JP2021084808A - Falling accident prevention type escalator - Google Patents

Falling accident prevention type escalator Download PDF

Info

Publication number
JP2021084808A
JP2021084808A JP2019224056A JP2019224056A JP2021084808A JP 2021084808 A JP2021084808 A JP 2021084808A JP 2019224056 A JP2019224056 A JP 2019224056A JP 2019224056 A JP2019224056 A JP 2019224056A JP 2021084808 A JP2021084808 A JP 2021084808A
Authority
JP
Japan
Prior art keywords
display sheet
handrail belt
display
escalator
seam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2019224056A
Other languages
Japanese (ja)
Inventor
桂一 木下
Keiichi Kinoshita
桂一 木下
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AD Communication Co Ltd
Original Assignee
AD Communication Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AD Communication Co Ltd filed Critical AD Communication Co Ltd
Priority to JP2019224056A priority Critical patent/JP2021084808A/en
Publication of JP2021084808A publication Critical patent/JP2021084808A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Escalators And Moving Walkways (AREA)

Abstract

To provide a falling accident prevention type escalator which can contribute particularly to prevention or the like of detachment and contamination of a joint section of a display sheet, extension of the service life of this section, and increased reliability, in addition to safety and advertising effects resulting from a display part, such as a direction display mark and a caution sentence, of a display sheet provided on a handrail belt surface.SOLUTION: A display sheet 6 is stuck to the whole surface of a handrail belt and almost covers its cross-sectional shape, and is divided into a plurality of sheets in a longer direction of the handrail belt, whereas a joint section 66 of the display sheet 6 comprises a joint material 6C with an adhesive provided so as to cover an overlap of a certain length. Further, the joint material 6C disposed at the joint section 66 of the display sheet 6 is provided with an adhesion reinforcing portion 6Cb at its edge part, in addition to an adhesive provided on its rear face.SELECTED DRAWING: Figure 7

Description

本発明は、移動する踏段と手摺ベルトが傾斜路あるいは水平路を形成して乗客輸送を行う転倒事故防止形エスカレーターの構成に関する。 The present invention relates to a fall accident prevention type escalator in which a moving step and a handrail belt form a ramp or a horizontal road to transport passengers.

従来、エスカレーターでの転倒事故を防止するものとして、手摺ベルトの表面に表示シートを貼付けて方向表示マーク、注意表示及び広告表示を行う表示部の構成が、例えば特許文献1のように、既に提案され権利化されている。 Conventionally, as a device for preventing a fall accident on an escalator, a configuration of a display unit in which a display sheet is attached to the surface of a handrail belt to display a direction display mark, a caution display, and an advertisement display has already been proposed, for example, as in Patent Document 1. It has been granted rights.

この特許文献1記載の手摺ベルト用表示シートは、世の中への普及度が増し人身事故、とりわけ転倒事故防止に顕著な効果を発揮している。 The display sheet for the handrail belt described in Patent Document 1 has become more widespread in the world and is exerting a remarkable effect in preventing personal injury accidents, especially fall accidents.

特開2006−347764号公報(登録第4989863号)Japanese Unexamined Patent Publication No. 2006-347764 (Registration No. 4998863)

上記特許文献1に記載のものは、表示シートによって乗客の目の至近位置に存在する方向表示マーク等によりエスカレーターの移動方向や速度感が分かりやすくなって逆方向乗り込みや乗降タイミングの失敗が少なくなる効果があり、結果として転倒事故防止の実効果が高いとの評価を受けている。また、方向表示マークの間隔内に設けられた注意文言や広告の表示部による安全、広告効果も評価されている。 In the above-mentioned Patent Document 1, the display sheet makes it easier to understand the moving direction and the sense of speed of the escalator by the direction display mark or the like existing at a position close to the passenger's eyes, and the failure of boarding in the reverse direction or the failure of getting on / off timing is reduced. It is highly effective, and as a result, it has been evaluated as having a high actual effect of preventing falls. In addition, the safety and advertising effectiveness of the caution wording provided within the interval of the direction display mark and the display part of the advertisement are also evaluated.

