 lb), compared to 703.1 kg (1,550 lb) for the same number of known step links.
It is.

Figures 5, 6 and 7 show a structure suitable for use in an escalator having a width of 122 cm (48 inches), constructed from the same three basic members or shell members that constitute the step link 30. It is a figure which shows the step link 30'.

5 is a front view of a step link 30' constructed in accordance with a second embodiment of the present invention, FIG. 6 is a plan view of the step link 30', and FIG. 3 is a cross-sectional view of the step link 30' in the direction of the arrow Vll-VII; FIG.

The same members of the step link 30' as the step link 30 are designated by the same reference numerals.

In the second embodiment, the same reference numerals except for the dash indicate changed members.

In contrast to the embodiment, FIG. 2 shows that instead of one shell member 121, two shell members 121 are used to connect the first and second basic members 6.
2' and 64', respectively.

Two shell members 121 are provided with their flanges abutting to form a hollow metal member.

Within this metal structure, a flange 124 cooperates with the opening 8.
An opening having a length twice as long as 6 is formed.

The flanges around the aperture 90 cooperate to form an aperture that is twice the length of the aperture 90, and the flanges 121 cooperate to form a sidewall around the composite hollow body.

The flanged sleeve bearing 102' is press-fitted into the opening 90'.

7 flange sleeve bearing 90' is the same as flanged sleeve bearing 90 except that it is longer.

The three basic members 62', 64' and 66' have aligned openings 86 and 78, and tubular members 92' and 94 which are force-fitted into the respective openings 88 and 80 and secured with stand-up members.
Assemble by '.

Tubular members 92' and 94 except that they are extended in length.
' is the same as tubular members 92 and 94.

The weight of each step link 30' is 2.5 kg (5,51b)
Therefore, the weight of the step link 30' required for a no-escalator 4.6 m (15 ft) high is only 308
kg (680 lb).

On the other hand, the weight of the same number of known step links is 703.1
kg (1,550 lb).

FIG. 8 is a partial perspective view of one side of endless belt 15 showing toothed step links 30' interconnected via step shafts 36, and FIG. FIG. 3 is a cross-sectional view showing the bearing structure of the step shaft.

The hardened steel sleeve 106 of the step shaft 36 is attached to the retaining ring 14
0, press the end of the step shaft 36 through the aligned openings of the two adjacent step links 30' and the sleeve bearings 102' and 100', and secure the end of the step shaft 36 by the washer 142 and retaining ring 144 around the sleeve 106. Assemble and hold the step link.

In this case, the support/guide wheel 38 may be provided at the end of the step shaft 35 and fixed thereto using a retaining ring 146.

In summary, the novel step link of the present invention has a thickness of 1.22
Since it is constructed from a formed steel plate or a laminated plate having a diameter of 0.048 mm (0.048 in.), the manufacturing cost and the weight of the endless belt 15 having the required strength can be significantly reduced.

Reducing weight not only lowers the manufacturing cost of parts, but also
This is the most important feature of the present invention because it suppresses the dead load acting on the drive chain and track system, extending the life of the chain and making running smoother.

The same stamped profiles or shells used for the step links of a 122 cm (48 in) wide escalator can be used for the step links of an 81 cm (32 in) wide escalator, but only half as much is used. It is.

The molded laminate or shell members are held in alignment by press-fit bushings and tubular members.

The tubular member is secured at each end with a raised member for secure retention.

These tubular members connect the female end of the step link to the male end so that tensile loads are transferred from the female end to the male end.

The strategic arrangement of the molded shell members provides them with the required strength.

Although the step link has a large, uneven appearance, it is lightweight.

Additionally, the corners of the molded part are rounded, making it safe to handle.

The tooth shape of the novel step link according to the invention allows for easy insertion and removal of the drive chain.

The pitch line can be set close to the tip of the tooth, ie, only 3.01 mm (0.12 inches) above the tangent to the curved tooth tip.

The circular profile of the teeth allows the drive chain to engage the teeth as close as possible to the tips of the teeth.

This minimizes the amount of weight retention between the teeth and the drive chain and therefore provides smoother running in the area of the modular drive.

[Brief explanation of the drawing]

Fig. 1 is a front view of a passenger conveyor to which the step link of the present invention can be applied, Fig. 2 is a plan view of the step link constructed according to the first embodiment of the present invention, and Fig. 3 is a front view of the step link of Fig. 2. 4 is a cross-sectional view of the step link in the direction of arrow IV-IV in FIG. 2, FIG. 5 is a front view of the step link constructed according to the second embodiment of the present invention, and FIG. The front view of the step link in Figure 5, and Figure 7 is the arrow Y in Figure 5.
a cross-sectional view of the step link in the direction of II-Vll;
8 is a partial perspective view of an endless belt constructed of the step links shown in FIG. 5, and FIG. 9 is a partial cross-sectional view of the endless belt in the direction of the arrow -IK in FIG. 8. 15... Endless belt, 30...
Step link, 62.62'...First long member, 14.14'...Second long member, 66.66
'...Third long member, 76...Sleeve bushing, 84.84'...Teeth, 86.8
8...Opening, 92...First tubular member,
94... Second tubular member, 102, 102'...
... Sleeve bushing, 112 ... Pitch line, 121° 135 ... Shell member.

Claims (8)

[Scope of utility model registration request] (1) A toothed step link for interconnecting like step links by step shafts to form an articulated endless belt for a transportation device, having first and second ends spaced apart from each other and having the same end. a first elongate member and a second elongate member of similar configuration disposed adjacent to each other; a first end and a second end having a plurality of teeth; a third elongate member disposed in a gap between the first ends of the first elongate member and the second elongate member; the first elongate member, the second elongate member, and the third elongate member;
the first long member of the third long member.
the ends and said second ends of said first and second elongate members forming an assembly forming a male portion and a female portion, respectively, so as to cooperate with said female portions and said male portions, respectively, of like structures; the third elongated member includes at least one hollow metal assembly formed of assembled right and left hand shell members, each of the right and left hand shell members having a predetermined a flat earthen wall formed of a metal plate having a through opening and a plurality of teeth along the outer edge; and a flat earthen wall extending outward from the same side of the flat earthen wall and including the plurality of teeth; an integral flange portion having a portion surrounding the outer periphery of the wall portion and a portion surrounding the predetermined through opening; at least one end of the flange portion lies within a common plane; The ends of the flange portions located in a common plane with the left hand shell member contact each other, the flange portions surrounding the outer periphery cooperate to form a side wall and a plurality of teeth, and the predetermined penetration A toothed step link for a transportation device, characterized in that the flange portion surrounding the opening is assembled to form a wall of an opening passing through a hollow composite structure formed by the assembly. (2) Each of the first elongated member and the second elongated member has at least one shell member, and the shape and dimensions of at least one shell member of the first elongated member are the same as those of the second elongated member. at least one shell member of the elongate member, and the at least one shell member of the first elongate member and the second elongate member is a predetermined flat member made of a metal plate having a predetermined through opening. the flat earthen wall, and an integral flange extending outward from the same side of the flat earthen wall; a portion surrounding the opening, at least a portion of the flange portion being in a common plane, the first elongated member, the second elongated member, and the third elongated member.
The side opposite to the flanged side of the long member is the first
, a toothed step link for a transportation device according to claim 1, wherein the second and third elongated members are in contact with each other when assembled. (3) The teeth formed in cooperation with the third long member are
Utility model registration claim 1, which has a semicircular curved end when viewed from one side of the flat earthen wall, and a pitch line located 3.05 mm (0.12 inches) above the center of the semicircle.
A toothed step link for a transportation device according to item 1 or 2. (4) the openings of the first elongated member and the second elongated member have first and second openings adjacent to their first ends, and a third opening adjacent to their second ends; the opening of the third elongated member has a first opening adjacent to a first end thereof;
said coupling device for coupling said first, second and third elongated members, said coupling device having second and third openings adjacent said second ends thereof, said coupling device for coupling said first, second and third elongated members; and a first tubular member force fit within the second aperture of the third elongate member; the second aperture of the first and second elongate members and the third aperture of the third elongate member. and a second tubular member press-fitted therein, the toothed step link for a transportation device according to claim 2 or 3 of the claimed utility model registration claim. (5) a sleeve bushing force-fitted within the first opening of the third elongated member; and a second bushing, and the flanges are arranged on both sides of a gap between the first elongated member and the second elongated member. Toothed step link. (6) the third elongate member comprises at least two hollow metal assemblies disposed in contacting juxtaposed relationship between the first elongate member and the second elongate member; The toothed step link for a transportation device according to any one of claims 1 to 5, wherein the at least two hollow metal assemblies are formed of right and left hand shell members. (7) The first elongated member and the second elongated member are two shell members having the same configuration, and the ends of their flange portions in a common plane are in contact with each other, and A utility model according to any of claims 2 to 6 which constitutes a hollow metal assembly in which the flange portions cooperate to form a side wall around the outer periphery and a wall of an opening passing through the hollow assembly. A toothed step link for a transportation device as described in . (8) said third elongate member has at least two hollow metal assemblies each comprising a right hand shell member and a left hand shell member, the at least two hollow metal assemblies comprising said first elongate member and said third elongate member; A toothed step link for a transportation device according to claim 7, which is arranged in parallel in a gap between two long members.