一方、最近のエスカレーター利用においては、上記の安全、広告効果にプラスして、特に表示シートの継ぎ目部分の剥がれ防止等、この部分の長寿命化、高信頼化が切に望まれていた。 On the other hand, in the recent use of escalators, in addition to the above-mentioned safety and advertising effect, it has been urgently desired to extend the life and increase the reliability of this part, such as preventing the joint part of the display sheet from peeling off.

本発明の目的は、手摺ベルト表面に設けた表示シートの、方向表示マークや注意文言等表示部による安全、広告効果に加え、特に表示シートの継ぎ目部分の剥がれや汚れ防止等、この部分の長寿命化、高信頼化に寄与できる構成とした転倒事故防止形エスカレーターを提供することにある。 An object of the present invention is the length of the display sheet provided on the surface of the handrail belt, such as the safety and advertising effect of the display part such as the direction display mark and the caution wording, and particularly the prevention of peeling and dirt at the seam part of the display sheet. The purpose is to provide a fall accident prevention type escalator with a configuration that can contribute to a longer life and higher reliability.

上記目的を達成するために、本発明の請求項1は一方の乗降口から他方の乗降口にかけて移動し、乗客を輸送する踏段と、この踏段と同期移動する無端状の手摺ベルトとを備えたエスカレーターにおいて、前記手摺ベルトの表面に、その断面形状をほぼ被い、かつその長手方向において複数枚に分割される一方、その継ぎ目部分は一定長さの重ね代を有し、その移動方向を表示して前記エスカレーターに乗り移る際のタイミングを図る目印となる方向表示マークを複数個有する表示シートを貼り付けて設け、また前記表示シートの継ぎ目の重ね代部分よりも長い範囲を被い、さらに前記手摺ベルトの断面形状を被うように設けられた接着剤付き継ぎ目材によって構成される表示シートを設けたことを特徴とする転倒事故防止形エスカレーターとしたのである。 In order to achieve the above object, claim 1 of the present invention includes a step that moves from one entrance to the other entrance and transports passengers, and an endless handrail belt that moves synchronously with this step. In the escalator, the surface of the handrail belt is substantially covered with the cross-sectional shape and divided into a plurality of sheets in the longitudinal direction thereof, while the joint portion has a stacking allowance of a certain length and the moving direction is displayed. Then, a display sheet having a plurality of direction display marks serving as a mark for timing the transfer to the escalator is attached and provided, and a range longer than the overlapping margin portion of the seam of the display sheet is covered, and the handrail is further provided. The escalator is a fall accident prevention type escalator characterized by providing a display sheet composed of a seam material with an adhesive provided so as to cover the cross-sectional shape of the belt.

また、本発明の請求項2は前記表示シートの継ぎ目部分に設けられた継ぎ目材は、その裏面に設けられた接着剤のほかに現地施工により、その両縁部に接着強化部を設けたことを特徴とする請求項1記載の転倒事故防止形エスカレーターとしたのである。 Further, claim 2 of the present invention is that the seam material provided at the seam portion of the display sheet is provided with adhesive strengthening portions at both edges thereof by on-site construction in addition to the adhesive provided on the back surface thereof. The fall accident prevention type escalator according to claim 1, which is characterized by the above.

上記構成によれば、手摺ベルトの表面に設けられた表示シートの方向表示マーク等によってエスカレーターの移動方向や速度感を視覚的に示すことで踏段への乗り込みタイミング取りの容易化、逆乗り込み防止を図る一方、前記表示シートの継ぎ目部分に設けられる継ぎ目材の剥がれや汚れが防止でき、その部分の長寿命化、高信頼化を図り得る転倒事故防止形エスカレーターを提供するものである。 According to the above configuration, the direction display mark of the display sheet provided on the surface of the handrail belt visually indicates the moving direction and speed of the escalator, thereby facilitating the timing of boarding the escalator and preventing reverse boarding. On the other hand, the present invention provides a fall accident prevention type escalator capable of preventing peeling and dirt of the seam material provided at the seam portion of the display sheet, extending the life of the portion, and increasing the reliability.

本発明の一実施形態を示す全体側面図。The whole side view which shows one Embodiment of this invention. 本発明を示す図1のX−X線に沿う部分断面図。FIG. 1 is a partial cross-sectional view taken along line XX of FIG. 1 showing the present invention. 本発明を示す図2のY−Y線に沿う部分断面図。FIG. 2 is a partial cross-sectional view taken along the line YY of FIG. 2 showing the present invention. 本発明を示す表示シートの要部単体斜視図。A perspective view of a main part of a display sheet showing the present invention. 本発明を示す概念的全体斜視図。Conceptual overall perspective view showing the present invention. 本発明の表示シートの継ぎ目部分を説明する概念的縦断面図。The conceptual vertical sectional view explaining the seam part of the display sheet of this invention. 本発明の表示シートの継ぎ目部分を設明する概念的縦断面図。The conceptual vertical sectional view which establishes the seam part of the display sheet of this invention.

以下、本発明の転倒事故防止形エスカレーターの一実施の形態を図1〜図7に基づいて説明する。 Hereinafter, an embodiment of the fall accident prevention type escalator of the present invention will be described with reference to FIGS. 1 to 7.

本発明の転倒事故防止形エスカレーター1は、建屋2の上階床につながる乗降口2Aとその下階床につながる乗降口2Bを備えて建屋2に装架される主フレーム3と、無端状に連結されて往路から復路にかけて反転して移動する多数の踏段4、この踏段4と同期して往路から復路にかけて反転して移動するものでその断面形状が平坦部5Aとこれに連なる両縁の半円部5Bとで馬蹄形状をなす幅W1の手摺ベルト5と、この手摺ベルト5の長手方向に沿い、その平坦部5A(幅W2)から半円部5Bにかけて接着固定(詳細な図示は省略するも、内面側に接着剤層を備え、その外側には後述する方向表示マーク6A等が印刷されるシート部層や表面のラミネート層などで構成される複層材となっている)される長尺の表示シート6が貼り付けられている。 The fall accident prevention type escalator 1 of the present invention has a main frame 3 mounted on the building 2 having an entrance / exit 2A connected to the upper floor of the building 2 and an entrance / exit 2B connected to the lower floor thereof, and an endless shape. A large number of steps 4 that are connected and move in reverse from the outward path to the return path, and move in reverse from the outward path to the return path in synchronization with this step 4, and the cross-sectional shape is the flat portion 5A and half of both edges connected to it. A handrail belt 5 having a width W1 forming a horseshoe shape with the circular portion 5B and adhesively fixed from the flat portion 5A (width W2) to the semicircular portion 5B along the longitudinal direction of the handrail belt 5 (detailed illustration is omitted). (It is a multi-layer material composed of a sheet portion layer on which an adhesive layer is provided on the inner surface side and a direction display mark 6A or the like, which will be described later, is printed on the outer surface, or a laminated layer on the surface). A scale display sheet 6 is attached.

また手摺ベルト5は、駆動歯車7の動力をチェーン8を介して駆動ローラ9等に伝達された動力によって摩擦駆動されるもので複路を案内ローラ10、往路を欄干11に案内され反転部11A、11Bで折り返し反転して移動する構成となっている。 Further, the handrail belt 5 is frictionally driven by the power transmitted to the drive roller 9 and the like via the chain 8 of the drive gear 7, and is guided by the guide roller 10 on the double path and the balustrade 11 on the outward path to the reversing portion 11A. , 11B is configured to fold back and move.

そして表示シート6は、手摺ベルト5の全長に、一枚ものあるいは複数に分割された状態で継ぎ目部分66に継ぎ目材6Cが設けられた状態でその内面側の接着層が前記手摺ベルト5の表面の平坦部5Bと半円部5Bに貼付けられるとともに、表示シート6の表面のシート部層には、その移動方向を表示する方向表示マーク6Aが目立ち易いように平坦部5Aの幅W2いっぱいに印刷によって設けられ、さらに方向表示マーク6Aは手摺ベルト5の全長方向に適宜の間隔Pをもって複数個設けられ、手摺ベルト5の反転部の半円周範囲である高さH(図1、図2)内に少なくても1個存在する間隔P(図4)をおいて複数個配置されている。そして、いま乗り込まんとする利用者(乗客)が転倒事故防止形エスカレーター1を見ると常に正面となる符号Hの範囲内に少なくても1個の方向表示マーク6Aが存在して、移動速度の速度感と動き方向を確実に視覚に訴えるものである。加えて、方向表示マーク6Aは、例えば黄色や白色に着色印刷され、そのマークも図2、図4に例示した円形に限らず大きめの矢印や菱形などでも不都合はなく、その大きさも任意である。 The display sheet 6 has a seam member 6C provided on the seam portion 66 in a state of being divided into one or a plurality of the entire length of the handrail belt 5, and the adhesive layer on the inner surface side thereof is the surface of the handrail belt 5. Along with being attached to the flat portion 5B and the semicircular portion 5B of the above, the direction display mark 6A indicating the moving direction is printed on the sheet portion layer on the surface of the display sheet 6 to the full width W2 of the flat portion 5A so as to be conspicuous. In addition, a plurality of direction display marks 6A are provided in the total length direction of the handrail belt 5 at appropriate intervals P, and a height H which is a half-circumferential range of the reversing portion of the handrail belt 5 (FIGS. 1 and 2). A plurality of them are arranged at intervals P (FIG. 4) in which at least one exists. Then, when the user (passenger) who is about to board the vehicle now sees the fall accident prevention type escalator 1, at least one direction display mark 6A exists within the range of the code H which is always in front of the escalator 1, and the movement speed is increased. It surely appeals to the sense of speed and the direction of movement. In addition, the direction display mark 6A is printed in yellow or white, for example, and the mark is not limited to the circle shown in FIGS. 2 and 4, but a large arrow or rhombus is not inconvenient, and its size is arbitrary. ..

また本発明の手摺ベルト5に貼り付けられる表示シート6には、上記方向表示マーク6Aの間隔P内に図2及び図4に想像線の枠で示したように注意文言等の表示部6Bが設けられていて、必要に応じて「手摺をつかむこと」、「降り口の左側が改札口」「降り口の右側が地下鉄銀座線」等の安全上の注意文言や案内表示、それに図示しない各種「広告」が印刷によって表示されている。この場合、表示シート6は、前述と重複するも手摺ベルト5への接着層、印刷が施されるシート部層に加え、表面のラミネート層などの複層材で構成されている。 Further, on the display sheet 6 attached to the handrail belt 5 of the present invention, a display unit 6B such as a cautionary statement is provided within the interval P of the direction display mark 6A as shown by the frame of the imaginary line in FIGS. 2 and 4. There are safety precautions and guidance signs such as "grab the handrail", "the left side of the exit is the ticket gate", "the right side of the exit is the subway Ginza line", and various types not shown. "Advertisement" is displayed by printing. In this case, the display sheet 6 is composed of a multi-layer material such as a laminated layer on the surface in addition to an adhesive layer to the handrail belt 5 and a sheet portion layer to be printed, which overlaps with the above.

さらに本発明の手摺ベルト5に貼り付けられる表示シート6は図5以下にその縦方向断面(図3、図4が横断面であるのに対し、手摺ベルト5に貼り付けられる表示シート6のみを縦方向に断面した図)を概念的に図示したように、手摺ベルト5の全表面に貼り付けられる表示シート6は図5、図6、図7に示す構成となっている。図5ではその継ぎ目部分66が2ヶ所ある例を示し、その各々の

Figure 2021084808
よりも長い範囲の長さLの継ぎ目材6Cで外見的には図4のように被っている。Further, the display sheet 6 attached to the handrail belt 5 of the present invention has a vertical cross section (FIGS. 3 and 4 are cross sections, whereas only the display sheet 6 attached to the handrail belt 5 is shown in FIG. 5 and below. As conceptually illustrated (a cross-sectional view in the vertical direction), the display sheet 6 attached to the entire surface of the handrail belt 5 has the configurations shown in FIGS. 5, 6, and 7. FIG. 5 shows an example in which the seam portion 66 is provided at two locations, and each of them is shown.
Figure 2021084808
A seam material 6C having a length L in a longer range is covered in appearance as shown in FIG.

加えて本発明の手摺ベルト5に貼り付けられる表示シート6は、次のような接着強化部6Cbを備えている。すなわち、表示シート6の継ぎ目部分66の継ぎ

Figure 2021084808
の端部からの一定範囲mに現地施工(現地施工以外でもよい)の別の接着剤による接着強化部6Cbを設けて接着部の長寿命化と高信頼化を図っている。In addition, the display sheet 6 attached to the handrail belt 5 of the present invention includes the following adhesive strengthening portion 6Cb. That is, the seam of the seam portion 66 of the display sheet 6
Figure 2021084808
An adhesive strengthening portion 6Cb using another adhesive for on-site construction (which may be other than on-site construction) is provided in a certain range m from the end portion of the adhesive portion to extend the life and increase the reliability of the adhesive portion.

なお、上記継ぎ目部分66に対して、本発明者は次のような施策も有効と考えている。すなわち、継ぎ目材6Cに対して常に引張り力が作用して凹みK(ここを起点に破れて剥がれたり、この部分に汚れが溜まる)が生じないように駆動ローラ9によって発生する駆動力の仕組みを、手摺ベルト5に引張力をもたらす引張範囲が大きいZ1の範囲(図1に示す。Z2の範囲は駆動ローラ9による手摺ベルト5の押し出し側、すなわちZ1とは反対の収縮側になる)となるようにするのが好適である。(この状況を作るには、表示シート6の一方の端部が終端まで手摺ベルト5に接着され、他の一方の端部が前記の終端を被い、かつ継ぎ目材6Cで継ぎ足す図6、図7の構成が望ましいと考えられる。ここで、発明者は図1に示すように手摺ベルト5への引張範囲が機構的にその走行路の過半となると凹みKが発生し難いことを体験的に承知している。ただし、本発明では、この点を限定しないこととする。) The present inventor considers that the following measures are also effective for the seam portion 66. That is, the mechanism of the driving force generated by the driving roller 9 is provided so that the tensile force always acts on the seam material 6C to prevent the dent K (the starting point is torn and peeled off, or dirt is accumulated in this portion). , The range of Z1 in which the tension range that brings the pulling force to the handrail belt 5 is large (shown in FIG. 1. The range of Z2 is the push-out side of the handrail belt 5 by the drive roller 9, that is, the contraction side opposite to Z1). It is preferable to do so. (To create this situation, one end of the display sheet 6 is glued to the handrail belt 5 to the end, the other end covers the end and is replenished with the seam 6C. It is considered that the configuration of FIG. 7 is desirable. Here, as shown in FIG. 1, the inventor has experienced that the dent K is unlikely to occur when the tension range to the handrail belt 5 is mechanically the majority of the traveling path. However, the present invention does not limit this point.)

以上説明したように、本発明によれば手摺ベルトの移動方向や表示部の内容が見易く表示されて安全効果、案内効果、広告効果など多岐にわたって総合的な転倒事故防止形エスカレーターを提供でき、かつ表示シート6の継ぎ目材6Cの長寿命化、高信頼化を図ることができる。 As described above, according to the present invention, the moving direction of the handrail belt and the contents of the display unit can be displayed in an easy-to-see manner to provide a comprehensive fall accident prevention type escalator having a wide range of safety effects, guidance effects, advertising effects, etc. The life of the seam material 6C of the display sheet 6 can be extended and the reliability can be improved.

なお、上記の実施形態は、一般のエスカレーター構造を例に説明したが、隣接踏段同士に段差を有しない動く歩道にもそのまま適用することができる。 Although the above embodiment has been described by taking a general escalator structure as an example, it can be applied as it is to a moving walkway having no step between adjacent steps.

1 転倒事故防止形エスカレーター
2A、2B 乗降口
4 踏段
5 手摺ベルト
5A 平坦部
6 表示シート
6A 方向表示マーク
6B 表示部
6C 継ぎ目材
66 継ぎ目部分
6Cb 接着強化部
1 Fall accident prevention type escalator 2A, 2B Entrance / exit 4 Step 5 Handrail belt 5A Flat part 6 Display sheet 6A Direction display mark 6B Display part 6C Seam material 66 Seam part 6Cb Adhesion strengthening part

Claims (2)

一方の乗降口から他方の乗降口にかけて移動し、乗客を輸送する踏段と、この踏段と同期移動する無端状の手摺ベルトとを備えたエスカレーターにおいて、前記手摺ベルトの表面に、その断面形状をほぼ被い、かつその長手方向において複数枚に分割される一方、その継ぎ目部分には一定長さの重ね代を有し、その移動方向を表示して前記エスカレーターに乗り移る際のタイミングを取る目印となる方向表示マークを複数個有する表示シートを貼り付けて設け、また前記表示シートの継ぎ目部分の重ね代よりも長い範囲の長さを被い、さらに前記手摺ベルトの断面形状を被うように設けられた接着剤付き継ぎ目材などで構成される表示シートを設けたことを特徴とする転倒事故防止形エスカレーター。 In an escalator provided with a step that moves from one entrance to the other entrance to transport passengers and an endless handrail belt that moves synchronously with this step, the cross-sectional shape of the escalator is substantially formed on the surface of the handrail belt. While it is covered and divided into a plurality of sheets in the longitudinal direction thereof, the seam portion has a stacking allowance of a certain length, and the movement direction is displayed to serve as a mark for timing when transferring to the escalator. A display sheet having a plurality of direction display marks is attached and provided, and a length in a range longer than the overlap margin of the seam portion of the display sheet is covered, and further, it is provided so as to cover the cross-sectional shape of the handrail belt. A fall accident prevention type escalator characterized by providing a display sheet composed of seams with adhesive. 前記表示シートの継ぎ目部分に設けられた継ぎ目材は、その裏面に設けられた接着剤に加えて、その縁部に接着強化部を設けたことを特徴とする請求項1記載の転倒事故防止形エスカレーター。 The fall accident prevention type according to claim 1, wherein the seam material provided at the seam portion of the display sheet is provided with an adhesive strengthening portion at the edge portion in addition to the adhesive provided on the back surface thereof. escalator.
JP2019224056A 2019-11-26 2019-11-26 Falling accident prevention type escalator Pending JP2021084808A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2019224056A JP2021084808A (en) 2019-11-26 2019-11-26 Falling accident prevention type escalator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2019224056A JP2021084808A (en) 2019-11-26 2019-11-26 Falling accident prevention type escalator

Publications (1)

Publication Number Publication Date
JP2021084808A true JP2021084808A (en) 2021-06-03

Family

ID=76088408

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2019224056A Pending JP2021084808A (en) 2019-11-26 2019-11-26 Falling accident prevention type escalator

Country Status (1)

Country Link
JP (1) JP2021084808A (en)

Similar Documents

Publication Publication Date Title
US20040099503A1 (en) Passenger conveyor device
US7320393B2 (en) Conveyor
JP2021084808A (en) Falling accident prevention type escalator
JP2021084809A (en) Falling accident prevention type escalator
JP2021084810A (en) Falling accident prevention type escalator
JP2018165215A (en) Escalator for falling accident prevention
JP2018065687A (en) Fall accident-preventing handrail belt for escalator
JP2014065605A (en) Handrail belt for escalator mainly for weak-sighted person
JP2018193241A (en) Handrail with fall prevention measure for escalator
JP2015224136A (en) Handrail belt for escalator
JP4989862B2 (en) Handrail belt for preventing escalator from falling accident and escalator for preventing accident from falling
JP2014218367A (en) Handrail belt of parallel-installed escalator and method of cleaning the same
JP2018165214A (en) Escalator for falling accident prevention
JP2018065688A (en) Fall accident-preventing handrail belt for escalator
JP2013006694A (en) Handrail belt for escalator for weak-sighted person
JP2007191304A (en) Handrail belt of escalator
JP7309970B1 (en) Passenger conveyor system and passenger conveyor
KR100723445B1 (en) People moving apparatus
WO2007139186A1 (en) Handrail belt and escalator with such handrail belt
JP2007091458A (en) Escalator
JP2009102160A (en) Handrail belt of escalator
JP2014152038A (en) Handrail belt of escalator and cleaning method thereof
JP2008254922A (en) Handrail belt for escalator
JP2014218368A (en) Handrail belt with print sheet of escalator
JP2015051871A (en) Handrail belt for falling accident prevention of escalator and escalator for falling accident prevention